Question about noise? - Page 3

Dougie085 · 31st March 2008, 01:03 AM

Like I said old picture and it was back when I had another thread where I pretty much tried everything.

cuibono · 31st March 2008, 01:33 AM

I'm under the impression that these amps are not prone to electromagnetic noise (noise pickup from magnetic fields, like transformers) - so I really doubt wiring layout/gauge is your problem. I'd guess your problem is your grounding scheme. What are CHG, PG+ and PG- connected to?

I would connect CHG and the chassis to the power input connector ground directly.

Try connecting your source to the amp with a different cable. I had subtle noise issues that resolved when I got rid of my rat shack interconnect.

Also, is your transformer true dual secondaries (has four wires not three)?

cuibono · 31st March 2008, 01:37 AM

also, wrt 'danielwritesbac' - the resistor he suggests adding is already there - it is one of the 22k resistors. R2?

the board pic makes it hard to see

Dougie085 · 31st March 2008, 01:37 AM

Yes dual secondaries. I plan on doing the grounding like Peter showed in one of the threads.

Dougie085 · 19th April 2008, 11:31 PM

Well I did the grounding scheme just like that thread said. I used a nice thick wire from the wall outlet ground to a star point and then used thinner wire from the 4 connections on the rectifier board and then the thinnest wire used for the inputs. So I had a star ground scheme. Anyways the noise is like completely gone no hum at all. There is a bit of static sound but I can only hear it if I put my ear up to the speakers. Also my speakers are quite sensitive something like 95dB. Sounds excellent now though very happy

31st March 2008, 01:33 AM	#22
cuibono diyAudio Member Join Date: May 2006 Location: City of Angles	I'm under the impression that these amps are not prone to electromagnetic noise (noise pickup from magnetic fields, like transformers) - so I really doubt wiring layout/gauge is your problem. I'd guess your problem is your grounding scheme. What are CHG, PG+ and PG- connected to? I would connect CHG and the chassis to the power input connector ground directly. Try connecting your source to the amp with a different cable. I had subtle noise issues that resolved when I got rid of my rat shack interconnect. Also, is your transformer true dual secondaries (has four wires not three)? __________________ double complete rainbow all the way!!

31st March 2008, 01:37 AM	#23
cuibono diyAudio Member Join Date: May 2006 Location: City of Angles	also, wrt 'danielwritesbac' - the resistor he suggests adding is already there - it is one of the 22k resistors. R2? the board pic makes it hard to see __________________ double complete rainbow all the way!!

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31st March 2008, 01:03 AM	#21
Dougie085 diyAudio Member Join Date: Nov 2005 Location: Ohio	Like I said old picture and it was back when I had another thread where I pretty much tried everything.

19th April 2008, 11:31 PM	#25
Dougie085 diyAudio Member Join Date: Nov 2005 Location: Ohio	Well I did the grounding scheme just like that thread said. I used a nice thick wire from the wall outlet ground to a star point and then used thinner wire from the 4 connections on the rectifier board and then the thinnest wire used for the inputs. So I had a star ground scheme. Anyways the noise is like completely gone no hum at all. There is a bit of static sound but I can only hear it if I put my ear up to the speakers. Also my speakers are quite sensitive something like 95dB. Sounds excellent now though very happy