RARE VINTAGE AUDIONICS OF OREGON SPACE & IMAGE COMPOSER QUAD DECODER UNIT

[Asklia]

Some pictures of my restored Audionics S&IC, late number 17013. The power supply chips with the original small feathered heat sinks got incredibly hot (at least on my device). Some high lights:

- humming transformer replaced, lower voltage for less heat
- angled plates made of black coloured copper, mounted to the housing
- electrolytic capacitors replaced
- input caps replaced with WIMA caps
- new precision sockets for all chips
- analog standard chips replaced
- new RCA sockets from Lumberg, gold plated (instead of ugly nickel and tin inside)




I am not using the Audionics anymore; so it might find its way to Ebay.

 

[LB-V]

Very nice! Did you do the work yourself?

 

[Asklia]

DIY: Yes.
You might have a look here:
https://www.quadraphonicquad.com/forums/threads/bose-4401-cd-4-demodulator.33861/

 

[Akaiquadster2]

Some pictures of my restored Audionics S&IC, late number 17013. The power supply chips with the original small feathered heat sinks got incredibly hot (at least on my device). Some high lights:

- humming transformer replaced, lower voltage for less heat
- angled plates made of black coloured copper, mounted to the housing
- electrolytic capacitors replaced
- input caps replaced with WIMA caps
- new precision sockets for all chips
- analog standard chips replaced
- new RCA sockets from Lumberg, gold plated (instead of ugly nickel and tin inside)

View attachment 93624 View attachment 93625 View attachment 93626
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I am not using the Audionics anymore; so it might find its way to Ebay.

I wish you could work that kind of magic with mine!

 

[Asklia]

I would do, but:
a) Lumberg does no longer manufacture the very special RCA sockets
b) postage and customs to Switzerland will kill you probably

 

[Akaiquadster2]

Yes - I’d need one of those Swiss bank accounts of movie stars to get it to and from Australia

 

[Asklia]

There is a chance, if you send the board only. But I do not have these nice golden RCA sockets from Lumberg any more. A very small chance is Ebay as ususal for these.

 

[par4ken]

For what I know, this is the later chip. But you experts please confirm! Plus this unit was sold in 1981 and has the odd serial number. I figure it may have been a serial number series assigned the units with a factory remote.

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Those are the Tate II, Exar chips.

 

[par4ken]

Some pictures of my restored Audionics S&IC, late number 17013. The power supply chips with the original small feathered heat sinks got incredibly hot (at least on my device). Some high lights:

- humming transformer replaced, lower voltage for less heat
- angled plates made of black coloured copper, mounted to the housing
- electrolytic capacitors replaced
- input caps replaced with WIMA caps
- new precision sockets for all chips
- analog standard chips replaced
- new RCA sockets from Lumberg, gold plated (instead of ugly nickel and tin inside)

View attachment 93624 View attachment 93625 View attachment 93626
View attachment 93627 View attachment 93628

I am not using the Audionics anymore; so it might find its way to Ebay.

Nice! I would have used the gold plated jacks as well if I would have known where to get them.

You should also replace the other coupling capacitors with something better like the WIMA's.

I'm all for using better or higher quality parts where possible.

About the transformer, years ago SMYTH SOUND EQUIPMENT LIMITED was the Canadian distributor for Audionics. I wanted to purchase a Composer. They offered to sell me one direct as there was no dealer in my area. I sent them a certified cheque for the requested amount. J.B. Smyth, informed me that there was a delay in getting CSA approval. For the unit to be approved for sale in Canada it would require a heftier power transformer. The modded Canadian units never arrived and my cheque was eventually returned.

I never felt that the supplied transformer ran excessively hot but it has a habit of detaching from the board with rough shipping! My first unit had the transformer mounted by 2" nylon screws. In two other units were ty-wrapped, the ties became brittle after years of service and broke leaving the transformer mounted only by the solder pins.

Years ago a former co-worker was impressed by my unit and purchased one for himself. He moved a number of times, I only rarely saw him. On one occasion I remember him saying that he needed a power transformer for it. Then a few years ago a friend of mine introduced me to someone who had purchased the unit from the former co-worker. The story was the same that it needed a power transformer. Now when I ask my friend about the identity of this person he doesn't recall. I hate to hear of a Composer that doesn't work, especially if repairable. The original transformer is still manufactured and is available from Digi-Key (Signal Transformer DST-6-36).

 

[Asklia]

Yes, the original transformer is still available. But its output voltage, especially now with 230 Volts input, is by far to high. The transformer itself does not get hot, but the heat sinks of the power regulator transistors get incredibly hot. Therefore I replaced the transformer wirh another model with lower output voltage. Enough high for regulation headroom, but low enough for less excessive heat. And rebuild the heat sinks.
There is no isolation under the PCB for 230 Volts AC, like in the Tate. This is a horrible dangerous design. A solid isolation must be mounted onto the metal ground plate for safety, in the Tate as well.
Not all of the coupling capacitors are in the audio path, by the way. Some are used for the display. And the old green ones are foil capacitors, so no need to replace.
The golden RCA sockets have been manufactured by Lumberg, but unfortunatly (like those for the Bose 4401) no longer under production.

 

[Asklia]

And thanks for the history of your Audionics!

 

[par4ken]

Not all of the coupling capacitors are in the audio path, by the way. Some are used for the display. And the old green ones are foil capacitors, so no need to replace.

There are four 10µFd capacitors that couple into the DES chips and another four that couple to the output. Others are mostly for the display, no real need to replace those.

 

[gene_stl]

Ken did you win that lot of parts on fleabay???

 

[par4ken]

Ken did you win that lot of parts on fleabay???

No, someone sniped me!

 

[Owen Smith]

No, someone sniped me!

Sniping appears to be the only way to win an ebay auction these days, that or get the seller to accept an offer.

 

[par4ken]

Sniping appears to be the only way to win an ebay auction these days, that or get the seller to accept an offer.

I usually win those! I just didn't want to go too high. I could have dropped something like 2K down at the last second an likely would have won. I just couldn't justify risking money like that! I chickened out!

 

[gene_stl]

How much did they go for??

 

[par4ken]

How much did they go for??

Winning bid:
US $1,125.00

 

[Owen Smith]

Winning bid:
US $1,125.00

That must have been a LOT of parts!

 

[par4ken]

That must have been a LOT of parts!

There were a lot of National Chips, not as desirable as the Exars but still "Unobtainium" any place else!

The four decoders have some Exar chips in them, whether or not they are functional, who knows! The purchaser should be able to get something working out of the whole lot. They would have to adapt the National (detector) chip to the Exar pinout if the Exars are non-functional. The resulting repaired decoder likely would produce more artifacts than it would with the original chips.

I hope that we hear from the purchaser sometime soon!