Impressions of PS Audio GCPH

Sorry for these 2-3 weeks of delay on reply, I was out of country for a conference back in EU.

DHL93449, Glad to hear that you did successfully relocate power transformer outside of the Box and you are happy with results. BTW I do appreciate that you took time time to look at MX135 Manuel, thanks a lot.

To answer you question, yes, earlier I did try to use BAL1 of MX135 input (used for CD player) for GCPH and still had the same problem of sound degradation. I used other type of cables too, but not a big improvement!

I also looked at the internal circuitry of MX135, to find out how to bypass pre-amp stage and lead gcph signal directly toward MX135 output. In schematic MM phono goes through a first stage pre-amp, along with other inputs (RCA), it gets buffered before switching stage with Balance inputs. Selected input after another amplification stage goes to the processor where as an option one could choose external inputs too, without these pre-amp stages fed to the processor. Output of processor gets treated for Bass/TREB boosting options before final stage. Therefore, I tried different configurations to ameliorate sound quality of GCPH+MX135 and the result was not really encouraging!

This last weekend, I took my GCPH with some selected LPs to a friend’s house and tried to test it on his hi-fi system (Roksan Xerxes, AQVOX phono, Krell 280, krell PFB250s, Focal Diva speakers). We made some experiments with Krell-280 pre-amp, ps-Audio GCPH, AQVOX phono and different cartridges (MM/MC). Issue concerning gcph+preamp sound degradations was present but a little bit less audible; I mean Krell 280 compared with MX135. Again, GCPH + AMP were much better in sound quality. I have to say AQVOX phono was phenomenal! AQVOX phono+pre-amp were excellent and AQVOX+AMP were even better! There were some differences but not really very audible. We also tried different phono cartridges and compared related quality of GCPH and AQVOX phono. AQVOX outperforms GCPH in details especially in fastness and imaging aspects, as well as different range of frequency, better midrange, and higher freqs with a bass deeper than gcph.

I brought home for a couple of days the AQVOX and made some test with my MX135 and my new JA MICHELLE Gyro turntable. AQVOX+MX135 present an excellent sound, much better than GCPH+MX135. In case of AQVOX+AMP I got same sound quality with deeper bass. With AQVOX, I got much more details in sound compared to GCPH. The MM phono stage of AQVOX is as good as MX135 phono stage where I got a little bit more forward sound with MX135.

As for different cartridges, MM cartridges in GCPH present reasonable sound quality but with LO MC GCPH couldn’t handle it properly. I used MC cartridges too, where I found out MCs with an output of >0.45mv should be fine but with very LO MCs the degradation is really audible. Contrary to PS-audio GCPH, AQVOX is perfectly capable to handle even very LO MCs. Unfortunately, in PS-audio manual/specification it doesn’t provide any information on min/max input sensitivity for MM or MC cartridges!!???! It is bizarre …

Once again, I checked reviews on GCPH, nobody mentioned quality differences between GCPH W/Wo external pre-amp because they didn’t perform these sorts of tests. I also asked a ps–audio dealer in SF area and they didn’t have any experience on this regard!?

Based on my experience with both AQVOX phono and ps-audio gcph, I would certainly recommend AQVOX phono with a price tag of 998.00 Euro~$1250. It could handle very LO MC (>0.15mv) and it is totally configurable for different phono cartridges. It could be purchased only online from Germany website which might be inconvenient for some people!!? I wish I had purchased AQVOX instead of GCPH.

Being frustrated with GCPH experience, I decided to disconnect my ps-audio gcph from the system and will use only MX135 with its MM phono which is excellent, until I purchase a MCintosh MC2300, having both MC/MM phono stages. It is sad but that’s my fault to not have tested gcph before, and just trusted the reviews …

Michel:

Maybe you have a problem in the GCPH? If it's still under a warranty (and even if not, PS Audio is very liberal with potential warranty issues), I would contact PS Audio and explain your situation. I would think that maybe you have a problem in those gain cells. Can't hurt to send to PS Audio for a check up. If they say it's OK, then just consider selling it.

Mr D.,

Yes, It is a new device!!! 4 weeks ago I contacted PS-audio and someone named MArk, after a few exchange messages , suggested that he will find a dealer that I could take my GCPH there and eventually use different cables or loan me some cables and ... since then I didn't have any feedback from them!!?!

If there is an internal circuitry issue with my ps-audio it would be so shameful for Ps-audo that they don't have a quality check line on their products!

My guess is that the problem is the overall quality of GCPH which is on question, some people find it perhaps reasonalbe quality for $1000! I am not sure ... Honestly speaking that is a lot of money! that's why I expected a high quality sound out of it ... and that's why I am disappointed ...

Michel:

With all fairness to PS Audio, how can you blame them when the product sounds much better directly connected to the power amp? Adding any amp in between is most likely to reduce the quality of the sound, but that is not the fault of the GCPH.
As for the comparison with the AQVOX, perhaps the GCPH is inferior to that product, I don't know. I took a look at the 6moons review of this product, and it looks quite interesting. But remember Stereophile also gave the GCPH a rave review as well. So you cannot tell much about the sonic -preferences of a product from reviews. Sometimes when you make comparisons you get surprised, but you can only chalk that up to learning. The AQVOX appears to be more expensive (1000 euros list which is $1200-1300 US) and you can typically get a new/demo GCPH for $750 (as I got mine from Parts Express). But cost is another parameter that may not be all that relavent. Some folks like the CA products (if modified) and they are considerably cheaper than the GCPH. If you like the AVQOX that much, then sell the GCPH and move on. Life is too short to fret over how the GCPH should sound versus how it actually sounds.

You have nothing to lose by having PS Audio check it out. I cannot imagine anything about the circuitry in the GCPH that would degrade the sound through pre-amps that would not also be heard through a power amp. Unless you have the gain of the GCPH too high and you are overloading the pre-amp which would degrade the sound. But again, that is not the fault of the GCPH but how you are using it. I think I suggested you run your tests with the gain on the GCPH as low as possible if you are feeding a pre-amp.

Mr. D.,

To me GCPH issue is a closed case which is a worse pre-amp for $1000 as I mentioned in my previous message! That’s why I removed it from my system.

The answer to last part of your e-mail was already given in previous messages. It is not an issue of low/high gain...

The sound quality differences between phono preamp W/WO line pre-amp are normal at certain extent! However when I compare sound quality of GCPH with other ones in almost same price range , you may find GCPH is not well placed at all in the ranking ... this is when you realize the sound degradation between GCPH W/Wo extra line preamp is much worse than other phono preamps. That should be something wrong with its circuitry design … for this price range ($1000) there is a lack of honesty too! When they don’t mention min/max input sensitivity, or make believe you it is made in USA where it is made in china, where there is no any serious product quality check. Two days a go with a friend, I visited a hifi store (turntable guru store) in San Jose having an excellent reputation, during discussions the owner mentioned they used to be ps-audio dealer of GCPH, he got too many complains from customer and he is not caring any more gcph because of that! He was saying even Music Hall phone line ~$150 is better than gcph.

As for Stereophile review that you mentioned, Robert Deutch says it is a preview and not a review … he is not an expert for phono stages or turntables related devices… he quoted:” my listening to LPs is rather sporadic, and not so much for sound quality as for content: much of my LP collection is sufficiently obscure that it has not been—and is unlikely to be—released on CD, let alone SACD or DVD-Audio”. By the end he says it is a good match for ps-audio GCC-100 integrated amp …. Actually I wouldn’t consider it as a good review … Of course for analog components if this was come from Michael Farmer of stereophile I would have given more credit to the review !!! BTW look at Michael Farmer review in ST about AQVOX phono, it is a very good review …. Besides other reviews on GCPH, use only integrated amps rather separate devices, which changes the usage context …

I don’t have any intention to make publicity for any band like AQVOX or any other one! I presented my experiences on GCPH, AQVOX with different systems in order to be shared with other fellows in Audiogon…my previous comments would perhaps present a sense of reality in GCPH quality, testing in different circumstances, devices, cables and phono cartridges … BTW I don’t push the idea that GCPH is the best because I bought it … Regarding pricing, there is always a price degradation on second hand devices even demos or used ones, I think there is always a way to find an AQVOX phono as used (~$700-$800 instead of $1250) like the one your gcph that you bought at $750 instead of $1000+tax …

I got GCPH (HUGE mistake) as a temporary solution for using with my MC cartridges before moving toward a robust phono line like C2300. This unpleasant experience just motivated me more to move toward a good integrated phono stage… If you use CD player and other sources in the system, it seems for a >$25K whole hifi system, it is better to have an integrated phono stage in a preamplifier even with a higher price tag ... other wise one should invest in extra cables, power cables and not having the same sound quality as expected …