Thanks! I ran across your video after I installed the bias mod to TSL100, but wasn't getting any good sounds... back to looking to see what wire I crossed. I am curious, if you use 6L6s, did you have to do any different setup for them? Are they biased differently? I use 6CA7s, which are essentially EL34s in a 6L6 bottle... I just thought I'd leave a comment while i waited on the tubes to cool. Again, thanks!
Great vid, thanks, I have a 1998 dsl that has a hum on the classic gain channel and the bias drift issue, was going to junk it, but after seeing this I am going to give this mod a try, thanks again
Hello , I have a TSL100 and I have the bias drift mod done but not with this kit you installed , what site you get it from and what’s the need for the little board , cool vid too 👍🏼👍🏼
Great vid. How is that amp doing today. Bias still stable do you check it. Also do you still have the instructions for this bias mod kit I would love to have a copy or maybe you can post on this vid with a pdf link to them. Also do you remember if the bottom of the bias mod kit has DR TUBE printed on it.
Unforunately these boards have various different other issues in the Bias circuitry that the mod pcb doesnt cover. - R74 screen resistor Highside leg to Bias feed supply (Bias broken) - All Screen resistors low and high side to the Heater pcb plane underneath Especially on Issue 10 boards they had used screen resistors which had slightly wider legs that almost touch the Heater PCB Plane - R2 and R3 Feed voltage is too close to R4 Leg which also causes the bias to drift Just to name a few Actually there is also no real need to drill out the pin. Peeling off the trace is pretty much all it takes and giving the board a good cleaning. With drilling out the material and not sealing it again the chance is much higher that this area picks up moisture
I've worked on a few of these and just as a note to other viewers , you can just remove the 6 screws holding down the top cover where the tubes plug in on top of chassis to remove the bottom PCB . You don't have to remove the rear PCB from bottom of chassis like the video shows . Also how did this fix work , did it solve the problem with the bias ?
I bought one of these a year ago and I love it and also use the lead channel more than anything else but I have a Zakk Wylde overdrive (barely turned up) to give it a boost and it sounds killer but somehow your lead channel doesn’t sound like it needs a boost at all. Could that be a sign I need new tubes?
Thank you for this video. So has the mod completely resolved the issue? Does the bias hold steady after prolonged sessions at gig levels? Just order this for my DSL and I'm curious
@@RestorationObsession thanks for the response man! I only know of one legit tech around town and he's got an 8 week backlog on stuff that has to be left at his place, so I kinda need to have a REALLY good idea of what the problem is lol.
Hi! You need to do it manually. I believe the Mesa Boogie amps such as the Dual and Triple Rectifiers have auto bias but the Marshall TSL does not. I recommend that you check the bias periodically just to make sure it hasn't drifted out of spec. Mine drifted way high and the amp was running really, reeeeally hot.
@@RestorationObsession thanks for answer. You think its better to adjust bias little lower than normal Just to save the El34? So i dont need change them so often?
@@grimarkraka7784 You are welcome. I think biasing them a little lower would help extend the life of the tubes, but probably not by all that much since they are not really being pushed too hard unless you play the amp at super loud volumes, say... over 3 or 4. I've been in very loud metal bands with a second guitarist adding to the noise and I never had my TSL over 2 lol. I think your tubes would give you the same life time either way (biased normally or lower).
Thank you for this: I followed your lead to help me through the process and it worked great. Appreciate the time you took to make this video.
I just received the Dr.Tube kit today and your video is really valuable to me! Merci baby 😉
really useful just doing this mod this week on a customers amp
Thank you so much for all your help, Stewart! You are THE valve amp man!!!
Hahah, I commented before I far enough in too see that you are installing the same kit. Nice
Thanks for posting - exactly what I needed to see right now!
Thanks! I ran across your video after I installed the bias mod to TSL100, but wasn't getting any good sounds... back to looking to see what wire I crossed.
I am curious, if you use 6L6s, did you have to do any different setup for them? Are they biased differently? I use 6CA7s, which are essentially EL34s in a 6L6 bottle... I just thought I'd leave a comment while i waited on the tubes to cool. Again, thanks!
Great vid, thanks, I have a 1998 dsl that has a hum on the classic gain channel and the bias drift issue, was going to junk it, but after seeing this I am going to give this mod a try, thanks again
Awesome! I hope the mod brings your amp back to life
Hello , I have a TSL100 and I have the bias drift mod done but not with this kit you installed , what site you get it from and what’s the need for the little board , cool vid too 👍🏼👍🏼
I changed the mother board on mine, 20th revision i think it was , works fine now
Dónde la conseguiste en qué sitio web ? Gracias
Great vid. How is that amp doing today. Bias still stable do you check it. Also do you still have the instructions for this bias mod kit I would love to have a copy or maybe you can post on this vid with a pdf link to them. Also do you remember if the bottom of the bias mod kit has DR TUBE printed on it.
Unforunately these boards have various different other issues in the Bias circuitry that the mod pcb doesnt cover.
- R74 screen resistor Highside leg to Bias feed supply (Bias broken)
- All Screen resistors low and high side to the Heater pcb plane underneath
Especially on Issue 10 boards they had used screen resistors which had slightly wider legs that almost touch the Heater PCB Plane
- R2 and R3 Feed voltage is too close to R4 Leg which also causes the bias to drift
Just to name a few
Actually there is also no real need to drill out the pin. Peeling off the trace is pretty much all it takes and giving the board a good cleaning.
With drilling out the material and not sealing it again the chance is much higher that this area picks up moisture
lol it's a dud
Would this mod be the same with a DSL2000
Mine is year 2002
I've worked on a few of these and just as a note to other viewers , you can just remove the 6 screws holding down the top cover where the tubes plug in on top of chassis to remove the bottom PCB . You don't have to remove the rear PCB from bottom of chassis like the video shows .
Also how did this fix work , did it solve the problem with the bias ?
I bought one of these a year ago and I love it and also use the lead channel more than anything else but I have a Zakk Wylde overdrive (barely turned up) to give it a boost and it sounds killer but somehow your lead channel doesn’t sound like it needs a boost at all. Could that be a sign I need new tubes?
did you made a mods for this to take the 6L6 tubes? ..to my understanding this only runs el34s
Thank you for this video. So has the mod completely resolved the issue? Does the bias hold steady after prolonged sessions at gig levels? Just order this for my DSL and I'm curious
So, I have a jcm2000 dsl that sometimes has a ton of gain, sometimes has hardly any... Is this the bias drift that I'm seeing?
Hi Joey. I would bet money on it. You can test the theory by checking the bias while it's doing that.
@@RestorationObsession thanks for the response man! I only know of one legit tech around town and he's got an 8 week backlog on stuff that has to be left at his place, so I kinda need to have a REALLY good idea of what the problem is lol.
Did this stop the bias drift permanently. Looks like it could be done by just removing the rear board and do the main board in place
Hi Mark. Yes, the bias hasn't changed since I did the mod. She's been purring right along!
On this model i need to adjusted bias when i change the el34 or its automatic bias on this?
Hi! You need to do it manually. I believe the Mesa Boogie amps such as the Dual and Triple Rectifiers have auto bias but the Marshall TSL does not. I recommend that you check the bias periodically just to make sure it hasn't drifted out of spec. Mine drifted way high and the amp was running really, reeeeally hot.
@@RestorationObsession thanks for answer. You think its better to adjust bias little lower than normal Just to save the El34? So i dont need change them so often?
@@grimarkraka7784 You are welcome. I think biasing them a little lower would help extend the life of the tubes, but probably not by all that much since they are not really being pushed too hard unless you play the amp at super loud volumes, say... over 3 or 4. I've been in very loud metal bands with a second guitarist adding to the noise and I never had my TSL over 2 lol. I think your tubes would give you the same life time either way (biased normally or lower).
Tq for the video..
Hey buddy cool vid ! Checking my ig Diablito Speedz. I didn’t get your last comment
Thanks!