finished express style clone-need some help with mods

Express, Liverpool, Rocket, Dirty Little Monster, etc.

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72fetter
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Joined: Fri May 08, 2009 3:45 pm
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finished express style clone-need some help with mods

Post by 72fetter »

first off I am quite taken with this amp. first build from the ground up and i built it with the intention of being able to upgrade it to a 4 power tube monster down the road.
-first off there is not enough bass response-it sounds really clear and loud but the gain is a bit too intense after 12'o clock and the bottom end is not really there.
-second i need to figure out this 1 meg single pole pot master volume type 3-it doest work and i get this horrible jackhammer sound at low setting.'

any advise?
72fetter
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Joined: Fri May 08, 2009 3:45 pm
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Re: finished express style clone-need some help with mods

Post by 72fetter »

also one power tube seems to be lighting up to the beat...i mean noticeably glowing like a light bulb when i hit notes especially low notes .

rookie here...need help
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gearhead
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Re: finished express style clone-need some help with mods

Post by gearhead »

The Express is not a bass heavy amp. It's geared for mid to treble; inherent in the design.

Set your vol control at 12 to one o'clock and control from clean to crunchy to mean solely from your guitar's volume knob(s).

As far as the pot, have you put in some master vol control?
72fetter
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Re: finished express style clone-need some help with mods

Post by 72fetter »

i have tried twice and both times it was pointless...didnt do a thing other than add a jackhammer sound at low volume.
72fetter
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Joined: Fri May 08, 2009 3:45 pm
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Re: finished express style clone-need some help with mods

Post by 72fetter »

ok so far it looks like changing cap values from .022 to something higher helps according to other posts. Any issues with going extreme to say .1uf?



and that 1 power tube is really bugging me. could i have gotten my output tranformer wires wrong?
paulster
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Re: finished express style clone-need some help with mods

Post by paulster »

The Express isn't heavy on the bass so may not be voiced exactly as you want but before you start trying any mods on the amp you want to ensure that it's fully debugged as is first.

If you've got a tube red-plating then you'll have a dead tube now in all likelihood.

You may find that you're not getting a proper bias voltage on that tube socket, or it may be a parasitic oscillation that's running it flat out but outside the audible spectrum.

Whatever the cause of the current problems, get them ironed out so you're on a level playing field, and then look at changing the voicing afterwards if necessary.
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