Help adding reverb to Hybrid A

[paddy]

Greetings to all,
Can anyone give me some advise on adding a tube reverb to my Hybrid A build.In particular,which circuit to use and which reverb tank and transformer.I have access to the accutronics tanks and some fender
transformers.
Any help is greatly appreciated.

Cheers
Paddy

[Bob-I]

Glasman has a schematic posted on his web site for a single 12AX7 reverb. You'd put if just before the PI. Sounds good if you're not looking for Dick Dale surf reverb. It's got a nice rich sound but it's not extreme. To my ears it's just right turned up to about 5.

[paddy]

Hi Bob,
Thanks for the advice,I'll give it a go.Do you have any idea what the value of R10 might be?Also do you think I should use a 12AT7 or AX7?
I'm planning on using the Accutronics 4AB3C1B Tank,any opinions?

Thanks for the help

Cheers
Paddy

[rfgordon]

That tank would work fine with a standard (Fender) reverb transformer. The input is 2250 ohms and it wants an 8 ohm output load. See this link for reverb tank codes: http://www.ampwares.com/reverb_codes.html

I have used that verb circuit, and it does work nicely. A 12AT7 puts out more power than a 12AX7, so it'll push the xfmr a bit harder for more verb.

[Bob-I]

Hi Bob,
Thanks for the advice,I'll give it a go.Do you have any idea what the value of R10 might be?Also do you think I should use a 12AT7 or AX7?
I'm planning on using the Accutronics 4AB3C1B Tank,any opinions?

Thanks for the help

Cheers
Paddy

That tank's fine. I like the sound of the 12AX7 better, but experiment. The 12AT7 drives teh reverb harder, the 12AX7 has a stronger return gain. In one of my amps I used this circuit but used 2 tubes with parallel triodes. IMHO it doesn't sound better, just a bit deeper.

R10 is a dropping resistor. Adjust until you get about 325-350 on the first plate. I used 10K.

[paddy]

Thanks for all the help guys

Cheers
Paddy