Here's an interesting one - Sansui "Switch Box" -The Ultimate A/B+ selector (and related discussion)

JimEGR said:
They are all quite different.
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Sorry for potentially dragging this a bit off-topic, but this Kenwood AX-201 certainly is different!

@skippy124 acquired this one around 15 years ago (we think!) and it's an interesting unit, with a different layout and configuration to most.

The speaker connections almost "look" Sansui-ish, but are different and more heavy-duty in design.

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The "no frills" rack mount components you are speaking of include:

BA-1000 VFET power amp
QSD-1 QS decoder/synth
CD-10 electronic divider
QSD-4 quad decoder
QSD-5B quad decoder

There was another 2RU device in the quad lineup, model and function escape me. Was probably one of the QSE encoders.

Then there were some 4RU quad encoders based on the same enclosure design, QSE-4 and 5. None of these are commonly seen, as they were pretty much exclusively used in recording studios for quad mastering, and radio stations that broadcast quad OTA.
 
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The Sansui and Sony look very similar - likely identical under the hood. Would be interesting to follow the manufacturing dates on these. The Sansui Switch Box looks much more like Sansui gear from that period than the Sony Switch Box looks like similar Sony gear from the period. Wondering if the Sansui Switch Box was first out of the gate and then Sony followed with a few tweaks to the faceplate.

The Kenwood @pete_mac and @skippy124 have looks to be quite unique.

And I updated the title of the thread with "and related discussion" so this is still all on topic. Charting the development and history of this family of components is interesting and helpful for now and in the future when this comes up again.
 
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All of these devices were made for a sole purpose - to provide audio stores a convenient way to demonstrate equipment. McIntosh had one as well - the P349, which they made in house. In mere seconds, the salesman could connect the desired components to a given pair of speakers.

The "lamp" facility was used to light up a pair of lamps aimed to shine on the speakers selected - to let the customer easily see that during the demonstration. Most devices as these include that feature.
 
damacman said:
All of these devices were made for a sole purpose - to provide audio stores a convenient way to demonstrate equipment. McIntosh had one as well - the P349, which they made in house. In mere seconds, the salesman could connect the desired components to a given pair of speakers.

The "lamp" facility was used to light up a pair of lamps aimed to shine on the speakers selected - to let the customer easily see that during the demonstration. Most devices as these include that feature.
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Definitely looking forward to recreating this exact experience here. The Sansui Switch Box was just what I needed to pull my Sansui collection together - and pretty cool to discover a solution I've been pondering for sometime existed already, in none other than Sansui dealer form. It is perfect.
 
I had the same Sansui switchbox that I acquired many years ago, I intended to try it out to accomodate my Sansui collection, but the time went by and I never got around to it. Eventually, as I recall, I sold or traded it.

Let us know how it turns out, hopefully the sound quality is above par, as audio purists tend to frown on switchboxes and how they tend to degrade the signal quality, or so they think. Only the user can decide that once they have a chance to implement it. Hopefully, its beneficial, as its not easy to utilize a whole collection of audio gear, especially if they are all configured in the same room, rather than spread apart into various subsystems in other rooms. Preamps are easier- they dont need any physical wiring connections to speakers, which is not the case with all main amps, so unless someone is ok with moving cables around on a regular basis, a switchbox can make things more manageable. However, you will find that it will be a challenge to keep things neat and tidy- once a bunch of components get hooked up, there will be lots of cables to deal with, so its good to take some time and arrange it properly as I imagine you will do.. Many switchers dont leave alot of space between terminals, so extra care is needed to avoid accidental shorts from cable tip accidentally touching each other- electrical tape for insulation might come in handy for that.

Luckily, the Sansui box has some weight to it, Ive noticed that smaller/lighter switching devices will easily be tugged along its resting surface by the pulling force of all the wires connected to it.

Ps: Yes- x balanced amps wont work with switchboxes, I forgot about that when I once hooked up an AU-G77X to a switcher and it did not put out a proper stereo image.
 
Bright_Star said:
I had the same Sansui switchbox that I acquired many years ago, I intended to try it out to accomodate my Sansui collection, but the time went by and I never got around to it. Eventually, as I recall, I sold or traded it.

Let us know how it turns out, hopefully the sound quality is above par, as audio purists tend to frown on switchboxes and how they tend to degrade the signal quality, or so they think. Only the user can decide that once they have a chance to implement it. Hopefully, its beneficial, as its not easy to utilize a whole collection of audio gear, especially if they are all configured in the same room, rather than spread apart into various subsystems in other rooms. Preamps are easier- they dont need any physical wiring connections to speakers, which is not the case with all main amps, so unless someone is ok with moving cables around on a regular basis, a switchbox can make things more manageable. However, you will find that it will be a challenge to keep things neat and tidy- once a bunch of components get hooked up, there will be lots of cables to deal with, so its good to take some time and arrange it properly as I imagine you will do.. Many switchers dont leave alot of space between terminals, so extra care is needed to avoid accidental shorts from cable tip accidentally touching each other- electrical tape for insulation might come in handy for that.

Luckily, the Sansui box has some weight to it, Ive noticed that smaller/lighter switching devices will easily be tugged along its resting surface by the pulling force of all the wires connected to it.

Ps: Yes- x balanced amps wont work with switchboxes, I forgot about that when I once hooked up an AU-G77X to a switcher and it did not put out a proper stereo image.
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Yes thanks. I will definitely keep this thread updated as I assemble everything. Likely months or years out from final(ish) studio configuration with lighting.

I have many plans for using it sooner than later though. First will be a three-way comparison of the AU-101: 1 bone stock, 1 like-in-kind "restoration" by the PO and 1 I restored with a highly informed spec from @Leestereo. Then the AU-*17 series once I finish the AU-517/717, and a bunch more listening comparisons.

Your comment about the switch box degrading sound quality is interesting. Had a long time audiophile friend make a similar comment today - and in that I'll have to try some testing with and without the switch box to hear if I can tell a difference. More to be revealed.

Pretty fun Sansui score.
 
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Having worked at a chain of Hifi stores back in the 70’s through the early 80’s, there was a team of people that built our A/B switches. They worked quite well as long as we were using a single source (i.e. one receiver/integrated amp/separates with a dedicated turntable/tape deck, etc.)

Once we tried to use this custom system to A/B different receivers/integrated amps/separates into a a given set of speakers, that’s when things got complicated.

What we learned was that unless there is some sort of accommodation to be able to switch back and forth instantly from one amplification to another, it created many “farts”, “pops” and reset issues.
Could have been due to impedance issues(?).

While I do not specifically remember the details on said accommodation and not knowing if OP’s Sansui switch can accommodate these issues, I will leave it to more informed AKer’s to opine accordingly.
 
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^ that is a valid concern with a switcher like this. Since it is a passive switcher (signals are routed through the ganged multiple pole switches directly (versus powered relays as with the Yamaha version, and even that can have bad relays), it will be subject to the same issues all of our (unrestored) vintage gear suffers, with dropouts, pops, etc. from tarnished or worn switch contacts. Given the age and likely long term lack of use of a unit like this has seen, I'd say a teardown and cleaning will end up needing to be done. Certainly to ensure best possible signal transfer, it should be done.

A modern electronic matrixed switcher is the route commonly taken to achieve this sort of functionality now, though those are usually only switching line levels, not the speaker loads.

I will be interested to see how much (or little) trouble is encountered with this unit once it is hooked up and being used.
 
We used to demonstrate how tough a given amp was by using a 1x2 to depress all of the speaker switches simultaneously and run them all. Some amps could do this no problem. Others, not so much.
 
I seem to remember seeing this recently on my HiFishark 'Sansui' search output and stirred some interest as I have the same issue....many items and in 3 separate, [partially interconnected] systems. I do use a modern line-level 4 way switch with volume & remote [3 actually] to handle inputs but with 2 speakers sets it gets harder. I haven't seen a larger multi switch like the Sansui but with digital switching and a reasonable price tag!
 

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Does anyone have a schematic for any of these switchers? I assume they're pretty basic and one could easily build a DIY version. I would think they need some way to avoid hot-switching to avoid creating transients that could harm components. I'm sure with enough time almost anyone could design a switcher, but it's always nice to see a design that has been designed to avoid pitfalls that could destroy an expensive set of speakers.
 
@JimChap, these are very rare in the wild, so expect to spend a lot of time looking for one. That said, one could just as easily show up on eBay tomorrow. More likely you will be looking for months or even years before one shakes loose. I base this on my being a collector of Sansui (and other vintage audio) since 1996, and have a pretty solid feel for what's around and how often the real rarities show up for sale.

Keep in mind, this switcher wasn't exclusive to Sansui, and they didn't even make it. It was produced by a subcontractor, and similar units were supplied to other companies (Yamaha, Pioneer and Toshiba that I've seen myself, among others). Don't limit yourself to looking for only the Sansui version, there 's nothing particularly special about it versus the other branded units (outside of having Sansui's logo affixed) since it wasn't even produced in house.

Which is to say you aren't getting "Sansui quality" specifically, you are getting a pretty generic passive switcher that just happens to have a lot of I/O capability. I don't think it has ever been determined just who built these, but I suspect it was an American outfit who built and supplied them for audio dealers located here. It may have even been based on an existing product that was tweaked for offering to big HiFi makers who sold their product line in dealer showrooms. There are similar modern switchers made for retail display and control of home and car audio. These typically use logic controlled switching with the signal path being routed through relays instead of multipole switches.

I'll add that the Pioneer and Yamaha units were upgraded with 2 digit nixie tube external displays (though these were optional, I believe) so were actually better appointed, feature wise. These are, of course, just as rare - if it more so - and their price will reflect the dearth of supply.
 
These used to come up on eBay every two or three years (I only looked for Sansui versions). I stopped looking at audio postings about 5 years ago. If I remember correctly mine needed a transformer replacement (I have no real knowledge of electronics) and because I found mine before I found out about the later silver X balanced Japan only models, I had mine painted black.

Although I have this, most of my amplifiers are connected to my AMCO switchbox, and it is just too much trouble to make the change over to this unit.

As Sansuiman and others have pointed out, these were not made by Sansui, were made with the names of other audio manufactures, and probably (I am told) should not be used to switch between X-balanced amps or tube amps.

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@mjs1 raises a very important point that needs to be stressed: these switchers cannot be used with an amp that has ungrounded outputs, as with all the X-Balanced and Alpha amps by Sansui. The switch boxes use a common ground bus for all speaker in and out connections, and will damage such an amp of connected.

Edit to add: having gone back through this thread, I note now that there is some similarity between the Yamaha and Kenwood versions, as both appear to use the same level meters. Both units have differing input/output provisions, and vastly different wiring accomodations, but I again suspect both units (and others) were sourced from the same supplier, who would customize to spec for the right price. Whether it was Azden, or a US manufacturer like Switchcraft, despite some obvious differences, they mostly appear to go back to a common source.
 
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