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TO-3 SYMASYM

Carl,

please do not misunderstand me.

The original SYMASYM was designed /evaluated with a DC-blocking capacitor with a value of 10µF!
I only told you, in case you do not have a 10µF capacitor at hand.
Try, what you have, and take, what pleases your ears most.

Best regards - Rudi_Ratlso

The solens are kind of large so I may start out with the WIMA's and let them burn in for a while...The daytons came out of a JFET preamp that I abandoned...but they did sound nice.
 
Carl, which value did you order for the input DC-blocking capacitor C1?

The schematics in the "Builder'S Manual" that I sent you, shows C1 with a value of 10µF.
As I have been told, the highpass consisting of C1 and R3 + R4, results in a 240ms time constant. That gives a F-3dB = 0.66Hz.
I have never tested, if the SYMASYM can handle frequencies as low as these.

A 3.3µF, even a 2.7µF DC-blocking capacitor will do it as well.
The PCB accomodates for capacitor grid-sizes from 5 - 27.5mm.



Best regards - Rudi

The MKS4's I ordered have a lead spacing of 15mm - it is hard to tell but looks like the board will accommodate this spacing - correct?
 
Yes, it does, Carl.
The position is marked in "neon-green".

Best regards - Rudi
 

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Carl, the value / type of DC-blocking capacitor on the input is not as essential as you think.
Take any "good" Polypropylene, Poly-Carbonate (if you find), Polyester, you may even have a look at

Humble Homemade Hifi

do not use a Mundorf Silver/Oil, whose long leads act like an antenna, ...

Maybe that your music player, a CD-player for example, uses a very low-cost coupling capacitor in its output network.
You will not be able to raise the quality of the frequency spectrum in this case by using a Silver/Gold cap as DC-blocking capacitor.

What is more important, is to use:

- closely matched transistors in the input differential pair (Q1, Q2)
- matched 2N5401 (Q5 and Q6)
- matched 2N5551 (Q8 and Q9)

These transistors are mainly responsible for a low distortion on the output.

If you want to "play around" with different types of transistors of the input differential pair (2SK170, MPSA18, BC550C, 2N5551, ...),
I recommend you to use a rig like the one attached to this post.

Best regards - Rudi
 

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Gentlemen,

the SYMASYM-PCBs are on their way to me, and you all will have them by the end of this week / next week at latest.

I sent to all of you the "SYMASYM - Builder's Manual (German version)".
I did not yet translate it into English - this would be a very hard job for me.

Have you all been able to translate the "significant parts" of the manual to your mother language?
Do you all know, how to build, how to adjust, ..., the SYMASYM?

Best regards - Rudi
 

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Symasym BOM,

Here is the latest version I put together...

Joshvi - not sure if you are talking about this pdf but I put this together from the schematic and the PDF's of the board in the manual.

I took all the corrections to date and made all the necessary changes.

Again, this would be for one channel.
 

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I received the PCBs some hours ago and will begin to pack your letters right now.
I will take your letters to the post-office tomorrow morning.

I have ordered more PCBs than I actually needed for this round, and I have a couple of PCBs left.
If somebody comes across this thread, sees the beautiful red-and-gold PCBs and thinks: "I am too late again" - No! You are not!

Best regards - Rudi_Ratlos
 

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