Leslie relay switching

[ubxf]

Hello,
i was wondering if it was possible to bypass the relay for switching the motor on a 31H Leslie. Plug the 2 motors in an auxilary
outlet and turn them on and off directly with a switch. This way the audio on pins 1 and 6 of the Leslie cable wouldn't have to carry the dc for relay switching.This seems too simple and there is probably a good reason why it is not done this way.

 

[Rochey]

I dOnt know leslie cabling, but couldn't you use dc blocking caps after your relay or something?

I'm thinking of the tricks they use with phantom power for microphones.

Only potential issue are the thumps and pops.

 

[ubxf]

yes there are already dc blocking caps in the Leslie amp. I was just trying to avoid using a connecting kit and send the audio
through the Leslie cable and send ac directly to the cabinet and power the motors without going through the relay.

 

[Michael Tibes]

I don't know the 31H, but I've successfully modded my 251 with solid state relays in order to make it switchable with a low voltage derived from the tube heater supply, so that I can safely plug in any footswitch. The relays are zero-crossing switches, so that there is no audible clicking any more, a nice side effect.

Actually, the Leslies I know all have 4 motors, you mention only 2? Afaik you have to switch between 2 sets of 2 motors, which makes the 'normal household switch solution' more complicated (that's what you have in mind if I got you right?). With one switch you'd only have one speed or stop...

Michael

 

[geoff004]

Plug the 2 motors in an auxilary outlet and turn them on and off directly with a switch. This way the audio on pins 1 and 6 of the Leslie cable wouldn't have to carry the dc for relay switching.This seems too simple and there is probably a good reason why it is not done this way.

From what I've heard Joey D actually uses this trick when something goes wrong with the leslie switch (I've seen them go bad on gigs - especially one that's a foot switch).  Usually he just plugs the slow motors in to an extension cord.  Then he'll put the fast motors on a power strip.  Just turning the strip on and off will change the leslie speed. 

It's AC that the cable carries - so the relay is AC also.  If your relay is worn it will make a loud click when you switch speeds.  This is why so many people go with solid state relays.

I'm not sure how your leslie is configured for speakers - if it's only got 1 rotating speaker it will only have 2 motors.  I think the reason it's not  done this way is simply the convenience of having 1 wire going to the leslie.

 

[ubxf]

Thanks guys, the 31H is a one speed Leslie. The relay is dc but i was thinking of not using it.
so it looks like i might be able to try this without damaging things . Eventually i'll get the proper connection kit but
for now i'd love to hear the M3 through the Leslie