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Hey has anyone thought about cloning the pye compressor limiters and does anyone have schematics on them ?


  • PYE Compressor Limiter


anonymous Thu, 01/22/2004 - 22:04

I've heard that the cool Pye compressors were diode-bridge type designs similar to the Neve 2254/33609? Did they use other designs as well, and/or is this the type you'd want to DIY?

I don't know if I could be much help designing, but I'd personally LOVE to build a stereo/dual-mono diode-bridge compressor.


anonymous Fri, 01/23/2004 - 10:57

I'm bang up for a diy Pye. I don't have a scanner at the moment so can't get a better schem quality than the one sent to PRR, but I am snail-posting the original to someone in the UK (Zebra??) for re-scanning.

edit: copied from Funky Junk London's vintage section:

Funky Info

Classic British solid state mono unit with unique circuit principles. The basic compression amplifier is model 845751, and is contained in all the 84 series. There are two versions and the suffix /00 or /01 indicates that the unit either does not or does have noise gate circuitry respectively.

Electrically identical, model 845752 is a portable design, and 845753 is rackmountable. All mountings are for two units with one side blanked out if appropriate; stereo operation is an option. Suffixes /00, /01, /02, and /03 after these latter two model numbers indicate that the unit has either one or two channels of 845751/00s or of 845751/01s respectively. How boring was that.

An unusual beast that works on the Mark-space principle, which takes energy out of peaks rather than crushing them. As compressors they perform marvellously, very musical and exceptionally easy to use with few parameters to adjust and very smooth automatic gain make up. A must for real retro nuts, or indeed anyone at all. Rare.

Description mono
Principle solid state
Metering VU
Controls noisegate threshold, threshold, decay time, compression
Performance signal noise ratio: > 60db
compression ratio: switched 1:1, 2:1, 3:1, 5:1
attack time: compression < 0.5ms, limiting 1 mS
Bypass no
Dimensions 3.5" x 19" x 15"

Some nice pics:



RemyRAD Fri, 11/18/2011 - 21:10

As you have seen, perhaps, this original post is back to 2003. Or was that 2004? Either way, I wasn't here until 2005. I actually owned 8 PYE PDM compressor/limiters, back in the early 1980s. They were rather fascinating because they utilized " Pulse Duration Modulation ". So basically, the audio is chopped up really quickly like faster then a chef can chop parsley. I believe it was modulated with a 235 kHz pulse oscillator. This also requires some low pass filtering on the output to keep that clock frequency Out of your audio. As a result of that, response was only good out to 15 kHz before it was brick wall filtered.

Around that time, Cyndi Lauper had come out with " Girls just want to have fun...". Word got around I believe that Joe Albano utilized one of those on her vocal. And suddenly, I got a bunch of good offers for mine. They were good but I actually didn't care for them much. I'm really more busted up about the 2 blackface earlier release 1176's I parted company with. Sure the newer silver faced 1980s 2 I have are fine, they're not the blackface early release versions. Both good, both different.

The PYE's also didn't have an output gain makeup potentiometer. With the particular console I had at the time a Philips 12 x 4, the insert patch couldn't make up the gain. So it caused me mixing problem's when you had a fair amount of gain reduction happening. I'm not sure if I still have the schematics? I just moved and all of my years of schematics & manual are currently boxed up and unavailable to me at this current time. I'm going to be moving lots of Stuff around to see if I can locate one? Even though I sold them all, we all make xerox copies of manuals. And I'm sorry, I don't remember the precise model numbers of the 2 or 3 different versions I had? Some were vertical mount & the others were horizontal mount. Circuitry though work fairly identical.

One of the funny things I saw a recently was an advertisement for Sterling Microphones I think with Bob Rock. He's standing there looking real cool for the camera. In the lower foreground of the picture one can easily identify Neve 1073's and also in that rack is just the edge of the right side of that PYE limiter. And he's standing in front of his AKG BX 20 E, LOL. I have all the same stuff or had. OK, so I didn't have 1073's but I have 3115's which look virtually identical. So I thought that was cool. Send me a PM about your request. I really don't even remember the last time I looked at that schematic? I may have just said ug and tossed it?

We'll see?
Mx. Remy Ann David

enewhuis Wed, 06/14/2023 - 13:22

I'm a bit late to the Pye Party but I have two 4060 compression amps and have started the restoration process that hopefully ends with the new paint I applied to the front plate.  I've been looking for at least a schematic.  These are the upright versions that plug into a rather heavy chassis that itself plugs into a mother chassis.