A big thank you to … A big thank you to Jay and the team at Eurotubes – I had a problem with my DSL100 and sent them an e-mail.Jay replied within 24 hours – I followed his detailed instructions and things are looking good.I set the bias to 88mv per side using just a meter – It can be a bit fiddly,so get someone to help you by holding the meter and probe whilst you do the pot adjustment – Regards Dave B.
that is Marshalls … that is Marshalls standard recommendation, however you have to know the plate voltage and compute your setting. MOST DSL50’s will plate voltage around 450-470. You take 17.5/450×1000 to get your bias setting. Most DSL’s I’ve ever worked on had settings 36-39mV. 45mV is really really high and too high for most tubes.
Hey, I’ve got a … Hey, I’ve got a Carvin V3 head, and it’s making really weird noises and smells. I’m new to tube amps, so I don’t know if this is normal…it makes a noise not unlike a lawnmower when it’s not plugged in to a cabinet.
yes, because … yes, because components may have changed; as the get older they are less efficient. Thus, the bias must be changed when anything is changed to correct possible changes. Hope it helps.
I have a tsl 122 … I have a tsl 122 combo that has the same problem… these amps are very unreliable… I was about to say check cap 46 but i see you already did… I think I will have to take mine to service
The tubes on my … The tubes on my TSL100 are glowing blue! And getting really hot to the point at which it burns my fingers if I touch them after being on for just 30 seconds.
I know this ain’t right, it also hummms like a mother fucker, and doesn’t hum any louder or quieter after adjusting the volume..
I changed the bias to as low as it can go (turning it counter clockwise) and it seemed to help as far as the valve’s cooking is concerned..
I also opened it up and done away with cap C46, still no change?
Just a shameless … Just a shameless plug for this guy… I’ve pretty much exclusively bought tubes from him for the last 3 years because his customer service is so good. I’ve experimented with alot of tubes, and IMO, JJ’s are the best sounding new-stock tubes for the money. Don’t be fooled by rebranded Sovteks/Chinese garbage.
When you’re biasing … When you’re biasing a head do you need to have it plugged into a cab as well? I only ask because Marshall say you shouldn’t run the head off standby without a cab plugged in, and I can’t see the output jacks clearly on this video…
February 7th, 2010 | 
Author: 
Eurotubes how to movie Working on a Marshall JCM2000 DSL100 Amp Head.
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Actually, less than …
Actually, less than 5 mins later I answered my own questions, disregard what I asked.
Now, I just mean to ask, when he kicks it off standby, does he turn the amp fully on? Doesn’t this damage the amp?
Also, how to you adjust the bias pots on this amp? What tool would I use?
Thanks.
that was freaking …
that was freaking AWESOME!! thank you for explaining it to were I didn’t feel like a idiot
any vids on how to …
any vids on how to bias a JCM 900?
A big thank you to …
A big thank you to Jay and the team at Eurotubes – I had a problem with my DSL100 and sent them an e-mail.Jay replied within 24 hours – I followed his detailed instructions and things are looking good.I set the bias to 88mv per side using just a meter – It can be a bit fiddly,so get someone to help you by holding the meter and probe whilst you do the pot adjustment – Regards Dave B.
Do you need the …
Do you need the Bias meter and the Multi-Meter, or can you just do one or the other to bias?
80-90mV on this …
80-90mV on this 100w DSL -Is it about the same 80-90mV on a 100w JMP from the 70’s?
Why do you have to …
Why do you have to bring it up before you take them back down?
You should never …
You should never ever have a tube amp turned on when it’s not plugged into a speaker
that is Marshalls …
that is Marshalls standard recommendation, however you have to know the plate voltage and compute your setting. MOST DSL50’s will plate voltage around 450-470. You take 17.5/450×1000 to get your bias setting. Most DSL’s I’ve ever worked on had settings 36-39mV. 45mV is really really high and too high for most tubes.
Hey, I’ve got a …
Hey, I’ve got a Carvin V3 head, and it’s making really weird noises and smells. I’m new to tube amps, so I don’t know if this is normal…it makes a noise not unlike a lawnmower when it’s not plugged in to a cabinet.
Where can you find …
Where can you find how many millivolts a particular brand recommends?
looks like ted …
looks like ted nugent
yes, because …
yes, because components may have changed; as the get older they are less efficient. Thus, the bias must be changed when anything is changed to correct possible changes. Hope it helps.
Should show how you …
Should show how you hook up the digital volt meter. start from the very beginning.
depends how the …
depends how the tube is configured in a diagram.
Blue burning tubes …
Blue burning tubes usually means oxygen made it in the tube. …which of course means a leak in the tube.
Bias Settings:
…
Bias Settings:
DSL50 45 mV as advised on harmony central forum
do ALL tube amps …
do ALL tube amps have to be biased before retubing?
hi is this the same …
hi is this the same with the dsl 50? please reply
I have a tsl 122 …
I have a tsl 122 combo that has the same problem… these amps are very unreliable… I was about to say check cap 46 but i see you already did… I think I will have to take mine to service
The tubes on my …
The tubes on my TSL100 are glowing blue! And getting really hot to the point at which it burns my fingers if I touch them after being on for just 30 seconds.
I know this ain’t right, it also hummms like a mother fucker, and doesn’t hum any louder or quieter after adjusting the volume..
I changed the bias to as low as it can go (turning it counter clockwise) and it seemed to help as far as the valve’s cooking is concerned..
I also opened it up and done away with cap C46, still no change?
You NEED a load of …
You NEED a load of some kind plugged in, but not necessarily a cab, some kind of dummy load would work.
Just a shameless …
Just a shameless plug for this guy… I’ve pretty much exclusively bought tubes from him for the last 3 years because his customer service is so good. I’ve experimented with alot of tubes, and IMO, JJ’s are the best sounding new-stock tubes for the money. Don’t be fooled by rebranded Sovteks/Chinese garbage.
can you do a video …
can you do a video biasing a 77 JMP 50 watt amp w/6550’s
When you’re biasing …
When you’re biasing a head do you need to have it plugged into a cab as well? I only ask because Marshall say you shouldn’t run the head off standby without a cab plugged in, and I can’t see the output jacks clearly on this video…