[sdiy] Re: did someone say "tube"?

[jhaible]

If LDRs are allowed for frequency control, it cannot be that difficult.
I would think two ECC83's would do the job to buffer the RC's
and provide  a loop gain of 4.

If you want to use tubes for frequency control, however, I wouldn't know
how to do it for 10+ octaves.

JH.



-----Ursprüngliche Nachricht-----
Von: René Schmitz <uzs159 at uni-bonn.de>
An: <metasonix at earthlink.net>
Cc: <synth-diy at dropmix.xs4all.nl>
Gesendet: Samstag, 7. Juni 2003 13:38
Betreff: Re: [sdiy] Re: did someone say "tube"?


Hi Eric and List,

metasonix at earthlink.net wrote:
> Golly. You guys keep ending up talking about tubes. How strange.
> I thought we all agreed that tubes were useless crap and that
> I was a low scum.   ;)

Did we?

> Hey Tom. Here's a challenge for you. Make a workable 4-pole
> lowpass filter capable of resonance...entirely out of pentodes.
> A really, really smart designer could do it with 6 to 8 tubes.

Without xformers, resistors and caps it would be a bit tough I guess... :-P

I don't think its a problem to use triodes in there as well. They don't
need to be genuine triodes, triode connected pentodes work equally good.

> Any other takers?

Well, my tube filter design is capable of self oscillations, albeit only
2-pole.

Cheers,
  René


--
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159