Formant synth

Verheyden Tom h5020503 at rsbib.khk.be
Wed Jan 22 18:51:03 CET 1997


Hi there,

If you want to replace the µA726 in the FORMANT VCO-circuit, just take a
dual-transistor with almost the same specifications (this is important for
the 1volt/oct conversion). Make sure that the dual-transistor has an iron
package. 
Place around the transistor a cooling plate (this can be in a star-form,
wich fits perfectly around the transistor.)
I use this system for about two years and i've never realy had any problems .
It even works for more than one VCO (in this case three).
I rather prefer to keep heat-sources (Like POWER SUPPLIES) out, the formant
has the best results with an external power supply and a metal (HF-proof)
casing.
I 'll look after the replacing transistor (that I've used) for the µA726 and
send the number to the mailing list.
For the BC107C and BC109C can be replaced by BC107B and BC109C, the
difference is that the C-types have a higher HFE-level. In the FORMANT-case
is this not really a problem. 
The BF245 still excists !!!!!!! Otherwise try a B-type (I think I've used them)

Any other questions about the formant synth are always wellcome

TOM




More information about the Synth-diy mailing list