diyAudio (
-   Group Buys (
-   -   TO-3 SYMASYM (

Rudi_Ratlos 13th May 2011 11:08 AM


I will be able to offer you:

- the AMP PCB for 13€
- the DX PSU PCB for 7€
- the LSProt PCB for 5€

International shipping in coated letter is 5€.
If you pay via PAYPAL please add 4% PAYPAL cost.

The main group-buy thread is documented here (German Analog Forum - have a look at the pictures):

I will close the group-buy next week.

Best regards - Rudi_Ratlos

Rudi_Ratlos 16th May 2011 07:17 AM

This group-buy is closed now.
The interest in these PCBs has not been big in this forum, but I have a lot of orders from the German DIY forum.

Yesterday night I rendered the PCB with EAGLE3D and Povray(though some components are still missing).

This is, how the PCB will finally look like:


Best regards - Rudi_Ratlos

Rudi_Ratlos 18th June 2011 01:05 PM

This is the result:

Isn't this PCB a beauty?

I did not apply power yet, but I am sure, it will sound as good as it looks.

Best regards - Rudi_Ratlos

meanman1964 18th June 2011 03:05 PM

Rudi,very nice ,clean and ordered layout.

Rudi_Ratlos 29th July 2011 04:03 PM

The 1st round of my TO-3 SYMASYM group-buy has been an incredible success in Germany.
This version includes a Cap-multiplier for the frontend and uses 2 pairs of TO-3s on the output.

The German DIYers like to build mono-blocks, and here is an example, how the TO-3 SYMASYM has been set up by one of them:

There has been one flaw concerning my design (the power dissipation of the driver transistors), and I did a few minor corrections
(after simulating them thoroughly) on the schematics and mounted the drivers on the L-profile as well.

Have a look at the resulting version 2 - layout:

The red pads and tracks are showing the copper pads and tracks on the top-side of the PCB.

The layout, PCB - quality and sound of this amp is unmatched. I do currently not see any rival to this amp.

My TO-3 SYMASYM is not only a hommage to TO-3 transistors; this AMP "plays" music.

I will offer a very limited edition (a "Small Kit", consisting of PCB, TO-3s, MPC74 emitter resistors and ALU-L Profile) - the TO-3 SYMASYM LE -
by the end of August.
The price of a small kit will be very fair.

Best regards - Rudi_Ratlos

dadod 3rd August 2011 10:45 AM


Originally Posted by Rudi_Ratlos (

The layout, PCB - quality and sound of this amp is unmatched. I do currently not see any rival to this amp.

Best regards - Rudi_Ratlos

This is quite a statement. Can you explain why is this the best amp of all?

RKH 4th August 2011 03:08 PM

I am interested in one of your "small" symasym kits. Please add me to your list.


Rudi_Ratlos 4th August 2011 05:16 PM

...why is this the best amp of all?

I did not use these words, Damir, and I did not say:" ... sounds better than ..."

I emphasized the quality of the PCB, the elegant layout - approved by my layout-mentor -that took many, many hours to do,
resulting in vivid, smooth tracks, clear distinction between Power- and Signal-tracks, take - off points, where they should be,
the beautiful "TO-3 SYMASYM Builder's Manual", ..., and the sound.

I did some small enhancements on Michael Bittner's original design (added a CAP-multiplier for the front-end, for example), but
maybe it is the synergy of his folded cascode structure, his toughly coupled feedback and TO-3 transistors on the output that
produces a sound: power and dynamics, more than you can bear, smooth, with a timbre that you feel like in heaven,
a feast for your ears.

I will give you another example.
You listen to a "bootstrapped" AMP (I do not tell you the name of his designer) and you say: "Well - it sounds allright."
Listen to the same AMP having original, non-fake SANKEN 2SA1216 / 2SC2922 on the output - and you will not stop listening.

This is, what counts "in my ears": to have the chance to "listen to an event".

The TO-3 SYMASYM, having two pairs of MJ21193/MJ21194 on the output, is such an "event", and it is simply the best.

RYAN: you are in for 2 small kits.

Best regards - Rudi_Ratlos

dadod 4th August 2011 07:25 PM

I see Rudi what you whant to say, just be careful when you state
" I do currently not see any rival to this amp."
This is in a way as DX amps are descibed and it's preposterous.
I am sure the PCB is exelent and the support too. Original SYMASIM uses faster output transistor and technically it should be better. I would like to listen to both but it's no possible as I do not have them and no time to bild as I have other project in line.
I am fascinated how DIY in Germany is good, so many enthusiasts.
regards Damir

StevieK 6th August 2011 08:58 PM

Hello Rudi,

Im interested in 3 x 2 PCBs. Are they still aviable?

All times are GMT. The time now is 09:25 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 18.75%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio