Tone of an A20 cabinet vs. Leslie 122 when not spinning

[ChristopherDB113]

When I bought my RT3 about 25 year ago it came with an A20 tone cabinet. Two stationary full range speakers. Great tone quality for classical and church music, which is mostly what I've played when taking lessons.

My original background is in rock and when I occasionally bust out some old classics the chorus/vibrato settings almost get it done, however I often think about replacing the A20 with a Leslie of some kind. Most likely the 122 even though I know they are expensive.

I've never heard one in person, without the baffles spinning, and wanted to know if the tone quality was somehow radically different than what I am used to with the A20. I seem to remember hearing that the Hammond tone cabinets like the A20, the amplifier reduces the key click.

[David Anderson]

A Hammond A-20 Tone Cabinet from the 1930s? Wow. That's so old and rare that I don't think I've ever seen one in person. That said, I have heard some DR-20 cabinets, which are similar in overall configuration. It's kind of amazing that the A-20 is still working unless it was completely rebuilt at some point. And 2A3 triodes are pretty expensive these days.

The Hammond Organ's frequency range is from roughly 30Hz to 6,000Hz. Although you can get decent bass from a pair of 12" speakers working in tandem, depending on the enclosure, most 12" speakers roll off pretty sharply above 4kHz, and what you do get from them at those frequencies is very directional.

I think the 2 x 12" Hammond cabinets do have a cool sound all their own, but it's quite different from a Leslie with a horn driver and 15" woofer, especially with the sound radiating in all directions from the Leslie.

You can use both at the same time. That can be a very nice sound.

[joecool240]

The 122 will be much brighter than the A20. The 122 crosses over to the horn starting at 800 Hz. The 122 will also be much louder than the A20, and will have much better bass response being a closed back ported cabinet. I do believe the A20's amp and speakers frequency response will substantially reduce the audible key click.

WOW, it's a coincidence that I just read your post just now about the A20. I am restoring an A20 cabinet (s/n 1344) for my Model A (s/n 2409). Just an hour ago I came in from my garage (it's very hot and humid today in southern New Jersey) where I was stripping and sanding the cabinet of my A20 in preparation to refinish it to match the Model A. When I got the A20, the cabinet was completely brush painted yellow, including the front louvers. Fortunately, the cabinet's wood panels are intact and in good shape , including the doors, feet and hardware. So far, the wood is making a very nice comeback.

Joe

[ChristopherDB113]

Thanks for the response. I am a little surprised that someone would go through the effort to restore an A20. That said, the doors on my A20 are covered with a book matched veneer in a dark brown stain, making it a really nice piece of furniture. If your veneer is similar, it will be worth restoring.

[joecool240]

Christopher, my A20 has the same beautiful veneer on the doors. It even has the intact original wooded curved feet. I wanted to save it not so much for the sounds, but for the historical association to my Model A.

Joe

[Baldwin51]

I had a model A V 1936 and a a20 cabinet , also a 22-h Leslie, I added a cross over and a altec driver . to the a-20 and come up with a super sound, I also added the smooth drawbars, this thing had a wonderful sound high and blended well with the Leslie, also changed the model a keys as the original ones were pretty square, I made a major mistake when I sold that thing and wish I had it back, when you get one right I don't think any other model can top it. but of course it,s only a opinion. but the modification on the A-20 was a good one. cross over was at 800 cps like Leslie

[David Anderson]

12" speakers usually have pretty good output up to ~4kHz. I added a horn driver to an HR40 for someone, and I crossed it over where the twelves ran out of response. I let the twelves run full range and simply used a capacitor to block lower frequencies from the horn.