Conn 651 to a Leslie 720?

[Hamman]

I have a great opportunity to score 2 cherry condition, inside and out, Leslie 720's! I have been hesitant to put a Leslie with a upper treble horn on my Conn 651 since I did not want a shrilling sound. But since I'm going to be incorporating a pro audio DSP (Digital Signal Processor) in the audio system of my 651 anyway I think that I could set it up to roll off the upper highes as well. My biggest question is; I would like to use the 2 stationary speakers (in the upper 45 degree corners) for just the reverb channel. I know there isn't, per say, a seperate reverb channel but couldn't I just "intercept" it at the spring box? My other question is, are there 2 differnt reverbs on this organ? 1 for the Tibia and 1 for the strings? It seems that by just using the preset piston button labeled reverb that it only adds reverb to the tibia channel whereas the cheek block reverb rocker switches seems to only add reverb to the string/reeds so are they both going through the same reverb system?...anyone know?

[Jan Girardot]

As I recall, the 651 had a "leftover" Reverb which was simply a short Tibia Sustain AND a spring-type "reverb" delay line which was applied to both Tibia and Pulse (everything except Tibias) channels. I would run your Pulse channels through both 6x9s in both cabinets.

. . . Jan
the OrganGrinder

[andyg]

The 651's spring reverb is for complex voices only, it doesn't affect the tibias.

IIRC, isn't the 651 three channel? 1) Main, 2) Tibia (leslie) and 3) percussion/solo manual reeds. Or maybe those percs and reeds are sent to the same amp as the main? Either way, two 720's would do! Don't worry too much about sending the tibias to the horns. It makes them sparkle nicely. Here's a 580 with two leslies, a 700 and a 251, plus pipes. http://www.box.com/shared/2p66t0e9z3

You would need to use those smaller stationary speakers for the complex voices themselves, not just the reverb, I don't think you'd get enough highs out of the woofers in the 720's.

For better reverb, you might like to consider this: Send the tibia and main signals from the organ to something like an Alesis Microverb and then mix its wet output only (perhaps with a HPF to prevent reverby bass) back into the signal that's sent to the leslie (or amplify it separately).

[StageaXSam]

Hi Andy
The 651 had 3 channels from generators through pre-amps, but was combined into two amp/speaker systems.

However, at one time I had a set up where I took the piano preamp output and added another pot on the swell pedal, then took it through a custom set I had using Ampex theater speakers combined with Conn replacement speakers. It worked well. The amps and leslie relay were concealed in a closet, while the speakers were mounted on 3/4 inch mdf panels that were finished to look like a folding decorator screen. I used a lightweight curtain fabric that matched the drapes in a large dining room. It sounded great.

If I were to do a 651 that way today, I would add another preamp and combine the square-wave voices through a separate channel. That would give a better sound-spread.

Regards

Sam

[Hamman]

Thanks guys!
The string/reed section will be ran through all my pipe ranks.I should have said this in my orginal posting. I may even run them through my 540's since they are meant to be mounted atop of the 720's of which I do indeed pick-up tomorrow! Yes! Since I wil be using a DSP (4 in 8 out all assignable) I can manipulate the gain going to the 540's so as to just be present and not over power the pipes. As far as the reverb, thanks for the suggestions! This is the one organ project that I have few dollars involved compared to all my other organ/leslie endeavers! Since its Conn 650, 651 and leslie 720/540 instead of Hammond B3 and Leslie 122 this stuff is easy obtainable! So unfortunate that most of it I acquire is on its way to the dump if I don't intervene! I told my wife that I'm a organ "resque" 501 c-3 non profit org. now! LOL Happy Thanksgiving to everyone!!

[andyg]

Thanks for the info, Sam. I think I was probably thinking of the 652 when I spoke of the 3rd manual's reeds and the percussions.

Adding digital reverb to a Conn is something I've personally only done to old recordings, and it certainly gave things a boost. I'd imagine that adding it to the real thing would be even better.

[Hamman]

Good day everyone!
Well I picked up those 2 Leslie 720's on Friday and man are they in great shape! Pulled the backs off and the motors, mounts, belts etc., look brand new! The insides of the cabinets also look new. Wood condition is perfect...as if these were stored for the last 30 years! These Leslies were in a church most of their lives that has now been converted to a Christian filming studio/media center. I'm in the midst of putting together a homemade hook up kit to mate to the 651 that will allow me to use the 651's leslie speed tab(s).

Sam, could you elaborate on your theory of adding another preamp to combine the square wave to act as 3rd channel

[Hamman]

Here are some pics of my new acquisition:

[Hamman]

I finally hooked both 720's to the 651 and they do sound sweet! I have yet to rectify the Leslie tremolo switching, though I prefer the chorale for now. I think I'm going to use a SS relay and have it triggered by the 651's internal fast motor voltage. Jury still out on that since I'm still trying to figure a way to incorporate the 651's Leslie Tabs and be able to have all three positions; off, slow, and fast. If not I'm happy with slow-fast. The 720's internal stationary 8" speakers were too harsh in the mid to low frequency range. So I placed my set of 145 pipes up on top of each Leslie and wired them directly to the Leslies stationary amp, by passing the internal 8" speakers. Made a world of difference and now the strings sound great! The stationary channel of these Leslies have a TRC control to roll off the treble response....3 position. I rewired that to be in the upper rotor now to take some of the shrill of the tibia sound out. It works well. Thanks to all that help me get this configuration figured out!! I'm well pleased with the sound and even have decided against going the way of the more complicated DSP set up. I still may insert an E.Q. on the string/reed channel to lightly shape some tonal anomalies.