The Amp Garage

Hello -- A pair of mil-spec quality 6AQ5/6005 ($10-15 at most) will work durably in a Princeton circuit with a 330VDC B+. Keep plate current within max dissipation using a sensible bias. Data sheet value for 6V6 "max voltage" spec is 315VDC, and yet Fender's Deluxe Reverb run between 410-450VDC work...

Hello —

Depending on guitar pickups somewhere round 4 to 5 is that obvious edge threshold. This was consistent within one notch across half dozen examples I had here at one time. Martin, as expected, has the guidance for you. Check preamp plate voltages too, if you haven’t already.

..

Mmmmm --

Reeltarded wrote: ↑Thu Feb 29, 2024 11:17 pm QUAD CORTEX AWAY!!

Jumpin' the SHARC.

..

Hello --

I have had good experiences with both 6CA7EH and JJ KT77 as stand-ins for EL34 in the few amps here with aggressively high plate voltages. Small sample as it's just my personal collection, plus family and friends.

Best ..

Hello -- Another solid (perhaps better) option from the Hammond catalog is the 378CX ; with slightly higher secondary, bunch more current, and no winding wasted on 5V rectifier. .. Nice . Bias winding is only 6A instead of 8A…probably works fine still , we all know 183 Twin PT can handle the extra ...

Cool to see uptake suggestion on sharing success wisely ..

That looks amazing. We had homemade pizza last night but I forgot to get a pic I somehow missed this comment in passing. T'was excellent. Briefly accused of putting on too much pepperoni, and forgiven once the first slices disappeared. Enjoying watching the ribs (and other BBQ/smoke) passing around...

Colossal wrote: ↑Sun Feb 25, 2024 2:20 pm

Roe wrote: ↑Sat Feb 24, 2024 9:43 am Output transformer should be 2k2, with a good frequency reponse like a dynaco a451

I had Heyboer wind one for me for a bass amp. Sounded fantastic. It was nearly 11kg!

Did they "can" it for you like the Dynaco originals?

..

If it's one thing I've learned about this kind of product, its less about what it does, and more about the status it will elevate the user. Whomever buys this is merely signaling to their peers that they have something that no one else has. A Van Gogh. A Rembrandt. They are buying a story and the h...

Hello --

Search works -- 6SJ7 Pentode Operating Conditions.

..

Hello --

I've had to rescue a few. Good advice so far. Careful slow work. Softer tools when possible. Magnifier is a great recommendation. For an adhesive, suggest finding a hi-temp electrical RTV that cures stiff and hard.

Best ..

Seems like you've found that nearly finished sweet spot ..

Hello --

Another solid (perhaps better) option from the Hammond catalog is the 378CX; with slightly higher secondary, bunch more current, and no winding wasted on 5V rectifier.

..

Hello Matt -- I ordered some 3W Metal Oxide off Amazon. I'm sure those'll be fine. I definitely would be curious to hear more explanation of adding resistance to the PT secondaries... in addition to the drop in voltage that I need. Would being before the rectifier reduce the possible sag compared to...

Hello -- I haven't even pulled the chassis out yet, but I pulled the rectifier out and measured from the outside of the socket (I think between pins 4 and 6) to be 115 ohms. So I guess I want to add 2x 68 ohm resistors as well... Yes. Best recall, what I'd used were a pair of 2W 68R metal film resis...