How To Bias a Deville Amplifier

Rob Hull guides you through how to bias your Deville amplifier in this no-holds-barred, drag-down discussion of multimeters and millivolts. He gives you clear and concise step-by-step instructions, with some impromptu guitar playing along the way.

[@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.

[@ArtDonna84]

Rob, was looking for a simple video for biasing a Vibrolux and came upon this one. Since I purchase tubes like I'm sure many below from you all, I was happy to find this video. Very well presented, clear to understand and a great help for dummies like myself. Thank you.

[@VintageRandom]

Excellent instruction. Just got a HRDV 410 and walked through the steps. Fantastic result. Beautiful cleans for days and very silent even with single coils. Thanks very much.

[@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!

[@rudolphgaroa1960]

G'day Rob, I hope you've been well in this time of crisis. I'm 11 years or more late on this, but I guess it's better late than never. Amongst most of the Biasing for the Hot Rod Deluxe I've seen, I decided to follow yours because it is the most clear (visually plus the audio & explanations) I've just done my Hot Rod today .. with 101% confidence thanks to you. Just one thing which I thought is super important, for those non-techo's like me. .... that's the detailed settings of the multimeter. I had to go over your video a few times to be sure. Where you set the multimeter to "Volts" to take the reading of the plate behind the Bias adjust knob, but mentioned very little about changing the multimeter to mV when setting the actual Bias while at the same time looking at the mV readings. I was lucky I saw the different settings showing on the video for your multimeter and so followed. In my case every detail of the procedure is important. Hope this will help you help us (non-techos) for future video releases. Stay well and all the best. ru

[@mjs28c]

Great video! Very helpful and informative. I've had my Deville for probably 10 years and I was never 100% happy with the gain/overdrive channel. It sounded.......raspy.....not smooth at all. I installed a Fromel kit, which made things better....but still....something wasn't quite right. I had the amp serviced/biased/etc. Again.....better, but not quite 'there'. So I found your video and did as you suggested. The bias was set at 58-59, and the blue trimmer was epoxied in place. I powered-off and carefully trimmed the epoxy. I set the bias to 68 (the alleged 'sweet spot'), let it warm-up and took it for a spin. Much better! I was more satisfied with the gain....definitely an improvement. I also thought the clean channel had improved as well.....I could hear a difference. I kicked the bias up to 70 and I'm happy with it. Looking forward to next band rehearsal.

[@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

[@GameLevelEditor]

Most excellent straight forward biasing video ever.

[@JeffDumps]

Excellent video production and clear instruction, thank you!

[@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

[@wildparlor5456]

Great info and sick blues at the end. Love it

[@bill.clifford.59]

Thanks for this awesome video! I just bought a deville and this video is a big help!

[@j_music_8779]

Nice video man! Very informational and easy-to-follow 👍

[@jeremyberg9693]

wonderful presentation!!! breath of fresh air!!!!!!

[@jamessanscrainte9533]

Thanks so much for making this video. Great explanation and instructions.

[@bostonmassappeal]

Awesome. One of the best vids on youtube.

[@real_fjcalabrese]

Great video! Kudos for mentioning the connections.

[@devinyuceil]

Thanks dude, great video, very well spoken and nicely put together! I'm just about to change the tubes on my Blues Deville and I hope I goes as smoothly as your video!

[@PeterDad60]

That's some purty good playin at the end Rob!

[@mrgroise]

Excellent. Thank you for your time and incredibly helpful reply. I really appreciate it.

[@nickgiovannucci7922]

Oh ok! Thank you for the quick reply! Your video was very informative and helpful!

[@tamuna61]

Great vid, clear and to the point. thanks for that

[@01MrGibson]

Hi. OK understood now, I'd got milliamps on my mind. Got the right measurement now. Thank you for all your help. Brilliant.

[@cuzimamadman]

thanks rob, and thanks for posting! great vid!

[@rubentrevino6288]

excellent video and kudos for providing safety review . . . very important!

[@TubeDepotTV]

thank you for your wonderful comment.

[@01MrGibson]

Good. Point taken. I just bought a fender hotrod deville that had a very loud microphonic howl, seemed to be the first valve in line of the 3 small ones, was going to buy a complete new set, but then I just swapped the first to around absolutely perfect now. A good hint to try first.

[@RSethTV]

Great Video Rob!

[@aidodonnakgb3065]

this was very informative, cleared up a few things for me. cheers mate much appreciated p.s guitar playing at the end was killer, should upload a video with just you jammin

[@dstrats]

Great video, well done! I own a HotRodDeluxe and this thing is always frying tubes. I took it to a tech who claimed to have biased it correctly but two days later at a gig I only had one 6L6 working, glowing extremely bright amber, distorted badly on the clean channel (I only use the clean channel) until it died all together. This was back in '05. I have a tech friend install new tubes 'bout a year ago and bias it, and it distorted again. I bought new tubes and I'll use your vid to DIY. Thx

[@4Dcruz]

@TubeDepotTV thanks a lot! I ended up settling at 70mV, messed with it back and for for a while and 70 just seemed to be a good middle ground where i got the best tone without killing my tubes

[@glennkubik3774]

Very Good Explanation! Glad you mentioned safety. Too bad for the Test Point - the PCB should have a Tip Probe socket for holding the DMM's probe. To minimize the chance of getting an electrical shock (although not UL approved/tested) I wear the Black thicker Mechanics "Nitrile Gloves". Love 6L6 amps like the Deville (I have a Peavey ValveKing 2x 6L6). A dab of Nail Polish or RTV/Silicone keeps the pot from moving after being set.

[@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!

[@ChadBoston]

Fantastic presentation!

[@TubeDepotTV]

Thanks ...

[@RoxxHoffner]

Very informative and to the point. Thanks for sharing.. Mighty fine guitar playing as well. That's how my amp used to sound. I repaired a cracked solder joint at the "foot switch" connector, but now I find there's something not right with the far right, small(pre-amp) tube. A friend tested my tubes by removing them, then stuck new tubes in thew sockets(1 by 1). That's when I noticed he wasn't quite somber enough to be doing this test. He either bent the pins and/or caused damage at the connection. I realized this when it popped and cut in and out as I barely wiggled the the tube. Are the tube pins worth messing with till they fit again(If that's the only damage) or should I just replace them with new tubes?

[@aerocharles8207]

Thanks!!!! Right on spec , just did mine....sounds great!!!!!

[@waitin4winter]

extremely helpful video. thank you so much.

[@memoglz]

@TubeDepotTV i knew it was a legacy because of the bridge and the tremolo arm.... they´re just the best guitars for me, i have the legacy special model, and also have a deville amp... awesome combination... excelent tutorial i am about to do this to my amp, greets!

[@brandonbarker9421]

Great video man.

[@Mindstrikedojo]

Great vid just subscribed glad to find someone who can explain step by step for a D.I.Y. saved me money. I have the blues deluxe reissue is this similar process as well?

[@moogmanXanders]

thanks, I also tapped the reverb tank and could hear the springs through the speakers so thats working ok, it was bad timing too cause my Wampler tweed 57 pedal had just came in the mail and I was itching to try er out. Still in Awe over how many tools and tube accessories you have on the tubedepot store, wouldnt mind getting one of the 18 Watt british amp Kit sometime in the future.

[@alvin10388]

thank you for the great videos as always.Sir i have question,I have hammond 291AEX 240 euro power transformer,but the primary has two black wires not like us version ,in this case when i connect to champ 5F1push pull pot.do i have make sure which is hot and return or i can connect any of these two leads switch and fuse?any help really do appreciate.

[@erikolson2897]

Hey Rob, thanks for the great video! I followed it very closely, and my volume is still very low when I tried to do a sound test. power tubes flicker blueish purple as I send a guitar signal to it. these amps are very loud as you know, but I have to turn up a lot to hear anything. I checked the voltages at the large grey caps and they appeared to be stable. I also replaced the 2 12ax7s closest to the inputs 1& 2 I was hoping you might have some thoughts on what might be going on here. thank you

[@MrElmerrocks]

nicely done video

[@Sandelb]

Awesome video, just what I was looking for. Recently picked up one of these babies used. It played fine for a day or so then started doing some heavy volume fluctuating. The jewel light also fluctuated but not always in synch with the volume trouble. I popped the back off and checked the connections as Rob did in the video and they looked solid. It's my first tube amp and don't want to assume anything. Would a good first step be to pick up some new power tubes and pop them in?

[@dcabinet]

thanks for the great videos!

[@1thess523]

I just got onw for my son 👍, can you clean the tone pots when you remove the backing plate?

[@robertnewman2864]

Excellent instruction. Can this similar bias adjustment be done on the Fender 410 blues Deville reissue, 2005 model?

[@Christophe_L]

Sweet playing!

[@MatthiasLenardt]

Really good. Keep on rockin.....

[@zarrir]

Your videos are so cool

[@rccarsandmusic2641]

thanks for the help I lowered my bias as low as it can go 30. now its playable beyond 1

[@erikolson2897]

Hey there thank you for your speedy response. so I seem to have found out the source of the issue, and I'd thought I'd share what I found. The speaker jack was plugged into the ext. speaker output on the chassis. someone must have plugged it back in incorrectly. does that sound like that would cause that kind of volume drop?

[@LewisShieldsUS]

Great vid, thanks.

[@AlessandroBertocz]

@TubeDepotTV Thanks for the quick response! Is it normal for the bias to oscillate a bit over time? If i let the amp warm up and then set the bias to, for example, 65mV, it will eventually drop to 61 after a couple of minutes. I thought it was normal for it to rise a bit due to the amp getting warmer, not to drop! Right now the amp is on and i'm checking the bias every couple of minutes, when i first turned it on it seemed to be around 65mV, then dropped to a stable(ish) 60mV. Is it normal?

[@bryanmanio_]

Great video! I noticed the volume level on my 212 has dropped a ton (I'll have it maxed and it's lower than bedroom level). Do you think this is a power tube issue? Is there a common way to test if thats the case?

[@anthonyfigueroa9289]

This is amazing! Thanks

[@CesarRomeroTheOriginal]

great video

[@LeviSiccard]

hey, yes, all the solder connections are fine. I just thought it was strange that i couldn't get it under 73mV but i made a call to the store and they said it's perfectly normal. They offered me to return them in if i wanted, so they could give me another pairbut as you said 73mV is a nice value. Great vid by the way! nicely explained for electronica noobs (like me)

[@Cro55co]

Thank you so much for your video mate! Can you please tell me why did you need to read negative voltage before you read positive also do you only bias when changing power amp tubes or also when changing preamp tubes! Many thanx

[@sixstringer82]

Thanks for the reply and help David or guys at tube depot!!

[@someguyonaguitar]

@TubeDepotTV Thanks man. I just got JJ 6l6gc's and a tung sol 12ax7 for the V1 spot and two electro harmonix for the V2 and V3 preamps. Sounds great even without biasing it yet. Which leads me to my next question: I have an analog multimeter, any idea what setting it should be on? AC or DC? 500, 250, 50V?

[@bryanmanio_]

@TubeDepotTV Looks like one of the preamp tubes was a little loose! Thanks for all the help, do you guys ship to Canada and if so, can you ship via USPS?

[@alburboy]

very informative video. i enjoy it, and u play great too. keep posting some good stuff. :)

[@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?

[@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

[@twirlyboggs]

awesome post!!!!

[@justplanecrazy3d]

Good video, nice guitar playing ! I just replaced all the tubes on my brothers Deville, looking at the back of the amp, the left power tube looks like it never comes on, the amp still plays and seems strong. Could this be the solder connection you were talking about, or else what may be causing this ? Thanks !

[@Aljester]

thanks for sharing. Very well explained! :)

[@BETILYO]

Thank you so much, i will take care of those issues!

[@MylesJP]

Nice demo! I have the same amp and it has been great aside from one issue. Is the volume knob on your amp extremely sensitive? There seems to just be a fraction of a degree between inaudible and glass-shattering loud with mine. Is there an easy way to either adjust this or perhaps replace some hardware to distribute and voltages a bit more evenly? Thanks!

[@gaur1000]

Hi Rob! Thanks for the great manual for replacing the power tubes on the DeVille. I've the same amp (only difference: I've got the 4x10" version) and recently I replaced my 6L6 tubes. Now I've got a question: My other amp is a Fender Twin Reverb Reissue from 1992 and would ask you for a replacement manual for the power tubes there. Same as on the Deville? As far as I know the Twin has also a BIAS knob. What are the measure data for the BIAS there?

[@Karlspace0u812]

Thanks for the info on the math!

[@jameslomax1271]

I have a acquired a fender De Ville 410 and we used it while having a practice it sounded a bit distorted, and after an hour we had a rest and whilst we were sat down it did a few pops. Have you any idea what could cause this please.

[@zoomer51]

when you said "there's a newer model", i suppose you were talking about the hotrod deville 3 ? as far as gettin new tubes, i'm gonna check out your catalogue see if there's any special custom sets for the 212 deville.. Thx once again for you answers and kindness.

[@cravelp1115]

Hey, excellent video! Very informative. Would the Hot Rod Deluxe be the same way, but set at 40v instead of 60v? or would it also be 60v?

[@Thecaveandcognitionmusic]

Great video thank you!

[@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 ,,

[@kj677]

Hey Guys, great video! Can you please tell me if the biasing on a Fender '59 Reissue Bassman LTD is the same or similar? Thanks!

[@peanutavalon]

Hi..thanks for the response..I checked my Blues deluxe and it did have a test point ..I went and bought a multimeter at the hardware store. The meter he sold me only had a 2000 milivolt setting..not a 200mV like shown in a lot of these videos..He told me that was ok and the meter would measure 0-2000 mV..Is that correct in your opinion?

[@almpinho]

Hi, fantastic video! I have this same amp and at now I know do the bias adjustment in my HRD 2x12". But I would like to know which is the plate voltage of this HRD for calculate the 100% of bias value and 70% also. I thing this value varies from each same amp and I would like to know how measure this value. Please, if it's possible to you, make a video explaining how to measure the HRD 2x12" plate voltage value!!! Thanks

[@cassvirgillo3395]

Hi Rob, Tube Depot, Just a little FYI, the ribbon connectors on the Deville can come loose and this will cause issues with the amp and performance of. El Paso Tube amps on KZbin did a video about this problem, worth a view. Discharge filter caps first when working on amps, use only one hand when hooking up meter. Also see Uncle Doug on YT, very knowledgeable. Take care, C.

[@al94551]

Hi Rob, Like the video. Good solid and easy to follow. I have just changed to TAD 6L6 tubes and during biasing could not get less than 61mV at the bias test point (highest voltage pot would go was -60V, which gave me 61mV at the bias test point). I therefore backed off the pot voltage until I got 70mV as the bias voltage. Is there large tolerances between amps, or should they all be able to get 60mV without having the pot at max counterclockwise Regards, Allan

[@382002mat]

Thank you for your answer,i'll contact Soldano soon! Great video!!

[@justplanecrazy3d]

Thanks for the reply TubeDepotTV.

[@brenfen]

Great video. Should the bias level be set differently for different brands of tubes or is 60 generally a safe bet?

[@elkien5225]

Great video - Do you know if this is the same in the Fender Blues Deluxe?

[@funkyjones]

Wow! You made it look easy. I have a question. I have a Hot Rod Deluxe. I put new JJ power tubes in and the started rattling shortly after. The guy at JJ said it's because I have a combo and the amp vibration is the cause. What do you think? Also what replacement tubes do you recommend? I play rock, blues, country.

[@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

[@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.

[@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.

[@nathanexplosion7442]

excellent video thanks a lot!!!

[@jacobchidester1079]

Great video. I tried biasong my own amp, but after I stop turning the bias pot the voltage just keeps climbing and climbing.The amp will sit steady up to about 55mV but even the tiniest turn past that and it slowly climbs up and up into the 80s and 90s. Any thoughts on why that might be?

[@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..

[@entrenuves]

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

[@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..

[@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????

[@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.

[@zoomer51]

first off thx for this tutorial, im planing to get a used 212 deville and that's exactly what i need to check it out in a basic way.. Just a question though since im no tech or whatsoever, you first checked the "general" voltage by putting the red pin close to the bias pot, is there any solder point there since we can't see from that cam angle ? thx in advance for your reply. Cheers from france

[@tommyapplegate30]

Thank you I found the problem it needs new tubes 1 overloaded due to the lack of electricity. I'll retube it & be careful of what is tied into the outlet before I plug it in. Thank you for your videos on tube amps & a walk though of my & many other peoples post.

[@yimmiytube]

I don't know much about amps,I'd rather watch your playing.I like it,U teach?