The Amp Garage

Update on the playtest. Changed the screen resistors to 1K and still find the screens hotter than the plates, around 3-4 volts hotter. Looking at the Marshall 18W circuit and looking at the Marshall OT (that this OT is a copy of), I see that the screen (choke) resistor is 8.2K. This was something I ...

I'm all wired up at this point, ready to start connecting the many leads. I confess, the multi-colored wire that Andrea presents in his build diagram might make this last part a bit easier. However, yellow wire was on hand... A couple of things I'm doing diff from the stock AA1164 is to add a Band-M...

This period in Fender amps was a bit odd. First off, understand that you can tie the screens directly to the plates of the 6L6 without harming the tube. This is a design feature of the tube, btw. Past this, you mentioned the choke placement seeming odd. Well, this is in an odd placement by most 'con...

xtian, 'Mr. you're a better man than I' is playing in the background as I respond... (May the Great Mr. Beck rest in peace!) I do respect the PCB quality that Andrea has produced here but I have spent too many hours with studio consoles (and perhaps too many Russian mics, not to mention a Sovtek amp...

My build is coming along. The board is unique vs. the stock Fender boards. One niggle I had was the possibility of removing/lifting the PC board without a lot of work should something fail someday, or a part might need to be changed. I'm not sure what others might do here, but the easy solution was ...

No worries, Phil. I'll delete my post.

Fender 5E3 Tweed Deluxe used a 5K screen resistor and 10K was used in earlier models, cathode biased 6V6 pair. He's copying a Fender circuit although the parallel 6V6 is not a Fender design exactly. And, like noted in the post before this one, a larger screen resistance creates more sag, note the Ex...

RG, a great read there! Thank you.

That is funny, and yep, I've done this with a blue pullover on, thinking my new tubes were gassy...

But back to the KT66s (I think I see) there? Are the added silicon spacers really necessary? Also, have you or anyone ever run into a Marshall RI of the original 'China Hat' tube holders?

I have a Classic Tone 40-18037 made for the 18W Marshall and EL84s that is taking up shelf space. (It's as large as a BFBM OT, btw). I'm building a PR using the AAElectronics PC board. I'm overbuilding things, the PT is MM with 5A Filament, 4A rectifier and 150mA primary and the plan is to swap from...

I'm thinking about a 5K and 8K in a 35W push/pull OT. I see that ClassicTone made a SE version when they were around, and it caught my eye. I see that TW OT with something setup for a Rocket and an Express. Anybody used this OT? Thanks.

slucky, I loved the LED use you suggested, and xtian I dug that you bumped it to 10mm. I'm using this in a DR now and it performs very well. Great build and demo, xtian; I'm just starting an AAE PR build and I hope it sounds as good.

Oh. I thought your post was talking about stored voltage on the caps after the amp was turned off....

FWIW, I've been 'trained' not to touch any cap, axial or radial, when the amp is on.

Addressing the fear/safety concerns presented here, linking the radial pairs with 220K 1W resistors will negate the charge on the 2nd radial cap. Pretty simple fix. Fender did this in the 70s on their single axial pair and Dumble did this on his multiple pairs, as well, in his case before and after ...

Happy to be the first purchaser of this PR board, Andrea! Thank you for adding this to your products.