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Old 1st September 2011, 08:35 PM   #631
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0.1uF film caps could be put over the fuses. Otherwise it looks pretty to me.
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Old 1st September 2011, 11:18 PM   #632
a.wayne is offline a.wayne  United States
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Why over the fuses Gerhard ...?
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Old 1st September 2011, 11:22 PM   #633
a.wayne is offline a.wayne  United States
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Quote:
Originally Posted by Lazy Cat View Post
I like this thread because of two things:
First, "two building blocks" were presented in basic topology info: SSA sym-diff CFL front-end and BIGBT output device, both very well practically tested, recognized as very stable and reliable, just what a DIY-er needs.
Second, simplicity of the SSA design is very appealing to many but just because there is no no-brainer cook-book recipe it is only available to experienced builders who knows and who dares. Like Nico in the first place, who immediately recognized benefits of the SSA design.
So the Q is, who dares next?

P.S. My current "work in progress" goes on this. I am sure that at the end, if something like that exists, there will be a few "Best of SSA" versions.

LC post 347 is that schematic good ?

also ,

- post #224 dual mono PCB, Nico's version according to Nico sch, one pair 2SJ162/2SK1058 laterals
- post #227 single mono PCB, Alex's version according to Nico sch, one pair 2SJ162/2SK1058 laterals
- post #301 single mono PCB, Alex's version according to Miib sch, three pairs 2SJ162/2SK1058


Which one is Nico running with ...?

Last edited by a.wayne; 1st September 2011 at 11:25 PM.
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Old 1st September 2011, 11:34 PM   #634
AKSA is offline AKSA  Australia
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Lazy Cat,

Your design is excellent, but the 15V supplies you use to elevate the fb nodes are required only because the input devices are bjt devices.

Your circuit is very, very close to Jean Hiraga's Le Monstre, but the advantage topologically of a jfet front end is the joining of the sources of the input devices, making fb injection very much simpler.

I have been simulating variants of Le Monstre, and the performance is very similar to your circuit. I feel your SSA has the great advantage of being all bjt; comp jfets are very hard to find these days. But here is something to consider, this is a pretty good first and second stage for a conventional output stage, though my preference is for a diamond buffer.

Again, hats off to you, to Nico and to Alex_MM, who does brilliant pcbs!

Cheers,

Hugh
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Old 2nd September 2011, 12:01 AM   #635
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Quote:
Originally Posted by Idefixes View Post

Click the image to open in full size.

Hi Lazy Cat,

Can I replace ECF20N20/ ECF20P20 with 2SK135 /2SJ50?
Can we expect to see any time soon:
- SSA BIGBT High Performance, sch, PCB (single ch), separate PWS

Regards to all
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Old 2nd September 2011, 12:38 AM   #636
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Thanks for encouraging words Hugh. It was not a SSA lucky strike to me, on contrary a lot of logical thinking to resolved it like it is now. Complementary j-fet input is simplicity in its pure meaning, but to put BJT's instead was a challange to me. I started from a simple question: "How to put BJT's in CF diff input and arrange all DC working points in proper function?", so I came up with tha SSA. It is probably closest replacement to Hiraga's input and it is made from all BJT-s resulting in extreme low noise and wide bandwidth. SSA input's vital parameters are of so high performance that scalability to any kind of amp (VAS+output) as well as 0dB diamond output buffer presents no difficulties. As I already mentioned before, the limits are within designer's imagination.
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Old 2nd September 2011, 12:46 AM   #637
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Quote:
Originally Posted by a.wayne View Post
LC post 347 is that schematic good ?
It should be in general, I am currently working on it. All the details will be presented soon.

Quote:
Originally Posted by a.wayne View Post
Which one is Nico running with ...?
This one:

- post #224 dual mono PCB, Nico's version according to Nico sch, one pair 2SJ162/2SK1058 laterals
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Old 2nd September 2011, 01:02 AM   #638
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Quote:
Originally Posted by buzz2 View Post
Hi Lazy Cat,

Can I replace ECF20N20/ ECF20P20 with 2SK135 /2SJ50?
Can we expect to see any time soon:
- SSA BIGBT High Performance, sch, PCB (single ch), separate PWS

Regards to all
Yes you can, but aren't 2SK135 /2SJ50 a little obsolete? Still, you can put them in action if you have them laying around.

SSA BIGBT High Performance is a work in progress and will be presented soon.

But you can overtake me with SCH, PCB, PWS.
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Old 2nd September 2011, 01:05 AM   #639
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Quote:
Originally Posted by Idefixes View Post
So i made corrections and modifications that you advise me :

Click the image to open in full size.

Marc
Bravo Idefixes, you are planing a great PCB there. It will be a very nice SSA amp with TO-3 output pair.
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Old 2nd September 2011, 01:12 AM   #640
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I found that bypassing the fuse holder with a film cap sounds better.
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