Spectra Sonics 610 Stereo Link

[inkster]

Has anyone had experience linking a pair of vintage Spectra Sonics 610 compressors?
Years ago I ordered the link accessory from William Dilley which turned out to merely be a 5.6uf polycarbonate cap with screw terminal connectors attached via leads.
Never really worked all that well(if at all) and I was thinking of messing with a buffer to get better results but I'm open to any suggestions.
Schematic with the EXT stereo link is on page 21 of the attached PDF.

Cheers

 

[thomasdf]

Following ! Wondering the same

 

[inkster]

Following ! Wondering the same

Have you encountered the same issue?
Here's the hand drawn cards.

 

[thomasdf]

I have no 610 but I've read the manuals and looked at the schematics and wondered what that gizmo was

 

[kags]

The behavior of the 610 is like no other compressor/limiter in that the dynamic range seems to be what triggers comp vs. limiting vs. both. Perhaps the stereo link is doing its thing? Below is how the newer units describe the link condition, which seems to imply a different type of link than other compressors use. Maybe contact the company, which is still in business to see if they have changed the circuit for the link function over the years. The current units use a TS jack to link units and no special stereo adapter is required.

"Stereophonic Operation
The interconnection couples the attack and release action of the limiting and compressing functions of the two units. The input
(compression/limiting) and slope controls on either unit may be independently set for the desired mode of operation. However, when
the attack action of either unit is activated, the other will follow so as to maintain the stereophonic perspective. The release action will
follow the fastest setting on either unit. Prior to differing applications, the accessory may be switched in or out of the circuit as
desired.
¼” TRS cable required for two channel operation."

 

[inkster]

The behavior of the 610 is like no other compressor/limiter in that the dynamic range seems to be what triggers comp vs. limiting vs. both. Perhaps the stereo link is doing its thing? Below is how the newer units describe the link condition, which seems to imply a different type of link than other compressors use. Maybe contact the company, which is still in business to see if they have changed the circuit for the link function over the years. The current units use a TS jack to link units and no special stereo adapter is required.

"Stereophonic Operation
The interconnection couples the attack and release action of the limiting and compressing functions of the two units. The input
(compression/limiting) and slope controls on either unit may be independently set for the desired mode of operation. However, when
the attack action of either unit is activated, the other will follow so as to maintain the stereophonic perspective. The release action will
follow the fastest setting on either unit. Prior to differing applications, the accessory may be switched in or out of the circuit as
desired.
¼” TRS cable required for two channel operation."

I don't have factory 610 units, I bought an old quad SS console in the mid 90's that was falling apart for $500 I think.
I pulled all the cards, EQ's, trannies, meters, etc and sold off most the parts keeping just enough trannies and cards for a pair of preamps and I kept the 4 601 and 603 cards along with enough parts to utilize the compressors.
Oddly enough the console had the 4 compressors hardwired to the quad buss with no type of link for them, the console was custom made and not a factory design.
I actually visited SS in Ogden when Dilley was still alive...he wanted nothing to do with me! I did buy the accessory which is just a 5.6uf non polarized film cap.
I eventually built a pair of 2 channel rack units, at one time I had all 4 in one giant old rack I threw together from bits dug out of DA audio in SF...a real beast.
Engineers tell me mine sound cleaner than the factory units but everyone that uses mine loves them.
I saw(and see) no use in duplicating the threshold and overload indicator circuits, at least not for me.
But if I were duplicating the 610 I would not go with the individual card layout they used originally...it's a total pain to wire up and come up with a support system for the cards and all the point to point wiring involved but that's just me...I've wired all 4 up twice and I hated it more each time!
Good luck

 

[kags]

I'm embarrassed to say that I once was given a 16-channel SS console (from a club) in parts and I planned to make some preamps from the 101 cards and EQ modules. The console was stored in a friend's garage and one of his family members tossed all the boxes of "junk" into the trash before we knew it. What a loss! I do have one VU meter left and also one original 610 rackmount compressor that sounds fantastic! I hope you get your compressor to work how you like!

 

[MidnightArrakis]

I don't have factory 610 units, I bought an old quad SS console in the mid 90's that was falling apart for $500 I think.
I pulled all the cards, EQ's, trannies, meters, etc and sold off most the parts keeping just enough trannies and cards for a pair of preamps and I kept the 4 601 and 603 cards along with enough parts to utilize the compressors.
Oddly enough the console had the 4 compressors hardwired to the quad buss with no type of link for them, the console was custom made and not a factory design.
I actually visited SS in Ogden when Dilley was still alive...he wanted nothing to do with me! I did buy the accessory which is just a 5.6uf non polarized film cap.
I eventually built a pair of 2 channel rack units, at one time I had all 4 in one giant old rack I threw together from bits dug out of DA audio in SF...a real beast.
Engineers tell me mine sound cleaner than the factory units but everyone that uses mine loves them.
I saw(and see) no use in duplicating the threshold and overload indicator circuits, at least not for me.
But if I were duplicating the 610 I would not go with the individual card layout they used originally...it's a total pain to wire up and come up with a support system for the cards and all the point to point wiring involved but that's just me...I've wired all 4 up twice and I hated it more each time!
Good luck

[I pulled all the cards] -- WELL-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L-L.....I -- may -- be able to help you out here, but.....you will need to first provide me with some information. Several years ago on this forum, I was contacted by a member who had purchased an original 1974 API mixing console that he wanted to restore. Upon him learning of me on this forum and my background in designing electronic equipment, he then physically mailed me one each of each different PCB within his console so I could go through the process to "Reverse-Engineer" each circuit card. My task was to create all new PCB-designs with GERBER files so he could then have all "New/Old" PCB's made. And, even though after I reviewed the original PCB's and I could easily see many areas of PCB-layout improvements, he wanted all of this PCB's to be -- EXACTLY THE SAME -- as the original circuit cards. I guess he was afraid of losing any of the "Audio Magic Mojo" that his console possessed!!!

In any case, I carefully made multitudes of mechanical measurements of the original boards and created all new PCB-designs using my CAD-software. Once I had all of that, it was then easy enough to ZIP-up all of his PCB fabrication files and e-mail them to him. From there, all it took was for him to buy all of the electronic components and send my GERBER and N/C Drill data files to whatever PCB fabrication shop that he chose and put everything together. And, as a side-note.....I have also done the same thing when I was once contacted by a huge aerospace company who had contacted me to "Reverse-Engineer" a PCB of theirs that had been originally designed in 1979 and they no longer had the manual hand-taped artwork to fabricate new PCB's. So, in this instance, not only did I "Reverse-Engineer" this 40+ year-old PCB-design, but the aerospace company also wanted me to update the design from using old "Thru-Hole" components to modern "Surface-Mount" components. So, that was easy enough for me to do when I created the schematic and inputted "Surface-Mount" PCB-footprints for all of the parts. EZ -- PZ!!!.....

Similar to what I just mentioned above, if you can physically mail me one each of your Spectra-Sonics PCB's, I can go through and obtain all of the information that I need to accurately recreate each of the PCB's. In addition, since you had also mentioned that you would like to have your own individually styled PCB, if you can clearly sketch-out what the dimensions would be, where and what size any mounting holes are and anything else that "your heart desires", I could incorporate all of your requirements into a new custom-designed PCB!!! NO BIG DEAL!!!..... But, I physically need to have the original Spectra-Sonics PCB's in my hands first. Once I am done "Reverse-Engineering" them, I'll mail them back to you. How's that?

Of course.....you have no idea who I am or even if I am capable of doing what I just wrote. So.....the attached PDF file should easily answer that for you. Should you be interested in moving forward.....I'll help out as much as I can, OK???.....

Just sayin'.....

Former Audio Engineer
Former Studio Recording Engineer
Former Sound System Design Engineer
Once worked with one of the largest concert sound-reinforcement companies in the world
Former "LIVE" Recording Engineer
Former "Other Stuff" Dude.....
Currently "Too Old" to do audio work, so now focused on "Equipment Design Engineering" projects

/