asm1- dirfts on mods.

[Debby and Gene Stopp]

Here's some ideas....

Usually when the LFO affects the VCO's, or when the frequency pots cause a
pitch droop when they're turned all the way up, means that the impedance of
the power supply rails is non-zero. Either the power supply is not capable
of providing zero ohms to the rails (another way of saying that the current
rating is not high enough), or there's some impedance in the wiring to the
circuit board. Most often this means that the wires from the power supply to
the circuit board are too thin. Try using thicker wire for power
distribution (like 22 gauge or larger).

I have several running ASM-1's in different environments and none of them
have any LFO or frequency pot problems, so I know that these problems can be
solved... keep experimenting!

- Gene


----- Original Message -----
From: "e" <edgarfov at zahav.net.il>
To: <synth-diy at node12b53.a2000.nl>
Sent: Tuesday, September 12, 2000 5:39 PM
Subject: asm1- dirfts on mods.


> Hi all
>
> i have posted the lfo bad influ on the asm.
> tnx for all the advices.
> as i investigated the drift facts ,and implanted my own build
> regulator i (7815/7915) i have notice this new disturbinese in the force
>
> every pot. that has + to - 15 range and works as the modulator
> such as the FC (filter section) pot , or pwm pot.
> when the turn reaches the limit suddenly a small shift in the osc, is
heared.
> i scoped it , the change is measured like 30 to 40 mv shift.
>
> another fact is when i use my lab regulator , this anomaly
> almost dissapear , at least from the hearing range.
>
> tnx
>
> Aln
>
>
>
>