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i'm on a roll... the kgsshv


kevin gilmore

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Some questions for the experts for the offboard 0.6 amp board.

 

For Q17 and Q18 the PCB shows A970 and ECB (with the flat side facing you).

 

This datasheet http://www.futurlec.com/Transistors/2SA970.shtml gives the orientation as BCE (with the flat side facing you).  I'm assuming the datasheet is wrong?

 

I'll be using MPSW56 as a sub for A970. This datasheet http://www.onsemi.com/pub_link/Collateral/MPSW55-D.PDF gives the orientation as EBC (with the flat side facing you).

 

So if I use MPSW56 I'll have to cross 2 of the legs, right?

 

 

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Nope, no dummy load needed for any adjustment.  PSU works just fine without any load and the voltages should stay the same with a load. 

Thanks.

 

So it is safe to measure at the STAX socket without connecting the headphone?  Even with signal feeding to the input?

 

I want to make sure the amp is as close to 100% stable as possible, before connecting my headphone to it.

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Thanks.

 

So it is safe to measure at the STAX socket without connecting the headphone?  Even with signal feeding to the input?

 

I want to make sure the amp is as close to 100% stable as possible, before connecting my headphone to it.

 

Ditto what Kevin said  and it is perfectly fine to have the amp "playing" when testing it. 

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Thanks Kevin.

Can anyone enlighten me in regards to following behaviour of my KGSS. I built this back in

2000.

All supplies are stable and I carried out Kevin's setup.

Set the first pot for zero volts on meter between + and - Outputs.

Set second pot for zero output at + and Ground.

Reset these after running for 30mins.

After doing all of this I watched the both meters and meter between + and - varies between

-100mv and 500mv while the other one reads about 1.0v even though both of these were set initially

at 0.Both channels experience the same effects and both never get greater than 1 volt over 1 hour.

Is normal for the amplifier?. It sounds GREAT.

Appreciate any comments.

Thanks

Les

Edited by iwik
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Got my off-board PCBs back from the fab.  Thank you Kerry for sharing your design.  I have made a few changes to go with my plan.  Actually, I'm making both on-board (standard) and off-board version of the amp.  One will stay at home, while the other one may go to my office.

 

9BC77B6F-4F4F-4E93-8223-33DE5CD8DE43_zps

09FF0226-F0DD-4CCB-87E8-97B4FAF51166_zps

 

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