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Ibanez - CP-830 ( Compressor )

PostPosted: 24 Feb 2008, 13:50
by analogguru
Here is your chance for guts of the CP-830:

http://www.megameier01.homepage.t-online.de/eyComp.jpg

very intersting:
three transistors, one 741 and a LDR-optocoupler...
reminds me a little bit to the Dod 280....

you can buy it here for further investigation:
http://cgi.ebay.at/Ibanez-Compressor-pr ... dZViewItem

analogguru

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 29 Feb 2008, 22:22
by modman
First link is already down, missed my chance...
Did anybody save it?

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 29 Feb 2008, 22:35
by analogguru
modman wrote:First link is already down, missed my chance...
Did anybody save it?


Do you mean something looking like this:

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 13 Aug 2008, 12:40
by Kinki fuzz
I've got one of these, I wrote the schematic out of it, got it somewhere, maybe I can scan it (handwriten...) or something to post it here. Will try. Pretty similar to DOD280...

The issue is it doesn't work, (bought it realy cheap because it was faulty, I thougth that just the box was worth the price), it sounds, but doesn't compress and does nothing. After much fooling around with it, I discovered the problem was the optocoupler, but it has nothing I can understand writen so I can find a replacement. Tried a couple optocoupler but did not work fine (distorted), I guess changing optocoupler you also need to change some resistor or so, but well, if I'm gonna change the circuit that much, Id better mount my dinacomp clone inside, which was my intention when I bought it. Anybody has a clue about what kind of optocoupler did maxon use or whatever?.

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 13 Aug 2008, 22:08
by borislavgajic
You could try LED/LDR.........and see what hapens

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 14 Aug 2008, 07:04
by Kinki fuzz
I already tried the led/LDR option and it was the same as with the optocoupler, which in the end are led + ldr in a case, if I'm right (?). Tried different led colors, different position/angles, even changed some resistor to vary the light intensity. I don't remenber the details, cos it was like 1 or 2 years ago. In the end, I think the circuit is tuned for a given LDR/led conbination, with its given sensitivity, and so on, and this is critical for the correct function.

I will post schematic and maybe some photo, although the pcb it is pretty fucked up, since I fooled around a bit soldering and dissoldering components and so on.

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 14 Aug 2008, 18:50
by borislavgajic
post all you have......close up pictures...both sides of pcb......schem
..I guarantee there is somebody here that can help :thumbsup

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 02 Jan 2012, 15:30
by pedalgrinder
this is a great compressor i think mictester made his own version of it somewhere

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 02 Jan 2012, 15:54
by mictester
pedalgrinder wrote:this is a great compressor i think mictester made his own version of it somewhere


Mine was based on a Maxon board that wasn't ever released. Maxon had problems procuring the specified optocoupler, so abandoned the design.

I liked the way the rectifier transistors provided the current for the LED part of the opto - it was an elegant solution. I modified it so that it would work with the RPY58A LDR (nothing special - I just had a lot of them!) and a green LED. The amount of compression available without distortion was quite amazing, but there was one minor design issue - it was possible to start to clip the signal (audibly) if you took the output from the emitter of the phase splitter transistor, as originally designed. The ones I built took the output from the output of the op-amp and through an emitter-follower buffer transistor. That eliminated the distortion altogether.

The other issue was that it was sensitive to supply voltage - the amount of compression available reduced as the battery discharged!

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 02 Jan 2012, 16:08
by pedalgrinder
yeah fair enough i just knew you'd done something somewhere thanks for verifying. :thumbsup

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 17 Sep 2014, 19:17
by Keijo
Hello all, my first post here!

I have the Ibanez CP-830 and its broken. When its off guitar signal goes through like it should, but when its on signal sounds like farting.

Does anyone have any idea what could be the problem?

I measured about 9 volts from op-amp pin 7 and about 5 volts at pins 3 and 6 so they should be alright. I also tested the transistors be-junction with DMMs diode-tester and it showed about 0,7 volts and the led of the optocoupler showed about 1,4 so they should be alright.

Re: Ibanez - CP-830 ( Compressor )  [schematic]

PostPosted: 17 Sep 2014, 19:42
by Keijo
Forgot the schematic, so here it is.

IBANEZ_CP830_Schematics.jpg

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 17 Sep 2014, 20:51
by mirosol
Moikka Keijo! Tervetuloa.

Have you tried probing it to see where the signal dies? http://www.diystompboxes.com/pedals/debug.html
+m

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 17 Sep 2014, 20:53
by Dirk_Hendrik
Voltages on CP2 and 6 please.

After that,
Start with the electrolits. They're the most common cause of failure.

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 18 Sep 2014, 07:54
by Keijo
Dirk_Hendrik wrote:Voltages on CP2 and 6 please.

After that,
Start with the electrolits. They're the most common cause of failure.


CP2 voltage is about the same that pin 3 is (as it should be, right?). All transistors collectors have a little under 8 volts so they should be alright too.

I sent 1kHz signal from signal-generator and measured with oscilloscope and it showed things like this. :) Yellow is signal in and blue is signal out.

Image

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 18 Sep 2014, 19:44
by gigelmargel
Anyone has a veroboard layout for it? I searched, but I didn't find any...

Thank you!

Re: Ibanez - CP-830 ( Compressor )

PostPosted: 19 Sep 2014, 09:36
by Keijo
Ok, changed the electrolytics and the op-amp. It works now. :)

Ibanez - CP-830 Compressor 1979

PostPosted: 24 Dec 2017, 21:00
by modman
IBANEZ CP-830 COMPRESSOR Original "R" Serie 1979 Made In Japan

http://www.hendrixguitars.com/Ef248.htm