eXStata DIY Electrostatic Amp for Intermediate DIYers - Page 4  

Plus the insane all DHT amp and the equally nutty SS amp.

I'm not sure i'd really call it low-end. From my vague memories of headphoneaddict's srm-1, I think the low-end is still held by the cheaper stax amps.

You could ask sachu why he sold his SRM-1 recently, too.

This is just by far the most accessible DIY option.

Quite right Alex.

I don't remember my ESP950 sounding this good even with the SRM-717 but I reserve judgment till I compare head to head.

The best 'dynamic' amp I have heard to date is the original stacker of Don's and he put it together for less than 100$.
Parts cost doesn't necessarily translate into high end or low end and those involved in the DIY scene know this all too well.

So lets not play that game.

If i can put down the normal-bias lambda for long enough tonight I'll finally wire up an esp950 socket to my eXStatA.

But from memory, esp/950 + e/90 > SR-lambda + srd-7, but SR-lambda + eXStatA > esp/950 + e/90.

I suppose I should have chosen my words more carefully

Have anyone gotten this on any test equipment yet? I'm assuming Alex at least has some square wave traces lying around somewhere

heh, that's funny, I thought I was the only one who thought the 950, e90 was actually better than with the SRD-7 and Lambdas or 950. The e90 gets a lot of bad press, largely deserved but it still does a good job for the 950 compared to anything else in the low price range.

This amp should do a great job of filling a gap in what's available at reasonable cost, and that's something I never imagined would ever happen as most designs coming out/existing are solidly in the high price area. This is a very welcome addition that will help give us 'less financially fluid' people a real step up.

Precisely the frustration that led me to post that initial rant bemoaning the nonexistence of this amp.

I think runeight did an outstanding job of answering that challenge, and far exceeded my expectations.

Sachu, Have u ever heard your ESP950's with a KGSS amp? I built one P2P for my ESP 950's about 6 months ago and it sounds great. Was kinda wondering how this new amp might sound compared to the KGSS. Also, I use my Cavalli Bijou tube amp for a preamp with my KGSS/ESP950 rig, as I feel it gives that tube sound that I love, better, fuller bass, etc. I'm sure I'm going to go ahead and build this amp too (probably the tube version), since I already have the KGSS. Just wanted to know if you'd ever heard the KGSS/ESP950 combo and how it might sound compared to this new stat amp.
Thanks

I am very excited about this project. so.. how "intermediate" is this thing. what intermediate skills should you have before attempting it. I'm fairly new to diy, but building this amp is pretty high on my "want to do" list. maybe this question is better off in the original thread. it can be moved if so.

Cool project. Color me interested.

What's a reasonable ETA for boards and a BOM ?

And I've seen the posts on Stax jacks, but not anything about availability to unwashed masses. Is there a resolution for jacks ?

I haven't heard it with the KGSS but would love to. I have been toying with the idea of building one for myself but I would like to listen to it first.

Going from memory (do take this with a grain of salt), the ESP950 with the BHSE was sounding great in the mids and the highs but the bass left me wanting. Not the case with the O2, just the ESP950.
Then agian I would love to listen to my ESP950 with the BHSE again with a higher bias setting (the one i heard was set at 580 volts) and in a more controlled environment. Meet conditions are pathetic to do critical listening.

All I can say is that this amp does make the ESP950 sound more balanced instead of sounding dark (as is the case wit the Stax amp I have) and brings out details that I didn't notice earlier. I am looking forward to doing a comparision between this amp and the SRM-717 and i think a SRM-006. Also looking forward to listening to the O2 and SR-404 on it.

Don't really know about ETA for boards, only runeight can answer that. The tube version is not up yet. But, expect one or two tube versions if everything goes well by the end of the week and few more the following week.

I wouldn't call this a difficult build at all.

But with the voltages involved, it's certainly more dangerous.

We're talking about voltages that are potentially fatal if you disrespect them in the wrong way. It's not hard to avoid dying, but we can't stress enough the need for care when working with an amp with 600 volts DC across it.

Runeight has done a lot to make it harder to kill yourself with the amp. Most of the transistors turn out to be in all-plastic packages so there can be no chance of electrical potential in the heatsinks (Two transistors do have a metal pad on the back, and using an insulator there is a good idea). The heatsinks are not grounded, so they cannot be used to provide a path to ground through something like a screwdriver or your arm. An insulated trimpot tweaker is included in the BOM and it's both cheap and entirely decent.

But we're still talking about a 300-0-300 DC power supply.

For anyone who isn't 100% sure if they're ready to build this - I'd have to say, consider what your error rate was on the last 2 amps you built - how many components in the wrong place or the wrong way, how many solder bridges in the wrong place, how many times you damaged the board or a component along the way - and certainly if you ever did something like accidentally drop the bare amp board off the workbench while it was powered or while there may have been juice in the capacitors.

Ask yourself, if you concentrate and really get serious about it, could you have brought that error rate down near 0?

If you're pretty sure you can, I say you can probably successfully build this amp without killing yourself, injuring your cat, or having to order too many replacement parts.

Most of us made at least one mistake while prototyping this amp. I myself misplaced a single diode, and was lucky enough that it's placement didn't damage anything.

But if you have recent memories of a ruined, smoking hulk of a low-voltage amp board, you should give it some serious consideration before playing with high voltages.

Sachu, You got PM. Let me know if you got it