eXStata DIY Electrostatic Amp for Intermediate DIYers

[n_maher]

Quote:

Originally Posted by smeggy /img/forum/go_quote.gif Thanks Eric. I was wondering whether the Hammond 380(?) might be a better transfo for this, it's not much more expensive but supposedly a significantly better transformer. I doubt it's necessary but you never know. Well, I don't anyway

For my money I'd definitely run a 300 series Hammond. In my experience they are functionally much better than their similarly spec'd 200 series counterpart and as you said, not that much more $$.

 

[pabbi1]

I have Tung Sol in the eX and Amperex in the Vulcan...

Doubt many of us will be rolling tubes any time soon, as other changes will be in the offing first.

 

[runeight]

I know that many of you have been waiting for more information on boards and/or kits.

We now have at least five sand amps and three tube amps working. So we know that others can build the amp besides me and wiatrob.

I have been discussing how to take the next step in releasing these with wiatrob who'll be doing most of the work getting the kits together.

I'd like to make a limited release right at this moment because I'd like a few more amps in, what we might call, a beta release. I also want to be able to fully support the builders and, despite the fact that this amp is a pretty easy build, the 600V rail to rail voltage is something we need to be deliberate about.

The other thing I'd like to avoid is a mish-mash of parts that might be cobbled together from parts boxes and surplus stores, etc. At least for this first release. Harder for me to support if this happens.

So, I'd like to make 10 of each board available along with the PS. That's 10 amp boards (both channels) and 10 tube boards (both channels) each with its PS board.

I'll make a limited run of PCBs for this. Thus, they will be slightly more expensive than if I had ordered 100 or more.

I will handle the group buy for the boards. Only one set per person.

What will be helpful is if the first 20 folks will get to their builds as quickly as possible to provide feedback on this beta run. So if you sign up, we're counting on you.

wiatrob will offer kits based on sign ups, probably pre-paid. He will have information on this towards the end of the week.

It is my preference that you buy these kits for reasons stated above. Just to control the part selection. They will priced to cover costs and shipping.

In the next week or so I'll post the website and start adding additional information for building and setup.

Then if this phase works out, we can offer a more general release that I can manage with the time that I have.

Your ideas are most welcome.

After you guys have posted comments, assuming that there are any, I'll start soliciting the PMs.

 

[sachu]

Quote:

Originally Posted by runeight /img/forum/go_quote.gif We now have at least five sand amps and three tube amps working.

Hope to make that 5 out of 5 for the tube amps tonight

 

[les_garten]

Quote:

Originally Posted by runeight /img/forum/go_quote.gif I know that many of you have been waiting for more information on boards and/or kits. We now have at least five sand amps and three tube amps working. So we know that others can build the amp besides me and wiatrob. I have been discussing how to take the next step in releasing these with wiatrob who'll be doing most of the work getting the kits together. <<SNIP>>

Hi Alex,
I guess it's reasonable to assume then that these boards are pretty much a final design?

 

[runeight]

Why yes. One of the reasons I've been taking this slowly.

There may be one resistor tweak, but the board layouts won't change because of it.

 

[manaox2]

You guys are doing a tremendous job.

Do I ever wish I had the time to participate right now.

 

[smeggy]

Indeed! It's a great time to be a fairly broke 'stat fan

 

[HeadphoneAddict]

The big question for me is - do I add the eXStata to my GES and have two amps for different flavor electrostatic headphones, or sell the GES and some other stuff for the WES? (see RMAF impressions thread if I didn't put all my eXStata impressions in here).

Like I said before, I liked the timbre and tone of the GES better, but the power, soundstage and separation of the eXStata a little more. To me the WES combines the best of both in one amp.

 

[sachu]

we have 4 out of 5 tube amps running now

Though there is some offset problem which I will check on later, the board seems to be balancing out to 0 nicely.


Smeggy's tube board is prepped and ready but too lazy to hook up now..and with cold solder joint problems due to the haste in which i put my board to gether I want to cehck and reflow any such bad joints on Smeggy's boards tomorrow before firing it up.
Some work left on the two PSU boards and waiting for some zeners due to arrive on wednesday by which time I plan to get some casework done for my tube amp...its all slowly coming together.

 

[Emooze]

What is everyone using for pots? I'm assuming they are wired between the inputs and the boards from what I've seen.

 

[ericj]

I'm using a 10k noble i picked up years ago, spliced in between some lengths of shielded 22awg silver-plated.

If you're going for balanced input, you will need two stereo pots or attenuators, or a four-deck pot or attenuator. Or some other magic I'm unfamiliar with.

 

[sachu]

and now we have 5 out of 5 tube amps!!

I'll bet Smeggy is itching to get his hands on this, as he should.

2 remaining power supplies will be brought up tomorrow or the day after at the latest at which time I will ship one set out to Smeggy.

Congrats Alex!! Thanks for such a wonderful amplifier.

 

[smeggy]

Actually, that's 'another' wonderful amplifier.

 

[les_garten]

Quote:

Originally Posted by smeggy /img/forum/go_quote.gif

If I were you, I'd be sportin' a smile as well!