Schematic / info request: Calrec console from 70's (J Series perhaps)

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kilmister

Well-known member
Joined
Aug 22, 2008
Messages
284
Location
Helsinki, Finland
Hi all!

I've been asked to service an old 70's Calrec console. Unfortunatly client doesen't have any info about the console so there's no schematics or even info which model this console is.
Client has also asked me to build Direct Outs. Quick look in the channel bus module showed there's a place for a trafo and (propably) a driver stage. There's also plenty of empty pins in bottom connector so I think this should be easy task to do. Anyway, schematics would be great help.
Please see pictures below (click for high-rez). All info is highly appreciated.

Cheers,
Paavo

Console:



Input Module PQ10-242



Bus module RL42-411


Bus module guts


Fader


PSU ZN30-732


 
Got reply from Calrec that they don't have schemos for J Series consoles :(
Well at least I know what series console is. Living in hope someone might have documents for it.

-Paavo
 
Sorry I cannot help with schematics but I am very interested in module mechanical construction. I don't suppose you would take a few more pics of the innards of other modules so I can see how they go together mechanically?

Cheers

Ian
 
ninopelo29 said:
Hey Ian,
Did these images or schematics find their way to you?

Thanks!
Om

No images but I have a schematic of a Calrec module somewhere but not sure if it is one of these.

Calrec are particularly interesting to me because they were a close competitor of Neve back in the 70s especially in the BBC market. They made some considerable simplifications in the mechanical design which must have made a good impact on costs.

Cheers

Ian
 
I've seen several times that it is possible to re-surface service manuals for large-ish items like this by tracing back it's owners AND their service departments (who all too often keep the manuals, for just-in-case).

It might be worth a shot - make sure to tell the owner that the value of the desk suddenly increases with 50% AND the cost of future service decreases the same amount with documentation in place..

/Jakob E.
 
Nice desk :)
Thanks for posting pics.  I bought a similar one circa 1998, originally built for the BBC with PQ15S input modules rather than your PQ10's.

Good luck with the docs. 


 
I even have a couple of the little 'B205' sub board amplifiers AND the 'upgrade' version too, which had a NE5534 on it. They used plus and minus 22 Volts (from a pair of 24 Volt supply units) and a local 'regulator/dropper to get 22 Volts (sometimes).
There was a desk using these modules that was used by the BBC at Broadcasting house for Radio 4 (I think) that was on air for a year or more and at a service visit I discovered that the main summing using the 'upgraded subcards with NE5534 had been accidentaklly fitted without the dropper so had been running at plus and minus 24 Volts for a year. I did work on a desk using PQ10 modules but that was a long time ago and I am not sure if they had the schematics.
Matt S
 
I know this is an old thread, but this might be exactly what the OP was after. I have 6 Calrec AY 1354 Output Cards. Each has what looks like some CMOS switching and 3 NE5532N output stages, each of which have a Lundahl LL 1517 transformer. I am not sure which console they are from but the triangular shape suggests they might have lived in a meter penthouse. If anyone has any information or schematics for the boards I would be very interested. They are also potentially available for sale too.
 

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  • Calrec AY 1354 Output Card with 3x Lundahl LL 1517 IMG_2305.jpg
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I know this is an old thread, but this might be exactly what the OP was after. I have 6 Calrec AY 1354 Output Cards. Each has what looks like some CMOS switching and 3 NE5532N output stages, each of which have a Lundahl LL 1517 transformer. I am not sure which console they are from but the triangular shape suggests they might have lived in a meter penthouse. If anyone has any information or schematics for the boards I would be very interested. They are also potentially available for sale too.
Depending upon how badly you wish to have some schematics for this PCB assembly, I could "Reverse-Engineer" one of your boards in order to derive a "New/Old" schematic from it. However, I would need to physically have one of the boards here in front of me in order for me to do that. And, just as an example and as a reference.....a large aerospace firm had contacted me a few years ago to "Reverse-Engineer" one of their PCB's that had been originally designed and "manually hand-taped" back in 1979 for a U.S. fighter jet. The aerospace company mailed me their last remaining -- bare-board -- so I could not only create a new schematic, but also come up with all of the pertinent mechanical details so they could re-manufacture "New/Old" circuit boards.

One item that the aerospace company required that you probably don't (but, "might"), is that they also wanted me to convert all of the Thru-Hole parts over to Surface-Mount components so they could re-manufacture their "New/Old" PCB using new "Pick & Place" equipment and wave-soldering processes. Their "New/Old" PCB turned out really well and they were quite pleased with my new design of their old layout. I could do the same for you.....if you would like!!!

/
 
Oi Boomerang, give that card back!
It may be from a Calrec' GP desk or one other M series? desks one of which I commisioned at BBC broadcasting House in 1986 or thereabouts. They lived in a 'nest box' in the rear of the desk and plugged into a motherboard with power rails, wiring turret tags and interlinking traces that made up sections of monitoring, main/Aux/whatever circuits. the transformer drive is 'distortion cancelling' which helps prevent transformer core saturation at low frequencies. A more cunning implementation came about after those particular boards were designed that improved the maximum output level capability.
 
Hi Matt,
Thanks for your reply. I too was at BH form 1981 to 1984 and worked on all 3 flavours of GP desks. I was in Technical Services Radio (fixing them), I guess you were in SCPD if you were commissioning them. I then moved to BBC local radio.
Also, thanks for your offer MidnightArrakis, but I can, and probably will end up reverse engineering it myself to get the pinouts and to see what the two HEF4053B (Triple 2-channel analogue multiplexer/demultiplexer) are doing. I guess each output stage has a choice for two sources, or they may just be muting. The boards aren't very complicated.
If you, Matt, or anyone else does have schematics for it, that would save me a job.
 

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