"The Wire" Ultra-High Performance Headphone Amplifier - PCB's

[Stixx]

I'll be offering bare PCBs, completely assembled PCBs, and likely a fully assembled product style version.

I knew it....

[IanAS]

Originally Posted by opc

It's in the works right now. I will be offering all variants in a new layout that is designed to fit in an extruded chassis.
Cheers,
Owen

Any chance that you'll be able to butt up a ESS 9023 to the headphone amp input? As used in the ODAC.

[kuribo]

what kind of power output will these have? I am wondering if I can use one with a stax adapter and set of electrostatics...

[ExStaxy]

Originally Posted by IanAS

Any chance that you'll be able to butt up a ESS 9023 to the headphone amp input? As used in the ODAC.

Are you asking for a piggyback board along the lines of a Dragonfly or Meridian type dac as an add on?

[IanAS]

Piggy back; no.

Same board; yes.

Minimum possible track length, DAC chip output pins as near as touching head phone amp input pins; yes.

Maybe the DAC chips 200 Ohm resistors can be missed out in this case?

Assuming the 9023 is good enough. I've not listened to one yet. I like the lack of any output chips and passives smearing the analogue sound.

Going by the measurements numbers here: http://nwavguy.blogspot.co.uk/2012/0...-released.html (scroll down a tiny bit to what might be page two, paragraph called The Real Numbers) the DAC1 is a lot better. Do those numbers mean much though compared to missing out everything between the DAC chip and the amp input?

[ExStaxy]

Originally Posted by IanAS

Piggy back; no.

Same board; yes.

Minimum possible track length, DAC chip output pins as near as touching head phone amp input pins; yes.

Maybe the DAC chips 200 Ohm resistors can be missed out in this case?

Assuming the 9023 is good enough. I've not listened to one yet. I like the lack of any output chips and passives smearing the analogue sound.

OK I get the idea now, and it is a good one. Not overly intimate with the 9023, but does it not have an onboard amp? Would feeding that amp into the wires cirucuits not cause havoc?

[qusp]

that would really limit the appeal for many who already have much better dacs

[ExStaxy]

Originally Posted by IanAS

Piggy back; no.

Same board; yes.

Minimum possible track length, DAC chip output pins as near as touching head phone amp input pins; yes.

Maybe the DAC chips 200 Ohm resistors can be missed out in this case?

Assuming the 9023 is good enough. I've not listened to one yet. I like the lack of any output chips and passives smearing the analogue sound.

Going by the measurements numbers here: NwAvGuy: ODAC Released (scroll down a tiny bit to what might be page two, paragraph called The Real Numbers) the DAC1 is a lot better. Do those numbers mean much though compared to missing out everything between the DAC chip and the amp input?

Well in the original Wire spirit, perhaps a look at some instrumentation DAC's would be in order and a better fit. Although last I heard (and I do not follow that closely) they were only 20 bit.
And of course there is the WM8742 which has just about everything but the kitchen sink on board and supports 24/192 inherently

[opc]

MLW168:

Great looking setup! Very clean wiring and a nice simple layout. I'm really glad you got everything up and running without any issues or damage.

Originally Posted by kuribo

I am wondering if this amp would work well driving a stax adapter and stax headphones? I am told the stax phones need about 3 watts or so....I think the imput impedence of the adapter is around 30 ohm....???

Kuribo:

It should indeed work quite well for that application. It has no problems with low impedance loads, and it can source a whole lot of current for a headphone amp.

It might be worth doing a little further research into exactly what the drive requirements are for the headphones as any headphone spec given in watts is always a little suspicious since the load varies so greatly. If you need a lot of voltage swing, then the BAL-BAL version is definitely the best option, but if you need a lot of current, then all the amps are the same 250mA peak. The ideal load for maximum power delivery is roughly 64 ohms, which can draw 2 watts RMS. With the BAL-BAL version and a 130 ohm load you can deliver twice that power level, for roughly 4 watts.

I suggest getting the sensitivity spec on the headphones and working your way backwards from your maximum desired output SPL to see how much power you really need. I have heard some pretty obscene comments about power requirements for various low sensitivity headphones, but when you crunch the numbers, they often turn out to be a little inflated.

Originally Posted by IanAS

Piggy back; no.

Same board; yes.

Minimum possible track length, DAC chip output pins as near as touching head phone amp input pins; yes.

Maybe the DAC chips 200 Ohm resistors can be missed out in this case?

Assuming the 9023 is good enough. I've not listened to one yet. I like the lack of any output chips and passives smearing the analogue sound.

Going by the measurements numbers here: NwAvGuy: ODAC Released (scroll down a tiny bit to what might be page two, paragraph called The Real Numbers) the DAC1 is a lot better. Do those numbers mean much though compared to missing out everything between the DAC chip and the amp input?

Ian:

I'm personally not all that keen on the 9023. If you're on a tight budget, or you like the simplicity of a single IC solution then it's probably a good choice, but it's not up to par with the 9012 or 9018. I even prefer some of the TI parts and one of the ADI parts to the 9023.

I'm not exactly targeting mediocrity with "The Wire" series. It's more of a "performance at any cost" approach. If the end product happens to be affordable, then it's purely by coincidence (or luck depending on how you look at it) For that reason, it's unlikely that you'll see a 9023 from me.

There will be a 9012 solution coming, but it will be on its own, and probably not with a headphone amp built in, although it's something to consider. Right now I'm focused on the 9102 ADC, and once that's done, it'll be on to the DAC.

Cheers,
Owen

[qusp]

Owen, hes looking to drive the Stax adapter, not the headphones, the headphones need 600V swing or more, it will in effect be driving the transformer in the adapter, the load of the headphones themselves is mostly capacitive. the transformer primary load is very low due to the massive voltage amplification step up

the STAX adapters are to allow using speaker amps to drive the headphones and avoid the expense of a purpose built Electrostatic amp