Greetings from sunny and distant
Croatia! What a great pleasure it is to
read your column every month and
experience your vast amp knowledge.
Like many other guitarists on a
budget who want a solid rock tone, I
bought a Marshall DSL401 tube amp.
I never did any repairs or mods on
it, and since it’s getting a little bit old
now—I’ve been playing it for nearly
eight years—I’m curious what servicing you’d recommend. I feel that the
sound is getting muddy and bassy.
What should I do to keep the amp
running at its optimum level? This is
a very popular amp, so I think your
advice would help other readers, too.
Thank you in advance.
—Stipe Ursic
Thank you for reading Premier Guitar and reaching out from so far away!
To start with, your Marshall DSL401 is a
40-watt combo powered by EL84 output
tubes. This is a bit different from what we
traditionally think of as a Marshall. Most
players associate Marshalls with EL34
output tubes. It’s EL34s that provided the
“Marshall sound” in the classic 50- and
100-watt heads we know and love.
After having the same
power tubes in your amp
for eight years, anything
you install should yield a
vast improvement.
bias, while the increased, more aggressive
distortion of hard rock and metal benefits
from a cooler bias, as this tends to keep the
amp tighter and more focused.
Don’t be afraid to experiment with bias
settings, within reason, of course, to see
what works best for you. Just as a point of
reference: In a working musician’s amp, you
should consider replacing the output tubes
once every six months to two years.
Now, I know all this information has
been directed toward the output tubes,
which is where I believe you’ll notice the
most improvement. But after all this time,
you might want to consider replacing the
preamp tubes, too. I say “consider,” because
the result can often be subjective. Many times
I’ve replaced old preamp tubes in a working
amplifier with new ones, only to find that the
original tubes sounded better. Or were quieter. Or less microphonic. Just because a pre-amp tube is new, doesn’t mean it will sound
better than its predecessor. And, as with
output tubes, different manufacturers’ tubes
sound different. Bottom line is, if your pre-amp tubes are not giving you trouble, there’s
really no reason to replace them. Unless, of
course, you’d like to experiment with every
preamp tube you can get your hands on to
see which sounds the best in which location.
In that case, have at it. It’s the “no biasing
necessary” way to have fun with tubes. Now
you can continue crushing in Croatia!
JEFF BOBER, one of the godfathers
of the low-wattage amp revolution, co-founded and was the principal designer
for Budda Amplification. Jeff launched
EAST Amplification in 2010, and he can be
reached at pgampman@gmail.com.
