[2MnyToys]

Thanks Jude. Look forward to comparing it with some of the new Headroom amps.

 

[OracleGuy]

Thanks Jude! I believe they are planning on pricing this box < $1,000 -- it sounds like it should do quite well.

Did you test the built-in USB DAC functionality?

I'm still deciding what to do for my next upgrade--either a better DAC (DAC-1? PS Audio DAC?) or an amp w/DAC combo (new Headroom amp? GCHA?).

 

[zatara]

Jude,
Do you know anything about the dac in the GCHA? i was wondering if it resamples the signal or not.

 

[OracleGuy]

Quote:

Originally Posted by zatara Jude, Do you know anything about the dac in the GCHA? i was wondering if it resamples the signal or not.

According to a post on the PS Audio discussion board (Jon from PS Audio):
The DAC is not upsampling. 44.1kHz/16 Bit is the maximum resolution. It does have a low jitter clock pll circuit.

Note that PS Audio is also planning a stand-alone DAC (with USB input) which is supposed to be higher-performance than the GCHA's internal DAC.

 

[jude]

Here's what I know about the GCHA's internal DAC (along with some comments about PS Audio's upcoming standalone DAC).

1. The GCHA uses the PCM2702 for both USB retrieval and as the DAC. It's a 16-bit DAC with pretty good specs, that has a circuit to reduce jitter.
   
2. PS Audio used separate regulators for the analog and digital supplies in the GCHA.
   
3. I've only used the USB input with my laptop computer's USB output, and it sounds good. I've used it to listen to Rhapsody, and it's the best I've heard Rhapsody sound. Dedicated source components plugged into the RCA inputs sound clearly better, however. This isn't surprising to me given that the DACs I use are probably significantly better than the PCM2702 receiving USB from my laptop, not to mention the fact that Rhapsody isn't exactly CD or SACD either. I think the USB input is definitely a useful feature to have, and I think we'll see it available on more and more amps, with the growing popularity, credibility and capability of computers as source components.
   
4. In their upcoming standalone DAC, I believe PS Audio is going to use the PCM2902, but only for USB retrieval prior to upsampling and conversion by a separate higher-end DAC chip. It will be interesting to see how that DAC sounds using its USB input (I'm curious to see if the higher-end implementation has sonic benefits when using a laptop's USB out, versus, say, the GCHA). Of course, I'm most interested in finding out how the upcoming DAC compares with other standalone DACs.

Some other things I neglected to mention about the GCHA in my previous post.

1. This amp is one of the best I've yet heard for very low level listening. Sometimes, when there's a lot of activity at the office, I like to keep my listening levels very low. The GCHA maintains very good detail at even very low listening levels. Additionally, its channel matching sounds perfect to me, even while very slowly turning the volume all the way down to inaudibility.
   
2. Due to its class A output stage, the GCHA runs warm for a solid state amp. Not hot, just warm, but warmer than most other solid state amps I've used. This doesn't surprise me. The GCHA appears to have a heavy, beefy output stage that runs class A, and can drive even the K1000 (although, again, PS Audio, in my opinion, should dial maximum gain up in the production units).
   
3. If it's plugged in, the GCHA is pretty much always powered up, in order to keep the output stage warmed up. When you turn the amp off (volume knob left-lock position), it just turns off the blue LED and the output relay. PS Audio's position on this is that the amp sounds better when it remains powered.

 

[OracleGuy]

Quote:

Originally Posted by jude In their upcoming standalone DAC, I believe PS Audio is going to use the PCM2902, but only for USB retrieval prior to upsampling and conversion by a separate higher-end DAC chip. It will be interesting to see how that DAC sounds using its USB input (I'm curious to see if the higher-end implementation has sonic benefits when using a laptop's USB out, versus, say, the GCHA). Of course, I'm most interested in finding out how the upcoming DAC compares with other standalone DACs.

Jude, thanks very much for your detailed thoughts. I too am looking forward to seeing how their upcoming DAC compares. I did see a post (in the PS Audio forums) that the DAC uses USB as "just another digital source", so it should be a convenient, presumably bit-perfect, alternative to S/PDIF for us computer-as-source folks. Also Paul claims that it compares favourably with every other DAC they've tried (to which I made a comment about it "benchmarking well"). The only problem is that they aren't projecting any production date yet. I guess they have a lot on their plate at the moment.

I hope you're promoting yourself as a beta tester for the DAC too!

BTW, if you still have the GCHA, I'd be interested in your comments if you try the USB input from your laptop using lossless (e.g., FLAC) source files.

 

[OracleGuy]

Just checked the PS Audio forum, and Paul posted this morning that the GCHA should "for sure" ship in July, but unfortunately the price is now about $1,000 vs. his original guess of $795.

 

[Zanth]

Quote:

Originally Posted by OracleGuy Just checked the PS Audio forum, and Paul posted this morning that the GCHA should "for sure" ship in July, but unfortunately the price is now about $1,000 vs. his original guess of $795.

1k is not all that bad for a high level amp performer + dac. It has me interested. Though so does that new fancy Max

 

[Anders]

Lastest news from the PS Audio forum, Paul McGowan wrote:

"Yup, we've increased the gain as Jude asked"

So this becomes really interesting

 

[OracleGuy]

I'm quite impressed when the principals of a company reply on discussion forums in a timely fashion. Kudos to PS Audio and also Headroom for that.

Hey Jude, have you hit Paul up for Head-Fi sponsorship yet???

 

[Zanth]

Quote:

Originally Posted by OracleGuy I'm quite impressed when the principals of a company reply on discussion forums in a timely fashion. Kudos to PS Audio and also Headroom for that. Hey Jude, have you hit Paul up for Head-Fi sponsorship yet???

Screw the sponsorship, how about a free amp for all its members

 

[Nik]

I'm never been interested in headphone amp + internal DAC...

Best!
Nicola

 

[Zanth]

Quote:

Originally Posted by Nik I'm never been interested in headphone amp + internal DAC... Best! Nicola

Such things are quite convenient for say a college dorm room or for an office. One can use a small HD DAP --> amp/dac combo-->headphone of choice. Small footprint and excellent sound to boot!

 

[Hello]

As a DAC + amp, how does the GCHA compare to the Benchmark Dac-1?

I think we need a Dac-1 vs GCHA vs Headroom Home 2005 shootout.

Something to look forward to....

 

[OracleGuy]

Quote:

Originally Posted by Hello As a DAC + amp, how does the GCHA compare to the Benchmark Dac-1? I think we need a Dac-1 vs GCHA vs Headroom Home 2005 shootout.

I'm not expecting the DAC in the GCHA to compare with the Benchmark--I'd expect it to be comparable to the "basic" DAC in the new Headroom amps (as a guess), and the amp section of the GCHA will be miles ahead of the DAC-1.

I do however expect the standalone PS Audio DAC to compare very well with the DAC-1.

I agree on the shootout idea though! From Jude's comments, it sounds like the GCHA will give the Headroom Home Reference a run for its money.

When the PS Audio DAC is released, a shootout against the DAC-1 will definitely be in order. I'd also be interested in adding the new Perreaux DAC to the mix.