Steve Naples
New Member
Ok, so now I have taken this amp apart, how do I check and set bias, I find no test points or pots on the back side of it? Nor do I see anything around the tubes at all. Not cool... I guess it's now hidden inside somewhere?
DSL100H how to bias?
- Thread starter Steve Naples
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JIMMIEVANS
New Member
Pull the chassis out of the cabinet and turn it over 3 prong test points near trim pots.
If you want to save yourself alot of grief buy your tubes from tube depot they mark the bias raiting on the tube . I just replaced mine with tung sol el34bs rated at 27 ea. So my bias is 77.1 . Each side
If you want to save yourself alot of grief buy your tubes from tube depot they mark the bias raiting on the tube . I just replaced mine with tung sol el34bs rated at 27 ea. So my bias is 77.1 . Each side
charveldan
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Bias drifts, always good to bias with new quad.
Im glad i got my UK DSL with external points.
Why did Santiago eliminate that ???
Im glad i got my UK DSL with external points.
Why did Santiago eliminate that ???
Rahlstin
Well-Known Member
the UK DSL is very much different than the new build. Havent seen any bias drift in the new builds.
I didn't eliminate anything as I personally wasn't involved in that project...
I am afraid not. The numbers on the label shown on your power tube or boxes represent the plate current and transconductance of that particular tube.
Bias is calculated using the voltage and measured current on each tube or pair of tubes. There is no way anyone can measure it or predict what it might be for your application. The numbers measured with a tester are generally for matching tubes with the same TC numbers for use in amplifiers that do not have adjustable bias for individual tubes or pairs.
Ken
Well-Known Member
I agree the Vietnamese DSL's pass the "eye test" better than my 1999 model as far as a cleaner layout.
I do like the bias pins on the back but I have a feeling (and I may be wrong) that Marshall didn't feel comfortable having the owner mess with it for whatever reason upon further review, so the pins were moved inside to the chassis. There is always a warning we see, "Do not open. No user serviceable parts inside". Well, there's actually quite a few but there's a liability issue with customers opening amps, so Marshall (and everyone else) pretends otherwise. Putting the pins inside keeps their liability low if someone screws up biasing their amp incorrectly.
Ken
I do like the bias pins on the back but I have a feeling (and I may be wrong) that Marshall didn't feel comfortable having the owner mess with it for whatever reason upon further review, so the pins were moved inside to the chassis. There is always a warning we see, "Do not open. No user serviceable parts inside". Well, there's actually quite a few but there's a liability issue with customers opening amps, so Marshall (and everyone else) pretends otherwise. Putting the pins inside keeps their liability low if someone screws up biasing their amp incorrectly.
Ken
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Seriously Dan, I'm embarrassed right now. I'm really beginning to wonder whether or not you are going to understand just how disruptive / disharmonious your behavior here is, or whether we are just going to have to part ways for good. I'm not going to do anything right now, but if I see this kind of trolling again then I'm going to have to cut you loose.
flyingskull
Member
Studies show that 100% of forums gain a 100% improvement when Charveldan is permabanned....
Hi. I just bought my first Marshall and it didn't work. Brand new DSL/100H.
It came one after a long period of warming up and it really stunked up my basement. The next day the same, played it for about 30 minutes, really stunked up my basement, then nothing. I noticed one of the el34's wasn't glowing, moved from socket to socket, it was just that tube. Well I sent the amp back and will receive another new one. Here is my question: My amp's book stated 4 el34's, and 4 ecc83's, all the videos I've watched, and the pictures I've seen here(I've learned a lot), show 4 ecc83 tubes, mine had 3 and a canister in line from them, the first one a canister, then the three tubes. Is this normal? It is a 2015 model.
It came one after a long period of warming up and it really stunked up my basement. The next day the same, played it for about 30 minutes, really stunked up my basement, then nothing. I noticed one of the el34's wasn't glowing, moved from socket to socket, it was just that tube. Well I sent the amp back and will receive another new one. Here is my question: My amp's book stated 4 el34's, and 4 ecc83's, all the videos I've watched, and the pictures I've seen here(I've learned a lot), show 4 ecc83 tubes, mine had 3 and a canister in line from them, the first one a canister, then the three tubes. Is this normal? It is a 2015 model.
Thanks. For 30 minutes I got the sound I've always dreamed of owning. Been playing 50 years now, gone through a ton of amps, and finally get my dream amp and it poops out on me. I think the amp Gods sent me that amp to force me to learn more about it, it is working, I can't wait for the replacement. Still got the 414 cab waiting patiently. Also I've learned how to bias the valves, learned the deference between tubes and the whole valve thing. Cool. Thanks again.
Ufoscorpion
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Really don't like board mounted tube sockets , it's a recipe for eventual disaster . Particularly with an amp with so much glass which = heat .
