Hi Everyone,

I have a Crumar burn Leslie simulator I play with my B3, so that I dont have to use the 122. My apartment is small and the 122 draws complaints.

I built the circuit shown in the Crumar Burn Manual. It's just a 1k resistor, a 1 microfarad cap, and 1 100k pot all? in series to ground. the output is of the wiper of the 100k pot, so the level is adjustable.
I connected the "1k resisitor end of my circuit to one of the "G" terminals on my B3 (AO-28 pre amp).

When I try to adjust the pot in the circuit above the sound coming out of my Burn Leslie sim can't get loud enough without being distorted. I have the distortion effect turned off on the leslie sim.

ok here are my questions:

1.Is this circuit??I am using correct ?? I see other "line out" circuits at "


2. I think the two G terminals on the AO-28 are a differential pair. Why wouldn't we want a balanced signal? "differential pair" from both the G terminals?...? ?I am thinking of putting together a? circuit similar to what I have but with ganged pot so that I can control a balanced output taken off the two G terminals. I see the?the Art Tube MP. It is an inexpensive tube preamp that also works as a direct box.?I could put the Art Tube Pre MP between the Balanced line pad circuit and the Burn Leslie sim.

any ideas or comments would be appreciated.
John in Brooklyn

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The variable line out circuit is exactly what you would find on Hammond Wiki, it should be possible to control the output level to suit the input of almost any amplifier, mixer desk, or effects box.

I've just had a look at the Crumar manual online. If you've set the input level according to the instructions, so that the clip light isn't lighting, then the sound through the Crumar Burn shouldn't be distorted.? If you can't get loud enough without turning the input up to the point where the clip light comes on, you need to look further along the amplifier chain. What amplifier are you using? If the amplifier isn't capable of producing your required volume, no amount of fiddling with the input to the Burn will help. Try connecting your line out directly to the amplifier, and see what results you get then.

My guess is that either, you are overdriving the input of the amplifier used, quite likely if it's a guitar type amplifier. Or, the input of the amplifier being used isn't sensitive enough, and you're overdriving the Burn in an attempt to get enough drive. This may possibly be the case if you're using a line in input on a Hi-Fi type amplifier.

Hi Everyone,

I have a Crumar burn Leslie simulator I play with my B3, so that I dont have to use the 122. My apartment is small and the 122 draws complaints.

I built the circuit shown in the Crumar Burn Manual. It's just a 1k resistor, a 1 microfarad cap, and 1 100k pot all? in series to ground. the output is of the wiper of the 100k pot, so the level is adjustable.
I connected the "1k resisitor end of my circuit to one of the "G" terminals on my B3 (AO-28 pre amp).

When I try to adjust the pot in the circuit above the sound coming out of my Burn Leslie sim can't get loud enough without being distorted. I have the distortion effect turned off on the leslie sim.

ok here are my questions:

1.Is this circuit??I am using correct ?? I see other "line out" circuits at "


2. I think the two G terminals on the AO-28 are a differential pair. Why wouldn't we want a balanced signal? "differential pair" from both the G terminals?...? ?I am thinking of putting together a? circuit similar to what I have but with ganged pot so that I can control a balanced output taken off the two G terminals. I see the?the Art Tube MP. It is an inexpensive tube preamp that also works as a direct box.?I could put the Art Tube Pre MP between the Balanced line pad circuit and the Burn Leslie sim.

any ideas or comments would be appreciated.
John in Brooklyn

开云体育

Open or low value C26 would certainly reduce gain of the stage. I've seen treble boost circuits in guitar amps that work by disconnecting a large electrolytic cathode bypass capacitor leaving a much smaller capacitor to effectively bypass the cathode resistor only at higher frequencies. Thus reducing the gain at low frequency due to the resulting negative feedback at the cathode.

I would have expected a fault in the AO-28 to also cause distortion through the 122 playing the same chords at the same swell pedal opening. It might be interesting to turn the volume control on the 122 down so that you can play with the swell wide open without annoying the neighbours. If you get the same distortion through a "throttled back" Leslie, then the problem is very likely to be in the AO-28.

Hi Chris,

Thanks for replying to my request for help.

The distortion occurs long before the Burn clipping indicator comes on.

What I realize is the the lower range is where most of the distortion is.?

I think my problem is in the AO-28 preamp not the Burn Leslie Sim or the pad circuit.

I had been playing single notes to test ...The lower range is always distorted and at a very low volume compared to the higher octaves. When I play chords in the upper range the distortion shows there too, but much more volume.

I am trying figure out whats going on. I'll measure the AC voltage between G and G should be 3 to 4 volts.

I was reading on Bentons Site that if C26 in the AO-28 is open? it will cause an attenuated lower range.

John in Brooklyn