markusw wrote:
Did you try a 12dw7 instead of the 12ax7? JJ makes them.
The 12au7 half might work better as a driver....
That's a tempting idea. The return stage would also have higher gain than any tube in the ecl family.
I tried the 12DW7 a few years ago in that circuit. The only problem is that the 12AU7 side does not have enough voltage gain to adequately drive the reverb tank. A 12AX7 works better.
If you are looking for something different. Take a look at the old Ampeg amps. They drove the reverb off of the plate of the reverb drive. Of course, the standard 9AB3 style tank is not going to work. Might be a cool alternate. Might be a great choice with the 6BM8. Haven't tried it so this is only supposition at this point.
Gary
Located in the St Croix River Valley- Afton, MN
About 5 miles south of I-94
aka K0GWA, K0 Glas Werks Amplification www.glaswerks.com
12au 20% gain....Trust me wire the Pentode as a triode Plenty of drive... Use the 12 AT side as a recovery plenty of recovery works great drives a long delay tank no sweat ...This reverb passed Tomo Fujita's tone test and this guy has some serious ears and plays Pro Reverbs with the reverb on!!
Aurora wrote:How would one connect this in a Rocket??
feeding via a resistor directly to the main PI input, or through the lower cap that is grounded in the normal schematic?
Have a look at the Matchless Lightning Reverb schematic. Dry signal to the top of the PI, reverb signal to the bottom.
briane wrote:... it really is a journey, and you just can't farm out the battle wounds.
glasman wrote:
I tried the 12DW7 a few years ago in that circuit. The only problem is that the 12AU7 side does not have enough voltage gain to adequately drive the reverb tank. A 12AX7 works better.
Gary
Thanks for sharing your observation!
talbany wrote:12au 20% gain....Trust me wire the Pentode as a triode Plenty of drive... Use the 12 AT side as a recovery plenty of recovery works great drives a long delay tank no sweat ...This reverb passed Tomo Fujita's tone test and this guy has some serious ears and plays Pro Reverbs with the reverb on!!
Yeah, that saved me quite a few frustrating hours. Thanks!
glasman wrote:
I tried the 12DW7 a few years ago in that circuit. The only problem is that the 12AU7 side does not have enough voltage gain to adequately drive the reverb tank. A 12AX7 works better.
What about the 6DX8 instead of the 6BM8. The former one would operate on smaller grid signals. About the same benefit as using a 12AT7 instead of 12AU7...
Anyone tried those soviet equivalents 6F3P, 6F4P you see on ebay for next to nothing?
