Tweedle Dee on Carter

[Stephen1966]

So not a particularly exciting amp then?!!!

Didn't say that

[Stephen1966]

Okay, that didn't take long. The schematic is done. First draft anyway. If you see any errors or think it could be improved, please let me know.

Now! Who's going to bite the bullet and build it?

https://ampgarage.com/forum/viewtopic.php?f=5&t=37167

[Chris Brown]

Richard McDonald talked about this amp, and his experience with Dumble on Guitarwank 253.. It's a really cool listen: https://open.spotify.com/episode/4ZrxGk ... e680664706

[Stephen1966]

Richard McDonald talked about this amp, and his experience with Dumble on Guitarwank 253.. It's a really cool listen: https://open.spotify.com/episode/4ZrxGk ... e680664706

Thank you. It was nice to hear of the real legacy of his friendship with McDonald. Dumble lives through his work but he is still sorely missed.

[Stephen1966]

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

[ijedouglas]

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

Piher?

[hitchcaster]

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

Piher?

its a prototype for fender to mass produce... so its not gonna be any hard to get vintage parts... new mercury transformers and parts you can buy now easily.

[Mr. dB]

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.

[Mark]

Richard McDonald talked about this amp, and his experience with Dumble on Guitarwank 253.. It's a really cool listen: https://open.spotify.com/episode/4ZrxGk ... e680664706

I listened to it hoping to hear Richard McDonald play through the amp, but regrettably it never happened.

[rschiller]

I'm coming real late to this discussion so if anyone's still out there.

The 10k in the MacDonald 3 filter version changes the PI plate resistor value. The 10k in the 4 drop version that C. Wilson so gratiously has provided so much info about is set at the top of the cathode tail just below the 4k7 bias resistor. HAD in the 4 drop version used 110k plate in the PI and below the 4k7 bias resistor 99k in total.

But the intent is the same: control and balance (or not) the AC voltage to the 6V6. But I conjecture where HAD set them. You can balance them at 0; that is there is no difference in what the 6V6 grids see. But we're not talking about hi-fi amps here. Vintage 5E3s have about 2.5% or so mismatch to the grids and I suspect this is inherent to the tone.

Any thoughts on this?