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evette 18th January 2013 04:17 PM

No Junie,,470 Ohm,s. Evette

franzm 19th January 2013 01:26 PM

Depletion MOSFET will also work fine. I've tried Temic ND2020 and Infineon BSP129.

mcds 23rd January 2013 03:59 PM

I've realised that an impending move, a child and other commitments mean I won't get around to building the TO-3 Symasym in the foreseeable future, so if anybody is interested in sets from this group buy, they can send me a PM. I'd like to pass them on before my move so I have less stuff to deal with.

den054 20th February 2013 04:33 AM

Include me for 2xAMP and 2xLSP PCBs in the next GB please.

Rudi_Ratlos 2nd April 2013 11:27 AM

3 Attachment(s)
Gentlemen, I have been asked to do another round of group-buy for the TO3_SYMASYM.
Be sure: the TO3-SYMASYM is the best-sounding SYMASYM.

The SYMASYM - schematics include 2 pairs of TO3-MJ21195/96 as output transistors and a cap-multiplier for a stabilized frontend-voltage/current
and input-transistor protection.

I have once more re-worked the layout and made it as compact as possible. The size of the PCB is now 140 x 112 mm.
You need an ALU-L - profile 50x50x5 mm, length: 140mm to mount the TO3s on them.
I will also offer PSU-PCBs in this group-buy.

I do not offer any components.
The SYMASYM does not use any fancy components. The TO3s can be easiy ordered from MOUSER, ..., you can use 2SK170, BC550, 2N5551, ...,
as input transistors, ... I have prepared a Builder's Manual and a BoM.

I will keep this group-buy alive until weekend 13th/14th of April.
Your orders are welcome. Find attached the EXCEL with the current order-list.
Worldwide shipping costs 3.45.
You can use PAYPAL to transfer the total sum to:

Best regards - Rudi_Ratlos

Rudi_Ratlos 2nd April 2013 11:37 AM

1 Attachment(s)
I am unhappy to see that the Gerber-files' preview (shown above) does not reflect the current state of the layout.
Find attached the current preview.

I apologize - Rudi_Ratlos

hallodeletue 2nd April 2013 11:55 AM

Great news! I sign up for 2 TO3 boards, and 2 PSUs.
Are you planning to re-offer the LSProtect and Softstart PCBs any time?



Rudi_Ratlos 2nd April 2013 12:36 PM

1 Attachment(s)
Rudolf: from your order I can see that you are going to build 2 mono-blocks (either in one case or two cases).
You need the "Soft-Power-On - PCB" only in case that you switch on the mains with a "transformer-load" of more than 500VA.
So you won't need it.

Regarding the Speaker-Protection-PCB: if there is any further demand (more than 10 pcs.), I will be able and offer you
my Speaker-Protection-PCB for 5 per PCB.

Best regards - Rudi_Ratlos

jprco 2nd April 2013 07:43 PM

Hi, Rudi. I really like this version of the SymaSym so please count me in for 2 TO3 boards and 1 PSU board. Will transfer $ as soon as you total up!
Thanks again for doing this.

hallodeletue 4th April 2013 01:10 PM

@Rudi_Ratlos: jep, monoblock is the way to go. I am also assembling a DCB1 buffer to go in front of the symasyms, and i wanted one switch to start them all (via relais), hence the thought that a soft starter might be a good idea.

Just out of curiosity, is there anything else boiling in your kettles groupbuy-wise?


the other Rudi

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