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Vintage threads from the first ten years

'True' Tube chorus anyone?

9/11/1998 12:40 PM
Craig	'True' Tube chorus anyone? I have recently been working on Hammond organs a bit, and there are some really cool design concepts at work in these things. One such feature is the chorus. In a nutshell, the input signal can be sent to one of two 1st preamp stages; one is 'clean', the other passes through the vibrato scanner before being reintroduced into the preamp. The chorus effect is acheived by sending the signal to both channels simultaneously. It's not really a true chorus - while the vibrato is true vibrato (pitch modulation vs. volume modulation), it is always modulating. So juxtaposed against a straight signal, it does achieve a fatter, 'chorus-like' sound, but a real chorus would maintain a parallel, static, differently-pitched signal, creating the illusion of two 'voices', slightly out of tune with each other. Does anyone know of a tube chorus design that could be considered 'true' as per my above description? Please don't hesitate if you have other ideas about what 'true' chorus is. I'd be interested in any thoughts on the subject. Thanks - Craig

9/11/1998 12:40 PM

Craig

'True' Tube chorus anyone?

I have recently been working on Hammond organs a bit, and there are some really cool design concepts at work in these things.

One such feature is the chorus. In a nutshell, the input signal can be sent to one of two 1st preamp stages; one is 'clean', the other passes through the vibrato scanner before being reintroduced into the preamp. The chorus effect is acheived by sending the signal to both channels simultaneously.

It's not really a true chorus - while the vibrato is true vibrato (pitch modulation vs. volume modulation), it is always modulating. So juxtaposed against a straight signal, it does achieve a fatter, 'chorus-like' sound, but a real chorus would maintain a parallel, static, differently-pitched signal, creating the illusion of two 'voices', slightly out of tune with each other.

Does anyone know of a tube chorus design that could be considered 'true' as per my above description?

Please don't hesitate if you have other ideas about what 'true' chorus is. I'd be interested in any thoughts on the subject.

Thanks - Craig