BA-F1 restore

Will also be interesting to see how those outputs perform and if you will need to add any small value caps to the feedback circuit to prevent overshoot during square wave testing later on.

:lurk:
 
Will also be interesting to see how those outputs perform and if you will need to add any small value caps to the feedback circuit to prevent overshoot during square wave testing later on.

:lurk:

Yep, I did some signal generator testing of the set of original OP transistors before I removed them, I have a good idea of the square wave output at various frequencies. All was nicely damped, nice and square with no overshoot - I took the trouble as I thought this would be important to know. :)
 
I know it's not new. It just seems to be explained and done in such a way to be practical for most people. Maybe someone that wouldn't consider this before, will now.

Got to agree with that; the detailed instructions make this much more approachable for many of us.
 
This should work for the X1 as well. I guess this solves the output transistor problem for those impossible-to-find high-speed outputs! Let's spread the word!!!!
Yes, and the approach reaches other models/brands, too, including KA-907's 2SA165 / 2SC2489 (50MHz), L-07MII's 2SC2337/2SA1007 (70MHz), etc...
 
Well, bench testing complete, listening to it now for the first time, being driven by my C-2102 pre-amp (- fully reconditioned) - it's beautiful, plenty of bass with a very nicely presented image. Female vocals are very nice, and rock music makes you feel like turning it up!

Just a soak test and final set up to do - then cosmetics such as speaker terminals, remove and clean the front panel etc.
 
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Nice. Look forward to your extended eval and your results regarding the bench testing.
 
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Well, bench testing complete, listening to it now for the first time, being driven by my C-2102 pre-amp (- fully reconditioned) - it's beautiful, plenty of bass with a very nicely presented image. Female vocals are very nice, and rock music makes you feel like turning it up!

Just a soak test and final set up to do - then cosmetics such as speaker terminals, remove and clean the front panel etc.

Great thread! I've been following all the way along. Can you comment on sound and build of BA-F1 vs AU-X1/11 ?
 
Can you comment on sound and build of BA-F1 vs AU-X1

Yes, the BA-F1 is similar to the AU-X1 - but less refined although it does extract a fair amount of detail. The rock music presentation of the BA-F1 reminds me a bit of the AU-717. I should think the BA-F1 would sound significantly different depending on what pre-amp it is paired with.

But I may just be telling you what my C-2102 sounds like paired with the BA-F1. :confused:

I could do with trying some more rock music, and some classical. :music:
 
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Yes, the BA-F1 is similar to the AU-X1 - but less refined although it does extract a fair amount of detail. The rock music presentation of the BA-F1 reminds me a bit of the AU-717. I should think the BA-F1 would sound significantly different depending on what pre-amp it is paired with.

But I may just be telling you what my C-2102 sounds like paired with the BA-F1. :confused:

I could do with trying some more rock music, and some classical. :music:

I guess the ultimate comparison would be to have the BA-F1 paired with the CA-F1.
 
That is excellent ! As comparison the pre-drivers I swapped to in the 999, ksa1220/ksc2690 are 26/19 pf ! - they are rated at +1A and that's the problem - high Ic = capacitance. I am afraid to use the ksa1381/ksc3503 since they are only rated at 100mA with originals at 500/200.

-----------------------------------------------

John - Your restorations are always so well considered and thoughtful, striking a balance of staying true the original design while only carefully and deliberately up-rating specs when called for :thumbsup:


And here I was all impressed with the new Toshiba TTA/C004 devices with 17 and 12 pf Cob.

Nice work on the BA-F1, btw.
 
I installed the replacement speaker terminals over the past weekend, what a job. Who could have guessed that Sansui used a round hole in the outer rear panel but used a square hole in the stiffener plate behind the rear panel. This meant some filing was required to the square holes (8 of them) in the stiffener plates to ensure that the through panel insulators for the terminals seated correctly and did their job.

I also changed the mains lead for a 3 core round cable, in favour of the figure of 8 (2 core) original cable. (earth in the new cable left disconnected).

I got the meters and their illumination cleaned and set up, and managed to view the peak lights working without blowing up my puny 8 ohm loads. :D

So there you have it, I am listening to it now with covers off, I will post some final pictures when its modesty is restored. :D
 
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