8010 Leslie kit for A100

[eenaoo]

I've started to assemble my A100 and I got a surprise today when I checked the Leslie connector kit to my 122 Leslie. I noticed that the audio signal was taken from the AO-39 speaker out terminals. Also the kit breaks the speaker signal between the PA (AO-39) and the speaker, leaving the amplifier with an open load, when only the leslie has been selected. I found that strange since I thought it is a bad practice to not connect a tube amp to a load. Also with this arrangement the AO-39 will always amplify the signal since the input is not broken.

So I had a look at the various lesile kits, and it seems my A100 has the 8010 kit, see picture. However as I understant this is the wrong kit for the A100. The correct kit is the 8101 kit. Do anyone else use the 8010 kit for a A100?

I had a look at the circuit diagrams for those two kits. My understanding is that both kits uses the same 1:1 transformer. Hence with a few resistors and an additional connector I should easy to convert the 8010 to the 8101 kit. Any comments?

Arne

[tpappano]

I can't speak to the connector kits, but Hammond seemed to have no qualms about leaving certain amps unloaded. If you look at your A100 reverb amp, your notice when the reverb is turned all the way down the amp remains fully driven and unloaded. Same thing with the reverb amps in M100s, and maybe others.

[eenaoo]

Yes. I did find the reverb amp connection also odd. I would have connected a high ohm potentiometer in parallell with the power amp speakers and tap the signal to the reverb amp from the viper there. Has anyone tried that? Maybe it needs the current arrangement to drive the reverb tank

Arne

[David Anderson]

It is best to have am appropriate load on the output transformer of any tube amp. Marshall heads and Fender Bassmans end up with arced tube sockets and shorted output transformers all the time. I've had to replace a Leslie 147 amp output transformer when it was run without the speakers plugged in.

This is why I never buy Leslie kits. I just build what's needed based on the original designs.

There is still some load on the A100's reverb amp even when the volume is turned down.

[eenaoo]

I can agree with that David. Where do you buy these 1:1 transformers that are used in those kit? All do you skip those. I think it should be sufficient to use the AO-28 output transformer for this purpose.

Arne

[David Anderson]

Tonewheel General sells the 1:1 isolation transformer, but you're in Norway, so there will probably be the usual issue of the cost of shipping. I'm in the U.S., so shipping is not a problem.

[eenaoo]

Thank you. I'll add that to my shoppling list for next time I'm off to US. Do you stick to the original connection kits with regard to the switches, or do you add relays, where the switch(es) just control the relay on/off?