Mystery Quad Eight rack unit?

[celtkid11]

Hi guys, I just acquired some really cool old Quad Eight gear from a production studio that is remodeling, and part of the gear I got are these two rack modules that are unlabeled and I’m not sure what they are exactly- so I’m hoping someone here can shed some light on it!

There are two racked CL-22 stereo-linked compressors (two per RU for a total of 4) and sharing their 28V power supply were these other two mystery units, also doubled up so there are four total. Looking at the CL-22 schematic and pin out, it had me thinking these are the optional D-S units (which I can’t find any photos of) except that they aren’t linked by the external D-S pin on the CL-22 output. It’s possible that they wired it so that the audio out of the CL-22 went in to the input of this, but the audio ins and outs were cut so I don’t know. As far as I can tell this mystery unit is sharing a power supply with the CL-22 but nothing else.

It is definitely a Quad Eight product as the PCB is stamped with their logo, and I believe this whole studio was setup and installed by Quad Eight techs back in ‘79. It’s kinda weird that the PCB’s are not enclosed in a box or anything, they are just attached to the 19” faceplate and stuck in the rack, but maybe it didn’t matter and was a faster install this way or a custom build.

Just looking to see if anyone here knows what these are, as I’m curious to try them out but don’t want to mess anything up or wire it wrong since it’s probably a nice piece of vintage Quad Eight. Appreciate any help or info!!

I’ve attached photos of the units for you guys to peruse. Thank you!

 

[ubxf]

I'm guessing they are gates/ducking units , here are pictures of the CL22 with DS

 

[celtkid11]

Gotcha, yeah that is a good possibility and would make sense. Thanks for the picture with the DS unit- definitely looks different than that, so I think it must be something else entirely. Thank you!

 

[celtkid11]

a quick bump to see if any other Quad Eight fans out there have seen these units before and have any more info. Thanks!

 

[Gold]

I’ve never seen them before. Have you asked Ken Hirsh? If anyone knows he will.

 

[ubxf]

https://reverb.com/au/item/56648061-quad-eight-q8-osc-gates-1970-s-brown

 

[celtkid11]

Thanks for the tip @Gold , I will try to reach out to him. And thanks @ubxf for that find!! Looks like it’s this osc gate of some sort- I’ll have to do some digging on the specifics of that unit but it’s nice to have a name for it at least- thank you!

 

[ubxf]

the oscillator is a separate thing. The gates though are very similar to yours, the second picture shows the boards

 

[jeremynothman]

GOOD SCORE!

The CL-22s are VCA based compressors - I used to use them at a studio where we had 8 built into the Coronado we used for tracking.
They can be fun on room mics, and can also be used creatively with the expander to make toms pop. I always found they added a pleasant bit of midrange dirt to the sound, but I've read that other people found them very clean and more suitable for Piano. Who knows. Maybe ours were totally out of shape. They certainly didn't all respond/meter the same.

+/-28V for racking, but they also run with a bit less (just with less headroom). I'm sure you can find the Pin-Outs on Ken's website or here.

 

[celtkid11]

the oscillator is a separate thing. The gates though are very similar to yours, the second picture shows the boards

Oh I see! So they are just gates then, that makes sense. It was my first guess when looking at the control labels. Thank you!

 

[celtkid11]

GOOD SCORE!

The CL-22s are VCA based compressors - I used to use them at a studio where we had 8 built into the Coronado we used for tracking.
They can be fun on room mics, and can also be used creatively with the expander to make toms pop. I always found they added a pleasant bit of midrange dirt to the sound, but I've read that other people found them very clean and more suitable for Piano. Who knows. Maybe ours were totally out of shape. They certainly didn't all respond/meter the same.

+/-28V for racking, but they also run with a bit less (just with less headroom). I'm sure you can find the Pin-Outs on Ken's website or here.

Thanks! Yes I'm especially excited to try the CL-22s, I've heard good things from other people as well so I look forward to trying them soon. Pleasant bit of midrange dirt sounds just what I like! I will experiment with using the expander as well, and also these gates- hell, it'll just be fun to see what it all sounds like! I have the original 28v power supply, and they turned on before I removed everything, so I think it's ok- I should double check its voltage output and some of the specs, since it is over 40 years old at this point.

The same production unit has a full 16 channel Pacifica desk that I'm also trying to get my hands on- certainly is a real beaut and would be very epic to have in my home studio!! We shall see...

 

[jeremynothman]

GET THE PACIFICA! They sound fantastic. Really punchy consoles. It's not the most ideal EQ for getting surgical, but the pres, EQ and master buss all sound good. Also, such a vibey look.
The MM series pres are bigger sounding (and the inductor-based EQ is smooooooth), but the AM10 based stuff is also great.

 

[celtkid11]

I'm certainly going to try! It looks way too cool to pass up, plus I've also heard good things about the pres and EQs, punchy is definitely a sound I appreciate- I'll keep y'all posted if I can get it!

 

[orphanaudio]

In order of importance:

YES!!! GRAB THE PACIFICA !
Agreed Jeremy, Its one of the cleanest, punchiest consoles ever built and ridiculously easy to service. As of the last time I spoke with his tech Matt, Garth Brooks still keeps his QE Coronado (24bus, big brother of the Pacifica) in top shape in his personal studio. Dozens of "Stock Series" consoles (Coronado, Ventura, Pacifica) are still in daily use worldwide and treasured for their reliability, speed of operation and consistently clean and creamy tones.
The channel strip's MP-401 preamp and EQ-333 equalizer are renowned for their clean and accurate tone and there are several very cool mods to add selectable Q and more to the 333 eq.
In addition, spares for just about anything are still in factory stock and I am happy to consult on restoration.
Make certain you can also grab the service documents (3-ring binders or a metal file box) as they are priceless for technical notes or mods that the facility technicians have likely penciled in on the schematics and note-book pages. If they are lost or damaged, I can dig into the archives and create new copies of the blueprints (not cheap to do but worth it).

The unmarked panels are QEE NSD-120 FET gates: Rare birds indeed mounted in rack panels like yours, as they were typically built as 3.5' tall slide-in cards in 2ru rack frames, but even in the DAW age they can still be quite useful.

CL-22 VCA compressor:
This is the first bit of QEE gear I ever owned (the exact same model in fact) a very snappy, versatile and clean dynamics unit. This also got me introduced to the QEE design and management staff in the early 1980's.

I had no idea then, that buying that dual CL-22 rack would lead to eventually picking up the entire company & physical assets a decade later, along with lifelong friendships with the design and production staff, and carrying the Quad-Eight banner into the next millennium.

Email me through the QEE or Orphan Audio contact pages and I will send pinouts and spec sheets for both dynamics units.


Thank you,

Ken Hirsch / Director of Engineering
Orphan Audio www.orphanaudio.com
Quad-Eight Electronics www.quadeightelectronics.com
Electrodyne Audio www.electrodyneaudio.com


"Education is the cure for everything"

 

[MidnightArrakis]

a quick bump to see if any other Quad Eight fans out there have seen these units before and have any more info. Thanks!

>> Just as a "side-mention".....should you be at all interested.....I could "Reverse-Engineer" these PCB's and then provide you with a new set of schematics and GERBER files to have new PCB's fabricated. A few years ago some guy down in Florida sent me one each of all of the PCB's in an original -- 1974 API mixing console -- so I could "Reverse-Engineer" them all so he could have all "New/Old" circuit boards made for the API console he was restoring. I have also "Reverse-Engineered" PCB's that a defense contractor had sent to me of circuit boards that were manually-designed in 1979 and were used within U.S. fighter jets!!! Just sayin'.....




More recently, another member on this forum had sent to me the channel strip of a SOUNDCRAFT 200B mixing console so I could "Reverse-Engineer" the sheet-metal design of its channel module. So.....if you would like to have something "New/Old" documented and/or made, I can help you out there in that department!!!

>> I AM NOT -- SELLING -- ANYTHING HERE, OK??? I am just offering to you my particular type of design engineering expertise.....that's all!!!

/

 

[orphanaudio]

CL-22 restoration/calibration:
Any properly restored and calibrated CL-22 should sound identical to all its nearby brothers.
The only variation that cannot be controlled is if the dbx 202 black can has aged significantly, drifted past ability to null distortion or simply become noisy.

The actual audio path is literally just three stages:
Input: TL-072 as a differential input amp.
Gain control: dbx 202 VCA.
Lastly a high-voltage QE AM-10 discrete opamp as the VCA's current to voltage converter and channel output amp.

All rotary controls are high-quality, sealed Clarostat conductive plastic type that rarely require attention or replacement.

Calibration, although simple (depending on revision of the card set & there are quite a few) is critical to clean and repeatable operation of the CL-22 as is true with any VCA based dynamics. Any significant variation in calibration or power supply rails can cause the channel to sound and operate differently from its neighbor.


And ,.... Yes, we have complete service document packages available if you need to work on them, or you can send them into the factory for full restoration, calibration and any upgrades desired (Frequency selectable DS'ing, Expander range shift, Stereo link, External meter driver, Fully enclosed racking using the original front panel.... and more).


Thank you,

Ken Hirsch / Director of Engineering
Orphan Audio www.orphanaudio.com
Quad-Eight Electronics www.quadeightelectronics.com
Electrodyne Audio www.electrodyneaudio.com


"Education is the cure for everything"

 

[celtkid11]

Wow!! First off thank you so much Ken @orphanaudio for all the information about this stuff! I will definitely email you about it as I’m sure a pin out and spec sheets would come in handy. I’m certainly going to try to get this Pacifica, so cool that Garth is still using his and I’m glad to hear that service is easy as well, that makes a big difference and I imagine this may need a little service. I’ll keep ann eye out for the service documents when I go back. Always interested to hear about mods as well. So cool that the CL-22 got you into QEE and now you own it! I’m most excited to try it out on some sessions, and will definitely let you know if it needs calibration or service once I dig in and try it out. Thank you! I will be in touch via the website.

And thanks @MidnightArrakis for the info! I will definitely keep that in mind

Much appreciated everyone, you rock!

 

[celtkid11]

CL-22 restoration/calibration:
Any properly restored and calibrated CL-22 should sound identical to all its nearby brothers.
The only variation that cannot be controlled is if the dbx 202 black can has aged significantly, drifted past ability to null distortion or simply become noisy.

The actual audio path is literally just three stages:
Input: TL-072 as a differential input amp.
Gain control: dbx 202 VCA.
Lastly a high-voltage QE AM-10 discrete opamp as the VCA's current to voltage converter and channel output amp.

All rotary controls are high-quality, sealed Clarostat conductive plastic type that rarely require attention or replacement.

Calibration, although simple (depending on revision of the card set & there are quite a few) is critical to clean and repeatable operation of the CL-22 as is true with any VCA based dynamics. Any significant variation in calibration or power supply rails can cause the channel to sound and operate differently from its neighbor.


And ,.... Yes, we have complete service document packages available if you need to work on them, or you can send them into the factory for full restoration, calibration and any upgrades desired (Frequency selectable DS'ing, Expander range shift, Stereo link, External meter driver, Fully enclosed racking using the original front panel.... and more).


Thank you,

Ken Hirsch / Director of Engineering
Orphan Audio www.orphanaudio.com
Quad-Eight Electronics www.quadeightelectronics.com
Electrodyne Audio www.electrodyneaudio.com


"Education is the cure for everything"

This is priceless info, thank you! I’m particularly interested in trying out the stereo link option, since my units have it already setup, and I’d like to try some stereo mix buses and whatnot through them. So I imagine ensuring that the neighboring units are properly calibrated will be crucial for maintaining stereo image. Thanks again!

 

[ubxf]

If for some reason you pass on acquiring the Pacifica , I would be interested. I have a 16 channel one but I'm looking to add some modules to fill up the frame

 

[CalavoBob]

I've got one of those Quad 8 gates that are shown in that link that ubxf posted in his reply. It's very fast, and I have had good luck with it on cleaning up snare drum.