Difference between various Sansui QSD-1 decoders

[Bonzodog]

I am new to these forums, but a long time fan of quad.

I have a couple of Sansui QSD-1's

One I bought from Pacific Stereo, the other was direct from Sansui.

The one from Pacific Stereo (serial number beginning 225) has a selectable AC voltage input, a firm rubber board retainer, and white printing on the circuit boards, which are labeled TP-N71-HB - just like in the service manual, with nickel-tin connectors.

The one direct from Sansui (serial number beginning 226) has a fixed AC voltage input, a soft foam board retainer (which is decaying,) and green printing on the circuit boards, which are labeled TPN 88.S or TP-N88-S, with gold connectors.

I also have a QSE-1 and a QSE-5B, obtained direct from Sansui, along with the Sansui Professional Quadraphonic Manual (a 3 ring binder with various technical papers.) I was working for a sound studio doing quad production at the time I acquired these.

Does anyone know the difference between these two QSD-1's?

I'm sure QuadBob must have had both come through his hands.
Is there any difference between the two QSD-1s that matters?
(Other than the gold connectors.)

 

[roundhousequad]

Welcome Bonzodog
Good to have you onboard. I'm sure there will be plenty of ? for you also. with your background.
Jim

 

[Cai Campbell]

You ask what the differences are but you've already provided the answer!

The fixed voltage unit was manufactured for the domestic (Japanese) market while the unit with selectable voltage was manufactured for the overseas market. The fixed voltage unit was designed for 100v (Japanese standard) but can easily modified for 120v use. Since you bought the fixed voltage direct from Sansui, I'm curious to know if it was modified for 120v operation before it was sent to you.

In any event, the units perform identically. My preference would be for the fixed voltage unit for three reasons:

1. Fewer parts.
2. Higher serial number.
3. Gold connectors.

 

[Bonzodog]

The “226” QSD-1 may have originally been for the Japanese market, but it definitely looks like this one was built for the US market. I bought it from Sansui Electronics Corp. (USA), not Sansui Electric Co. (Japan).

The voltage tag on the rear says 'Voltage AC 120V ; 60Hz'.

The power transformer inside is labeled '400 2142 Sansui 62-7'.

It also has a UL sticker and the requisite safety warnings.

I doubt Sansui would pay for the UL sticker 'tax' unless it was a legitimate import.

Also, often when a device has a long serial number like the QSD-1, the beginning of the serial number is a manufacturing code. I doubt that Sansui made over 226 million of these units!

 

[Cai Campbell]

Also, often when a device has a long serial number like the QSD-1, the beginning of the serial number is a manufacturing code. I doubt that Sansui made over 226 million of these units!

Right. And larger manufacturing codes (or whatever) usually indicate later generation designs, which presumably offer at least marginal improvement over earlier designs.

Also, I got to thinking about the gold connectors. I assume you mean gold RCA jacks? I've never seen these on a QSD-1, but they were standard on the QSD-1000.

 

[Bonzodog]

I'm sorry, I should have been more clear.

I was referring to the Molex connectors on the cards and mother-board.

But the audio-path goes through 36 Molex points internally, but only 6 RCA points externally.

Which would you expect to have the greater effect?

 

[Cai Campbell]

Which would you expect to have the greater effect?

No contest; the internal points will have much greater effect on overall sonic performance.

Well, it sounds like you have a variation of the QSD-1 I've never seen before. Admittedly, I have a small sample to draw from (I've had five different units in my posession over the years).

So, the variations include (at least):

1. Export unit with selectable voltage.
2. Japanese domestic with 100v fixed voltage.
3. U.S. domestic with 120v fixed voltage.