Leslie 147 amp rebuild

[canjorr]

Hi all,

If anyone in Europe needs 147/122/251/any other amp or AO-28 preamp rebuild, I would like to recommend friend of mine, Wiktor Krzak from Haiku-Audio in Cracow, Poland. Just wanted to show it to you guys, im stunned!
Price should be around €450 if chassis and all transformers are good. That price includes all electric work and parts inside. New custom build transformers are also an option, but you have to pay some extra. Let me know if you need something like this on this side of big water.

[David Anderson]

I'm sorry, but that it just a ridiculous amount of unnecessary work when the original Leslie parts layout works just fine. And mounting a cathode bypass capacitor right on the terminal of hot cathode resistor? That's not how any experienced amp tech I know would do it.

[canjorr]

I needed to change tube sockets vecause they were rusty and loose, and power transformer because there was not original one, was buzzing, bit to weak and mounted with wrong angle (turned 90 degrees). Since i had to remove sockets and transformer, technician mounted it back together in a bit nicer way, using new some good old and some new parts). It wasn't just my whim. Thank you for your honest opinion though.

[David Anderson]

I just think it's a lot of misplaced effort to fix something that's not broken. I've had to replace tube sockets and power transformers in Leslie amps before, but that did not require me to change the entire layout of the amp. Leslie amps in and of themselves are pretty low-noise amps; most of the noise comes from upstream, in the preamp and cabling, which all this work will do nothing to reduce.

If the Leslie 147 were a noisy, high-gain guitar amp, then this work might make sense.

Also, it states in one of the Leslie manuals that the 470Ω resistor on the 0C3 socket should not be replaced with a resistor rated more than 0.5W so that it will act as a fuse and open up in the event of a 6550 screen short. Using a 5W resistor there suggests unfamiliarity with this detail. The 12AU7 really does not need to be shielded. And tube retainer springs/clips have a nasty tendency to buzz and rattle at certain frequencies. I use micanol sockets whenever possible, not ceramic, because they tend to keep a better grip on tube pins and don't cause as many broken locating keys.

And I should say that I write this as someone who has had to do some reengineering of budget guitar amps in order to lower noise problems. It does sometimes need to be done.