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TO-3 SYMASYM

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#622
Hi Adrian.

Many thanks, the chassis is standard 19 inch rack mounted, I did a modification to make it look nice, well making chassis is really tedious but i'm glad all module fit perfectly.
I think i did a great job on the modules placement, the amp is quiet no hum, no noise and it sounded great too.

Regards,
Junie
 
#625
Rudolf, I have not yet planned another round of group-buy for the SYMASYM.
But if there is some demand for it: I will do of course.

And I would like and offer: SYMASYM-PCBs, PSU-PCBs, SpeakerProtection-PCBs and Soft-Power-On PCB.

The SYMASYM is easy to build, is not using any CARNIVAL-components, can be DIYed by a beginner on a Saturday afternoon
and sounds astounding well.

Junie's build is the most beautiful DIY-build of an AMP that I have ever seen.
My own build (see attached image) cannot compete with Junie's build from a craftsmanship point-of-view - allthough:
I have given my SYMASYM a very outstanding attenuator: a motorized, remotely-controlled potentiometer adjusting
George Stantscheff's Lightspeed Attenuator.

Tell me which / how many PCBs you want to have.

Best regards - Rudi_Ratlos
 

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#628
Rudi_Ratlos said:
Rudolf, I have not yet planned another round of group-buy for the SYMASYM.
But if there is some demand for it: I will do of course.

And I would like and offer: SYMASYM-PCBs, PSU-PCBs, SpeakerProtection-PCBs and Soft-Power-On PCB.

The SYMASYM is easy to build, is not using any CARNIVAL-components, can be DIYed by a beginner on a Saturday afternoon
and sounds astounding well.

Junie's build is the most beautiful DIY-build of an AMP that I have ever seen.
My own build (see attached image) cannot compete with Junie's build from a craftsmanship point-of-view - allthough:
I have given my SYMASYM a very outstanding attenuator: a motorized, remotely-controlled potentiometer adjusting
George Stantscheff's Lightspeed Attenuator.

Tell me which / how many PCBs you want to have.

Best regards - Rudi_Ratlos
Click to expand...
Hi Rudi_Ratlos,

There is some demand : I am also interested in getting these SYMASYM-PCBs, with the others too (it should be : 4x SYMASYM-PCBs, 4x PSU-PCBs, 4x Speaker-Protection-PCBs, 4x Soft-Power-On-PCBs). I should prefer to pay you by bank transfer if possible. Let me know. Thank you.

Regards

Rephil
 
#629
Hi Rudi_Ratlos (nice nick ;-),

I would be interested in buying

4x SYMASYM-PCBs, 4x PSU-PCBs, 4x SpeakerProtection-PCBs and 4x Soft-Power-On PCBs

if you are really starting another GB.

And WOW, I am definitely looking forward to that new PCB of yours!
So far, I was looking into the AMB Laboratories LCDuino for that purpose, but getting all PCBs from one source is definitely a feature. And I still haven't decided on the preamp/buffer to use, so I can wait....

What kind of microcontroller are you planning to use?

Best regards,

Rudolf
 
#631
Gentlemen, find attached two images showing how to wire up a SYMASYM amplifier.

The 1st picture shows a typical stereo-configuration (same as I have built).
The 2nd picture shows a what I call "Dual-Mono" configuration (same as Junie did).

The Soft-Start PCB is only needed, if you go for the "Dual-Mono" configuration and the combined power
of the 2 transformers is rated at approx. 500VA.

Please keep these pictures in your mind, when you order PCBs.

Best regards - Rudi_Ratlos

P.S. I will of course open a new round of group-buy, if there is demand for it.
 

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#634
Hi Rudi_Ratlos,

If you offer also something else (like transistors NJW0281-NJW0302 ?), I am interested too. Let me know. Thank you.

As I have many TIP35C and TIP36C, I would like to know if somebody did try them as output transistors with the TO264-TO3 PBL SYMASYM using a 25V-0-25V transformer, and what is the result. Thank you.

Best regards.

rephil
 
#636
I will not provide you with anything else but the PCBs!
Matching the output transistors (NJW0 for example) is a time-consuming job, and I am currently very much engaged with my own projects
(see attached image).

But: the success of a SYMASYM does not rely on perfectly matched output transistors.
One of the SYMASYM's secrets is the very fast and direct feedback!
Give the SYMASYM a matched pair of differential input-transistors - that is it.

@GrobAlt: please read this thread: http://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-new-passive-preamp.html

Best regards - Rudi_Ratlos
 

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#638
Hi, Rudi. I used the extra SymaSym 5.3 boards to build the TO-3 version as shown in the early posts on this tread. Some lead bending and components soldered under the pcb but is works and sounds excellent (Bias at 13mV per 0.22R and +-35V). I was wondering if I can safely increase the rail voltage to +-40VDC as I have a spare 28-0-28 toroid with a 15-0-15 VAC as well for a preamp. Any problem?? Same bias adjustment. I put in 63V caps already.
I think I prefer the sound of this amp version to either the 5.3 or even the FC100 dare I say !!
I would also like to be include for 2 amp PCB in the next group buy please.
Thanks, Jean
 
#640
Jean,

... but be aware of the breakdown voltage of the input differential transistor pair.
For example: VGDS of 2SK170 is −40 V! So: you will be "on the edge".

And yes: the TO3 version is the best sounding version of the SYMASYM in my ears as well, but cannot compete with the FC-100 in my ears.

Best regards - Rudi
 
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