Valvestate output boards

[drewl]

Anybody have an extra output mini board for an AVT50 before I go searching?

I need to call the customer, see if he has it, but this thing looks like it's been in a barn or shed for years judging by the amount of mouse crap and wasp nests inside.

I have a few of the output amp chips, but the board is missing in this pos.

Maybe I'll just breadboard my own, think I have the right connectors at work, aside from them its just a few caps and resistors.

[g1]

Not sure how different these are, or if they could be easily made to work, you would have to compare the AVT to the MG100 schematic.
https://www.tubesandmore.com/products/P-H216

[drewl]

I was checking out this MG100DFX boards from AES.
Looks like they can be made to work fairly easily.

I'm going to map out the differences, and of course you would need to cut the wires off the plug and attach to their correct places.

I started making up a PC board for this amp since I have everything needed to make it work with the stock connectors.

[Jazz P Bass]

For whatever reason, other than 15 pin header (8 pin AVT50) & the dual/ redundant wires, the MG100DFX board does not use pin 11 & pin 6 of the TDA7293 (Buffer & Boot Strap).

[drewl]

Right, pin 12 (8 on CN4) and pin 6 (6 on CN4) are not connected to anything and pin 6 (7 on CN4) has a 22uf to output pin 14 of the 7293.

On the MG100 replacement board that cap is there vs on the AVT50's main board.

Those ate the only differences aside from header pinout.

[drewl]

It's Alive!

Took a little while to figure out how I wanted to lay the board out, and looking at it
, it could have been a little more tidy but it works.
No oscillations, no noise or hum and amp is working fine now.

[Jazz P Bass]

Come on, how about a pic?

[drewl]

I took a couple, u figured someone would demand proof.
I just have to figure out how to get them from my phone, I probably have to put them on my computer or put them on photobucket first.