Unplug the speaker wire from the 122 amp and connect that to the guitar amp. Leave the tubes in the 122 amp because certain voltages in there are used for the speed switching function. Turn the input volume of the 122 amp all the way down. Lastly, you should plug in a speaker load resistor in the output of the 122 amp. The crossover is 16 ohms. A 16 ohm resistor (or something close) should work as the load.
The load resistor may not be necessary if the input volume control is indeed working correctly and you're able to turn the level down to zero. However, many of these pots are old and sometimes flaky. The load resistor is a layer of protection to keep the output transformer safe.
Unplug the speaker wire from the 122 amp and connect that to the guitar amp. Leave the tubes in the 122 amp because certain voltages in there are used for the speed switching function. Turn the input volume of the 122 amp all the way down. Lastly, you should plug in a speaker load resistor in the output of the 122 amp. The crossover is 16 ohms. A 16 ohm resistor (or something close) should work as the load.
The load resistor may not be necessary if the input volume control is indeed working correctly and you're able to turn the level down to zero. However, many of these pots are old and sometimes flaky. The load resistor is a layer of protection to keep the output transformer safe.
Geo
Thanks.
I'm a little confused regarding the 122's volume knob - I was of the understanding that this is merely an input attenuators, as it is on most power amps, and not an actual load across the amp's output.
How many watts does the 16 ohm load resistor need to be?
Current:
1971 T-202 with Carsten Meyer mods: Remove key click filters, single-trigger percussion, UM 16' drawbar volume correction. Lower Manual bass foldback.
Korg CX3 (original 1980's analogue model).
1967 Leslie 122 with custom inbuilt preamp on back panel for 1/4" line-level inputs, bass & treble controls. Horn diffusers intact.
2009 Marshall 2061x HW Plexi head into Marshall 4x12 cabinet.
Thanks.
I'm a little confused regarding the 122's volume knob - I was of the understanding that this is merely an input attenuators, as it is on most power amps, and not an actual load across the amp's output.
How many watts does the 16 ohm load resistor need to be?
Well, these are 40 watt amps so at full power, 40 watts would be at the limit. However, by turning the input volume down, little to no signal would be appearing at the amps output so the resistor is more for safety to protect the output transformer. I'd use a common 20 watt under this circumstance.
Could you use a motor switching unit available on eBay to control motors without needing to involve the 122 amp just to get motor control, if you're going line-out?
Could you use a motor switching unit available on eBay to control motors without needing to involve the 122 amp just to get motor control, if you're going line-out?
That's a neat solution, but I'm in the land of 240v.....
I would also need a 110v stepdown transformer.
At which point this becomes “too hard basket”
Current:
1971 T-202 with Carsten Meyer mods: Remove key click filters, single-trigger percussion, UM 16' drawbar volume correction. Lower Manual bass foldback.
Korg CX3 (original 1980's analogue model).
1967 Leslie 122 with custom inbuilt preamp on back panel for 1/4" line-level inputs, bass & treble controls. Horn diffusers intact.
2009 Marshall 2061x HW Plexi head into Marshall 4x12 cabinet.
Kon has one of these. Wonder if he's using a step down trans for his? :-B
Hi Goff.
I do not have a Dr Fishticks unit in my own Leslie, but around ten or so years ago l hooked up a Dr Fistick's unit in someone else's Leslie 122.
The owner of the Leslie 122 was not sure how to set it up so he called me to do it for him.
l do seem to recall a 240 volts to 117 volts stepdown transforner for the motors, but l do not remember if the transformer was part of the Dr Fishticks kit or whether the owner of the Leslie 122 had to buy the stepdown transformer from elsewhere.
All the best.
Kon.
Hi Goff.
I do not have a Dr Fishticks unit in my own Leslie, but around ten or so years ago l hooked up a Dr Fistick's unit in someone else's Leslie 122.
The owner of the Leslie 122 was not sure how to set it up so he called me to do it for him.
l do seem to recall a 240 volts to 117 volts stepdown transforner for the motors, but l do not remember if the transformer was part of the Dr Fishticks kit or whether the owner of the Leslie 122 had to buy the stepdown transformer from elsewhere.
All the best.
Kon.
Hi Kon, good to hear from you again.
Yes the trials and tribulations of living in 240/50Hz land.
I bought a Dr. Fishsticks for my Vibratone DIY.
It's 110v as I think Marc McElroy, the Dr. Fishsticks guy just makes them 110.
I could be wrong.
I ended up buying a complete rotor/motor assembly off of ebay for $50 someone pulled out of an organ.:emotion-49:
Could you use a motor switching unit available on eBay to control motors without needing to involve the 122 amp just to get motor control, if you're going line-out?
I looked further into this Dr Fishsticks motor controller - it gets its 110V power from the 122's fast motor outlet, so it will indeed work with a 240V Leslie as long as the power transformer provides a 110V tap for the motors, which mine does.
I guess the Dr Fishsticks controller is aimed at people who want silent switching, or if they have a failed relay
Current:
1971 T-202 with Carsten Meyer mods: Remove key click filters, single-trigger percussion, UM 16' drawbar volume correction. Lower Manual bass foldback.
Korg CX3 (original 1980's analogue model).
1967 Leslie 122 with custom inbuilt preamp on back panel for 1/4" line-level inputs, bass & treble controls. Horn diffusers intact.
2009 Marshall 2061x HW Plexi head into Marshall 4x12 cabinet.
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