Marshall TSL100 JCM2000 - How to change tubes and Bias with new Reverb Tank
ฝัง
- เผยแพร่เมื่อ 1 ต.ค. 2024
- A not so short, but simple video on the service I did on a Marshall TSL100 a few weeks ago.
The customer wanted new tubes as well as get the reverb working. The reverb was easy. The amp cabinet was void of a reverb tank. Being unfamiliar, I thought it was perhaps a digital reverb, but no... it is solid state driven via some IC's but it is driving a real reverb tank.
Power tubes were swapped, the amp was biased, and the customer is extremely happy with the amp. This is a classic example of preventative maintenance, unlike the Blackstar that came to me the other day which I didn't end up recording. The power tubes had simply failed and caused the amp to misbehave in a very predictable manner. - แนวปฏิบัติและการใช้ชีวิต
I was able to squirt cleaner in the pots through the front between the knob itself and the knob housing and was able to get them cleaned out. Still waiting to see if the scratchy pot’s syndrome is gone. But definitely cleanable
Ah, nice one. I’ve never had success with those pots. I just replace them.
@@whatsstefon well I gotta tell ya that amp is still down waiting on parts so I truly don’t know if that’ll fix the scratchy pots or not once I plug it back in and play through it. But fir now I tell ya those pots turn pretty easily
Also it’s a good idea to drill two small holes in the board on each side of the footswitch connection and attach a zip tie so it relieves pressure on the solder connection when attaching the footswitch cable.
Great idea!
I really appreciate this video... you just never know who it will help out down the line. I have the same head on my bench right now (got it from an old bandmate to keep it in the family) and am about to re-tube it and also have a reverb issue. I was about to start testing the non-IC components on the reverb board until I noticed a gigaohm resistor on the board (my Fluke maxes at 40 M Ohms) and decided that maybe I need to scope the ins and outs and test the power as I had already had a replacement tank on hand... so I appreciate seeing someone else taking the time to film it!
Thank you for taking the time to comment. Every bit helps.
Marshall still make replacment TSL footswitches. Its a 5 din pin cable. Five button footswitch, clean, crunch, lead, reverb, and fx loop.
Thanks for the info mate.
I'm sure it's 7 pins
It’s 6. Pin one is clean, pin two is crunch, pin three is power for the footswitch, pin 4 is reverb, pin 5 is effects loop, and pin 6 is the common. The lead channel is activated by turning pin 1 or 2 off. The cable itself that comes on the pedal typically has 8 leads and two are just not connected.
@@floflomas1322but you were correct that it wasn’t 5. My bad.
Hello Mate, thanks for the video!!! I got this amp and gain is so weak, gain is almost 9 on the crucnh channel but there is no gain at least, preamp tubes also new.. but result is same i wonder that have you any video that kind of problem? By the way i faced same issue with all channels , clean-crunch and lead😢
Without being able to signal trace, it’s tough to pin point. However the fact that it’s affecting all channels would at least help guide you towards the output stage of the amp. So it could be the phase inverter or power section.
Marshall recommends 90 mV per side. i.imgur.com/VfEUihY.jpg I think that's too high. I like how you didn't bias the valves that high. I would have liked to have seen these new tubes on the oscilloscope.
90mV would have been too high indeed.
I always try and bias an amp to the spec of the tubes. However I do always try and find what the manufacturer states, just to see what they’re recommending.
Thank you for the comment and clarification.
Maybe Marshall liked selling a lot of those replacement spares lol
@@CHAOSMOVEMENT you’d think they’re in business of selling new amps or something. 😂😂😂😂
Hi, I have the JCM2000 TSL100 running into a 1960A cab. When at home or in the studio I use the Bugera PS1 Power Soak 100w Amp Attenuator so I can drive the amp yet keep levels right down. My gain/lead tone is amazing however when I play live without the attenuator my tone sounds terrible. Its super crunchy and awful. I have tried using the MXR 10band EQ in my FX loop and in front of the amp to try and take the crunchy sound out however its just as bad. Why is it the tone changes so much when not using the attenuator or what could be the reason it behind it?