Whats on your amp workbench?

[RectifiedAmps]

I always smile when I see that ground wire coiled around the power supply lines in SF amps. I’ve always thought there’d be an interesting story behind their decision to make that a manufacturing standard for so many years. Someone in the factory must’ve thought “Stuff lead dress and proper shielded wiring - this’ll work just fine!”

[MikeC]

Progress... I have tested the orig rectifier & the pair of 6L6GCs - they'll do and I've replaced 3x 22uF 500V electrolytics in the doghouse but have left the 2x 70uF items as I don't have the parts (yet). I installed the rectifier and with a light bulb limiter in play slowly bought her up & checked the DC (it's present - good so far). Then installed 3/6 pre-amp tubes, all good, then 6/6 preamp tubes, all good, then the 6L6GCs with the speaker cab plugged in. She lives & she's amplifying!

[MikeC]

Continued... now playing my Strat into the SR with the light bulb limiter removed. She sounds surprisingly good and both the reverb and trem are operational although the trem is weak & ticky. The reverb is very lush and I suspect those 4x10 alnicos help. I won't start proper checking of voltages, biasing etc until we get a 240V PT. So, old Schumacher PT now removed and it's off to Transformer Rewinds (Brian Smith) for a 240V rewind. I have retained the existing USA mains lead (it has an earth conductor) which I'll terminate with a NZ mains plug. I've removed the ground switch and the aptly named "death cap" from circuit. I've discovered that the power supply node resistor values are not the standard values but I'll tackle that when the 240V PT is installed.

[MikeC]

A little more info.... after more research I've confirmed that this is a 1974 Super Reverb and that there are (at least) 4 different circuit versions for the amp. Turns out this one is actually an AA270 which answers a few questions (previous posts edited accordingly). In this version Fender themselves have removed the interesting fixed/cathode biased power stage that's in other Super Reverbs. It's so much easier when you have a solid base of facts to work from.

[NZTone.e]

Here’s the 1974X clone I picked up a while ago and got rebuilt.

You can probably see which parts are new and old.

It’s ready to be picked up, haven’t heard it roaring yet!

[Slowy]

Here’s the 1974X clone I picked up a while ago and got rebuilt.

You can probably see which parts are new and old.

It’s ready to be picked up, haven’t heard it roaring yet!

This Bill again? Can't wait to hear what you think.

[NZTone.e]

Here’s the 1974X clone I picked up a while ago and got rebuilt.

You can probably see which parts are new and old.

It’s ready to be picked up, haven’t heard it roaring yet!

This Bill again? Can't wait to hear what you think.

Yip, had to really twist his arm to get him to do it too!

It’s built to the Marshall Schematic as well, not the kit one it was supposedly before, so should sound pretty wicked!

Optimus has had a facelift also, I’ll post a pic when I get it back, hopefully this week…

[GrantB]

Here’s the 1974X clone I picked up a while ago and got rebuilt.

You can probably see which parts are new and old.

It’s ready to be picked up, haven’t heard it roaring yet!

To be fair, the normal channel sounded pretty damn monstrous prior. Looking forward to hearing your thoughts after this rebuild.

I note the new board. Looks like he kept the caps, which is good. Grounding looks way better.

[robthemac]

Here’s the 1974X clone I picked up a while ago and got rebuilt.

You can probably see which parts are new and old.

It’s ready to be picked up, haven’t heard it roaring yet!

This Bill again? Can't wait to hear what you think.

Yip, had to really twist his arm to get him to do it too!

It’s built to the Marshall Schematic as well, not the kit one it was supposedly before, so should sound pretty wicked!

Optimus has had a facelift also, I’ll post a pic when I get it back, hopefully this week…

If you can try the 1974 through a closed 2x12 or 4x12, it's.... something

[GrantB]

This Bill again? Can't wait to hear what you think.

Yip, had to really twist his arm to get him to do it too!

It’s built to the Marshall Schematic as well, not the kit one it was supposedly before, so should sound pretty wicked!

Optimus has had a facelift also, I’ll post a pic when I get it back, hopefully this week…

If you can try the 1974 through a closed 2x12 or 4x12, it's.... something

I stupidly sold my 2061CX…that with a 1974 was outrageous. But oh so loud. That’s why the cab had to go

[Bg]

I suspect I know someone who can build another.

[Cdog]

Nothing too exciting, but been wanting to change a few things in the 18W plexi for a while.

Moved the B+ regulator to a better location, (goodbye stand-by switch) and added some 'istors'... A Therm and a Var... for in-rush current limiting and over voltage protection. These amps are a hoot

IMG_20240728_145202933.jpg (1.37 MiB) Viewed 1063 times

[robthemac]

Nothing too exciting, but been wanting to change a few things in the 18W plexi for a while.

Moved the B+ regulator to a better location, (goodbye stand-by switch) and added some 'istors'... A Therm and a Var... for in-rush current limiting and over voltage protection. These amps are a hoot

IMG_20240728_145202933.jpg

Good to hear. My entire guitar/amp/pedal collection has recently been out of favour for 335-->cable-->18W.

[MikeC]

I really like Trinity stuff. Was it a kit?

[Cdog]

I really like Trinity stuff. Was it a kit?

It was a kit Mike, and I agree the trinity stuff is quality.