How To Bias a Deville Amplifier

[@rockbandgamer]

This video was so helpful. Replaced the tubes in my Fender Blues Deluxe reissue. Worked great! Thank you!

[@bobandy3197]

Same test point on the blues deluxe? Service manual for deluxe is different.

[@yusufandongvlogs6954]

MAds

[@gvb54]

Been using tube amps for 25 yrs and never truly understood how they work just loved the sound. Your series on tubes is second to none! Thank you so much for posting this and sharing your knowledge, it is appreciated. Looking forward to more.

[@rafaelzengo5534]

Great video. Cool guitar playing too. I thought these amps had 2 speakers.

[@ronniezzzz]

cordless screwdriver

[@hhscadets0925]

At 1:23 you say to not touch anything without first discharging the amp. How is this done? Will simply turning it off and unplugging your amp discharge it after a period of time?

[@xenod1066]

Mike Lowrey Well, probably, after a month.. I'm tempted to say "if you have to ask, don't do it." - Not to be snarky, but because it's actually dangerous. A power resistor is used to discharge the power supply filter caps. There's a lot of videos about it. If in doubt, take it to your tech.

[@bart99gt]

I made a wand out of a cheap screwdriver, alligator clip and a 1k resistor. Alligator clip lead is soldered to the resistor, resistor to the Clip the alligator clip to the chassis, touch the end of the screwdriver to the positive end of one of the filter caps. That will usually discharge most caps in less than 10 seconds. They will discharge after turning the amp off while the cathodes are still hot enough to emit electrons. But don’t rely on that alone before sticking your hands in there. Plus, it only works if the tubes are installed, if you’re testing something with the tubes pulled, those caps will hold a charge for quite a while.

[@harrykarmona]

Hi! great tutorial! I have a question, I have a old hot rod deluxe made in USA and I would like to know what are the valves you recomend me. I would like to change all of them. Thanks from Spain!

[@bazjones7349]

I have a mk2 deville ( made in mexico) I fitted a fromel supreme kit ,and changed all the valve sockets to gold ceramic .I usually set the bias a 68 mv ,I also recently changed the first ax12 to a at12 ,this has made the volume much more controllable

[@wildparlor5456]

Great info and sick blues at the end. Love it

[@garymattischannel6207]

Isn't 60 ma a pretty cold two tube setting ? Shouldn't it be more than that At Atleast 70 ? , At 60 for the pair or 30 ma each the dissipation is only at 14.5 watts each on A 30 Watt each tube . In theory 120 ma or 60 ma each should be fine. I know that 70-80 even 90 ma is considered acceptable for most people. I was wondering why Fender would have such a low bias point ? Is it the newer tubes that are the problem or the excessive gain ? . I'd like to understand it more because At 60 ma. For A pair, A lot of The Newer 6L6 GC tubes just don't sound very good.

[@joelkine]

Thanks Rob for the info. Can you suggest what practical brand of KT88 tube good for this dyna mk3 in terms of quality but not much expensive like the three choices below from your TubeDepot: 1. Sovtek 2. Electro-Harmonix 3. JJ/Tesla so what about these 3 NOS respective cathode currents then? Is 70mA still safe or they are just between 45mA - 60mA?

[@MatthiasLenardt]

Really good. Keep on rockin.....

[@entrenuves]

Holy shit thank God for this video!!! So well explained!!🙌🏻🙌🏻🙌🏻

[@divebomb99]

“This is a great amp”. Also, “The solder just breaks.”. These amps are pieces of crap! I have one so I’m qualified to speak on the matter. Fender = mediocre build quality.

[@VinnieBlues1]

Hi...I'm a layman so I need to ask a question...do these parameters (approx. 60mV) work for any brand of power tube? The original ones that came on my Hot Rod are two 6L6GC GT and I want to exchange it for two JJ 6L6GC. So the ideal parameter is still about 60mV? Thank you so much

[@aronchas]

Im fan of your videos, Sir. They are awesome. I have a Jet city jca20H, it says its fixed bias, you know i have a problem with it, in the last weeks I have noticed a undesired hum, i have tried it with another guitar, cable power outlet, but the noise is still there, even with humbuckers, should i change the power tubes?? its almost new, its been powered like 30 hrs in total :( I cant believe this is happening, heeelp!!!

[@deepbooka]

@TubeDepotTV Ok Rob but tell me somenthing The TAD web says: 'The bottle is made from very thick glass and my sample of four were consistently straight and internally well aligned. I have no worries at running them at 450 volts and above average current. The plate construction is more conventional than a JJ but TAD has added cooling fins to both halves of the plate structure. This helps get rid of the excess heat when you run them outside of the standard 6V6 envelope.'

[@jetmicbev2006]

hi again..the power tube,yes there is a sound coming out in the drive channel but its very very low i cant barely hear it not unless put my ear close enough to the speaker,i also found out that one of the 2 filament of one of the preamp tube is not glowing..my friend told me it might be the pre amp tube not the power tube because the volume will pass to the preamp section b4 power..is this true..thnk u very mch on ur advice i really appriciate it..

[@jetmicbev2006]

this one is very informative..i want 2 ask a question regarding my sound city sc30 amp..after i used the amp in a jam session i turn it on the next day but theres no sound coming out , there is a power & the tube is glowing ok but no sounds..i also check the speaker 7 its ok..do u think my tubes worn out alrady thats why thers no sounds or somthing else?dnt know much about tubes hope u can a help me...thanks very much..mike frm glasgow

[@billwilliams6338]

TUBEDEPOT When you're biasing the power tubes in an amplifier circuit how do you bias the compression of the power tubes the 1dB compression point of when the power tubes start to compression? because its say to bias tubes at a 30mA bias current per tube to be safe but how do you know when the tube is compressing? Most Power tubes 6L6,EL34 use a B+450vdc on the plates, if you increase the B+ to +600vdc would this increase the AC ripple but why would it increase the AC ripple? i would think it would decrease the AC ripple because more B+ voltage mean less current draw from the power tubes.

[@zbyszekskibinski]

so you didn't reply to my question? I'll tell you what. I'm fixing some of the tube amps myself and I think this video can be confusing for lay people. First of all you're talking about negative bias voltage on the grids than set your meter on mV to show a small positive voltage between cathodes (your magic test point)

[@LeviSiccard]

hey, i got the american fender hot rod deville 410 from '91. I had to replace the tubes, wich i did but I can't get the bias under 73. The tubes i bought are the electro harmonix 6L6, wihch were recommended by key music, the biggest store in Belgium. and I believe myself that these are pretty nice tubes made by sovtek in russia..

[@btguitarscnc]

hi Tube Depot, i have a problem with my marshall TSL 122 combo, one day i turned on the amp to play and it has no sound, all channels working, all leds working, power tubes glowing (6l6GC), the only thing i noticed is that the preamp tubes are not glowing like before (less glowing), i dont know what could be the reason for no sound, can you help me?. THANKS.

[@deepbooka]

@TubeDepotTV A few people have a 6V6's in their DeVille's.How is possible? In Eurotubes web sais: A note to JJ 6V6 users; For Hotrod Deville's the bias for 6V6's should be between 30 to 35mv at the test points because of the higher plate voltage. The tech amps of my city sais:'Is possible put a 6V6's but with a new BIAS settings. Why? Thank you very much Rob.

[@jetmicbev2006]

hi rob,,i checked the HTfuse looks ok.b4 all this happen about a month ago i noticed that the amp making a cracking & hissing sound when a i check the amp one of the tube is blinking..i wanted to know if the amp will still create sound even if one of the tube died? i just want to know b4 i buy a new pair of tube..thnks very mch ,,

[@guitartec]

Great vid. but I gotta question.... I have been told by techs to never handle vac tubes because the dirt & oil from your fingers makes the tube run hotter and have a shorter life span. Iso alcohol is to be used to clean tubes if they are touched. Has this rule changed because of some techno improvement I don't know about?

[@deepbooka]

Hi Rob! I follow your tips in my deville 2x12 and all ok.Now I wanna try with a pair of TAD Tubes 6V6GT-STR. Can you tell me the save level on test point for these tubes? Maybe a good video like this....This would be good!!...(Very people interested). Thank you!!

[@jetmicbev2006]

hi rob,i need ur advice please help..i mistakenly plug the footswitch to the speaker output of my amp. both channel are not working anymore its just hum coming out from the speaker i dont know if i blown the tubes or i shorted something else..tnx..

[@jwandhistools]

I have the same amp. 60mv is way too low. Fender set the original sovtec tubes at 60-65mv to extend tube life. 80-90mv is more like it, if you use better tubes like JJ's or whatever, and you want good tone.

[@antwannn111]

Best explanation ever... Happened to be the first video I clicked on, what luck. You have just saved me hours of my life! Thanks for that!

[@meldeer6253]

i have a Hot rod De Ville 4x10 lot-095270 some one unhooked the speaker wires do you know the wiring digram maby a picture thank you

[@mrgroise]

Is there any chance of salvaging a pulled PCB trace leading to the power tube socket? I'm fairly confident with soldering, and I have 18 gauge solid core wire I've used to replace bad traces in guitar pedals. I think my concern is long-term sustainability. It seems like once the solder mask is pulled, the copper trace continues to deteriorate pull off the board. I assume the only alternative would be a lot of work around hand wiring the traces off those finicky ribbon connectors.

[@moogmanXanders]

got the new JJs in the mail today and checked em out by swapping one position at a time, swapped V3 nothing put the original in. tried V2 still nothing, tried V1 which I suspected and got a low volume fuzzy tone even on 12, so I put another one of the JJs in the V2 position and she jumped back to life with even more tone, put the last new one in just to complete the set and i figure ill hang on to the one good one for emergencies till i get a few spares, Thanks again for your help

[@Satchmoeddie]

I just had a Blues DeVille come in with major blow out damage on the board, 5 resistors, a couple of caps, and a chunk blown out of the board. The ONLY remedy is to cut out the bad part of the board and jumper everything. There is so much carbon tracking to ground the only other option is a new board, or new amp. If only you knew how little it costs to make on of these!LOL They still sound good. They are just hard to repair when things go wrong, and hard to modify without making a mess.

[@MrAnders1976]

hhhmmm makes me think of the Dr.Z wreck amp and the very similar trainwreck rocket. THese amps has huge transformers, choke filter and fast GZ34 rectifier. These amps are tought as being super touch sensitive. But what I seem to have learnt recently is that amps with a lot of filtering of the preamp and PI tubes seems to be less responsive. Patfurlan here on youtube showed a video where he replaced a 47µf screen cap in a fender BF deluxe amp with the original 16µf filter cap to improves sound

[@inventhead]

good point however a tech should only use 1 hand and clip probe to ground leaving only a positive probe and 1 hand this way is something gos wrong or you slip you dont cross both poles at same time causeing electric shock to the heart also if amp power is weak check pre amp tubes for these feed signal to power tubes most of the time with coupling capactors output tubes out to an audiotransformer on a tube type soild state outs by capactor power supply caps are the 1s to watch out for

[@atourdeforce]

@TubeDepotTV hey buddy, i have a hot rod deluxe and my clean sound has gone kindda distorted(not battery) and im thinking of changing my power tubes, firstly are these the probable reason y its gone like this, and is there a way to test them, im very electronically proficient(i do alot of soldering etc) also if so what would be the best tubes to put in for the price, im thinking gold lion kt 66, i play alot of blues, such as clapton.

[@atourdeforce]

@TubeDepotTV hey buddy, i have a hot rod deluxe and my clean sound has gone kindda distorted(not battery) and im thinking of changing my power tubes, firstly are these the probable reason y its gone like this, and is there a way to test them, im very electronically proficient(i do alot of soldering etc) also if so what would be the best tubes to put in for the price, im thinking gold lion kt 66, i play alot of blues, such as clapton.

[@Satchmoeddie]

I have the same power supply. (Lambda 500 volt reg). You may want to wear safety glasses. This is great if you have the Fender repair manual. The old stuff usually is biased at full volume a 1KHz or .4KHz signal into a dummy load. Also this has test points and a pot to adjust. I retrofit Fender silver faces all the time using any center tapped or dual pots. I have 100K CT pots and put resistors across the pot to make it a 10K. Next show us how to fix a Maggnatone 480's vibrato, & M15's echo.LOL

[@andrewt248]

I have a Jet City JCA20H 20w 2xEL84 head. It doesn't have the nifty test point on the pcb. I saw a video here that showed how to bias it with a multimeter and I'd just like to verify the procedure before I make any adjustments. They suggest to check the plate voltage which is supposed to be around 350VDC (mine was 370VDC), then check the milliAmperes at each tube and plug those numbers into the following equation: 11.5watts x (600 / [PlateVDC]) = X [milliAmperes].

[@bahady30]

Hello Rob. I'm an owner of the Hot Rod Deluxe ( 12 inch speaker ) and the amp is the smaller brother of the Deville but looks prett much the same inside. I'm living in Holland so our current is 230V AC unlike the 110V in the states. Does that make any difference in biasing the power tubes? I read somewhere that you recommend 70mv for a Hot Rod Deluxe. Is this a safe value for my amp. I appreciate it that you took the time to explain this ! Thanks

[@stephentrageser]

I've got a Blues Deville, the reissue and I think the newer version of that, so the inside looks pretty much the same as the Deville here. I can see the bias pot and test point in the same position. The only thing I can't figure out for sure is whether or not it has the same recommend bias of 60mV. Is it? Where do they hide this information in the specs, or can you derive it from something else?

[@AlessandroBertocz]

Isn't the bias supposed to be measured (as per fender's schematics) with all the knobs minus reverb set to 50% rotation, and the yellow channel selected? On my amp, rotating the knobs, especially the volume one, seem to make the reading vary a bit... PS.: Is -42V a good bias voltage (measured on the tube pin)? Plate is 460V, it's a 1997 USA made deville i just got, so i wanted to check if everything is still working properly

[@sixstringer82]

Hi Fantastic video I plan to change my tubes watching this video as I have a hot rod deville. Last time I played the sound was getting fuzzy and losing power. Do you suggest any different tubes to the ones originally in the deville? another question. How do I know if the pre amp tubes need changing also? Im I correct in saying you changed the power tubes only in this video? is it the same method for pre amp tubes? Thanks. sorry for long message Cheers

[@putimail]

Hello! I am new with tube amps and I am planning to buy one. The amp I am planning to buy also has 2 power tubes. Is this method you showed is alwasy the same? 1. Turn the tripmot full counterclockwise while in standby mode 2. Turn the amp on (switch it out of bypass) and set the voltage to the desired amount while touching the sowder spot of the powertube? What do you recommend when replacing with different tubes? Does the safe voltage remain the same? Thank for you reply in advence!

[@OhHeyFixItGuy]

Hey Rob I really appreciated the video as I just bought a Blues Deluxe and it looks like the tubes are in same configuration. I have a lot of noise coming from the middle 12AX7, do I need to bias them as well as the 5U's if so is there are similar reference point and and adjustable potentiometer for the other side? Really appreciate the video, going to save me some money. Oh yah the noise goes away when I put pressure on the tube so maybe a quick solder is all that's needed.

[@wayfechylde3]

changing my power tubes without first rebiasing (even if using the same tubes as were in there before) isnt bad for the amp, is it? but i assume that i should then rebias...

[@tommyapplegate30]

Will a tube overload damage a amp? I have a pair of el34 & my ac power in the house kicked off causing 1 tube to over overload it got the color bright white. I shut the power off pulled the tubes out waited await a couple of days put back in re bias 1 read 39.2 & the other did not read anything. Is my amp thrash.

[@mecagau2be]

I need assitance!! I just changed the tubes on my deville. I set the bias at 60 mv. But after playing for a couple of minutes, the amp goes wild and starts making a lot of noise, even without the cable plugged in. The tubes glow blue and seem to be about to explode. I put these power tubes into another amp, and they work fine. Please help!

[@bromporke]

I followed all the directions with my Deville 2x12 and the DC mV reading was all the way up at 180mV at the testing point. I couldn't turn down the pot enough to get it down to 60mV... my bandmate tested his 4x10 Deville and got a normal reading.... what's wrong with mine that it would be running that hot?

[@brokenbones112]

Hi I opened my hotrod deluxe up and its got a pair of sovotek 5881's in the power section, now it is 10 years old and i am not the origional owner, so keeping this in mind and the fact that i have no idea what im doing other than dont touch anything on the circuit board is there a different bias point for these tubes

[@4Dcruz]

i have a Hot Rod Deluxe. I picked it up used, and swapped out all the tubes today. 2 brand new mesa boogie 6l6 for power, and 2 groove tube 12ax7-r for the pre. Since it's used, and i don't have the manual, any advice about what to bias to? Close to 60 like the deville? Already gave the new tubes a quick test, sounds much better.

[@solerso68]

Look at that the inside of that thing! Big electrolytics, 1 watt resistors, REAL 1/4 " jacks,etc., everything laid out to a tee, and spaced perfectly - and Thats an off the rack Fender amp (made im Mexico BTW). Thats why Fender amps RULE. Quality is infinetely superior to anything esle in thier price range

[@natejones423]

I have a deville and i switched to JJ 6L6gc matched pair from tube depot. When i went to bias the amp the highest i got when i turned it all the way up was -57.03 before doing millivolts... does it have to be over 60 V before i set the bias to 60 mV? all the solder joints are in great shape and i let it warm up still to no avail. Any help would be very appreciated

[@natejones423]

I have a deville and i switched to JJ 6L6gc matched pair from tube depot. When i went to bias the amp the highest i got when i turned it all the way up was -57.03 before doing millivolts... does it have to be over 60 V before i set the bias to 60 mV? all the solder joints are in great shape and i let it warm up still to no avail. Any help would be very appreciated

[@thenoras]

I am not getting any voltage when I test it from the bias test point. From the bias pot I get -58V when all the way to the left. My tubes are old and i've been blowing fuses, so I assume one is bad. Would that cause it to not give me a voltage at the test point? I tried switching my 6L6's around with the same effect.

[@eightGhosts]

Well, after watching the Gerald Weber Tube amp service DVD, I tried to bias by taking a reading at pin 3 of the output tube and the center tap of the output transformer, but I can't seem to get any reading. This amp has a PCB though, so maybe I'm not checking the right spot? (Don't worry--I at least know enough not to kill myself). Thanks for your help!

[@CARMINATISOUND]

Hi. Have a Deville 212. Cant get voltage on test point, but it is present on regulator... But even at max setting it only gets to around 54vdc. Local ac is around 109/110v. Any idéias?

[@nickgman123]

Hey, I have a question... I replaced the tubes in this exact same amp a year and a half ago but I didn't even know what biasing an amp was when I changed them. Should I bias them now that I know what it is or wait til I change my tubes (which will be a long time from now)? Thanks in advance.

[@rdannenh]

Hi! How can I do the Bias adjustment in my amp: is completly different to a HOT ROD. I have a Blues Deluxe 94 - tweed. The electronic board is different and I don't see any trim pot to adjust. Its no necessary this adjust? I need to replace my tubes. Thanks I have photos from electronic board...

[@JARVISMCJIGGLESTEIN]

i feel confident that i could bias my amplifier, but the potential for contacting lethal voltages scares the shit out of me. this is a great video though. i really like the SED output tubes in my hot rod deluxe, but i read on thegearpage that they're being discontinued? >:C

[@rockventures]

Brilliant vid and pickin ! The lad just picked up a HR Deluxe ii ....fantastic sound except the power tubes are noisy on some low notes. Gonna try some damper rings but if that doesn't work then may be putting your instructions to use soon with a pair of new tubes.

[@rsalmon63]

Which friggin volt setting on multimeter Dude C'mon! Milli Volts? 2,000 or 200 Dude I was on my way till I couldn't get a reading!!!!!!!!!! Even on milli volts there was no Negative sign on my meter!!!!!!!!!!!!!!!! Just a 1 all the way to the left and no decimal!!!!!!!!!!!

[@btguitarscnc]

@TubeDepotTV Yeah, thats it, i change the HT fuse and the amp sounds!, but i noticed the power amp tubes have a blue/purple glow, is this bad??. thanks.

[@brokenbones112]

@brokenbones112 aha apparently they are stock tubes. but not really audio tubes. as they were made for russian fighter planes real name being 5881wxt hmm any suggestions on some real audio tubes that i could use to sweeten the sound?

[@DjNorbax]

Nice vid, never had seen all this biasing thing ......Btw, I also have a Fender Deville with Sovtek tubes but one of the preamp's is microphonic so I'm thinking of buying new ones. Which preamp tubes would you recommend for this amp? Thanks

[@Ayte66]

if I replace the 6L6 for some JJ 6V6S are there any settings that i should change in my hot rod deville 410 besides the bias?? and if just the bias should be adjusted for how many millivots??? and which preamp tubes would be more suitable for the JJ 6V6S????

[@spoonful84]

Hi Rob. I replaced the stock groove tubes in my hot rod deville which read around 65mv on my meter. When I put the new harma 6l6gcs in I couldnt get the bias below 92 mv. Could this be a problem with the tube(s)? Cheers

[@joelkine]

Hi Rob, What's the correct Cathode current of "each" of the Dynaco MK3's KT88? is it 70mA? TIA.

[@Chromatype]

I played a gig last night with some band and the other guitar player's amp died on the gig...it was a Hughes and Kettner though....he came back 20 minutes later from his house with a Deville!

[@382002mat]

Hi, i have a Soldato Hot Rod 50 and I change the 6l6 power tubes. I'd like to know where i got to put the tester: between chasis and pin n°.....? of the socket. then i can adjust the bias, right?

[@manintoynenam]

Can u show us how to bias a TSL100 pls I tried mine but the reading is not the same I got 90mv to the left and 78mv to the right, everytime I adjust the right side the left side will follow I'm confused.

[@GlennJimenez]

I own a hot rod deluxe. I installed some tungsol 12ax7s and some JJ 6L6s and biased. the amp WORKS fine, but sounds kind of muffled. I biased to 65. any ideas? do tubes need to be broken in?

[@jordanlcombs]

When biasing my hot rod deville, my voltage meter won't pick up any readings off of my bias test point. But it had a reading when turning the voltage up when the amp was on standby.

[@fishmank27]

Does the same info here apply to a blues junior? And just to make sure, preamp tubes can be replaced w/o biasing? Thank you....

[@BeatlesGuitarPlayer1]

Hey I have a fender hot rod deville and supposedly these are very loud but mine with different guitar is very quiet. I don't know what the problem is, do you have any idea.

[@Mrdudelg]

Tube Depot should make a video showing how to safely discharge a tube amp because as a beginner, I see all the safety warnings, but no explanation on how to make it safe.

[@harryconover289]

This method of setting the bias works but doesn’t check the Queasiest current in the circuit. It assumes that the tube is working as prescribed in its specs they usually don’t and different manufacturers vary a lot . a better way is to where you look at a voltage across a low value precession resistance in cathodes which generally goes to ground.Dynaco. Wisely choose value of 1.56 ohms so the 100 ma bias current developments 1.56 volts precisely this amp was offered as a kit and setting the bias really maters but a good voltmeter was expensive and cheap ones were really inaccurate but a fresh d cell battery is 1.56 on the money so take your cheap meter and mark it using the battery as a reference so at that voltage it’s very good many hifi type amp have a jack per tube the jack is generally a short when you inset the jack you measure the current and it’s 100 percent accurate

[@cuzimamadman]

hi rob quick question. i have a hr deville III is it normal for the master to not do anything on the clean channel? or is there something wrong with my amp?

[@andrewt248]

So when I plug my numbers in it looks like this: 11.5w x (600 / 370VDC) = 18.6mA Is this a valid equation? It seems to compute correctly with the factory setup.

[@noahherne4626]

My amp is at 83 at the lowest bias setting. Its a 410 deville from 1997. What could be the problem?

[@guitarastig]

hi rob, hope you can help me with my hot rod deluxe. there is hissing sound even my guitar is not plug in. thanks!!!!

[@ijamsum]

I have a set of the expensive SED 6L6 quad pair and found they sound brittle and bright and lack any warmth and was told if you do not have at least 450 plate volts that they do not sound good and i only had 360 plate volts so there back in there boxes !

[@01MrGibson]

Hi. Have new meter now, it will only go up to 50mA, DOES THIS MEAN THE VALVES NEED CHANGING OR AS A RESISTOR GONE DOWN SOMEWHERE. THANK YOU.

[@01MrGibson]

I've just checked the bias its 20mA theres a red marker thats never been moved but I'll buy a new meter to be sure the reading is correct. Thanks.

[@Ayte66]

i have a question if i replace the power amp tubes for some JJ 6L6 to how many millivolts would i have to set the amp to be in a safe level????

[@tm1180]

so, the socket solder breaks when the amp gets hot? not a very good advertisement for FENDER!

[@rdannenh]

Ok...I bought a complete set of tubes (matched) in the tubestore-Canada. Probably arrives in 2week. I'll tell you the results. Thanks.

[@panzerschrekIOI]

You should buy or try to find "Designing Tube Preamps For Guitar And Bass" from Merlin Blencowe, it explains the bias thing real good.

[@eightGhosts]

Any tips on biasing a Deluxe Reverb Reissue? I'd have no problem biasing an original, but the reissue is extremely confusing. Thanks!

[@ssolooc]

I need to bias my 64 Vibroverb RI that hasn't been played for a while. Is it the same process as with the Deville...60volts?

[@Barnekkid]

Very good video. How do you bias an amp that doesn't have the test point, say like a 64 blackface with an AB763 circuit?

[@someguyonaguitar]

Hey does anyone know if you can replace the 6L6s with el34s and to what value you would have to rebias it to? Thanks.

[@01MrGibson]

Hi. Yes its set to DCA 200m the other side is DCV 200m. Full round on the bios reads 50m. Any idears.. Thank you.

[@TheRyanmluke]

what is the factory biasing level for a fender hot rod deluxe III? or where would i be able to research this?

[@prsplayer210]

only with amps with four power tubes or hughes and kettners with tsc

[@owlsonik37]

My circuit board where the power tubes connect is in the exact location as yours on my HRD and it’s a bit warped. Is that normal?

[@johnsfixton8857]

why there isn't anywhere a chassis mount 50k bias pot ? why ? you do that on purpose ? it is a deceit ? a conspiracy ? apologise

[@Chromatype]

My buddy Rob knows tube amps! Rob, my Bassman has issues. Could I ship the chassis to you for repair?

[@louisianaBluesBoy]

My HR deville is making a whisling sound, comes and goes... It also make a hissing sound sometimes...

[@jstaebler1]

I get a reading near the pot that maxes out at 58V but no reading on the test point. What can I do?