hello!
the device is a tube amp, model Handsome Devil by Blackheart
the schematic is attached below
what i wanna do is to 'lock' the amp into pentode settings and remove the toggle switch and wiring that select from triode (7w) to pentode (15w)
i've seen the schematics many times, but i couldnt get a clue on how to do this... maybe reverse-engineering the switch and checking with the beep where it links, but for a pro it could be easier to show how to do it
then, after doing it so, the unused hole from the toggle will allocate a p10 input/female jack for footswitching
i plan to enable a boost option by footswitching, but not that higain kind of boost that could easily send my preamp tubes into clipping... i want a boost that increases a bit of the volume and a bit of clipping
if possible, i can eliminate the presence control and use that spare hole for suiting a pot to adjust the boost intensity
i thought about a tonestack ground lift, because cathode caps boost maybe wouldnt suit this idea well, but maybe theres another, better trick that i am unaware of... its important to be a noiseless switching, no pops or clicking... no transistors or IC's either
i took into consideration using a boost pedal to slam the input of the amp, but it wouldnt do so great as a boost from the amp itself, right after the v1
the differences between the original schematic and my amp are the following:
*no bright cap on the vr-1 pot
*increased stopper on the vr-1 (from 470k to 1m)
*hf cap attenuator from the input ground decreased from 10nf to 1nf
*first stage plate resistor increased from 100k to 164k
*first stage ck 2.2uf
*second stage rk decreased from 1.5k to 820r, bypass cap 1uf
*v1 coupling caps increased from 22nf to 47nf (i needed that for 012 monel flatwounds)
*33k slope resistor +560pf treble cap + decreased bass pot from 1m to 500k
*added 470k grid stopper before PI to prevent cap saturation, but decreased to 470k the 1m grid stopper between the end of the tone stack and the vr-2 MV pot
*decreased vr-1&2 from 1m to 500k
*second plate of the PI decreased from 100k to 82k
*PI cathode resistor decreased from 1.5k to 470r
please help me with the booster and permanent pentode thingy XD
the device is a tube amp, model Handsome Devil by Blackheart
the schematic is attached below
what i wanna do is to 'lock' the amp into pentode settings and remove the toggle switch and wiring that select from triode (7w) to pentode (15w)
i've seen the schematics many times, but i couldnt get a clue on how to do this... maybe reverse-engineering the switch and checking with the beep where it links, but for a pro it could be easier to show how to do it
then, after doing it so, the unused hole from the toggle will allocate a p10 input/female jack for footswitching
i plan to enable a boost option by footswitching, but not that higain kind of boost that could easily send my preamp tubes into clipping... i want a boost that increases a bit of the volume and a bit of clipping
if possible, i can eliminate the presence control and use that spare hole for suiting a pot to adjust the boost intensity
i thought about a tonestack ground lift, because cathode caps boost maybe wouldnt suit this idea well, but maybe theres another, better trick that i am unaware of... its important to be a noiseless switching, no pops or clicking... no transistors or IC's either
i took into consideration using a boost pedal to slam the input of the amp, but it wouldnt do so great as a boost from the amp itself, right after the v1
the differences between the original schematic and my amp are the following:
*no bright cap on the vr-1 pot
*increased stopper on the vr-1 (from 470k to 1m)
*hf cap attenuator from the input ground decreased from 10nf to 1nf
*first stage plate resistor increased from 100k to 164k
*first stage ck 2.2uf
*second stage rk decreased from 1.5k to 820r, bypass cap 1uf
*v1 coupling caps increased from 22nf to 47nf (i needed that for 012 monel flatwounds)
*33k slope resistor +560pf treble cap + decreased bass pot from 1m to 500k
*added 470k grid stopper before PI to prevent cap saturation, but decreased to 470k the 1m grid stopper between the end of the tone stack and the vr-2 MV pot
*decreased vr-1&2 from 1m to 500k
*second plate of the PI decreased from 100k to 82k
*PI cathode resistor decreased from 1.5k to 470r
please help me with the booster and permanent pentode thingy XD
Attachments
i've done the mods and it worked... lets see on today's gig how it behaves under real conditions
*the 15/7w pentode/triode switch was sucessfully eliminated, i reverse engineered it to understand where did i had to jumper to lock on full pentode mode, then the hole is now a p10 mono jack;
*the presence control removed, now its a 1m variable resistor in series with the lifted ground from the middle pot lug... the output jack shorts the in and ground connections when footswitch is engaged;
no pops or noise when switching... more of an overall volume booster... works fine on all sweep settings, 1m log pot
*the 15/7w pentode/triode switch was sucessfully eliminated, i reverse engineered it to understand where did i had to jumper to lock on full pentode mode, then the hole is now a p10 mono jack;
*the presence control removed, now its a 1m variable resistor in series with the lifted ground from the middle pot lug... the output jack shorts the in and ground connections when footswitch is engaged;
no pops or noise when switching... more of an overall volume booster... works fine on all sweep settings, 1m log pot
Attachments
Last edited:
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