Which Sansui integrated amplifiers run toroidal transformer(s)?

[JimEGR]

Which Sansui integrated amplifiers run toroidal transformer(s) and are good/desirable?

 

[bubhardy]

It looks to me like the AU-D55X does.
I have one that I need to repair.

I’m sure that someone else can give you a more thorough list.

 

[pete_mac]

There are many - if you google “sansui transfomer toroidal” it brings up a few images as a starting point.

Amps like the AU-20000 B-2101/2102, AU-919 (EI and toroidal combo), and many of the big receivers spring to mind immediately.

I also seem to recall that the transformers for some of the bigger x-balanced amps are toroidals potted in a square metal enclosure, but I’ll need to find pics/info to confirm that so take it with a grain of salt for the time being.

 

[JimEGR]

There are many - if you google “sansui transfomer toroidal” it brings up a few images as a starting point.

Amps like the AU-20000 B-2101/2102, AU-919 (EI and toroidal combo), and many of the big receivers spring to mind immediately.

I also seem to recall that the transformers for some of the bigger x-balanced amps are toroidals potted in a square metal enclosure, but I’ll need to find pics/info to confirm that so take it with a grain of salt for the time being.

Thanks @pete_mac. I appreciate the response. I definitely started with Google (hard to decipher what the ranking or consensus is with the results), and searched here on AK (only 4 threads with “toroidal” in the title).

 

[JimEGR]

It looks to me like the AU-D55X does.
I have one that I need to repair.

I’m sure that someone else can give you a more thorough list.

Thanks!

 

[Hyperion]

some of the bigger x-balanced amps are toroidals potted in a square metal enclosure

AND, it has been alleged that some models have a toroidal shaped enclosure but are suspected to be EI type transformers submerged in hard potting compound, conveniently disguising what they actually are - the AU-D11 II being one of the ones under suspicion, I'll leave it to your imagination to decide what I think about that - being as I am such a fan of that model.

More Toroidal models AU-9900/11000 & AU-9900A/11000A, AU-X1 & AU-X11, C-2102, (C-2101 ?), CA-F1.

 

[bubhardy]

AND, it has been alleged that some models have a toroidal shaped enclosure but are suspected to be EI type transformers submerged in hard potting compound, conveniently disguising what they actually are - the AU-D11 II being one of the ones under suspicion, I'll leave it to your imagination to decide what I think about that - being as I am such a fan of that model.

More Toroidal models AU-9900/11000 & AU-9900A/11000A

So, that round can in my AU-D55X might not be a toroidal xformer? It boggles my mind to think that Sansui would try to disguise an EI xformer as a toroidal one. I’m not doubting you, John. It’s just that I would think the expense involved would not make business sense, especially for a company first founded as a transformer manufacturer. If exposed at that time, I would think that it would have been very bad for their reputation. Maybe I hold Sansui in too high of a regard?

 

[Hyperion]

It’s just that I would think the expense involved would not make business sense, especially for a company first founded as a transformer manufacturer. If exposed at that time, I would think that it would have been very bad for their reputation. Maybe I hold Sansui in too high of a regard?

I agree with you, a daft thing to do if you are a company with Sansui's roots and reputation. In the pictures of the allegation (on here), I did see what looked like a squarish shadow in the potting compound, but far from conclusive in my opinion. I think the simplest way to prove/disprove it, would be to crank the suspect amplifier for a couple of hours (no hardship) - then use a thermal imaging device to see what the transformer looks like.

 

[JimEGR]

Thanks @Hyperion !

 

[jd-audio]

..So, that round can in my AU-D55X might not be a toroidal xformer? ..

..far from conclusive in my opinion..

I did found the following text in a 1985 Sansui brochure stating a toroidal transformer is present:



So now it looks like a duck, it is described as a duck, ..

Have fun
-John-

 

[Trw]

An interesting consideration..i don't have a single toroidal in my Sansuis yet being from the uk many low end amps i've owned do have them

 

[bubhardy]

I agree with you, a daft thing to do if you are a company with Sansui's roots and reputation. In the pictures of the allegation (on here), I did see what looked like a squarish shadow in the potting compound, but far from conclusive in my opinion. I think the simplest way to prove/disprove it, would be to crank the suspect amplifier for a couple of hours (no hardship) - then use a thermal imaging device to see what the transformer looks like.

Great idea, John! And doable, with modern technology. I have no idea of the cost of a thermal imaging device, but it’s conceivable that isn’t expensive. You can probably buy one on Amazon! (I like this guy!)

 

[bubhardy]

I did found the follow text in a 1985 Sansui brochure stating a toroidal transformer is present:

View attachment 2670438

So now it looks like a duck, it is described as a duck, ..

Have fun
-John-

It IS in a round can. I don’t have a photo handy.
Toroidal became “all the rage” back in the 80s, in quality audio gear, as I recall. All about wringing the last little bit, from ideal amplifier design. I suppose it still is today.

 

[Rey1]

AU-G99X

 

[quadklipsh]

Which Sansui integrated amplifiers run toroidal transformer(s) and are good/desirable?

my AUD707X.

 

[Sui-Yogi]

Is this AU-517 counts or ?……

 

[bubhardy]

Is this AU-517 counts or ?……

Look like toroids to me. Nice big ones, that can source a lot of current. Just don’t have a cover.
I didn’t realize that the 517 had those, since the 717 doesn’t.

 

[pete_mac]

I didn’t realize that the 517 had those, since the 717 doesn’t.

They are aftermarket transformers, not originals.

 

[Sui-Yogi]

Look like toroids to me. Nice big ones, that can source a lot of current. Just don’t have a cover.
I didn’t realize that the 517 had those, since the 717 doesn’t.

I manage to blow up one so only way to make it work again, was winding two new ones.

 

[KeithD]

For Sansui's quad equipment, QRX-9001 has a toroidal transformer. I think it's the only quad unit to have one.