PPIMV on an AB763? Anyone tried one?

[rogb]

If so how did you get on?

I have just finished a Deluxe AB763 with a stock (apart from Mid pot and trem off switch) Vibrato and an abNormal channel, partly D*mbleized, which sounds great when dimed through my D*mbleator.

I was thinking I don't always want to take that around with me but I would like that great drive available.

Any joy with LarMar PPIMVs, folks?

Thanks
Rog

[Reeltarded]

In the immortal word of that dood on the show where they buy storage lockers...

YUUUUUUP!

Great, fine, super. They are only good for the upper 6db and a tad, my opinion!

[rogb]

Thanks, I will order the parts next week and try one.
The amp really sounds good with the Normal volume cranked and Mega Boost PAB in.

I have a little more tweaking to do, based around D style Bluesmaster mods, which are not too hard, but it is a gain monster ( in the context of being a simple Deluxe AB763) and I haven't had the chance to really let it rip yet.

EDIT: I just did, as I noticed my neighbours were out! There is enough gain on this to make me pull the chassis and retighten all the nuts and bolts and re-lock em with nail varnish ( !) I also removed the stupid spring tube retainers I had as they vibrated like Debbie Does Dallas's bedsprings

I think I am getting near to my goal...

[Reeltarded]

Cool! When I get close I have only just begun.. I came to realize! haha

It's nice to be able to use the PPIMV to stage gain earlier. I havn't been really baking power tubes in a while now while balancing the PI breakup. It's a nice rig!

[rogb]

However you could have all the gain in the world but if it aint musical, then...
this is what I am aiming towards, how near I get is another matter

===================================
"The "Vibrato" channel (which is actually amplitude modulation rather than pitch) is the clean side of the amp but gets a slight breakup when cranked. This channel takes effects very well and practically anything we threw at it sounded good. Sounds like the classis Fender clean but just...more! From what I understand the Tremolo was modified as well and it sounds very quiet and no audible tick can be heard from the LFO even at very high volumes.

The "Normal" channel has been converted to the overdrive channel and in my opinion this channel is scary good. The volume control sets the amount of gain and volume. It's fairly unlike the overdrive on an ODS in that it has a rawer more raspy sound, great for classic rock power chord galore. But the real magic happens when the Volume is on 10 (doesn't it always!). The sound gets absolutely HUGE and signal-to-noise ratio is beyond phenomenal. If I stopped playing I could have sworn there was a noise gate in there, it was that quiet and I'm not exaggerating one bit. Also, the amp had an unearthly way of producing controlled feedback. Every note played would sustain indefinitely and even chords! The feedback would retain the note played without running away with a crazy harmonic, again, even on chords. A particularly cool way I liked playing this channel was to pedal an open note, have it feedback and then play stuff over it! Although sometimes, when I played a particularly disonant chord I could hear some swichy inter-mod-type sounds emanating from the speakers but I didn't think it was ugly."

[Roe]

I'm using larmar MVs on two twins. one replace the 68k bias splitters with a dual 100k with 220k safety resistors. the other uses the standard 250k pot with 2m2 resistors instead of the 220k bias splitters.

both work fine

[rogb]

Thanks! I will order the dual pot today. Did you use shielded or regular wire twisted to suit?

[jjman]

Any Youtube links to any AB763 with PPIMV? I don't see any. I wouldn't be against trying it in my '71DR. Already have a mid boost that works very nice but has to be loud to do its thing productively.

[Roe]

there exist some youtube videos SRV style with EVM 10s.

use shielded wire

[spiralstairs]

There are quite a few boutique amps that are BF based and have ppimv, I believe (allen, bruno, drz ezg50, tophat, ?) - I'm not an expert on any of those so could be wrong, but thats what they seemed like to me

[Roe]

There are quite a few boutique amps that are BF based and have ppimv, I believe (allen, bruno, drz ezg50, tophat, ?) - I'm not an expert on any of those so could be wrong, but thats what they seemed like to me

allen is PostPIMV, DR Z is Pre PIMV

[rogb]

Just waiting for the parts to arrive, should be today, putting in a deep switch too to see how it goes, I liked it in my D style

[llemtt]

a good PPIMV should also compensate the reduced signal on the feedback loop

if you are going the LARMAR way you need a three-ganged pot, not easy to find...

cheers

[spiralstairs]

allen is PostPIMV, DR Z is Pre PIMV

Interesting. I had only ever seen inside an Allen, haven't seen inside any of the other companies I mentioned. Thx for info. I wonder about other companies - I had simply assumed they had used postPI, since it has good results.

to the OP, I have used PostPI in BF circuits and it works well for my needs, although I always think combining MV with an attenuator/etc is the only "good" way to get low enough for apartment. Using both in combination I think gives much more versatile possibilities. Of course, things never sound great when you're not moving the speaker

But if you don't care about low volume, and only versatile distortion at gig levels, then ppimv works well

[rogb]

a good PPIMV should also compensate the reduced signal on the feedback loop

if you are going the LARMAR way you need a three-ganged pot, not easy to find...

cheers

Don't think so, this is from the Metroamp forum, where it was conceived.