UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - 120W PP EL34 amplifier re-born.

Diabolical Artificer · 21st Sep 2018, 5:00 pm

Having finish the big amp, that started as an 807 amp, but morphed into a EL34 amp, I wasn't happy. The amp weighed over 60kg! Also the case just wasn't right, so I started pretty much from scratch, this time opting to make two monoblocks.

I kept the amplifier chassis's but redid the PSU's housing them in wooden boxes. One is pretty near finished, see pics, the other is about half way through. I've yet to apply a finish on the wood, which is sycamore and at the moment the PSU is wired up temporarally.

The fan is there to cool the cathode follower resistors and once I've drilled some holes around the EL34 OP valves, jets of cool air will cool them too.

It's meant a lot more work, but I'm a lot happier with the end result and the monoblocks don't need a crane to lift them.

TFL, Andy.

21st Sep 2018, 5:00 pm	#1
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,662	120W PP EL34 amplifier re-born. Having finish the big amp, that started as an 807 amp, but morphed into a EL34 amp, I wasn't happy. The amp weighed over 60kg! Also the case just wasn't right, so I started pretty much from scratch, this time opting to make two monoblocks. I kept the amplifier chassis's but redid the PSU's housing them in wooden boxes. One is pretty near finished, see pics, the other is about half way through. I've yet to apply a finish on the wood, which is sycamore and at the moment the PSU is wired up temporarally. The fan is there to cool the cathode follower resistors and once I've drilled some holes around the EL34 OP valves, jets of cool air will cool them too. It's meant a lot more work, but I'm a lot happier with the end result and the monoblocks don't need a crane to lift them. TFL, Andy. Attached Thumbnails __________________ Curiosity hasn't killed this cat...so far.