tube synths

[Eric Barbour]

On Thu, 25 Jun 1998, Ken Stone wrote:
> Tube modules that were compatible with existing synths would raise
> interest level
Henri said:
>> I totally agree. I would love to hear the sound of a tube filter in my
>> modular, but I'm too afraid to build such a thing. The thought of this
>> filter zaping my whole modular to the silicon heaven gives my the creeps.
>> So if anyone has a suitable isolating circuit preferably without the
>> typical optoisolating mess, a word about it would be much appreciated.

All you need to do is use a voltage divider from the tube output
to the solid-state input with two back-to-back 15-volt zener
diodes. THUS:


                                                        (100k resistor)                      (22k resistor)
>From tube audio output >-----------/\/\/\/\/\/\/\/\/\/---------|-----------\/\/\/\/\/\/\/\/\/--------gnd
                                                                                   |
                                                                                   |------------|<------>|------------gnd
                                                                                   |     (back-to-back 15v zeners)
                                                                                   |
                                                                                   |------->to solid-state module input

See how easy that is?? Yes, i've used this and it works excellently.

What is with you guys????
Excuses, excuses!............