TO-3 SYMASYM - Page 59

cjkpkg · 24th October 2012, 03:31 PM

No, I get the 16VDC when the Symasym is not connected..on BOTH protect boards...

I think it is coming from the "ground" of the protect board maybe? To each board I have connected one of the secondaries of the power transformer. That is the only way I can get at least 24V to the regulator. I think...Since I have one of the AC legs connected to the ground of the speaker protect board could that be where the 16VAC is coming from? From the schematic it looks like a plausible explanation.

Rudi_Ratlos · 24th October 2012, 04:37 PM

Carl, you use a transformer with 2 secondary windings, pink and turquoise, rated a 25VAC each.
One line of each secondary winding connects to "GND".

Connect the 2 orange coloured wires to the Speaker Protect PCB.
(In effect you are connecting a secondary winding to the Speaker Protect PCB).

Connect the orange AC-line to the top pole of the 2-pole power connector of the Speaker Protect PCB and the AC / GND - line to the bottom pole of the connector.

You should never have any AC voltage on the AMP-connector of the Speaker Protect PCB, if the PCB is not connected to the AMP.

Best regards - Rudi

AndrewT · 24th October 2012, 04:42 PM

If Cj had did what he was told and not connect the protect PCB, then we would have one set less of confusing reports.

Cj,
you are not helping yourself.

Rudi_Ratlos · 24th October 2012, 05:03 PM

I agree, Andrew.
Carl: forget about the Speaker Protect PCB for a while, please!
Do not connect it at all!

Rudi

cjkpkg · 24th October 2012, 06:16 PM

I know...my ADD got the better of me....

So I think I know what the problem is...my PSU board is different from the one Rudi laid out.

I do not see a connection scheme that will work here...at least not an obvious one. I am pretty sure that using both legs of one secondary in the speaker protect pins and then grounding the "ground" one would be bad right?

Rudi_Ratlos · 24th October 2012, 08:02 PM

Yes, you are right Carl.

Rudi

cjkpkg · 26th October 2012, 10:43 AM

Success!!!! It must have been one or more of the transistors.

I am now running both channels per specification.

Now I just need to figure out a speaker protect scheme....

Thank you all for your suggestions....and patience....

brianco · 26th October 2012, 11:44 AM

PHEWW!

Rudi_Ratlos · 01:24 PM

Carl: unbelievable!
The speaker protection scheme in your case: connect +Vcc (about 35VDC) of your PSU to the "AC-pole" of the 2-pin Speaker-Protection-PCB-connector and your PSU-GND to the "AC/GND - pole" of the Speaker-Protection-PCB - connector.

This way: you will have a Power-On delay, you will of course have DC-protection, but you will not have immediate shutdown of the speakers, when you turn power off (because of the reservoir cap's discharging).
Maybe this will introduce some "Hiiiiiiiisssss, SSssssssccccchhhht", when you switch off the mains, but this will definitely not hurt your speakers.

Best regards - Rudi_Ratlos

cjkpkg · 27th October 2012, 02:06 AM

Wow!

Tonight I rewired the speaker protects per Rudi's post above and worked like a charm. The relays engage after about 5 seconds and then disengage after 3-4 seconds upon power off.

I just need to get some more fuses and I can put the top on.

I am listening via a 5687 Aikido pre amplifier and everything is very quiet, sound is transparent much like my old Yamaha ca-810.

One question...if I have enough heat sink what is the harm to crank up the bias more?

26th October 2012, 01:10 PM	#589
Rudi_Ratlos diyAudio Member Join Date: Jun 2009 Location: Hamburg / Germany	Carl: unbelievable! The speaker protection scheme in your case: connect +Vcc (about 35VDC) of your PSU to the "AC-pole" of the 2-pin Speaker-Protection-PCB-connector and your PSU-GND to the "AC/GND - pole" of the Speaker-Protection-PCB - connector. This way: you will have a Power-On delay, you will of course have DC-protection, but you will not have immediate shutdown of the speakers, when you turn power off (because of the reservoir cap's discharging). Maybe this will introduce some "Hiiiiiiiisssss, SSssssssccccchhhht", when you switch off the mains, but this will definitely not hurt your speakers. Best regards - Rudi_Ratlos Last edited by Rudi_Ratlos; 26th October 2012 at 01:24 PM.

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24th October 2012, 03:31 PM	#581
cjkpkg diyAudio Member Join Date: Aug 2008 Location: Roswell GA	No, I get the 16VDC when the Symasym is not connected..on BOTH protect boards... I think it is coming from the "ground" of the protect board maybe? To each board I have connected one of the secondaries of the power transformer. That is the only way I can get at least 24V to the regulator. I think...Since I have one of the AC legs connected to the ground of the speaker protect board could that be where the 16VAC is coming from? From the schematic it looks like a plausible explanation.

24th October 2012, 04:42 PM	#583
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	If Cj had did what he was told and not connect the protect PCB, then we would have one set less of confusing reports. Cj, you are not helping yourself.

24th October 2012, 05:03 PM	#584
Rudi_Ratlos diyAudio Member Join Date: Jun 2009 Location: Hamburg / Germany	I agree, Andrew. Carl: forget about the Speaker Protect PCB for a while, please! Do not connect it at all! Rudi

24th October 2012, 08:02 PM	#586
Rudi_Ratlos diyAudio Member Join Date: Jun 2009 Location: Hamburg / Germany	Yes, you are right Carl. Rudi

26th October 2012, 10:43 AM	#587
cjkpkg diyAudio Member Join Date: Aug 2008 Location: Roswell GA	Success!!!! It must have been one or more of the transistors. I am now running both channels per specification. Now I just need to figure out a speaker protect scheme.... Thank you all for your suggestions....and patience....

26th October 2012, 11:44 AM	#588
brianco diyAudio Member Join Date: Aug 2005 Location: Scottish Borders - Kelso; on the famous Tweed River!	PHEWW!

27th October 2012, 02:06 AM	#590
cjkpkg diyAudio Member Join Date: Aug 2008 Location: Roswell GA	Wow! Tonight I rewired the speaker protects per Rudi's post above and worked like a charm. The relays engage after about 5 seconds and then disengage after 3-4 seconds upon power off. I just need to get some more fuses and I can put the top on. I am listening via a 5687 Aikido pre amplifier and everything is very quiet, sound is transparent much like my old Yamaha ca-810. One question...if I have enough heat sink what is the harm to crank up the bias more?