Hammond Vibrato Delay Line (questions for J Haible)

[stickjam]

Well, I've finally pulled the Hammond X-5 out of storage, purchased a scope and the organ "pimping" has begun. In addition to replacing the solid state amps with tubes, the next stage is an upgrade to the vibrato, adding scanner vibrato based on a design for which I am thankful to our own Jürgen Haible.

I'm trying to get a real Hammond vibrato delay line box to interface to the scanner, but I'm also considering contingency plans - especially if there's no room under the hood for the delay line.

Jürgen, I could probably extrapolate the schematic from Hammond documentation as you did, but do you have the schematic of the working version you created with the 25 33mH coils? (I may have asked you this offlist quite a while ago--if so, I apologize, as I can no longer locate your reply in my archives.)

Also, has Jürgen or anyone actually tried to realize his leapfrog filter idea in real life?

Thanks!

--Bob

 

[stickjam]

The more that I look at the leapfrog filter chain idea the more I'm tempted to prototype it.

Jürgen does mention that it works in simulation. I'd appreciate any of your wisdom on what I might face with constructing this in real life. Would this also incur the losses of the LC construct, or would each pair of active circuitry be more unity gain in nature?

Most of all, I'd like to get your input on what op-amp may be most suitable for circuits of this type. I'm looking for a device that is both economical (50 op-amps are needed to model a Hammond delay line) as well as ultra-low noise to minimize signal degradation down the chain (again, there are 50 op-amps!)

Thanks!

--Bob

 

[jhaible]

Hi,

I just found this thread.

I've started a thread about my Scanner Vibrato project over here:
http://electro-music.com/forum/viewtopic.php?highlight=scanner&t=19217

Best Regards,

JH.