Since I'm back in the world of valves I'm back to my age old problem of getting a solo volume boost out of a vintage Marshall. I've just picked up a late 70s JMP and love the sound of it but can't get any volume boost for solos since I'm already running the pre-amp on full.. boosting with a pedal won't increase volume.
I was thinking, would it be possible to mod a Marshall Power Brake with a bypass footswitch? have it attenuate for rhythm sounds, and bypassed for lead (or even have a 2nd level for the lead sound).
I know you can buy things like the Webber attenuator with this feature already but was curious as I've used a marshall before and it worked well.
Just wanted to think of a few options before I decide to either Mod the JMP or sell it.
Comments
But... it's potentially risky for the amp. You're introducing the potential for failure leaving the amp open-circuit, and even the momentary break in the connection when the switch is operating is hazardous if the amp is actually producing high power at the time - ie if you're switching on the fly and you don't have the strings muted.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
I rarely disagree with ICBM but I do not think any harm would come to the amp due to load switching.
I know of this being done to amps from one to two hundred watts at full power and for many,many cycles, never a problem.
I have a theory that the interwinding capacitance of the op transformer is sufficient load for the few mSecs of the open circuit to prevent the voltages rising to damaging levels.
An additional safeguard would be a 1mfd or so foil capacitor across the switch contacts.
Dave.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Alternatively when I had that amp I put an FX loop in the amp and stuffed a boost pedal in it. Probably easier. If you use the hole for the low input and fit a stereo (insert cable style) Jack for the send and return you can always return the amp to stock.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein