Thanks, Gordon

I am not in a rush. I hope you are enjoying the sailing.

We can kick this idea around when you get back. I may bite the bullet and buy a couple of 6973 valves. Electro Harmonix is making them again.

I may build the amp just like the schematic. It probably will not sound like to original in any case. The company that built the original transformers is still in business and I am researching that issue now.

The EL84 valves will have less headroom and break up quicker. That may be a good thing.

A quote from a friend of mine who has built a Supro.

"EL84s
I speculate that the EL84s may give less clean headroom, being more sensitive than 6973s. My experience of the 6973 is limited to my Supro clone, and I find the amp to have a lot of headroom. It's not necessarily very loud, but I can run the volumes well above halfway before there's any appreciable overdrive, and even if driven flat out, it's not as dirty as a Fender 5E3 Deluxe (Fender amp from the 1950s with similar power into a 12" speaker). However, the preamp in the 1624 has much larger anode load resistors than a typical Fender or Marshall, giving the Supro preamp a flatter load line. This would give it more headroom, too. In practical terms, it's loud enough to gig and it sounds very good with overdrive pedals, and likes fuzz a lot."

Both valves use the same socket but have very different pinouts. As I intend to build this on a turret board I could rewire and try both valves.

I have never been very skilled at electronics and everything I know has come from repairing amps and building them. I have never been to school or had any training.

If I use the original PT the voltage will be too high for the EL84 valves. I ASSUME I could use a zener diode to reduce the voltage. That is a bit over my head to design.

Fun stuff at any rate.

I am not sure where Trev is at the moment. He told me he was going on a long trip to the western coast in his new caravan. I hope he will post some photos.

Cheers,

Billy

“Amazing! I’ll be working with Jaco Pastorius, Charlie Parker, Art Tatum, and Buddy Rich, and you’re telling me it’s not that great of a gig?
“Well…” Saint Peter, hesitated, “God’s got this girlfriend who thinks she can sing…”