Frondelli vs Lar/Mar PPIMV

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Elad E
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Frondelli vs Lar/Mar PPIMV

Post by Elad E » Tue Mar 24, 2020 6:19 pm

Hi all,

I incorporated the Lar/Mar into each of my three amp builds (JTM 45, '68 spec Superbass and a '63 Brownface Vibroverb replica) and so far I'm quite happy though I'd love to avoid the affects on the NFB at lower PPIMV settings.
I would love to hear an account of how the two compare from anyone who tried the Frondelli.

Frondelli PPIMV on Rob Robinette's site:
https://robrobinette.com/Generic_Tube_A ... ter_Volume

Seems to basically differ from the Lar/Mar by having the wires from the PI caps connect to the wiper terminals and the other pair of wires running from the left terminals to pin 5 of the power tubes instead of going from the wiper to pin 1 (actually - to the 5k6 swamp resistors on pin 5 in my Marshalls).
It also doesn't need the failsafe resistors.

Roe
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Re: Frondelli vs Lar/Mar PPIMV

Post by Roe » Wed Mar 25, 2020 5:09 am

slightly different. the taper may differ
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Elad E
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Re: Frondelli vs Lar/Mar PPIMV

Post by Elad E » Tue Mar 31, 2020 12:34 pm

Thanks Roe,

Next time I open up the Vibroverb I'll switch things around and report back if I liked it, I gather from your answer that the difference is negligible.

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