I feel like kicking myself now. I had -15V hooked into the - pole instead of ground.

 

How the LED worked for so many hours with such a dumb mistake is beyond me... Anyway, do you have any of those orange switches you were planning on getting spritzer?

that explains the fried resistor.

Nope and won't order for a while. 

Beautiful Kerry!

So I replaced my output bias resistors today. Im using the IXYS parts at 500 volts, so I was kind of worried, since you guys were saying they drift alot more than the sanyo parts do, and not to raise it too much. But i replaced the 180 resistors with 100 ohm ones. to raise the current to 10mAs, and I rebiased after about 2-3 hours of leaving it on and got all my biases down under .2 volts so I was pretty pleased

It's not that you can't get it to zero out, it's just how different the voltages are at power on. 

It's not that you can't get it to zero out, it's just how different the voltages are at power on. 

Solution: leave it on all the time

So I replaced my output bias resistors today. Im using the IXYS parts at 500 volts, so I was kind of worried, since you guys were saying they drift alot more than the sanyo parts do, and not to raise it too much. But i replaced the 180 resistors with 100 ohm ones. to raise the current to 10mAs, and I rebiased after about 2-3 hours of leaving it on and got all my biases down under .2 volts so I was pretty pleased

 

Can you share the change in the sound impressions?

Edited September 4, 201313 yr by Victor Chew

I don't have a comparison from the lower powered to the higher powered KGSShv, but I did spend 4 hours listening and A/B'ing the Blue Hawaii and the KGSShv last night. 

 

I was listening to the Stax O2/Mk I and switching them between the two amps.  Without going crazy loud, it was hard to tell much of a difference.  I occasionally turned up the volume and the KGSShv did seem to hold its own.  All the things that make me smile with the BH were there - wide sound stage, deep and clear bass, remarkable separation of voices and instruments with incredible detail.

 

Makes me happy just thinking about it. 

Solution: leave it on all the time

 

What are the balance and offset after a cold start? Would be interesting to know.

Gents, I've got a few versions of the off-bards around.  Does anyone recall when the crossed feedback on the off-boards was fixed (which version)?

I am thinking it was still wrong on v 0.4

And I think it is right on the .6, which has the global and local feedback choice, but I'm not sure about .5

It was certainly fixed by version 0.5.

I have the .5 version offboards and am unsure whether to cross the diodes or not.  Can anyone confirm for sure this was fixed in the .5 offboard version?  (my original build was .4)

I think I have the v0.5 and it's fixed, but don't trust my word, because I don't have the board with me as I type this. You should just check your board against the schematic. It should be fairly easy to identify. I can check for you when I get home.

 

never mind that! I didn't see GeorgeP already answered it.

Edited September 6, 201312 yr by jwzhan

Yuo, 0.5V is the first production version and that one is 100% correct albeit huge. 

Birgir, you're going to give my build a complex with all this talk about being oversized!  It's just big boned.

Well I'm one to talk, I don't think I'd ever be called petite... 

Vikings are NEVER petite......

The new boards are tiny!

Edited September 7, 201312 yr by eggil

That was the point.   

I got a chance to put the amp on the scope.  It looks great!

 

Response is totally flat from 10Hz up through 40KHz + (I didn't look much beyond this).

 

I also looked at the FFT function on my scope and that looks great as well.

 

Here's some shots of the scope with the FFT window.  I'm showing 1KHz, 10KHz and 20KHz.

 

 

 

 

 

 

 

I also looked at noise with the volume all the way down and I was seeing about 50mV.  Not bad for my house.  I'm going to keep the chassis width at 8" since I don't see that contributing to the noise floor of the amp.

Well, not quite as exciting as the new stuff Kerry is working on, but I'm happy to report that I mounted and tested two amp boards today and everything is up and running!  

 

Another KGSShv is slowly coming to life...

 

I've got everything in hand now to case it and wire it.  

 

I've been at this one for a while, but I think I can see the finish line now.

Congrats!