BlackVibeWatt

[hiegdk]

Hey all, been toying around with the idea of mashing together the BlackVibe circuit and a 50W Hiwatt - BlackVibe preamp into Hiwatt output. Attached is my amateur attempt and throwing these two designs together with a PPIMV and presence control. Would love some feedback and any tomatoes you'd care to throw!

[tubeswell]

LTP should have 100k, 82k plate resistors - or similar (not 1k, 82k)

[d95err]

Note that the function of the presence control will be reduced as you turn down the PPIMV.

If you plan to use the amp at less than full PPIMV most of the time, the presence control may be next to useless.

[hiegdk]

Note that the function of the presence control will be reduced as you turn down the PPIMV.

If you plan to use the amp at less than full PPIMV most of the time, the presence control may be next to useless.

Ah, interesting. Would modifying the design to use a pre PI MV like in the Hiwatt (https://hiwatt.org/Schematics/DR_Pre4Input_v1a.gif) resolve that? Realistically I'd probably run this amp with the master at full most of the time anyway since my Twin Reverb doesn't have a master. So maybe this amp doesn't really need one...

[PRR]

Whatever this is supposed to be, it looks mis-copied....

Also this section.....

[GroundhogKen]

Make certain to ground the Black COM lead on the OT secondary -- otherwise no sound and the NFB/Presence won't work.
You probably did it right -- it's just not shown on the scheme.
Ken