Sansui QS-1

[Soundfield]

When an e-bayer says ‘refurbished’ or ‘serviced; you don’t really know how much or how little they’ve done (or ruined!). This Sansui QS1 for example-

Seller Refurbished QS-1

The ad says 'seller refurbished', but the rear panel looks pretty grubby and it appears that the sockets haven’t even been wiped clean (you’d think any seller, let alone one ‘refurbishing’ would at least do that to make the thing look half decent, but it’s amazing that so many can’t even be bothered with that simple task!).
The blurb says-“Light (sic) have been replaced with cool blue LEDs to keep the look original” - which of course has done the opposite, they never looked like this! The use of blue LEDs means that the red coloured part of the scale is now not really visible.
And “All controls have been cleaned with deoxit and lubed ” – fascinating how many people think squirting a load of that stuff about constitutes servicing something!
And “Solder is now to standards” – I’ve no idea what that means!

 

[Sonik Wiz]

When an e-bayer says ‘refurbished’ or ‘serviced; you don’t really know how much or how little they’ve done (or ruined!). This Sansui QS1 for example-

Seller Refurbished QS-1

The ad says 'seller refurbished', but the rear panel looks pretty grubby and it appears that the sockets haven’t even been wiped clean (you’d think any seller, let alone one ‘refurbishing’ would at least do that to make the thing look half decent, but it’s amazing that so many can’t even be bothered with that simple task!).
The blurb says-“Light (sic) have been replaced with cool blue LEDs to keep the look original” - which of course has done the opposite, they never looked like this! The use of blue LEDs means that the red coloured part of the scale is now not really visible.
And “All controls have been cleaned with deoxit and lubed ” – fascinating how many people think squirting a load of that stuff about constitutes servicing something!
And “Solder is now to standards” – I’ve no idea what that means!

I totally agree with you about the questionable "refurbishing". It's mentioned on so much vintage gear but I very rarely see any acceptable documentation for it. My 1st piece of real quad gear was a Sansui QS-1 & I'll tell ya there's not much to refurbish. Maybe PS caps. It's a very simple design all transistor with no IC's, a few Sansui mystery modules. I do think it's a very attractive piece of gear, well done for the 70's. Then I look at the condition of the wood case, the splotchy dirty back panel & of course the RCA jacks, & I think this unit may have had a rough time. Changing the VU meters to blue LED's is just ridiculous.

I think my QS-1 I bought for $120.00. So $225 on ebay would be a no go for me on top of everything else.

 

[Soundfield]

Yes, I agree Sonik, it's sad as I also think it's a great looking piece of gear - a classic of it's type really. I'm always on the look out for a decent one but whilst they often come up they frequently don't seem to have been well treated!

I wouldn't even think of buying some thing that claimed to have been serviced or refurbished if the seller didn't have, at the very least, before and after pictures!

 

[Floyfn]

I'm seeing a lot of dust covered old gear, or fast clean type stuff mentioned by Soundfield on marketplace websites all over.
I think people are panicking, having a hard time, etc. over the pandemic and grabbing anything old to sell to make ends meet fast.

 

[furui_suterioo]

I'm seeing a lot of dust covered old gear, or fast clean type stuff mentioned by Soundfield on marketplace websites all over.
I think people are panicking, having a hard time, etc. over the pandemic and grabbing anything old to sell to make ends meet fast.

I got a deal on a nice looking Sony TA-1130 online recently, the seller advertised that it tested works well which it does, but when I took the cover off it was so stuffed full of dust, it must have been sitting in a basement decades. The seller just did a really good job of cleaning the outside and pots, I was surprised to see that much dust inside at first, but its working great so no complaints.

 

[Soundfield]

I'm seeing a lot of dust covered old gear, or fast clean type stuff mentioned by Soundfield on marketplace websites all over.
I think people are panicking, having a hard time, etc. over the pandemic and grabbing anything old to sell to make ends meet fast.

Maybe, but people have been selling crap for years - it's not a new phenomenon!

 

[par4ken]

When an e-bayer says ‘refurbished’ or ‘serviced; you don’t really know how much or how little they’ve done (or ruined!). This Sansui QS1 for example-

Seller Refurbished QS-1

The ad says 'seller refurbished', but the rear panel looks pretty grubby and it appears that the sockets haven’t even been wiped clean (you’d think any seller, let alone one ‘refurbishing’ would at least do that to make the thing look half decent, but it’s amazing that so many can’t even be bothered with that simple task!).
The blurb says-“Light (sic) have been replaced with cool blue LEDs to keep the look original” - which of course has done the opposite, they never looked like this! The use of blue LEDs means that the red coloured part of the scale is now not really visible.
And “All controls have been cleaned with deoxit and lubed ” – fascinating how many people think squirting a load of that stuff about constitutes servicing something!
And “Solder is now to standards” – I’ve no idea what that means!

Yes I don't know why people put stuff up for sale without at least giving it a quick wipe down first. I assume that by saying solder is now to standards simply means that he used lead free solder. Who cares, I much prefer using the old stuff, I'm sure he didn't desolder and resolder everything! Yes it's a really cool looking unit but it's not much of a decoder.

 

[chucky3042]

Just a reminder, I have heaps (somewhere) of the 3 original Sansui decoder chip set. So if you have a pooched chip I can help!!

Regards

Chucky

 

[Soundfield]

.... It's a very simple design all transistor with no IC's, a few Sansui mystery modules.

I've just had a look at the service manual and it's a bit more complicated than I'd imagined-

Particularly as several of those 'mystery modules' are not just close tolerance resistor / capacitor combinations as was usually the case for such things but were transistor arrays -

One of its functions is the very, very strange frequency dependent 'phase modulator' driven by an 8Hz oscillator (!), I'm still trying to get my head around it!-

I've no idea what the thinking behind it was, although it clearly isn't hifi! And what on earth does rear channel phase wobulated at 8Hz sound like (an electrical implementation of a Lesley speaker perhaps)?

 

[par4ken]

That was the way they thought to create or enhance a surround effect artificially. The term "Synthesizer" really applies to this. The effect is subtle but sounds nice with closely spaced speakers in a small room. In a larger room the decoder does almost nothing. I always thought it was a cool idea reading about it in the early 70's. I didn't realise that (most) QR receivers used this circuit as well. Vario-Matrix made this attempt at surround totally obsolete. The term Synthesizer was retained, but doesn't really apply to vario-matrix technology as nothing is synthesised, stereo enhancement would of been a better term.
I'll have to try listening to it through headphones, to see what effect the phase modulation really has.

 

[Soundfield]

Out of interest I've now had a look at the User Manual which gives some sort of explanation of the Phase Modulation concept (although it is mostly hype)-

Basically the QS-1 a simple RM decoder which randomly flutters the phase of the rear channels! I seriously doubt that this really "produces the sound of numerous speaker systems", but it might be entertaining!

 

[MidiMagic]

It might have been an attempt to fix the side localization problem.

The original theatrical Dolby Stereo also used phase modulation so the ear could not find the back speakers.

 

[Sonik Wiz]

I've just had a look at the service manual and it's a bit more complicated than I'd imagined-
View attachment 57520

Particularly as several of those 'mystery modules' are not just close tolerance resistor / capacitor combinations as was usually the case for such things but were transistor arrays -

View attachment 57521

One of its functions is the very, very strange frequency dependent 'phase modulator' driven by an 8Hz oscillator (!), I'm still trying to get my head around it!-

View attachment 57522
I've no idea what the thinking behind it was, although it clearly isn't hifi! And what on earth does rear channel phase wobulated at 8Hz sound like (an electrical implementation of a Lesley speaker perhaps)?

It was a complex design to accomplish simple decoding. The Sansui mystery modules are (with exception of the phase modulators) nothing more than transistors & resistors. Considering the phase modulators were just incandecsnt light bulb coupled to a common photocell, I don't see how it could even keep up with an 8Hz modulation.

 

[Soundfield]

Considering the phase modulators were just incandecsnt light bulb coupled to a common photocell, I don't see how it could even keep up with an 8Hz modulation.

No, nor do I, especially since the filament is slugged by a 4.7uF capacitor! - perhaps that's why it didn't sound too bad !!

 

[jsrstereo]

I notice this thing has 4 surround modes: "Solo", "Concert Hall 1", "Concert Hall 2" and "Surround". Can anyone explain the effects produced by each mode, and is "Phase Modulation" applied to all of them - or ?

 

[Soundfield]

I notice this thing has 4 surround modes: "Solo", "Concert Hall 1", "Concert Hall 2" and "Surround". Can anyone explain the effects produced by each mode, and is "Phase Modulation" applied to all of them - or ?

The user manual describes the modes thus-

The only mode that isn't heavily tampered with is CONCERT HALL 1 all of the others have some significant tailoring of the frequency response of various channels. The Phase Modulation cannot be switched off.

 

[rareed]

When an e-bayer says ‘refurbished’ or ‘serviced; you don’t really know how much or how little they’ve done (or ruined!). This Sansui QS1 for example-

Seller Refurbished QS-1

The ad says 'seller refurbished', but the rear panel looks pretty grubby and it appears that the sockets haven’t even been wiped clean (you’d think any seller, let alone one ‘refurbishing’ would at least do that to make the thing look half decent, but it’s amazing that so many can’t even be bothered with that simple task!).
The blurb says-“Light (sic) have been replaced with cool blue LEDs to keep the look original” - which of course has done the opposite, they never looked like this! The use of blue LEDs means that the red coloured part of the scale is now not really visible.
And “All controls have been cleaned with deoxit and lubed ” – fascinating how many people think squirting a load of that stuff about constitutes servicing something!
And “Solder is now to standards” – I’ve no idea what that means!

The user manual describes the modes thus-
View attachment 57549
The only mode that isn't heavily tampered with is CONCERT HALL 1 all of the others have some significant tailoring of the frequency response of various channels. The Phase Modulation cannot be switched off.

 

[rareed]

I have an old Sansui QS1 that has a bad hum if anybody wants it and will pay for shipping hey can have it

 

[jsrstereo]

The user manual describes the modes thus-
View attachment 57549
The only mode that isn't heavily tampered with is CONCERT HALL 1 all of the others have some significant tailoring of the frequency response of various channels. The Phase Modulation cannot be switched off.

From that description, looks like the "Concert Hall-2" mode is the DuoPhonic mode.

 

[surteess]

Those transistors with resistors inside are called RETs (Resistor Equipped Transistors) - you can buy them from most hobby stores...