Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by rouss, Jan 23, 2012.
Just curious is to What this is and how it effects the tone to make it more ampegish?
I've heard of the Paul C mod but not the Paul C (Ampeg mod).
I saw a post using the terms interchangeably. Basically a grid bias (?) of the cathodyne phase inverter.
Apparently some Ampeg amps were built that way.
I found the "Paul C mod" image on the web awhile back. Modded my Z Galaxie and loved the change. Much nicer transition to distortion, less funky fizz.
It was originally touted as an improvement to Fender Princeton Reverb amps. 5E3 not so much, but YMMV.
would it tighten up the bass?
It delays the onset of distortion which could, in a small way, be perceived as tighter bass.
But in reality you need more power for tighter bass. It's all about physics and you can't revoke the laws of physics.
could this mod be made on a fender 40 watt fender like a blues deluxe or a bandmaster to give more clean headroom
No, it's related to a split load phase inverter circuit. Those amps have long tailed pairs.
To get tighter bass response in these amps use a solid state rectifier and more power supply capacitance.
what kind of inverter does an ampeg vt 40(or v2) head have?
Post a schematic. I'm pretty sure it's not a split load PI. I'll bet those amps don't have tube rectifiers.
they dont their solid state. . Anyway reason for all the strange queations, I can get a bandmaster or blues deluxe for kind of cheap. I was wanderning If their is any mods I could do to them to make them sound more vt 40ish . Best sounding amp I ever heard
www.littledawgamps.com/blog/archives/74Cached Read this.
Why don't you just BUY one of the best amps you've ever heard?
The Ampegs you like probably have bigger transformers than the Fenders mentioned. That has a big impact.
I havn't seen one near by and check all the time(for years now) . I wont buy a used amp off the internet again . fenders are a close causin I think And their everywhere around here. I could pick up a used deluxe reverb reissue for about 500 bucks that is mint. every music store has several lol. I love the 22 watt thing also . I wouldnt mind spenfing a couple hundred to make it sound more ampegish but could it be done?
A 22 watt amp will never sound like an Ampeg 50 watt amp. You need to set your sights higher for power to get remotely close.
I'm a big Ampeg fan. I'm not sure there's much you can do except get an Ampeg. They're unique. And the VT40 is a little different than the V4's also. The tone stack is different, the preamp tubes are different, there are BIG voltages running through the power section. Great amps. I love 'em. There are a lot of differences in the V series circuits compared to Fenders (and most other amps as well). An AB165 bassman would get you much closer than a bandmaster. You won't have the versatility of VT40 or the *ooomph* but those Fenders are solid amps and run through a 4x10" it may be a good alternative.
If you want more info on VT40's, call Todd Sharp @Nashville Amp Service - he be knowin' them.
The mod is to the cathodyne phase inverter in the princeton reverb amp. It was never about 5E3's or making a fender sound like an ampeg. It's about getting more headroom out of the anode side of the inverter to allow it to drive it's power tube into clamping like the cathode side can.
When I posted the tweak years ago on the weber forum I said that this was the text book way to setup this type of inverter and that it's older than I am, and has been used in other amps including some ampegs. It wont make the amp more "ampegish". It's just something ampeg used.