[Beefy]

Quote:

Originally Posted by studeb /img/forum/go_quote.gif Did you ground the PS heatsinks, and did that stop the buzzing?

I only had them grounded for a short time, due to something sparking - probably a shaving of aluminium from the tapped heatsinks.

But it didn't help.

 

[Scooba]

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif I have a few more spots for people willing to try the balanced attenuator mentioned in this thread. It's mostly SMD, so fair warning there. For those willing to get cracking on it immediately, I'm discounting the parts by 50% and throwing in the board. Also, for those waiting on jacks they'll go out on Monday. Sorry again for the delay.

May I join the attenuator team ?

I've received my Mouser order Friday. I've finished mounting both the PS and amp (SS), but I am still waiting for the teflon wire

. Damn local postal services...
I'll try to get a Stax female connector, or I'll have to cannibalize a friend's amp and extract the non-pro connector (he never uses it anyway) .

 

[luvdunhill]

Unfortunately I only burned 5 microcontrollers and those are taken. Once we get some feedback and I get some information up and what not, I'll let the rest go. Sorry about that.

They are also color-coordinated for no extra charge:

 

[pabbi1]

Just looking at those boards makes me queasy, and actually induce vertigo...

 

[nattonrice]

Very sexy Marc!
Can't wait to get stuffing =)

 

[Scooba]

It looks very nice, Marc ! I'll wait for the microcontrollers to become available then

. Count me in, it seems an easy enough job .

P.S. the teflon wire just arrived while I was typing this

. USPS priority + local post = 20 days

.

 

[ktm]

New tubes are in, and I'm off and running. I got a total of 6.
Three different brands. In testing, they vary quite a bit by brand.
CBS(?) branded tubes tested highest, and GE the lowest.
But they tend to be close in the same brand. I matched up
tubes in each channel, leaving two existing in place. One of the
new tubes had some hum, so it came out, now it's back to dead quiet.
It's all buttoned up. There still is some heat drift, but it follows a
predictable pattern, and stays reasonably in range. I'm calling this one "done"!
I've got 4 spare, but I'd like to get 2 more tubes so I can be sure to
have a good set down the road. It's about time for the other stax amps to
head out the door. Thanks everyone for your assistance. And thank
you Al for hooking me up with the boards.

 

[gilency]

luvdunhill, what board is that?

 

[Scooba]

I've got the PS running today.
T1-T2 = 360mV ; T1->342V ; V+ = 300V
T3-T4 = 420mV ; T3 -> -342V ; V- = -298V

Is this ok ?

 

[spritzer]

Quote:

Originally Posted by gilency /img/forum/go_quote.gif luvdunhill, what board is that?

It's a digital volume control based on Burr Brown chips.

 

[pabbi1]

Quote:

Originally Posted by ktm /img/forum/go_quote.gif New tubes are in, and I'm off and running. I got a total of 6. Three different brands. In testing, they vary quite a bit by brand. CBS(?) branded tubes tested highest, and GE the lowest. But they tend to be close in the same brand. I matched up tubes in each channel, leaving two existing in place. One of the new tubes had some hum, so it came out, now it's back to dead quiet. It's all buttoned up. There still is some heat drift, but it follows a predictable pattern, and stays reasonably in range. I'm calling this one "done"! I've got 4 spare, but I'd like to get 2 more tubes so I can be sure to have a good set down the road. It's about time for the other stax amps to head out the door. Thanks everyone for your assistance. And thank you Al for hooking me up with the boards.

So, how does it sound?

I have a couple of spares if you need.

 

[ktm]

It does everything the other two Stax amps don't.
Good low end, good highs and detail without being grating.
And that's with a sr404! The srm1 mkII didn't grate,
but it did noticeably roll off the high end. The sr404's and
the srm313 were awful. Not enough low end, and the high end
was way too much. The sr202's and the srm313 were a better match,
but far from perfect. I will try the sr202's with this amp again tonight.
Overall, well with the time and money. It's my first real DIY amp.
The Millett SS and minimax were other people's projects that had problems.
All I had to do was find and fix them. I've got a couple of Bantams
here I need to finish. Mouser was out of some parts for such a lot time
that I just shelved them. One is missing two parts, the other has just
the DAC soldered on. I guess it's time to finish them. Then it's off to build
a Nelson Pass f5 clone(I wish!).

 

[paxeaxe23]

Tomorrow I will be testing my Build! I still haven't got an answer as to why my LED's are not lighting up but everything measures up as expected otherwise so I will go ahead and try it out once I've mounted everything provisionally in its case.

If anyone has any thoughts on the LED problem, please speak now

 

[luvdunhill]

Quote:

Originally Posted by paxeaxe23 /img/forum/go_quote.gif I still haven't got an answer as to why my LED's are not lighting up but everything measures up as expected otherwise so I will go ahead and try it out once I've mounted everything provisionally in its case.

I would think the Hail Mary isn't quite the best idea.

 

[studeb]

Quote:

Originally Posted by paxeaxe23 /img/forum/go_quote.gif If anyone has any thoughts on the LED problem, please speak now

Did you reverse the orientation when you installed them?