The Amp Garage

Beach Boys #109 ODS

What is the serial number?

Has anyone tried a low-noise JFET such as the 2SJ74? No reason you couldn't use a low noise JFET, but that one is a p-channel. Its n-channel complement is 2SK170. Both are getting hard to find now. Dang I knew I was gonna get that backwards. There are some modern substitutes, and it seems like a qu...

Has anyone tried a low-noise JFET such as the 2SJ74?

So was this amp built for Tom Verlaine, or did he buy it pre-owned?

Stephen1966 wrote: ↑Sat Apr 20, 2024 6:24 pm Just curious. Does anyone recognise the make of this resistor? It's likely it's the cathodyne bias resistor: Rb = 1.5k.


9 - bias resistor.jpg

I'm gonna guess the body is rough blue.

Except for the 3 vs 4 filter caps, both have the unique HAB additions to the venerable 5E3: (1) VI Separate cathodes and (2) the VIIB PI has increaesed value for all components plus the LNFB and an adjustment pot to fine tune voltage on the 6V6s grids. What does LNFB around a unity-gain stage DO, a...

Denmark St. Guitar is the Harrisons' shop isn't it?

That would make one question its authenticity...

Isn't NTE the "artist formerly known as Philips ECG"? And before that, Sylvania ECG?

Even in the '70s the Sylvania flame proof resistors came from multiple suppliers. We used to look for the CGW (Corning Glass Works) ones.

Listening is a developed skill . Some people are operating at a different level. For example, watch Eric Johnson spend an hour biasing his Marshall, playing the same lick over and over whilst making minute turns on a trimpot, he's hearing something in the sustain, touch and texture that us mere mor...

Very tidy

ijedouglas wrote: ↑Wed Sep 06, 2023 2:48 am
PXL_20230906_022350745.jpg

That looks just like the amp Randy California had.



Also, what gauge aluminum is the bottom plate?

Is there a known, or estimated, serial number range for the amps with bolt-up chassis?

ic-racer wrote: ↑Wed Sep 06, 2023 11:11 pm Good to see some interest in the Manzamp. Especially since the EJ amp has surfaced. Like, what in the heck is a Manzamp preamp? My impression of the Manzamp I build was the tone was in the power amp section.

Maybe HAD recycled the name for a completely different product?