How to Bias Your NEW Marshall DSL 40CR

Got off the phone with Marshall today. Biasing must be done in High Power mode with the speaker connected and your guitar plugged in. After that it really can't be any easier.

[@kameel68]

The EL34 tubes are rated 25 Watt. 25/500 * 0.7 = 35mA. The 5881 tubes are 23 Watt. 23/500 * 0.7 = 32mA.

[@oldguyjammin9732]

That seems like a safe replacement to me. Should be fine, right!?!? The concern with power amp tubes is always over taxing the output transformer.

[@kameel68]

@@oldguyjammin9732 Marshall JCM900 SL-X amps are often changed from EL34 to 5881 and vice versa. I'll wait what the techs from Marshall say about it.

[@oldguyjammin9732]

@@kameel68 - excellent! Please keep us all informed with how it goes and what you experience tone wise \m/

[@nicholaskimpel]

Excellent tutorial. Short and to-the-point, easy to follow. I set my DSL40CR to 35 as well. It sounds great, and now I know it's right. One side was about 32 and the other was 29 before I adjusted it. Thanks!

[@real_fjcalabrese]

Great video! The ability to bias the DSL40CR is a deal maker!

[@jboy8735]

And you save money we’re I live they have a shop that works on them it’s like 100 an hour I’m like nope gonna learn it on my own

[@seangarland]

Thank you for this video! I’ve been playing for over 30 years, but I’ve never owned a tube amp. I’m just about to buy the Marshall DSL40CR, and this video is absolutely the kind of tech info I need in order to ensure that I’m getting the most out of my amp!

[@oldguyjammin9732]

Right on! It’s a killer amp BUT I will say that I sold sold it and bought the DSL20 instead and really, really like it. These Marshalls have to have their masters up to really sound good and I just couldn’t do it with the 40, I can with the 20. The 40 is a beast and with the 6 button footswitch, it really has tonal options, but you have to be able to play loud (or seriously attenuate) or it just sounds fizzy. Best of luck!! \m/

[@chefjlb]

Thank you for sharing this! I did this to mine this morning and I was off by 6mv and I got it dialed in to 35 mv even! It made a huge difference and couldn’t be happier with the way it sounds now. I hope you don’t mind but I had to share your video with Marshall DSL forum on FB. I know it will help a lot of others like me. Thanks again!

[@oldguyjammin9732]

Jason Bland - Happy for you man and always stoked to hear something’s been helpful. Thanks for sharing!! Maybe I’ll get a few subs from it, ha ha \m/ Rock on!!

[@walt957]

One of my pots will only go to 30 mV. the other 38mV. Sounded like junk going 30mV for both pots. So perhaps the screen resistor is out of spec. Called a famous amp tech in the area, asked if he could mod my screen resistor, and he interrupted me, told me to center the pots and use my ear - and ignore the meter. Or, pay him 75 dollars to do the same thing. So I centered the pots and used my ear - Now my amp sounds amazing. I been playing for 40 plus years so I think I can trust my ears.

[@jesse401]

Hi what do you mean center the pots? I’m having a similar problem where one reads higher than the other

[@andrewsmith3993]

I got a Marshall DSL40CR a few days ago. Came across this video while browsing. I'm glad I did. After watching, I turned my amp on and let it sit for a while. I then checked the bias, and they were 39.8 and 39.4 mV (Insert facepalm). Turned them down to 35. I'm surprised at how much better the amp sounds now. A lot less fizz, and better tone. Plus, my tubes will actually last the duration they are supposed to. Many thanks for the informative video.

[@MikeMCT]

I just changed out all of my preamp and power tubes and the hiss and crackle are gone and it sounds amazing. I love that bias setup section on the DSL 40CR. Between that and this video on what tool I need and what setting to shoot for, I did the whole thing myself which is huge for me. Thanks so much - would not have tried it without this video. Got both sides right to 35.0! Mike😊

[@oldguyjammin9732]

That’s Great! Really appreciate you saying so, glad it helped. Enjoy that beast!!

[@oldguyjammin9732]

Hey YO! I played around with the bias again today and settled on 32 mV - sweet - I went as high as 38 but the tone got thin and fizzy. 30 mV also sounded real good but since the Marshall dude said 32-38 I decided to bump it up just a bit. \m/

[@oldguyjammin9732]

Let us know if the bias was correct “as is” or if you had to change it.

[@IrishBoson]

@@oldguyjammin9732 Thanks for vid. I tried this and my amp wouldn't go past 34 mv, like the adjustment knob maxed out and I couldn't turn it any further. I ended up just settling on 32 mv as you suggested. Not sure why that is.

[@oldguyjammin9732]

@@IrishBoson - yes very weird. Only thing I can suggest is that perhaps it was in half power mode instead of full power mode? Don’t remember exactly but it seems I remember that the adjustment screws don’t even respond in half power mode... hmm.. even so, I bet it sounds great!

[@PeterDad60]

@@IrishBoson Bad power tube. Think about it. You are setting the bias for each power tube.

[@michaelsteven1090]

@@PeterDad60 same here..the tube on the right got to 35mV easily but the left one I had to max out to get it 35mV....bad tube, right?

[@you0nlylivetwice]

I had one at 35 and the other at 48, crazy, thank God i found this video. Thanks!

[@oldguyjammin9732]

Cool! Biasing isn’t as a big a deal as I used to think when I started getting in to tube amps... had me all sorts of concerned :o it can actually be part of tonal shaping. Rock on \m/

[@darinrugg176]

That crazy simple!!! Thanks for going through the work for us!!! much appreciated sir!!!

[@oldguyjammin9732]

Darin Rugg - absolutely!

[@brucecampbellx]

Great, helpful video. I have a DSL40CR on order, should have it around July 10th. I may ask the shop to check the bias and set it around 35 before I take 'er home. I have a Traynor DHX212 cabinet with G12M greenbacks in it. Can't wait to hear it all put together. Thanks again !

[@oldguyjammin9732]

Bruce Campbell - that’s great man... July 10th!?!? Dang! Whachya gonna do with yourself til then :o That’s gonna sound awesome. I really wish they had made a head version. The combo works well enough but Marshall doesn’t make an appropriate sized cab to stack it on - grrr.

[@brucecampbellx]

@@oldguyjammin9732 Ya, the wait sucks, but covid I guess. Stagecraft make a head cabinet for the DSL40CR. www.stagecraftgear.com/product/dsl-40cr-head/ It's interesting but an added expense. I even looked at the DSL20H but it just didn't come close to the 40CR. I'll drop a line back when I get my amp and get some hours on it. All the best.

[@AvnerRosenstein-ULTRA-LXV]

I have this amp and I love it a lot. Really great tube amp that can do bedroom to live easily. Thanks for this tutorial as I've wondered myself lol.

[@mikeweber74]

I just got one, amp sounds great but wanted to check the bias. Both were set at 38 so I didn’t mess with it.

[@alwaysrockn2009]

Best video I have seen on biasing amps.

[@oldguyjammin9732]

alwaysrockn2009 - thanks so much for the kind words, frankly though Marshall made it simpler than it’s ever been to re-bias an amp \m/ way to go Marshall!! Loving this amp :) recently through an Eminence Swamp Thang in it and it absolutely growls with lower tunings (Drop B).

[@ShredRexGuitar]

Just picked one up a month or so ago, and love it. Glad I found this was easy to bias for sure. Think this thing is a keeper! I agree with what other have said, to some the master volumes and adjust volume via channel. Once those el34 get cooking man this thing sounds great. I mainly play the green ultra for a classic rock tone and roll.of the volume to get "cleans".

[@oldguyjammin9732]

ShredRex - awesome! Yep, keep the masters up or it thins out. It's still my favorite.

[@thefreedomwall7904]

The info i needed. bulls-eye! Thanks, Man.

[@jonbradford457]

Thanks again for the additional info. 👍😎🎸🎼

[@TheTz750]

...the helping hand....thank you so much…!!!

[@robbyclark6915]

That same speaker is in my fender 68 custom deluxe reverb reissue. I have heard it compared to many different speakers from Celestion and I can find no good reason to replace it personally.

[@andybrown1439]

Omg I had NO idea it was SO SIMPLE! I was watching another vid on this guy doing it on a 40ç and I was like no way, no thanks haha! Live the channel dude! What would I look for on Amazon when ordering the tester? Thanks, Andy.

[@oldguyjammin9732]

A medium priced voltmeter with good accessories like clip leads is fine. This looks pretty good and is ‘auto-ranging’ which can be really nice. Have fun, good luck! Thanks for coming by \m/ www.amazon.com/AstroAI-Multimeter-Ohmmeter-Voltmeter-Non-Contact/dp/B0842HTN8C/ref=sr_1_3_sspa?dchild=1&keywords=Voltmeter&qid=1614571990&sr=8-3-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExTEY4UDVWUkhTMEJWJmVuY3J5cHRlZElkPUEwNDIwNjg1M0NRWlNZSkw0N0hPNCZlbmNyeXB0ZWRBZElkPUEwOTQyMTgxMUJPUUpMRzhPQzlITyZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

[@andybrown1439]

@@oldguyjammin9732 I got it...my tubes were biased at 28 so I rebiased them to 35 and the amp opened up so much! Thanks man, cheers!

[@oldguyjammin9732]

@@andybrown1439 - Atta boy \m/

[@mastopage3120]

It's about time that they put pots like this for safety and easy accessibility. All tubes amps should be build like that, easy and safe. +++ It encourage people like me to buy tube amp. I don't want to bring my amp to the tech every time it need to be bias. Another positive point, no chance to break something while removing the chassis etc.. Great Video an thank you. i want to buy one.

[@bobdillon1138]

Doesn't have to be spot on a few volts either side is fine and a bit of miss match can actually sound nicer.

[@ajayghosh2445]

Dear Sir Thanks for your prompt reply . Let me try. I will let you know the result .

[@lesterelkins4050]

Thank you for the video. Just did mine and made a big difference!

[@oldguyjammin9732]

Good to hear \m/

[@MrArchonta]

Very useful tutorial, thank you.

[@mreust230]

Thank you! This video was spectacular. I have one of these and the sound was not like the full, smooth Marshall sound I expected. Seemed more raspy, or thin and fizzy as you said. I checked the bias and it was at 36. So I bumped it down to 32 and it sounds great now. However, just want to ask you, to me it seems running the master volume at about 3 o'clock gives a nice full sound while running them at 12 o'clock or less seems to make the sound start to thin out a bit too much. What are your thoughts? Also, on the classic gain channel there seems to be a big volume difference between the clean and crunch settings. Do you find this also?

[@oldguyjammin9732]

Yes, yes and yes. You can get a free dB meter for your phone which is pretty cool, for me the Marshall comes alive at over 90 dB which is pretty loud but not painfully so, at 100 it's just bitchin'. I like the Masters up at least past 12:00 as well and there is volume jump on the Classic side. I use the red voice and roll my guitar volume off for cleaner cleans... even with 4 voicings it's still a two channel amp ;-)

[@brimill1980]

Thank you for this ❤ I’m not the most technical guy in the world 😂

[@oldguyjammin9732]

You’re welcome, come back with any questions that come up.

[@chadgauge]

Great Video! Thank you for sharing.

[@oldguyjammin9732]

Chad Zarn - you’re welcome. Still loving this amp \m/

[@J_Braz_]

Just got mine. Was set at 42 and 38.

[@rjake61]

WARNING: Although the amplifier has five speaker outputs, never attempt to connect more speaker cabinets than rated. The safe combinations are:1x16 Ohm,1x8 Ohm, 2x16 Ohm, 1x4 Ohm or 2x8 Ohm only. Any other speaker cabinet configuration may stress the power amplifier section and in extreme cases may lead to valve and/or output transformer failure. NEVER use DSL100HR or DSL40CR without a speaker load.

[@MERT454]

I replaced the stock 16 ohm speaker with the same Celestion V type, 8 ohm speaker, move the plug over, and now I can run the DSL40 with a 2x12 8 ohm extension cab for a smoking hot 3x12 set up!!

[@caryboudas5359]

Hey thanks for posting this. Where do you set the gain,volume and master at?

[@oldguyjammin9732]

Cary Boudas - it does not seem to matter Cary. I adjusted mine down today from a high of 38 to a low of 30 and then back up just a bit to 32 - sweet - while having the probes in I turned all my master, volume and gain knobs and none of them made any change to the biasing voltage at all. 30 - 32 is where I like it, higher than that and it gets a little thin and fizzy.

[@davemoran3406]

This is so helpful. Thanks for posting this! I purchased the DSL40CR two months ago and I love it! After watching your video I decided to get myself a tube bias tester. What bias kit do you use? Or is there one you would recommend?

[@oldguyjammin9732]

Dave Moran - what’s up Dave!?!? No ‘bias tester’ required but you will need some sort of Volt Meter. You could pick up a great little digital one like this www.amazon.com/Multimeter-Electrical-Resistance-Transistor-Continuity/dp/B07GZL1JPV/ref=sr_1_13?keywords=Volt+meter&qid=1578926899&sr=8-13 or check Harbor Freight as well. Really affordable and is useful for guitar related stuff.

[@JustBlueFish]

Thanks for the video, but quick question. I know nothing about how to use a multimeter or which one I should buy. Can you recommend one from Amazon and what setting on the dial I need to use for this testing? I appreciate it.

[@oldguyjammin9732]

www.amazon.com/Neoteck-Multimeter-Multimeters-Resistance-Transistor/dp/B01NAVAT9S/ref=sr_1_18?crid=2X7G2W4VP35BM&dchild=1&keywords=multimeter+tester&qid=1606659418&sprefix=Multimeter%2Caps%2C243&sr=8-18 This one is only about $4 more than the cheapies but stats for sure that it’s autoranging, has a backlit display, has audible continuity and comes with alligator clip leads which saves you buying them later. When you get it, read the manual :) you’ll then use the DC mV (milli volts) setting. Remover to have a speaker plugged into your head and have it in high power mode.

[@JustBlueFish]

@@oldguyjammin9732 Thanks for taking the time to reply with that I appreciate it.

[@williamwinn948]

just checked mine, right from the factory both where 34.4 right on the money just gonna leave it at that. tried it at 32 did not sound good to me 35 sounds the best i think.

[@saintghost]

did you turn on the amp? or you biasing on turn off amp ? please let me know

[@craigtodd8297]

What is the worst that could happen if biasing were not done and is was way out? Just curious.

[@dort7402]

I know this vid is been up awhile, but what fluke do you have ? Im thinking of getting the flike 101 cat 3. But the question is on the 101 the milivolt dont come with ac/dc milivolt i believe its only in ac? Or visea versa But will that matter, when i use the 101, to bias my Marshall dsl40cr? ..thanks was also hoping to hear this amp with the greenbacks and other cabs. Thats all the same

[@davemoran3406]

Thanks for the video. I’ve had my DSL40cr for 3 years. I’m getting ready to swap the power tubes and bias it for the first time. I’m new to this and my question is about the multi meter. What do you set the dial to? Would it be the mV setting?

[@oldguyjammin9732]

Yep, mV DC

[@MikeMCT]

This is incredible helpful. I have a DSL 40CR and just blew a power tube. It’s 3 years old and I just ordered replacement tubes for everything. I can’t find an amp person in my area but this actually looks easy enough for a non-mechanically inclined person to do. What is that tool / reader called? A voltage reader and is there a specific type that I should buy?

[@oldguyjammin9732]

Very cool! Good luck with the new tubes, should sound amazing! The tool is just a little volt meter. You’ll need one that reads down to mill-volts but they’re cheap. You might as well get one with resistance (ohms) measurements too, as that can be very useful to us guitar players. I’d spend about $20 and see if you can’t get one with a selection of clips or probes.

[@davidgaukrodger2769]

Very helpful. Just biased mine after watching the video. Easy as.

[@xxsouthxxsidexxroyxx]

This is a super helpful video!

[@oldguyjammin9732]

You’re welcome - have fun \m/

[@electrocity26]

Hi man, great tutorial, it is really usefull. How do you set up your tester?

[@cigdamagelungs]

Thinking about trying this,just bought the harbor freight gizmo but have no idea how to set it,but will try Looks easy i think Ty

[@oldguyjammin7485]

Set to DC millivolts, red to red and black to black. You can the adjuster with your fingers too. No need for a screwdriver. No need to lay the amp on its face either, put up on a chair or just lay down. Make sure you're in high power mode and let the tubes warm up for a few minutes before reading the meter.

[@cigdamagelungs]

@@oldguyjammin7485 ty very much Really appreciate it

[@tgchan]

Thank you. Now I know how to bias an amp I do not have xD

[@MrFirerobb]

Looks so much easier than the DSL 40…saw a vid on it and it was way more involved..I was wondering if the CR was gonna simplify it and it seems they did. I will find out as mine will be here tomorrow. Thank you.

[@oldguyjammin9732]

Yes, super easy. I set mine to 32 mV DC. I also ended up with a G12M Creamback speaker. The Marshall amps can be a little fuzz-like until the masters get up past 3:00 or so. Congrats on your new amp!

[@MrFirerobb]

@@oldguyjammin9732 what do the cream backs cost?

[@oldguyjammin9732]

@@MrFirerobb - most used “like new” speakers cost around $100. The Eminence Texas Heat would be another really interesting speaker to try.

[@jonbradford457]

Thanks so much for posting this. I just ordered a floor model DSL40CR and will probably put new power tubes in it and keep the old ones for spares. Can you please answer a couple of questions from another "old guy"? I bought a multimeter, but I'm not sure what setting to use on it to bias the amp. Also, what type of screwdrivers are you using in the video to adjust the bias - flat head or phillips? I've swapped tubes many times but never attempted to bias an amp in all of my 71+ years.

[@oldguyjammin9732]

Sure buddy, you can actually use your fingers to turn the bias adjusters but I used a small flat screwdriver. Use DC millivolts on your meter :) thanks for coming by and enjoy your new amp!

[@oldguyjammin9732]

I’d plan to swap out the first pre amp tube too, it’s just another $15 or so will ensure you get the most out of your amp

[@jonbradford457]

@@oldguyjammin9732 I have a PRS Sonzera 20 combo. I put a 5751 preamp tube in V1 (SRV used them in his amps) and it reallly improved the sound of that amp. About 20-30% less gain, but increased headroom and tighter, overall better tone. I may try one in the DSL40CR, depending on how it sounds when I get it later today. Many thanks for all your help!!!

[@JamesMcCutcheon]

Thank you I am liking my CR40.

[@acerob7173]

Ok, I've done it! 😃

[@oldguyjammin7485]

Crank it!

[@zept77]

Thank you sir I’m going to try this .

[@oldguyjammin9732]

Ivan Zept - great man! Couldn’t be easier and made a noticeable change in my amp’s tone for the better. I settled on 32 mV for less fuzz, but if you like the fuzz tone increase to 38 \m/ peace out

[@MERT454]

With guitar plugged in, in High power mode, guitar volume down!? where should the volume knobs on the amp be at?

[@oldguyjammin9732]

it matters not, but do plug a speaker in!

[@ryanlangelan2135]

Great tutorial! Thanks! Do you find that setting the master volumes at noon+ improves the tone even when the individual channel volumes are turned down to bedroom or small venue volumes? Where's your sweet spot between channel volume and master volume? Thanks again.

[@oldguyjammin9732]

Loud - Masters at atleast noon, best at 3:00 or full. Anything less is... less. I’m probably going to sell this and replace it with the 20W combo so I can get closer to diming the masters anywhere I play.

[@harryclarke8359]

I’ve had this amp for a little while now. There’s not really any need to crank the masters up as it doesn’t make any noticeable difference. Crank up the volume on the preamp section and keep your masters lower if need be. Cranking up the preamp really gives it that extra “fuck you im gonna step on your balls” sound. It’s a great amp at the end of the day. Any setting sounds nice!!

[@vin9976]

This is great! Thanks. Tone question, when using the Overdrive channels with any legit gain, it’s not nearly as tight on the lows as I was hoping. Kind runs away on the E and A strings. Sorta flubby. Any idea on dialing it in or tricks there? I’ll bias it and see if that helps.

[@oldguyjammin9732]

Bias it first, I preferred a lower setting to help get rid of top end sizzle. THEN, run your master up at 1:00 or higher and then bring up the gain, ONe thing with marshalls is you have to have the masters up. Lastly, boost it with an OCD, or a Flux Drive or Archer Clean to help tighten it up. If you need it tighter get an EVH Stealth 50W. I sold my DSL40 and got a DSL20 instead just so I could run the master up higher without the volume getting insane.

[@jboy8735]

What do you have to have your speaker connected ? to does it come with the hook ups to do that

[@brianewert6667]

It just means that you have to have the speaker plugged in to the amp. So if this was a Head instead of a combo you'd want to make sure the head was plugged into a speaker cab. Because this cool combo allows for other speakers to be plugged in, the point needs to be made - make sure a speaker of some sort is plugged in when checking the bias. That's all :) just have the normal speaker wire plugged in like you would when playing. Another way to say it would be to say "check bias under normal playing conditions - Amp on, full power mode, not in stand-by mode, guitar plugged in (you can roll the volume down). Good luck

[@jimihendrix4376]

Still have this amp? If not can I ask why not, thinking of buying one. thanks

[@oldguyjammin9732]

I do not, Marshall’s need to have their masters up in order to sound full, it was just too loud. I sold it and got the DSL20 combo and liked it much better. Still have to have the master up but it’s much more useable and still plenty loud to use for a show.

[@acerob7173]

Hi, thanks for sharing this. Does it means that when you purchase the amp, it is nor Biased properly and you have to do it on you own? what happen after the Bias adjust to 35.0? does it sounds better? thank you, cheers.

[@brianewert6667]

ACERob71 - biasing isn’t always ‘necessary’ from the factory but it’s a fun way (fun way?)... it’s how we make sure we are getting the best tone we can out of the amp. If nominal voltage for those tubes is 32-38 we can adjust the bias voltage to have the power tubes run really hot (38 mV) which adds to the distortion (and sometimes creates a fuzz effect) or cool them off (32 mV) which lowers the distortion, creating more of a ‘crunch’ tone. Plus your tubes will last a bit longer if the bias is lowered, but it’s up to the user to decide what they like. If the bias is too hot the tubes will ‘red plate’ and fail earlier than expected, if the bias is too cool the tone will sound thin and lack any sort of ‘meaty goodness’ \m/

[@acerob7173]

@@brianewert6667 I gess the best will be in the meaddle. many thanks for the clarification /m\

[@brianewert6667]

ACERob71 - you bet man, I should have mentioned that I settled on 32 mV. Nice and full without fuzzy hiss, with PLENTY of dirt still on tap.

[@carlosgarcia9225]

What the hell is Bias? What’s that for?

[@1960bobthebuilder]

Great video. Easy question. How do I find the bias voltage for a set of 6l6 power tubes, as opposed to the el34 tubes installed new into these amps?

[@oldguyjammin9732]

Hey- Bobthebuilder, are you planning to swap out the EL34s with a pair of matched 6L6s? Tell me more... from what I've gathered so far (if compatible) the bias mV should be just about the same 38 mV. I don't have a definitive answer as of yet :)

[@oldguyjammin9732]

Here's a link to a discussion board regarding tube compatability www.harmonycentral.com/forum/forum/guitar/acapella-28/1655340-

[@acerob7173]

Hi, thanks for sharing this usefull tutorial. I was wonder if it would be very dangerous to put the hands near the current transformers when the current line is live, isn't it?

[@oldguyjammin9732]

ACERob71 anything shown on the “test side” of the chassi is ok to touch.You can see if transformers get warm or if they’re buzzing. Caution is always best, but the nasty stuff is on the inside. That’s why these external test jacks are so great - no more danger when biasing power tubes!!

[@derekmc9580]

Thanks for the info man. That is so cool they made that so accessible . . Im buying one of these amps soon And i haven’t decided weather to get the 20w or 40w version. Do u think the 40 is to loud for home use. I really want the 40 because of the better pre amp section with master volumes and better speaker but am afraid it’s gonna be to loud to just jam it around the house. My first Marshall. Any input would be much appreciated. Thanks

[@oldguyjammin9732]

Derek Mc - it's too bad that "too loud" is so subjective and different for everyone. Personally I really enjoy even the low volume tones I get from the 40 Watt beast and when cranked it's just 'juicy good'. This Marshall and the new Blackstar are surprisingly good at low volume. Having said that, I would have kept the 20 except for how the fx loop is wired up. Because there is no master on the 20 Watt version you'll experience volume changes in whatever effect you may have in the loop. Depending on your settings it may not be too bad but it can be, especially if the gain is cranked on the dirty channel. You've got some things to consider 20 watt head or combo (you'll want to upgrade the speaker in the combo) or for the extra Benni and a half get the 40 and a Bugera Power Soak ($99 from Sweetwater). If you ever do have the chance to play loud the 40 would be the way I think. Sweetwater has a B-stock CR for $600 right now. Now if you really can't ever get loud, the 5 Watt CR is really sweet. Really nice Marshall cleans and a dirty channel that just sings. No mods necessary. It's light enough that the return shipping wouldn't kill you if you opted to upgrade, you could even check to see what return shipping would be... unless you live close enough to a Guitar center and could return it in store. Between the 20 and the 5 I take the 5. Check my Marshall dsl 5 vs Blackstar HT vid... Think about it \m/

[@derekmc9580]

Juicy good is what I’m looking for so I think I’m gonna get the 40w combo lol. This is gonna be my first tube amp. Can’t wait. Thanks again

[@oldguyjammin9732]

Derek Mc - Cool man, I did some checking tonight with a free Decibel Meter app. With my phone about 3 feet from the amp it really starts to sound good right around the 90 dB mark :) plus or minus a few here or there. I thought you might download something similar to get a feel for the noise level.

[@oldguyjammin9732]

Derek Mc - no head phone jack. I hate to dissuade you, especially if you’ve always wanted a Marshall, but have to say the Blackstar HT40 MKII is also a very nice sounding combo that you may want to check out. They are both really nice, slightly different tones but all good. The Blackstar has better power reduction for quiet playing. My HT50 can be played at 5W or 50W while the Marshall is 20W or 40W. Just something to think about. It’s a lot of money so if you could get to a store and try both.....? Have fun!

[@chrisconnelly5538]

Oldguyjammin It actually does have a headphone jack. The line out jack in the back doubles as a headphone jack, plug in headphones then set the amp to Standby to jam quietly

[@JamesMcCutcheon]

I have a Pentode and Triode switch on my amplifier. Which I like. This change to simplify the power options came about due to the average newbie players not getting the Jack on this amp. What do you think I should use Pentode or Triode mode or check both?

[@oldguyjammin9732]

James McCutcheon - try both and hear what sounds best to you. You can also play with master full and creep up the channel volume and the reverse, channel maxed and creep up the master. Love this amp \m/

[@kameel68]

Can you replace the EL34 tubes with 5881 tubes and than just bias it to 35mV?

[@oldguyjammin9732]

i"m too much of a wuss to recommend any tube changes, but... I believe the 34s, 5881, and 6l6 tubes are interchangeable. However the 6l6s draw quite a bit more heater current and could stress your output transformer. 5881s would be the way to go. I'd recommend asking an actual amp tech.

[@kameel68]

@@oldguyjammin9732 I just send an email to Marshall with the question.

[@tudortolciu1396]

Hi I just did this yesterday, but I had no idea you had to plug in the guitar. Does it affect it anyhow? I was reading spot on 35mV on both from the factory. Should plugging in the guitar make a difference? Anyway, thanks for the tutorial.

[@oldguyjammin9732]

Tudor Tolciu - no, you don’t “have to” have the guitar plugged in, I did that to satisfy my own nervousness :)

[@jimitremonte9655]

Love the video do you keep it on or do you put it in standby mode

[@pstock426]

I've been looking for a new amp and came across this DSL 40 CR. However, I've seen quite a few complaints about hissing, static, popping, whatever. What are your thoughts on these issues?

[@oldguyjammin9732]

Jerry Davis - We hear complaints about every amp out there; lots of popping, hissing, what sounds like a crash symbol decay in the cab or even ethereal wind sounds but in my experience most of these issues are a bad tube in which case the seller is more than happy to send out new tubes or accept the returned amp. I had a cymbal crash sound in my small blackstar (tube), I had popcorn sounds in my Egnater (tube), I had what seemed like too much hiss in my EVH (tubes), know what I mean. Comments regarding an amp (as well as number OF comments) on the GC site, Amazon or Sweetwater’s site are usually a pretty good indication of any issues that folks are having. It’s my belief that this particular DSL40CR CR is a rock solid amp. Sometimes people will buy something like this and then expect it to sound good at lower volumes too and when it doesn’t they complain that it sounds fizzy which is kind of true. This particular amp sounds ‘OK’ at lower volumes but doesn’t sound real good until you get above 90 dB which is pretty allowed. When I first buy any new amp I leave it on for a few days straight, push it, push buttons... play it like I want to break it :) and hopefully any problems I may have will show up earlier enough that the seller covers EVERYTHING which is usually at least 30 days if not 90. I’ve been turning my Marshall on and off and playing it at least 4 times a week for the last 6 months without any problems. Of course there are going to bad units out there, but that is true of all of them. Even Fender had a nightmare run with there Bassbreakers. Thanks for asking - sorry to be long winded :) cheers

[@ChrisThomas-yr5hb]

Hey OGJ I'm really a noob with being handy. What setting do you have the multimeter at on the dial on the multimeter front?

[@oldguyjammin9732]

That would be DC millivolts

[@ChrisThomas-yr5hb]

@@oldguyjammin9732 thanks man. I pick up my dsl40cr tomorrow and the multi meter arrives Sunday from Amazon. I appreciate you taking the time to answer my question.

[@KipCount]

Is Biasing the same on a DSL20hr?

[@oldguyjammin9732]

Nope, no biasing required on the 20 I believe. I would buy matched power tubes though.

[@kevinbills1]

Is this mV DC? I would think AC, but y multimeter only does 200 and 500V AC. I have also seen some other videos where they measure mA, not V. In any case, I am not getting any reading on any setting, but meter works - registers resistance measures a 9V batter correctly. Amp is in high power mode and well warmed up.

[@oldguyjammin9732]

This amp checks bias with mV DC. Even if you use DC volts it should give you a decimal value like 0.035. Older amps with variable bias are measured in milli amps, not this one though. Some meters require moving the probes for mV versus mA readings so make sure your probes are in the right holes too. Feel free to send me a pic of the meter if you still have problems, use the same setting you used to measure the battery.

[@kevinbills1]

@@oldguyjammin9732 managed to fiddle enough to get a readin. but one side measuring between .7 and 1.2, while other side was at 48 and i dialed down to 35. bad power tube maybe? i have a hellacious buzz going on.

[@oldguyjammin9732]

@@kevinbills1 - sounds like we’re getting there :) make note of which side gives you which reading (mV value) and then power everything down and switch the power tubes, left one to the right socket, right one to the left socket. Power it back up and see if the weird mV value follows, if so you probably have a bad power tube. If you do replace one, I’d go ahead and replace both.

[@Chrisz0rProductions]

Thanks a lot!

[@gill.5116]

Great video I have a digital Voltameter but it’s different that yours, my question is what setting do I use? Mine shows DCA DCV ACV with numbers?

[@michaelbarber1123]

I just bought a DSL100HR and I have a brand new matched quad of JJ KT77 tubes for it. Problem is I have no idea what would be ideal to set the bias at and I'm not sure if KT77's are supposed to be biased hotter or colder than the stock EL34's.

[@oldguyjammin9732]

Michael Barber - that would be a question for the Marshall Masters. Give Marshall customer service a call. If you struggle with the number Sweetwater service will give it to you if you’ve purchased something through them. Should be easy enough to find, look up Marshall USA.

[@davider7530]

Thank you, can i ask how much the speaker cable can go out from the cabinet? i'm trying to understand if it possible connect an attenuator without replace the original cable.

[@oldguyjammin9732]

Davide R - “as is” the speaker cable only extends a few inches, however you can use a 1/4 inch female coupler and then use regular patch cables to make whatever length you need. Hope that helps \m/

[@MrMetz2112]

Hey old guy, I’ve had this app for about eight months now and have never checked it. Is it necessary to check the bias on a new amp? Shouldn’t it come from the factory set correctly?

[@oldguyjammin9732]

MrMetz2112 - you’d think, but stuff slips by or changes after “burn in” which is a time when the tubes settle in stabilize. Tube depot sells pre burned tubes that have been “cooked” for 24 hours so that we, the grateful consumer can truly “set it and forget it”. Even tube to tube differences of the same type sometimes require a slight bias adjustment, like when you re-tube your amp after a while, just cuz you buy the same type of tube doesn’t mean they’ll operate at the same bias voltage. Probably not too big a deal if it sounds right \m/ but if it seems too fizzy the tubes could be running too hot and on the other hand if it doesn’t seem to have any THUMP behind the crunch it may be running too cool. Too Cool isn’t as big a problem as too hot, too hot will cook your tubes prematurely. You must know someone with a simple meter? Check it out just for fun :) Cheers

[@ironrooster79]

Im noob here, why do you need to bias the amp?

[@oldguyjammin9732]

Bias determines how HOT the power amp tubes operate. Too hot (over biased) and they’ll burn out prematurely, not hot enough (under biased) and your amp won’t ROAR. It’s not super critical but can affect the tone. Once the bias is set, it doesn’t usually need to be checked again unless one moves to a different type of power amp tube.

[@ironrooster79]

Thanks for taking your time to reply.

[@BrandonSellers1]

What is the difference between 32mv and 38mv in terms of tone, volume, etc ? Thanks

[@oldguyjammin9732]

Brandon Sellers - hey Brandon, the difference is subtle but definitely noticeable. Increasing the bias voltage will also increase the current driving the power tubes creating more distortion and saturation, less articulation and more ‘fizz’ like a fuzz pedal produces. Lowering the bias voltage decreases the ‘fizz’ plus your tubes will last longer because they’re not operating at such a hot temp. Lowering the bias results in more ‘chug’ without the ‘fizz’. No real difference in volume. It’s all personal taste.

[@vindaroca]

sorry, but I don't understand wich function of the multimeter you've used, can you help me please?

[@oldguyjammin9732]

Sure Bruno - millivolts DC. I settled on 32 mV DC.

[@vindaroca]

@@oldguyjammin9732 thank you so much!!!

[@mreust230]

Do you like the stock tubes or are you considering changing them?

[@oldguyjammin9732]

* because much of what I pick up are Demo Models or B-stock with the same As New Warranty, I often replace tubes with JJs just because of the countless hours and On/Off cycles the amps have been exposed to while being on the showroom floor, but even then not unless I hear noises that shouldn’t be there like distant whispering winds or little crackles like pop corn being made. Most tube swaps I’ve done result in little noticeable tonal change, except with Fender Groove Tubes - I usually notice those. Or in the case of lessening the gain by pulling the 12AX7 and replacing with a 12AT7. In this case I’m enjoying the tubes as is. I did put a Mullard in socket 3 and JJs in 1 & 2 but didn’t really notice much change. Put the stock tubes back in :) get my hours out of them.

[@mreust230]

@@oldguyjammin9732 Thanks!

[@mickhofman]

whats that yellow thing you are using, and what setting is it on ?

[@oldguyjammin9732]

mick - it’s a Fluke 79 Multimeter and I’m testing for millivolts.

[@ultratacoRX7]

I just ordered one of these. (yay!) Why would I want to bias it?

[@oldguyjammin9732]

ultratacoRX7 - because, the bias is fairly often OFF and/or set too hot. Super easy to do, I like 30-32 mV. When you get your combo, check the bias just for giggles and let us know what it measures, then roll it down to 32 and see if you don’t dig the tone a whole lot better :) rock on bruha \m/

[@ultratacoRX7]

@@oldguyjammin9732 Cool, thanks. I'll try to remember to do that and report back.

[@ultratacoRX7]

​@@oldguyjammin9732 I just biased my 40cr. It was at like 37-38 when I checked it, so not too far off the spec. I forgot you mentioned 32 so I just set it to 35. It sounded better I think but I could have just put the knobs in a better spot when I turned everything up again. Some time soon I will try 32mV (and make sure the knobs are in the same place) and see if I notice any difference. This is my first Marshall so it's taken some tweaking and getting used to but I'm liking it.

[@oldguyjammin9732]

ultratacoRX7 - That’s cool man, after you get used to it and find some tones you like, take it on down to 32. It won’t be as big a difference as going from 38 to 32 but still... I went from 35 down to 32 and it was more the tone I’m after. Have fun.

[@ultratacoRX7]

@@oldguyjammin9732 just to follow up, I checked the bias again tonight. One jack was close 35 where I set it last time (35 point something). The other was way up to 40. So I guess this is something you have to do occasionally? I put both to 33 this time and I think it sounded better and/or a bit louder. dunno. maybe placebo. Anyway, I also figured out I prefer the tone with all 3 EQ knobs all the way up. I got tired tweaking them to find my best tone so just said screw it and dimed them all and hey what do ya know that sounds pretty good to me (at least with the one guitar i tried like that so far).

[@daveedward6925]

I saw ur amp was plugged in and in high output during but does it need to actually be turned on? Thanks!

[@oldguyjammin9732]

Dave Edward - yes, the circuit must be ENERGIZED. Amp on, high power mode, guitar plugged in with guitar volume turned down and let it sit for 10 or 15 minutes so the tubes get up to normal operating temperature. Check, adjust, check, adjust, check and done :)

[@PeterDad60]

Is your question a joke? I mean come on man think!

[@JohnvanCapel]

You're reading the voltage. That means there has to *be* a voltage to measure, which means electricity has to be passing through. The only thing you can measure without powering the amp on is the resistance, which is a useless measurement within this context.

[@petkopeet]

Master volume cranked for biasing?

[@oldguyjammin9732]

Nope, just a speaker plugged in and have it in high power mode. I plug a guitar in as well cause it makes me feel better.

[@chriscalvert4625]

Quick question. What exactly is the meter called? Never played around with something like that. I need to buy one

[@oldguyjammin9732]

Chris Calvert - it’s an Electronic multi-meter available from Harbor Freight, Amazon, local hardware stores, etc. These days you can get them for under $20 and even sometimes under $10. It doesn’t need to be digital, an analog dial with a needle that moves works just as well - handy to have around for testing fuses, pots, voltages, resistances, etc.

[@chriscalvert4625]

Oldguyjammin I ended up getting on from my local auto parts store. Man, my dsl40c was running at 15mv per side. Couldn’t believe that

[@oldguyjammin9732]

Chris Calvert - good for you man! I imagine you’re a lot happier with the tone now...? You tell me :) any thoughts on the before and after?

[@chriscalvert4625]

Oldguyjammin Way better tone! Sounded stale before that’s what made me wonder on the bias. Wonder why it was set so cold in the first place. Makes me wonder lol

[@preciseaudioblog]

Hi! Should I bias the amp when I just buy it? Thank you.

[@oldguyjammin9732]

It doesn’t seem like you would need to, HOWEVER quite a few owners have found the bias to be pretty far off. It’s worth checking \m/ I like it set lower at around 32 mV DC.

[@preciseaudioblog]

@@oldguyjammin9732 Perfect. So far, do you consider this Marshal is reliable? Thank you.

[@oldguyjammin9732]

@@preciseaudioblog - yes, I’ve had 3 and still have the dsl20 and dsl5 and haven’t had problems with either. I drag them around to different places in my car, to work, talent shows, lessons, etc. No issues :)

[@preciseaudioblog]

@@oldguyjammin9732 That’s great! Thank you!

[@musicamaniabrasil9999]

Hi, I've tried with a 100HR, after connect the multimeter the bias controls didn't work, seeming it is disconnect from the board, the reading is 74 on both sides,.. suggestions from Marshall guys?

[@oldguyjammin9732]

Musicamania Brasil - 1) make sure you guitar is plugged in to the front of the amp 2) make sure the speaker is plugged in 3) make sure the amp is in HIGH POWER mode (or the controls won’t work). The first time I tried I had the amp in half power mode (or low power mode) and the controls did nothing and the reading was high just like yours. Good luck

[@musicamaniabrasil9999]

@@oldguyjammin9732 Thank you indeed, it is working! maybe 80 works fine for 100hr, Best, Edu

[@jgl8552]

i can only bias my new tubs to 22? the knob won spin anymore.

[@oldguyjammin9732]

Hmm… both sides? If it’s only one side, swap the power tubes and try again. If the problem moves than replace your power tubes. Amp on, high power mode (not low) and guitar volume rolled off just so it doesn’t start howling.

[@jgl8552]

@@oldguyjammin9732 yes Replaced both power tubes and with new ones . And for some reason I can't bias them past 22 and my amp has very little distortion. Makes weird noise and . I can put the old ones back in when I get home . Yeah my bias knobs only turn about 1/4 way before I can't turn anymore. I have E34 powertubes they should be hotter

[@oldguyjammin9732]

@@jgl8552 - how low do your bias pots go? Can you return the amp? You should be getting almost a full turn out of those pots. I’m starting to suspect that something is wrong with the amp, can you take it back? Or did you buy it used… Marshall is very good about picking up the phone, try giving them a call.

[@jgl8552]

@@oldguyjammin9732 if i turn the bias pots down it goes a whole turn but then the tube is generating next to nothing. It's when, the bias dial is turned all the way up it's only biasing the old tubes to 19 and the new ones at 22 max turn. I followed your advice, I replaced the tubes, let it heat it and checked the bias so i can adjust it and stock it was turn like 3/4 the way to max . The tubes were only biasing 18 then when i turned it to max on both then only get to 22 I believe this amp is out of warranty and i bought it new back in 21 or 22.

[@oldguyjammin9732]

@@jgl8552 - Marshall’s usually have a 5 year warranty so you should be covered. You could look around on the PCB for an obvious problem, like a blackened part but other than that I’d say do your best to get in touch with the retailer you bought it from. Sorry I couldn’t be more help.

[@barryh3607]

Thank you for putting out this video! I was trying to confirm if you could use an external speaker cabinet while using the combo speaker at the same time. I want to use an external 1 x 12 EVH cab along with the built in combo speaker.

[@oldguyjammin9732]

Barry H - you sure can as long as your combo speaker and extension speaker are the same impedance 16 or 8. I use the two 16 ohm outputs on the back of the combo, one for the internal speaker and one for an extension cab with a Swampthang in it. You’ll have to move your 1/4 speaker plug over a hole, your extension cab goes in the other.

[@barryh3607]

@@oldguyjammin9732 Thanks for responding. The EVH 1 x 12 cab is 16 ohm 25 watt, so moving combo speaker over to 2 x 16 ohm should work great. Now, if I had an 8 ohm extension cab, I would leave combo speaker plug in the 1 x 16 ohm plug and then use the 8 ohm cab in either one of the 8 ohm jacks?

[@oldguyjammin9732]

Barry H - I wouldn’t think so but you could call Marshall or look up the DSL40CR manual. It would seem to me that if using extension cabs you’d have to be in similar blocks; two 8s, or two 16s or one of either, but one 16 and one 8 sounds like “pishy caca” to me. Check it out and let us know. I’ve deliberately purchased 16 ohm cabs for this reason but would love to have an 8 ohm 25W Greenback cab around.

[@barryh3607]

@@oldguyjammin9732 You are correct, in the manual it says you can use 1 or 2 - 16 ohm speakers (with one being the combo speaker), 1 or 2 - 8 ohm cabs, or 1 - 4 ohm cab. If you used the combo speaker with a 2 x 12 8 ohm cab it would put an uneven load on the amp and cause damage.

[@preciseaudioblog]

Hi! How do you difference the C from the CR model? Thank you!

[@oldguyjammin9732]

Mostly obviously the Reverb which is just okay, biggest difference is a much tamer classic side on the CR and less fizzy Ultra channel. The old C had a really brittle and harsh ultra tone. THe 6 button footswitch is also pretty darn cool and being able to set the bias on the new CR is awesome cause I find I like mine down around 32 mV.

[@preciseaudioblog]

@@oldguyjammin9732 Awesome! Thanks!

[@markattaway4429]

If you wanted to use the internal 16 ohm speaker, in conjunction with an external 8 ohm cab, which jack would you plug the 8 ohm cab into?

[@oldguyjammin9732]

TheToneScientist - hmmm, don’t think I’d do that, but you could call Marshall to be sure. The call outs for speaker outs are 2 - 16, or 2 - 8 and it’s wired up to work that way. I blew a GK head once because I hooked it up to some house speakers that were 4 ohm - zap! Might be better to consider a speaker upgrade for the extension cab - one at 16 ohms...? Sorry, I know... $$$

[@markattaway4429]

@@oldguyjammin9732 I have a Marshall 8 ohm MX212 cab. If I wanted to replace both speakers, what ohm do they each need to be?

[@oldguyjammin9732]

TheToneScientist - is that the upright 212 with the slant? That’s an awesome cab, wanted one for a while but never worked out per “my space” either way, getting rid of those 70/80 speakers will be nice. It’s an 8 ohm cab so you have two 16 ohm 70/80 speakers wired in parallel. Since the speaker in the DSL is 16 ohm you’ll want your extension cab to also be 16 ohms so you can run them at the same time. If I were you :) I’d put an 8 ohm Greenback and an 8 ohm Vintage 30 in that cab, wired IN SERIES to create a 16 ohm load. Or an Eminence SwampThang 8 ohms on the bottom and an 8 ohm V30 (or V-Type for that matter) on top. I ended up with a V30 in my DSL combo and have it sitting on a cab I made and loaded with a SwampThang. The two together sound pretty darn good from cleans to blues to METAL. You could search around a bit for best speaker combos or mixes for 212 cabs... look for posts from THE GEAR PAGE. Have fun \m/

[@markattaway4429]

Oldguyjammin thanks, bro! I actually have the horizontal MX212. People trash talk it, because it’s made out of compressed particle board or something, but it’s been a solid cab. I always hear that the Texas Heat and Swamp Thang are good combos.

[@oldguyjammin7485]

@@markattaway4429 just thought I'd mention this, not that you don't know it already, you'll move the existing speaker plug from "1 - 16 ohm" over to one of the pair of the "2 x 16 ohm" and plug your cab into the other.

[@SmyganPro]

I'm doin' good

[@AJC-jo3ds]

I swapped my tubes to tungsol on my dsl40cr and have trim pots maxed but mv only go to 29, any suggestions? Thx

[@oldguyjammin9732]

Njwisenheimer64 CNJ - EL34s? Other than that, make sure the amp is in FULL Power mode, the guitar plugged in and your speaker connected. Make sure you’re testing in DC millivolts on the 0-200 setting (unless your meter in auto ranging)...? Does the millivolt reading move at all when you turn the pots? What was the bias voltage with the stock tubes in? Try putting the stock tubes back in and see if you can nail 32 - 38 mV, set it to 32 (that’s what I like) and then put the new TunSols in and check the reading again.

[@oldguyjammin9732]

Njwisenheimer64 CNJ - found this on the gearpage www.thegearpage.net/board/index.php?threads/tung-sol-el34bs-in-my-marshall-bias-range-to-shoot-for.1552720/. While the readings are mostly in mA the relative info I came away with is that some TungSol EL34s are different and may not be compatible with your amp (call tube store or tube depot) the other thing was that it’s all relative, so if 29 mV DC is max, 70% of that should be a good operating voltage for ANY tube, so 22 mV might just be the ticket. It would be interesting to see if 22 with your TS changes to 32 with the other tubes put in (with out you making any changes). Good luck and let us know.

[@AJC-jo3ds]

Oldguyjammin thanks man! I’ve been back and forth with JP at tube depot all morning, he suggested checking plate voltage which I did and got 457v, doing the calculations at 65% I should be at 35mv, but the pots are maxed and only read 29mv. think I’ll just go back to stock JJ tubes.. Hey, I noticed the preamp stock tubes are different, 2have red writing , 2 have white writing but I forgot(didn’t note) which went in what position, do you know by chance? Thanks bud!

[@oldguyjammin9732]

Njwisenheimer64 CNJ - I don’t imagine it’ll make a difference where those preamp tubes go back in as long as they are all 12AX7 or ECC83. You could visually look at the height of the internal plate and if one is shorter I’d put that in the #4 socket.

[@MarcinPapiernik]

Is that easy for DLS5CR too?

[@brianewert6667]

Marcin - hey there, I haven’t been in to the 5CR (only played it - really NICE :) so I’ll have to say ‘dunno’ \m/

[@GreatDocumentaries1]

Do I set my multimeter to 200mv or 2000mv?

[@oldguyjammin9732]

Antonio Racciano - set it at 0-200 mV DC

[@GreatDocumentaries1]

Thank you for your quick reply, I really appreciate it

[@vladonutyj]

How many mV's Marshall 100HR needs?

[@oldguyjammin9732]

Vladonutyj - dunno, ask the internet or call Marshall.

[@vladonutyj]

@@oldguyjammin9732 okay. Thanks for answer

[@markattaway4429]

What do you have your multimeter set at? Thanks.

[@oldguyjammin9732]

Guitar Tex - I used the mV (milli-volt DC) setting. I also found that I really liked the tone at 32 mV rather than 35-38.

[@markattaway4429]

@@oldguyjammin9732 Thanks, buddy. Is it set at 200 on the multimeter?

[@oldguyjammin9732]

GuitarTex - gotchya... mine is auto ranging but you’ll want to measure LESS than 200. Is the range 0-200? If so then you’re right on. Even if your meter is set higher you should end up with some variation of 35 mV or 0.035V. Use your lowest mV setting.

[@markattaway4429]

@@oldguyjammin9732 Thank you, sir. You enjoying the amp???

[@oldguyjammin9732]

GuitarTex - yep, really like it. I had it plugged in to my Greenback cab the other day and it was even better so I’m gonna be working on a mod to enclose the combo’s speaker and/or throw in a Eminence Texas Heat. But even as is, it’s really great. RIGHT??? Preachin’ to the choir cuz YOU GOT ONE TOO!

[@ajayghosh2445]

I mean the position of all the control switches during the adjustment of bias setting. Please elaborate.

[@oldguyjammin9732]

Ajay Ghosh - not that important. Set them all straight up if you like. What is important 1) speaker connected 2) guitar plugged in 3) turn on and then wait 10 minutes before adjusting bias to let the tubes reach full operating temp.

[@repetitivemotion]

Can you explain what setting to use on the voltage meter?

[@oldguyjammin9732]

repetitivemotion - millivolt. Many meters, if not ‘auto-ranging’ will have a 0-200 mV selection.

[@repetitivemotion]

Oldguyjammin I tried it with gains on full, channel and master volumes on full and amp on standby and I get no reading

[@oldguyjammin9732]

repetitivemotion - well back the turnip truck up :) gain and volume can be anywhere, so turn them down. Instead of Standby you should have the amp in High Power mode. MAKE sure speaker is plugged in. You can have a guitar plugged in or not, but the speaker is a MUST! Okay? Volume and Gains and Masters can all be at noon. The power toggle on the front in High/Full power mode, then try it again. You’ll get it!

[@repetitivemotion]

Oldguyjammin thanks I’ll try right now

[@repetitivemotion]

Oldguyjammin ok now I get a reading but the max for either tube is 23. I have the meter on DC 200

[@jboy8735]

What do you have to set the meter on when you do this

[@oldguyjammin9732]

Jonathan Barham - DC millivolts. If not auto-ranging then select 0-200 DC mV

[@jboy8735]

Thank you I have this same amp and it’s amazing and thanks to you video I now know the process I like that Marshall gives you the option to switch between 20 and 40

[@jboy8735]

Thank you for your help I appreciate it a lot very good video

[@searing7549]

These amps are junk!

[@oldguyjammin9732]

Oh c’mon man, this line of Marshall’s is a budget friendly entry into that hugely massive and popular “Marshall tone” \m/ they’re great and any beginner would be lucky to have one. Do they compare to my SLO30 or JVM410, no, but my little DSL5 gets more hours on it than anything else - love it!

[@searing7549]

@@oldguyjammin9732 well, I am an amp tech, and have seen plenty of these things on the bench. I would never recommend one. Built very cheaply, and terrible solder joints throughout. Just be very careful when changing those preamp tubes!

[@oldguyjammin9732]

@@searing7549 - lol, now I get you and ‘yes’ for longevity and ease of repair I would not go the Marshall route. I always pull my amps apart and I’d never be able to trouble shoot a Marshall unlike an Engl, Egnater or Soldano which use larger, discreet components. Still, “junk” may be a bit strong, lol. Thanks for all you do for us weekend warriors \m/ Much appreciation for you and yours.

[@gill.5116]

I have the same rig so basically on high power guitar plugged In volume down, also watch that transformer isn’t that live? What tubes were used?

[@oldguyjammin9732]

I usually put a 12AY7 in the tube socket closest to the input jack (V1). You’re gonna want to read millivolts so use the VDC and look for 0.032 or so.

[@gill.5116]

@@oldguyjammin9732 thanks for the video and response actually my interface on my voltameter looks just like the one you recommend so that would be on the right side, correct?

[@oldguyjammin9732]

@@gill.5116 _ can’t comment on which side it would be on, you need to dial in DCV or VDC for Direct Current Voltage.

[@musobill]

Great tutorial! Many thanks!

[@jamesabbott8208]

Great content. Thanks.