Leach Superamp PCB

[Sarge]

I am looking for PCB's for the Leach Superamp (I believe He named it the Double barreled amp) Anyway if you have them or if you know anyone that does , drop me a line.
Thanx,
Sarge

[pooge]

you'll probably have to make your own. Find the layout here:

Leach Superamp

[Sarge]

Thanks,
I was hoping to avoid this. I've only made a few simple boards with mixed results. If I have to ,I will ,after all this is DIY, but I would rather not. I am finishing several projects ( all Tube) and have plenty of time to hopefully find some
Regards,
Keith

[Tony]

i have 3pairs of leach double barreled amp pcb's as originally published in audio magazine....

[Sarge]

Thanks for the rapid response!! What is your asking price, including shipping?
Regards,
Sarge

[djss]

Have you considered bridging two leach amps? The superamp hasn't been updated in a long time, where the leach amp has has many changes over time. The leach amp is by far the superior version, and you can pick up the boards for 12.50 each (inc. shipping) from Prof. Leach.

[Sarge]

Yeah, I am thinking of doing that.
Sarge

[djk]

With the newer 250V rated MJ21193/94 outputs and MJE15032/33 drivers I see no point in series or bridge connected output stages.

The standard v4.5 can drive 1KW into 2 ohms with the right supply voltages and enough outputs.

[Greg B.]

"With the newer 250V rated MJ21193/94 outputs and MJE15032/33 drivers I see no point in series or bridge connected output stages.

The standard v4.5 can drive 1KW into 2 ohms with the right supply voltages and enough outputs."

Has anybody done this? I have been collecting the parts to build two Leach Super Amp mono blocks. I have the transformers, power supply caps, heat sinks and MJ15003/4's. It's time to commit to some boards. But I just happen to have a pair of Leach amp 4.5 boards assembled and looking for a home. I also have a bunch of MJL21193/4's and MJ15024/25's on hand. I don't want to give up reliability!

[djk]

The QSC USA 1310 is rated at 1KW+ at 2 ohms per channel.

It originally used MJ15024/24, and later the MJ21193/94.

Its just a matter of voltage and heatsinking.

If you do a real good job of heatsinking you can run about 40W per device. You would have to de-rate the MJ15024/25 some above ±80V or so for SOA, but the SOA is good on the MJ21193/94 out to ±100V.

±100V could get you 1.2KW at 2 ohms, about 480W of heat to get rid of. The Crown Macrotech 2400 is rated at 1.2KW at 2 ohms, it uses 12 outputs per channel (six pairs).

The Crown VZ5000 only uses 16 outputs per channel for 2.5KW, but the transistors are mounted without insulators to a very extreme forced air cooled solid copper heatsink. The voltages here are high enough to require bridging or series connections. The home constructor might be advized to use more outputs as the Crown heatsink tunnels cost over $200 each (ten years ago) for only mounting about $40 worth of transistors.