Dynacomp Improvements Any Suggestions?

I'm having a go at a Dynacomp type compressor, does anyone in the U.K. know where i might buy a CA3080 chip? It seems no one stocks them, or never return my mails. Seems to be getting a nightmare to try and get components in the u.k.
Vikki(uk)

http://www.cricklewoodelectronics.com

Put ca3080 into the search bar


Justin

Or .... you can get them from Banzai or smallbearelec.com

MM.

Great....one company i missed!
Just a question about the non electro caps in this circuit, what dialectric types would you use?
http://www.tonepad.com/getFile.asp?id=9
Vikki(uk)

Vikki said:

Great....one company i missed!
Just a question about the non electro caps in this circuit, what dialectric types would you use?
http://www.tonepad.com/getFile.asp?id=9
Vikki(uk)

Click to expand...

Have built three of these, used Panasonic ECB type from small bear ( Brown/Red colour ) and also AVX box and MKT box
poly's
Smaller Pf values I used ordinary ceramic caps.
I think the circuit calls for a couple of Tantalum caps too IIRC the 1uf's - Farnell standard 16v versions.

marty.

Maybe a bit late, but I would like to recommend
http://www.modecomponents.co.uk/
for CA3080s and other parts if you are in the UK.
He is especially good for hard-to-get germanium diodes etc.

Unfortunately, there are no pictures on the website which makes me a bit wary about capacitors, but he is very good value for money, and will actually send you ONE single resistor, if needed.

If something is not on the website it is always worth calling or emailing him.

Also, I recommend doing the Ross-Compressor over the dynacomp and while you're at it you might as well go for the 5 knob compressor from BYOC. http://www.buildyourownclone.com/ (Leave the IMO useless blend circuit out tho).

Great PCBs for this:
http://vibe-o-tronic.co.uk/

good luck!

Great info, thanks all.
I did take a look at the BYOC unit but the pcb never seems to be in stock, i'll take at stab at the byoc unit when it becomes available. Mode components does ring a bell i must have purchased there in the past, i think Mushroom components was another handy supplier, seem to have lost track since using another computer, all my favourites were lost.
I may put the 4 pole switch in the unit i'm building to make it switch between Dyna/Ross.
Does the blend feature not have much use in the BYOC model?
Thanks again
Vikki(uk)

The CA3080 ceased production about 4 years ago - that's why it's hard to find. It was a 40 cent part,
now it's several dollars when you can find one. If you do find it, get at least 2, as they tend to fail for no apparent reason, and the last bunch I got had several brand new dead ones in it. I would use an
NJM13600 or NJM13700 (same pinout, minor difference in output buffer). You get 2 in a 16 pin dip,
and if you don't use the linearizing diodes (pin 2 and pin 15) or the output buffer (take output from pins
5 and 12) you have 2 3080 workalikes that were actually designed for audio, unlike the original, which
wasn't. Much cleaner and more reliable, and much easier to find. Mouser has them, and also I think Digikey.
It was original made by National (LM13600), but I think they may have stopped, so the NJM part is easier
to find and works very well. The Dynacomp is a great guitar smoother - the Nashville guys like it alot.

Many thanks, very helpfull, i'll get the basic thing working and try timcas suggestions, may need a bit of help there though!
Vikki(uk)

Dynacomp is up and running not in a box yet so thought it would be a good time to have a bit of a play.....Seems to work quite well and gives a bit of squish, is there any point trying to go further with this circuit or are we mainly limited for noise and distortion by the chip?
Here's a bit of a clip i recorded to try this out, results seem pretty much ok.
tonepad dynacomp test.wav
I notice there's been a few mods to improve the basic dynacomp, here's one that I haven't tried, does this look as if it could improve this little unit ........taken from the diy stompbox website.
The addition of an extra transistor (Q6), and a few minor component changes, and the results are quite amazing. We win an attack control which gives the option of some interesting effects. The frequency response is improved - it's flatter, without the treble reduction that's normally associated with these pedals, just by the addition of the capacitor bypassing the resistor in series with the top of the output level control. There's much less distortion - with the older method of taking the output signal from the emitter of the phase splitter transistor, there was some clipping introduced by the diode in the rectifier circuit. The extra transistor (which doesn't cost much to add) makes a massive difference!



Vikki