Marshall Tube Amp Question?

[TomN]

Do we talk amps here? I just joined and didn't see an Amp section, I know it's project "Guitar" but I need some help.

Just plugged in a used Marshall DSL401 that I purchased and I am having a couple of issues. I wanted to know if they were major

or if it just needed some new tubes and general service.

The first thing of note is it's noisey. With my guitar volume all the way down, or even unplugged, I hear a real lot of swooshing sound in the

background that gets worse when I increase the volume. (Power amp Tube?, Biasing? ???)

I know it's a Marshall, but the clean sound is really thin and has no low end at all. Hitting lower notes just farts. Could this be related to the first

problem, or is there maybe a bad speaker as well?

Any input would be greatly appreciated. I knew the amp might need to be serviced so I am just trying to pin down exactly what I need to do.

Because I will probably learn how to do it myself on this amp. It's okay to just poke around in there with a screwdriver right?

Any links or sources of Tube amp service and diagnostics would be appreciated as well. I'll check on my own as well of course. But if someone knows a good

place to point me that would be great.

[unklmickey]

...Because I will probably learn how to do it myself on this amp. It's okay to just poke around in there with a screwdriver right? ...

hi Tom,

if you give us your real name, i'll post your obituary after your "poking" session.

cheers,

unk

[JohnH]

Hi Tom (and G'Day Unk, nice to see you out and about on the I'Net)

I have a DSL401, it should be:

very quiet with no input plugged in, even if volume turned up

Good bass on clean channel - with a very clear vibrant sound

OD channels are somewhat lacking in bass, particularly with the stock speaker (a Vintage 30 is much better), unless you turn up the gain. Its voiced to make screaming Marshall lead tones

If you are getting swoshing, even with master volume at zero, something in the output stage must be amiss.

And Unk is not joking. There's hundreds of volts inside, that can hang around in capacitors even when unplugged. As they would say in German (if they didnt speak German):

"Achtung!...Das machinen ist nicht fur gefinger poken!!"

John

[unklmickey]

...(and G'Day Unk, nice to see you out and about on the I'Net)...

ROFL ..... i was just thinking about sending you an e-mail.

i remembered you had added DSL a to the middle of your "MasterBlaster stack".