Demeter - Compulator

roseblood11 · Post by **roseblood11** » 28 Sep 2009, 14:30

So, what might have been changed in the circuit in the pro version?

Is it just replacing two resistors with the "attack" and "release" pots?

Immo

roseblood11 · Post by **roseblood11** » 06 Oct 2009, 21:26

roseblood11 wrote:So, what might have been changed in the circuit in the pro version?

Is it just replacing two resistors with the "attack" and "release" pots?

Immo

***BUMP***
No ideas?

mistral · Post by **mistral** » 25 Oct 2009, 10:40

HI

i've finished my compulator and i have a question:

i believe that the compress pot don´t do anything. I´ve built with a vtl5c1, not vtl5c10. is this the problem?.

Regards and sorry for my poor english

roseblood11 · Post by **roseblood11** » 27 Oct 2009, 23:19

mistral wrote: I´ve built with a vtl5c1, not vtl5c10. is this the problem?.

Yes, I think...

----------------

no new infos about the "pro" version? I´d really like to add attack and release pots...

lynessmy · Post by **lynessmy** » 28 Oct 2009, 09:14

i can confirm...it doesn't work with LED+LDR in a tube.

roseblood11 · Post by **roseblood11** » 28 Oct 2009, 09:34

Some people built it with a selfmade vactrol, but the values have to be close to the vtl5c10.

mistral · Post by **mistral** » 29 Oct 2009, 07:13

Thanks

i will buy vtl5c10

newly · Post by **newly** » 31 Oct 2009, 10:08

HI....this is my first post...amazed by the resources available here.
I had build COMPULATOR with BAJA layout but was stuck with problem now.
I'm using A25K, LF353N from ST and VTL5C10.
The output i get is very dim, less than unity even with the volume pot maxed.

Here are some voltage i tab.

IC1 (the one nearer to the trim pot).
1. 4.15
2. 4.15
3. 2.07 (any fishy here)?
4. 0
5. 4.14
6. 4.15
7. 4.15
8. 8.30

IC2 (Below Volume Pot)
1. 4.15
2. 4.15
3. 4.05
4. 0
5. 4.14
6. 4.15
7. 6.98 (Anything fishy here)
8. 8.30

VACTROL
LED+ 6v
LED- 4.15
LDR (opposite LED+) -5.15
LDR 4.15

Thanks ahead for any help.

newly · Post by **newly** » 01 Nov 2009, 01:05

bump for help.....pls.

Jarno · Post by **Jarno** » 01 Nov 2009, 08:38

What happens if you connect a LED in place of the Vactrol led? Is it lit continuously?

newly · Post by **newly** » 01 Nov 2009, 12:47

not yet tried. I will test that later and report back.

newly · Post by **newly** » 01 Nov 2009, 13:52

Jarno wrote:What happens if you connect a LED in place of the Vactrol led? Is it lit continuously?

Yes...it is always on. Any recommendation ?

roseblood11 · Post by **roseblood11** » 18 Nov 2009, 22:52

How is the orientation of the two diodes in series in your built? Picture?
The schematic is correct, the layout is still wrong!

newly · Post by **newly** » 19 Nov 2009, 01:11

roseblood11 wrote:How is the orientation of the two diodes in series in your built? Picture?
The schematic is correct, the layout is still wrong!

Yes...i found the same thing after comparing it to the schematic.
It is corrected and it is work now.
A25K didn't work that good for Volume, i changed it to B25K and it work like charm now.

roseblood11 · Post by **roseblood11** » 02 Dec 2009, 20:03

I used two 20k-W-taper pots (made for tone controls...) with good results.

Great sounding little machine!
Picture: http://farm3.static.flickr.com/2597/415 ... e073_o.jpg

gigelmargel · Post by **gigelmargel** » 02 Dec 2009, 21:23

How it's possible to add an attack pot to the Compulator?

Okonomiyake · Post by **Okonomiyake** » 05 Dec 2009, 17:25

stratogavster wrote:is that vero-board version verified?

I built the PCB version and it's ultra clean!!! no distortion or anything like it...best comp i've ever used, always on now!!

I use single coils though, Custom Shop 69's, and EMG DG20 Actives

When I first built mine it didn't work properly, all I did was remove the sockets I provided for the opto-coupler, solder it in directly then it worked properly

The vero layout is mine, and it's not verified. I posted an earlier version and asked if somebody could look it over for me with no replies. I triple checked everything and it seems like it's correct to the schematic.

When you say it didn't work properly until you soldered the opto-coupler directly to the board, what was it doing wrong exactly? My opto-coupler is also socketed and I'm starting to become suspicious of it. It's about the only place where I figure the distortion could be introduced into the circuit since the distortion seems to be directly related to how hard the compressor clamps down on the signal. I've also read that these opto-coupler's tolerances have a pretty big swing from part to part, so maybe I just got an extra sensitive one?

Are you sure yours is completely clean? It doesn't distort even a little bit at high settings?

Also, could somebody with humbuckers confirm this? I only have one single coil pickup to test on my guitar (in the middle position) but this distortion is almost impossible to hear using that pickup. The bridge humbucker is what really makes it stick out.

Thanks.

I can verify the vero layout works. I used more conventional off-board wiring for the on/off led and socketed the Vactrol with no problems. The only distortion I got resulted from turning the trimpot up too much. Dialed in a clean compressed signal with no problem when the trim is backed off. Great sounding circuit! Thanks for the vero!

Jarno · Post by **Jarno** » 06 Dec 2009, 14:22

Completed putting in all the parts yesterday, works like a charm (and I think my diodes are positioned as per the layout). I do wonder how this thing works, what do the diodes do? Usually, they are in the signal path of an "ordinary" envelope detector.

The only thing is, I do get a bit of the distortion other people are mentioning as well. I am running it at 12volts now, that helps a bit. Think I'll order the original Vactrol now, I have got two parallel LDR's in there (because most vactrols and LDRs are have a Roff of way above 1M, and the VTL5C10 has only 500k or so, paralleling two gets me in the ballpark) and a blue led (maybe I'll try a red one).
Ideally, I would like to add a "decay" control, or something to stretch the decay somewhat, as I think that some of the ripple problems are because of the lack of a cap or too short a decay time.

nanodocl · Post by **nanodocl** » 17 Dec 2009, 01:20

Did someone tried another optocouplers like VTL5C series??

dune2k · Post by **dune2k** » 17 Dec 2009, 13:00

Okonomiyake wrote: I can verify the vero layout works.

Hi!
Which one did you use? The first (bigger) or the second (smaller) one?
Just wanna check before I start building it and choose the wrong layout...

Cheers,
dune

Demeter - Compulator [traced]