Hammond BC Project

[Drawbar Dave]

Hi folks
I picked up a BC here in the UK for a very reasonable price and am looking forward to bringing it up to snuff. Firstly these are rare in the UK so for anyone in the US thinking don’t waste your time, I’m not!

Both generators work, every tone is present on every key and every drawbar works. The chorus generator works when the drawbar is pulled out.

Now the snag; the organ is fitted with an AO-29/M series matching transformer. I’d like to return the MT to a stock one and fit a Trek SSP1 preamp. The problem is that the original swell mechanism has been removed to allow the AO-29 to connect to the swell linkage. Does anyone have an BC swell box and matching transformer they would be interested in selling.

Also despite numerous searches I cannot find info or picture of the tremulant System. Is it part of that missing box and can anyone explain the tremulant system?

Thanks
Dave

[skydawg]

The tremulants are located behind the run motors and are driven by them.They`re a set of moving contacts that cause a fluctuation in volume.Yoy should have one on both generators.They`re in perforated steel housings.

[Drawbar Dave]

Ok, sounds cool. I’ll have a look!

[joecool240]

Have a look here too. . .

https://www.youtube.com/watch?v=ch0IE79MqpM

[Drawbar Dave]

I looked and both are gone. The run motor on the main TG has had a scanner fitted but it is not connected to anything. I would like to replace the tremulant but imagine that wiring them up would be a nightmare. I’d also like to reinstate the swell housing and fit a Trek SSP1. I’ll do a wanted ad but if anyone knows of tremulant mechanisms, BC swell mechanism or BC matching transformer for sale I’m all ears.

[enor]

Is this going to be a "collectors item" or a "player's instrument"?

If the latter, I have to point out that you're about 90% of the way towards "B-3 functionality". I don't see why you would want to convert it back to inferior standards?

- - - Updated - - -

Oh, and is your BC a 230V/50Hz one?

[Drawbar Dave]

Is this going to be a "collectors item" or a "player's instrument"?

If the latter, I have to point out that you're about 90% of the way towards "B-3 functionality". I don't see why you would want to convert it back to inferior standards?

Definately a players instrument, but I have a respect for the instrument as it was intended. I’ve had a C3 in the past and don’t want to make the BC into a fake B3 just to replace it. I’d just like to make the best of what is there. The AO29 only serves as an amplifier for the straight channel, there is no vibrato working and there is no percussion. The scanner is disconnected too.

I wondered whether most people had upgraded their BCs and there might be a surplus of original parts!

What have you done with your BC? I guess they are just as rare in your part of the world.

Yes mine is 230/50hz

[lcid]

No spare parts...

I have a BC, but unfortunately no spare parts of any kind. As a matter of fact, to my regret, I replaced the preamp years ago with a solid state. In hind sight (20/20) I wish I had kept the original amp and simply had it repaired, but needed to get the BC working for a performance. IMO you are doing the right thing trying to find original replacements and make the baby sing again!

[enor]

The AO29 only serves as an amplifier for the straight channel, there is no vibrato working and there is no percussion. The scanner is disconnected too.

Yes, but all that means is that you lack wiring (and a vibrato delay line).

Anyway - I have a 230/50 run motor/tremulant assembly (yes, you need both, the tremulant doesn't fit on a motor made for a scanner); the matching transformer, and the rheostat box, but am somewhat reluctant to sell - will consider parts trade though. PM me if you want to talk about this.

[skydawg]

If the organ was retro-fitted with the scanner vibrato,the tremulant would have been removed.The vibrato switch would be where the old tremulant switch was.You might find a paper sticker stating the organ was converted to a BCV,if the work was done by a Hammond field rep.And I feel the same about preserving the originality of the old timers.They`re historic,and don`t need to be anything more than what they were built to be.

[Drawbar Dave]

Yes, but all that means is that you lack wiring (and a vibrato delay line).

Anyway - I have a 230/50 run motor/tremulant assembly (yes, you need both, the tremulant doesn't fit on a motor made for a scanner); the matching transformer, and the rheostat box, but am somewhat reluctant to sell - will consider parts trade though. PM me if you want to talk about this.

PM sent. Many thanks.

[lcid]

Wanted: BC preamp

Dave,

Should you run across a preamp for a BC in all your searches, or if anyone on this forum has one, please let me know. Depending on the price, I may just want to restore one back into my BC and out the solid-state one. You got me interested and thinking again; a good thing. Thank you.

[JoeyB3]

I don't see why you would want to convert it back to inferior standards?

I don't find this comment to be anything more than non-fact, opinion.

Hammond made numerous changes to the design of their "vintage" tonewheel organs between 1935 and 1975....many were of them were just based on the need to go cheaper.
The Scanner Vibrato system was a cheaper alternative to the Chorus Generator. While it added Vibrato when there was none before, Tremulant is a legitimate part of a true pipe organ where Vibrato is not. Had Hammond embraced the Leslie in the 40s, it is quite possible that the Vibrato may have never come to pass.

Personally, I find the Chorus Genny sound superior to the one found in the scanner, in spite of there only being 1 sound selection. And since my main playing is Prog Rock, I rarely (if ever) use Vibrato and rely on simple Chorale and Tremolo from the Leslie.

Organists used the Vibrato and Chorus from the post war Hammonds simply because that was what was available. I don't think it had anything to do with a particular standard.

[enor]

I don't find this comment to be anything more than non-fact, opinion.

Hammond made numerous changes to the design of their "vintage" tonewheel organs between 1935 and 1975....many were of them were just based on the need to go cheaper.
The Scanner Vibrato system was a cheaper alternative to the Chorus Generator. While it added Vibrato when there was none before, Tremulant is a legitimate part of a true pipe organ where Vibrato is not. Had Hammond embraced the Leslie in the 40s, it is quite possible that the Vibrato may have never come to pass.

Personally, I find the Chorus Genny sound superior to the one found in the scanner, in spite of there only being 1 sound selection. And since my main playing is Prog Rock, I rarely (if ever) use Vibrato and rely on simple Chorale and Tremolo from the Leslie.

Organists used the Vibrato and Chorus from the post war Hammonds simply because that was what was available. I don't think it had anything to do with a particular standard.

Of course it's opinion. That's why I said "I don't see why...".

By "inferior standards" I mean "less functionality". A BC with an AO-29 and scanner vibrato still has ALL of the goodness of a stock BC, but lots more functionality as well when the desire strikes to use it. If I got an organ where someone had already started installing that stuff, I would certainly finish that work rather than scouting for older, simpler parts.

That said - I love old consoles. I have two pre-war consoles myself, and an A-100.

One of the prewar guys - an AV - is under restoration and is going to remain stock apart from an added-on percussion unit.

The other one - a BC - has massive modifications in order to be my "gig" console. It has "-2 series" scanner vibrato, and the rest of the signal path from the "-3 series" including the preamplifier, but retains the stock main generator, manuals and pedals. It sounds fantastic, still has the rawness of the old consoles but does more modern sounds as well. I absolutely love it!

[Papus]

Dumb question: does Hammond Suzuki offer any digital emulation of the old chorus generator?
Surely with the plummeting cost of DSP (Moore’s Law) it should be possible to include the additional chorus generator tonewheels in the DSP generator?