Sansui AU-X1 & TU-X1

Interesting video. I would love to one day, be able to look in the general direction of the TU-X1. I dont expect that I will ever get to see one in real life.
 
His follow-up video(s) on the AU-X1 should be very interesting. I'm looking forward to see how far he takes this restoration. :lurk:

Too bad the unit he got looks like it had been previously worked on. I hope he goes all the way with the resto and then put's it on the bench.
 
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I was a little horrified at what substitutes Tony used for the driver transistors, 2SA940 has a ft of 4mhz, the Toshiba's have a ft of 100mhz.
This high bandwidth design makes the amp very fast and is part of its sound, so hope he puts those Toshibas back in there.
 
He's got the right drivers on the way, I pointed it out on the comments, someone else had pointed it out too, but all good, Tony does a great job!!
I actually enjoy Tony's videos, they are actually a great resource if you are working on these old vintage amps, he does a lot of the Japanese receivers, integrated etc etc....
 
Tony just posted an update specifically talking about the high speed transistors. I learned something new about the X1, apparently another benefit of using these high speed transistors is that they were able to use a very small amount of negative feedback.

 
Ah, nice, I have been periodically looking and was hoping he'd get the next instalment up soon.....
Its nearly time for dinner here so I know what I will be doing after I have finished aligning the tuner on this QRX9001, with pretty much the same test gear Tony has I might add!!
I have the same HP RF Generator, I also have one of those Keithley THD multimeters too, they are really good, simple to use, and go to 4 digits for measuring low impedance things.....
 
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That video gives a really easy to understand description of the reasons why high speed transistors are used in audio amplifiers. Also how their use fundamentally affects the design and operation of some audio amplifiers. :thumbsup:
 
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Yeah great job of explaining all these .
I'm very lucky on 2sa968 2sc2238 or whatever they are since I've bought some of them in the past, for all my amps , since sansui used them everywhere from AU/X1 , G22K G33K, BAs , B2301 B2302 AND ALL THE ALPHAs and so on.
 

This is really enjoyable to watch, especially for those of us familiar with this amp. I can't wait for the next video. :lurk:

He brings up the point that has been discussed here recently about just going ahead and replacing those little transistors a la shotgun. One thing that surprised me was the quality of the binding posts (silver huh?), I had no idea. Glad I kept the originals in mine.

Looks like his unit has the early phono stage. I emailed him about the G5V-2 relays to make sure those little Fujitsu devils don't fool him into thinking they are working fine. As we know, replacement of those is a must.
 
That was great! We look forward to the next video. Thank you so much.
Now let's go listen to my recapped 919.:D
 
This is really enjoyable to watch, especially for those of us familiar with this amp. I can't wait for the next video. :lurk:

He brings up the point that has been discussed here recently about just going ahead and replacing those little transistors a la shotgun. One thing that surprised me was the quality of the binding posts (silver huh?), I had no idea. Glad I kept the originals in mine.

Looks like his unit has the early phono stage. I emailed him about the G5V-2 relays to make sure those little Fujitsu devils don't fool him into thinking they are working fine. As we know, replacement of those is a must.
Hahaha so did I!! He must think we are crazy or something!!

I haven't seen the next instalment, but I saw it turn up last night so I will have a look this morning whilst its breakfast time...
 
Hahaha so did I!! He must think we are crazy or something!!

I haven't seen the next instalment, but I saw it turn up last night so I will have a look this morning whilst its breakfast time...

:rflmao:CRAZY?!?! Who's crazy?? :naughty: :crazy:

Ahem...I think we prefer to be referred to as fervent AU-X1 aficionados :smoke:...
 
This is really enjoyable to watch, especially for those of us familiar with this amp. I can't wait for the next video. :lurk:
I agree, although I don't agree with absolutely everything he says, the walk through, with regular references to the test gear used, I am finding very interesting. I also watched his videos on the TU-X1 - similarly fascinating.
 
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