eXStata DIY Electrostatic Amp for Intermediate DIYers

[smeggy]

just mounting the chips 180deg should work when underneath.

 

[sachu]

Quote:

Originally Posted by les_garten /img/forum/go_quote.gif Doesn't that make the pinout on the board mirrored? I didn't think it was that easy to flip it over?

Depending on which side of the heatsink you mount it can be reversed or unchanged. Only a matter of making sure non of the vias are not being shorted by doing so.

 

[wiatrob]

There has also been some talk during proto discussion about air mounting - don't recall the outcome. Socket extenders and 90 degree mounted sinks will get them clear of all the other devices on the board.

 

[sergery]

Man, I can't wait to hear some impressions of the tube version. Maybe a little compare/contrast

Good work team, keep it up!

 

[smeggy]

I probably wont get to hear the ss version, but I think I'll be happy with the tube one

It'll certainly be nice having a proper stat amp again. I'll need to find out what bias and wiring the Koss ESP9 needs. I'd like to have that running on it too.

 

[n_maher]

Quote:

Originally Posted by smeggy /img/forum/go_quote.gif I'll need to find out what bias and wiring the Koss ESP9 needs. I'd like to have that running on it too.

From the all-powerful Headphone Wiki:

Bias = 600V (some have tested them up to 620V, do so at your own peril)

Pinout
http://wiki.faust3d.com/wiki//index....Out_ESP950.jpg

 

[wiatrob]

For simplicity's sake )and becuase of that god-awful par-metal enclosure on my quick-cased proto) I been setting the pro bias to 580 and not tweaking for individual cans.

Sachu, what you running at?

 

[manaox2]

I have some Sylvania 6S4A tubes on hand, they should be 6S4 equivalent I believe. Any problems worth noting about using these? (I want to build a SS and tube version).

 

[sachu]

Quote:

Originally Posted by wiatrob /img/forum/go_quote.gif For simplicity's sake )and becuase of that god-awful par-metal enclosure on my quick-cased proto) I been setting the pro bias to 580 and not tweaking for individual cans. Sachu, what you running at?

650 volts

 

[spritzer]

Quote:

Originally Posted by n_maher /img/forum/go_quote.gif From the all-powerful Headphone Wiki: Bias = 600V (some have tested them up to 620V, do so at your own peril) Pinout ImageinOut ESP950.jpg - Wikiphonia

I believe Gary's talking about the older ESP9 he got from me. The bias is around 400v but all the junk in the earpieces will have to be bypassed in order for them to work with any other amp then the E/9. Not only is the pinout different but the entire operational concept compared to the Stax standard.

Quote:

Originally Posted by manaox2 /img/forum/go_quote.gif I have some Sylvania 6S4A tubes on hand, they should be 6S4 equivalent I believe. Any problems worth noting about using these? (I want to build a SS and tube version).

Same tube but a higher rated version.

 

[smeggy]

yeah, ESP-9

It's an odd duck for sure, I would like to run it out of the exstata if possible but if the bias is 400V that may be tricky.

 

[ericj]

Quote:

Originally Posted by smeggy /img/forum/go_quote.gif yeah, ESP-9 It's an odd duck for sure, I would like to run it out of the exstata if possible but if the bias is 400V that may be tricky.

You can absolutely get 400v bias from the eXStata power supply board. Both of the bias supplies are adjustable within a wide range.

You can even theoretically get more than two bias voltages in the same box, though never more than two at a time.

The bigger question is whether the ESP/9 will sound at all good driven stax-style.

 

[HeadphoneAddict]

Quote:

Originally Posted by manaox2 /img/forum/go_quote.gif I have some Sylvania 6S4A tubes on hand, they should be 6S4 equivalent I believe. Any problems worth noting about using these? (I want to build a SS and tube version).

I'm pretty sure that's what I have running on my Woo GES with no problem. I could use an extra set if you decide to sell them.

 

[wiatrob]

I'm running 6S4As currently in the tube board...

 

[spritzer]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif You can absolutely get 400v bias from the eXStata power supply board. Both of the bias supplies are adjustable within a wide range. You can even theoretically get more than two bias voltages in the same box, though never more than two at a time.

You can also just setup the HB supply for a given value and then use a high impedance voltage divider to get any voltage you'd like. It's just 3 resistors so very easy.