Some time ago my friend Joe asked me, if I would like and design an AMP with 2 pairs of TO-3 output transistors.
Both, Joe and I, have a couple of MJ2119x transistors at hand, which are worth to be used.
I studied some of the DIY - AMPs in this forum and felt, that Michael Bittner's SYMASYM would be the best match to do the job.
I transferred his SYMASYM version 5.3 into EAGLE, did not change anything in the frontend, but added the pairs of TO-3 in the backend.
DADOD (thank you very much!) simulated the resulting AMP in LTSpice: the results look perfect!
I have attached the schematics as a PDF-file.
After finishing the layout, I had some space left on the bottom right and left side of the PCB and implemented a standard capacitor-multiplier
for the frontend there.
This is the resulting layout:
The red lines indicate tracks, that are running on the top side.
The TO-3s will be mounted on ALU-brackets.
The size of the PCB is 150 x 100mm.
Joe and I want the PCBs to be etched professionally, having the same quality as the PCBs, that I offered in my group-buys
for Carlos Mergulhao's DX Blame (see the picture below).
Since the SYMASYM, the backend and the capacitor-multipliers are proven circuits, we won't do prototyping.
In order to get a decent (about 13€ per PCB) price from the etching company, I must order at least 10 PCBs.
Maybe some of you like this design (SYMASYM with TO-3) and join the party.
I am sure, it will give you a big bang for your bucks.
Take a careful look at the schematics then and tell me, if I shall change anything.
Best regards - Rudi_Ratlos
Both, Joe and I, have a couple of MJ2119x transistors at hand, which are worth to be used.
I studied some of the DIY - AMPs in this forum and felt, that Michael Bittner's SYMASYM would be the best match to do the job.
I transferred his SYMASYM version 5.3 into EAGLE, did not change anything in the frontend, but added the pairs of TO-3 in the backend.
DADOD (thank you very much!) simulated the resulting AMP in LTSpice: the results look perfect!
I have attached the schematics as a PDF-file.
After finishing the layout, I had some space left on the bottom right and left side of the PCB and implemented a standard capacitor-multiplier
for the frontend there.
This is the resulting layout:
The red lines indicate tracks, that are running on the top side.
The TO-3s will be mounted on ALU-brackets.
The size of the PCB is 150 x 100mm.
Joe and I want the PCBs to be etched professionally, having the same quality as the PCBs, that I offered in my group-buys
for Carlos Mergulhao's DX Blame (see the picture below).
Since the SYMASYM, the backend and the capacitor-multipliers are proven circuits, we won't do prototyping.
In order to get a decent (about 13€ per PCB) price from the etching company, I must order at least 10 PCBs.
Maybe some of you like this design (SYMASYM with TO-3) and join the party.
I am sure, it will give you a big bang for your bucks.
Take a careful look at the schematics then and tell me, if I shall change anything.
Best regards - Rudi_Ratlos
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Yeah, I know. I frequently spend longer tidying up cosmetic stuff than working out the actual layout. 🙂
Thanks to Rudi who created the asc file and sent the other models included in his asc file.
Attachments
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I have just finished the "cosmetic improvements" of the layout and the silkscreen of the TO-3 SYMASYM - PCB.
Here it is:
Since there is some interest in the PCB in the German Analog-Forum, I will be able to order the minimum amount of PCBs.
Rich: are you still interested?
Best regards - Rudi_Ratlos
Here it is:
Since there is some interest in the PCB in the German Analog-Forum, I will be able to order the minimum amount of PCBs.
Rich: are you still interested?
Best regards - Rudi_Ratlos
Rudi, I see you moved the traces there around the top left TO-3, I didn't like the first one, and the second one you got almost right. I see you now allowed space for the mounting screw, but if possible I suggest you bring the left trace back out to the side to reduce capacitance between the two traces, unless of coarse you think a little in that position is benneficial, other wise nice work. I know Carlos would drive you mad to get all those TO92 transistors in a row
Do you have an idea on what postage would cost for a pair of boards to Australia? I may be interested in a pair.
Luke,
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):
http://www.analog-forum.de/wbboard/index.php?page=Thread&threadID=77848
I will close the group-buy next week.
Best regards - Rudi_Ratlos
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):
http://www.analog-forum.de/wbboard/index.php?page=Thread&threadID=77848
I will close the group-buy next week.
Best regards - Rudi_Ratlos
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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:
[img=http://www.abload.de/thumb/symasymz8k8.jpg]
Best regards - Rudi_Ratlos
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:
[img=http://www.abload.de/thumb/symasymz8k8.jpg]
Best regards - Rudi_Ratlos
This is the result:
http://s7.directupload.net/file/d/2559/kg8sw3qi_jpg.htm
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
http://s7.directupload.net/file/d/2559/kg8sw3qi_jpg.htm
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
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:
http://www.abload.de/img/image_d9ee32089d8c7ecda71x.jpg
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:
http://www.abload.de/img/untitledj7eu.jpg
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
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:
http://www.abload.de/img/image_d9ee32089d8c7ecda71x.jpg
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:
http://www.abload.de/img/untitledj7eu.jpg
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
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Rudi,
I am interested in one of your "small" symasym kits. Please add me to your list.
Cheers,
Ryan
I am interested in one of your "small" symasym kits. Please add me to your list.
Cheers,
Ryan
...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
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
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
" 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