[sdiy] More Drum ?'s. Replacing 566

[Dave Magnuson]

No the 556 and 566 are pretty different.   The 556 is a dual 555 timer. 
The 566 is a single chip VCO with tri and square outputs.

Check out Rene's 566 VCO for an idea of how it's used: 
http://www.uni-bonn.de/~uzs159/vco566.html
This design is a bit better then Midwest's, but uses the same chip.

I goofed when typing my original reply... my apologies.  The midwest design 
uses the 566.

You *could* do a VCO (two, actually) with a 556... look at the Paia 
Fatman... but that's not the chip used in the Midwest drum kits.  For a 
single VCO, use the 7555... less power hungry than the 555.

Dave

----- Original Message ----- 
From: "Bill Berzinskas" <wberzinskas at nc.rr.com>
To: "Paul Perry" <pfperry at melbpc.org.au>; <synth-diy at dropmix.xs4all.nl>
Sent: Monday, February 21, 2005 9:30 PM
Subject: Re: [sdiy] More Drum ?'s. Replacing 566


> so is the 556 a acceptable sub?  i thought it was just a dual 555 ish 
> device?
>
> ----- Original Message ----- 
> From: "Paul Perry" <pfperry at melbpc.org.au>
> To: <synth-diy at dropmix.xs4all.nl>
> Sent: Monday, February 21, 2005 9:08 PM
> Subject: Re: [sdiy] More Drum ?'s. Replacing 566
>
>
>>
>> ----- Original Message -----
>> From: "Bill Berzinskas"
>>
>>> one thing i do have is some of the Microchip V-F converters..  although
>> they
>>> put out sq and ramp, if i could muster a triangle out of it, it should
>> work,
>>> ehh?
>>
>> To make a triangle from a ramp, just shift the ramp to be from -5 to +5 
>> say
>> & rectify.
>> As for the 556 and 566, one is easy to get & one is impossible.
>> Guess which one is in the Midwest designs?
>>
>> paul perry melbourne australia
>>
>>
>