eXStatA Build Thread II

[gilency]

Thank you, but mine is a SS. And BTW, your proto SS build has been invaluable as a visual guide.

 

[pabbi1]

My poor communications skills strike again - the tube issue was to any and all eXStatA builders.
 
Still loving my eXStatA - just wondering where all these builds are, since it has been quite a while...

 

[sachu]

Al, I should have my personal exstata complete here in about 3-4 hours and will post pics once it is done Another SS exstata am building for my good friend Devin (dewild) in Portland will also be ready once the power switch comes in tomorrow. It will look identical to mine except mine will be using the luvdunhill digital attenuator while Devin's will use a quad quad Alps pot.
 
Now I need to start saving up for an O2 ...or better yet the C32  

 

[sachu]

Well just got done with my personal exstata..Al mins is running with the Sanyo 3675 that you generously donated to me, in lieu of the fairchild KSC5042/5027s...will post if i hear any differences as i got exstatas running both here.

 

[sachu]

Here are some pics of my amp that i just completed. Sounds pretty sweet..but now i find myself in the situation where i have no stat headphone to call of mine. Will need to start saving up . Currently am using an SR-404 on loan from dewild to help test his and my own exstatas.
 

 

 

 

[BoilermakerFan]

Normal bias Lambdas have an amazing synergy with the eXStatA.  Just saying so you can save $1K or more...  

 

[HiGHFLYiN9]

Nice work Sachu! Looks like those conical bumpers work well with the design.

 

[sachu]

Thanks...yeah got those feet from Justin over at headamp. I used them on my EHHA build as well. Most excellent and a steal for the price. Brian, I would need to get one of the normal bias lambdas on loan and test them out before I invest in a pair.

 

[gilency]

The power entry I have is to be used with a 250 V fuse. Is that OK?
 
http://parts.digikey.sg/1/1/786132-mod-pwr-entry-fuse-hldr-10a-pnl-4304-6090.html 
 
I also want to connect  a Bulging switch to it: http://www.mouser.com/ProductDetail/Bulgin/MP0045-1E2GN012/?qs=sGAEpiMZZMvxtGF7dlGNplr9LVjb3l8KS%252bIz5FPAvA0%3d
 
Any problems doing it?

 

[gilency]

Well, I have a problem: the -300V rail reads 300V and the LED turns on. The dummy load resistor gets hot. I get 410 mV after adjusting P2.
The +300V rail reads 4 V and the LED wont turn on. The dummy load resistor stays cold. I get 360 mV after adjusting P1.
The voltage from the transformers reads 250 on both.
Why is the high rail not working?
The instructions for testing the rails state to use the dummy resistors in parallel only for the negative rail, and only the 10K/25W for the positive rail. That's what I did.

 

[sachu]

hmm sucks..
 
well disconnect it first, double check to see all solder joints are goood on the positive rail side. 
 
Check to see if the components are in the right places against the BOM and the schematic. I am assuming at this point that none of the magic blue smoke has been released. 
 
Then bring up the PSU agian with the dummy loads on both rails and see what you measure on the positve rail.

 

[gilency]

The positive rail measures 47 volts only. The negative rail measures 300.
I had one diode backwards on the positive side, everything else looks OK. I will try again tomorrow.
I am using MTP2P50EG instead of FQPF3P50 at Q3 and the maxed power supply.
I checked all the solder joints, they all seem fine, and no, no blue smoke, both LEDs light up now.
Any ideas?

 

[runeight]

Which diode was backwards?

 

[runeight]

Also, what's the voltage from T1 and T3 to ground?

 

[gilency]

Diods Z10 and Z11
I'll measure T1 and T3 to ground right now