Re: Marshall DSL 401 - Juicing the JJs - how far?

Oh Yeah -- very interesting experiment. Like you I always trust my
ears -so setting it up with a longer speaker cable I adjusted the bias
lower - and it makes a HUGE difference in sound.

Set at the recommended level the amp sounds clean - no clipping. Yeah,
you get a great amplified guitar, but you don't that Marshall tube
sound of squeaky harmonics everytime you pick a note and sustain for
years.

Turn the bias down and it comes out - that was the sound I was looking
for - so bias DOES make a difference in the sound. I also get a lot
more variation in my tone and volume pots. The only downside is just a
little bit of that "I've hit my wall" harmonic distortion, but it
appears that is the price you pay to get the sustain you want.

FWIW, I was aiming for the .7 zone, but my bias pot hit its lower limit
at about 8.24, so that's where it stayed. That is good enough, but it
would be interesting to see what is down lower. I tried bringing it up
to 9v to see if there was a spot where the tone stayed but the clipping
went away, and I actually heard the opposite (lost the tone, kept the
clipping). So forget that.

Interesting that people say the amps come out of the factory generally
under-biased.

.

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