BIASING the new DSL100H head

[flashtilley]

I have looked everywhere for some sort of schematic or any information on how to check or set the BIAS on this new model but nothing. I guess because it's still fairly new. I know the BIAS trim pots are on the board inside and not outside anymore, but i'm not sure where the test points are located or what the setting show be for the new models. I called Marshall directly but they would not tell me anything since I am in Canada so they referred me to the Canadian dealer in Quebec... what a joke those guys are. All they could tell me was that if I do it myself, I will void the warranty and to take it to get serviced.

any help will be appreciated!

Thanks!

[Lizzy]

Just a thought but you might want to have a look at the pictures on this thread about biasing an MA. Both DSL and MA built in the same Vietnamese factory so there's always a chance they stuck with a similiar design. Each of the outer pins on CON7 are the test points on the MA and the center is the ground.

http://marshallroadhouse.com/viewtopic. ... hilit=BIAS

[flashtilley]

Just a thought but you might want to have a look at the pictures on this thread about biasing an MA. Both DSL and MA built in the same Vietnamese factory so there's always a chance they stuck with a similiar design. Each of the outer pins on CON7 are the test points on the MA and the center is the ground.

http://marshallroadhouse.com/viewtopic. ... hilit=BIAS

Cool! Thanks, I'll take a look!

[Lizzy]

Forgot to mention too that if you had one of these:

http://www.amp-head.com/product_info.ph ... ucts_id=70

you'd only have to locate the adjustment trim pots on the amp as you could measure the bias and plate voltage and determine what the correct setting should be using a bias calculator like this one:

http://www.webervst.com/tubes1/calcbias.htm

Definitely worth the money. They work great and are much safer than probing around inside the amp. And they cost less than 1 trip to have a tech do the same thing for you and not to mention having them keep your amp at the shop for who knows how many days.

[flashtilley]

Forgot to mention too that if you had one of these:

http://www.amp-head.com/product_info.ph ... ucts_id=70

you'd only have to locate the adjustment trim pots on the amp as you could measure the bias and plate voltage and determine what the correct setting should be using a bias calculator like this one:

http://www.webervst.com/tubes1/calcbias.htm

Definitely worth the money. They work great and are much safer than probing around inside the amp. And they cost less than 1 trip to have a tech do the same thing for you and not to mention having them keep your amp at the shop for who knows how many days.

Thanks! Excellent info!

[Micky]

The 100 should bias similar to the 40c
Check the bias for each side here:


And adjust each side here:


Micky