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 …

Hi there,

I purchased a new PS GCPH a while ago for MC cartridge usage and just used it in my system, which consist of a Mcintosh Mx-135, Denon Dp-A100 TT, Mcintosh MC402 and B&W 804d.

1. When I use ps gcph+amplifier, without another pre-amp, the sound is fine, but the MX135 with its MM is much better!
2. In connection mode “without PS gcph”, Denon DP-A100 (TT)->MX-135->MC402, the whole system sounds wonderful with MM cartridge (AT440ML). However when I put PS GCPH into the chain such as, Denon DP-A100 -> PS GCPH ->MX-135->MC402, the sound quality degrades enormously and gets lean where I loose some details such as imaging, staging, edges on Bass and midrange frqs. I still didn’t try MC cartridges with PS gcph+preamp but I guess I will have the same effect.

As a matter of practicality of using one main cable set with my amp and not switch it between Ps gcpj and pre-amp, I was wondering why using PS gcph+preamp degrades the sound enormously and what should I do to gain the sound quality that I would expect from ps gcph?

As for input level informations on MX135, here is the data:

Input Impedance
Phono: 47k Ohms, 65pf
High Level: 22k Ohms Unbalanced
50k Ohms Balanced

Sensitivity for inout
Phono: 5mV
High Level: 400mV Unbalanced
1V Balanced

Maximum Input Signal
Phono: 50mV
High Level: 5V Unbalanced
10V Balanced

I would appreciate your feedback. I tried PS audio support desk and so far there is no result!?!

Since a few days ago I left GCPH on and connected to the system, for break-in purposes. I tried again this morning and I was amazed how sound quality was improved. Perhaps after more break-in process the sound quality will improve. I read somewhere it would takes about 300 hours!. As for gain/sound adjustment, I use 48db knob and switched to 66 db where I put volume on 1:30-2 at GCPH, as it is recommended in the web sites. the result is much better in this case.

perhaps with more break-in process, the sounds will improve further. As a comment the PS audio has been very supportive ... thanks ...

Thank you DHL93449 for your comments.

for this purpose, I used balanced or (one of 11)unbalanced inputs of MX135. In either cases, the sounds degrades and looses a lot of details once signal goes through GCPH+Mx135. There has been some improvement with break-in process and perhaps it will get better but maybe not too much! I need to add GCPH+AMP sounds very good better than SIM-LP5. Of course it doesn't have the same deep bass and mid-range quality offered by MX135 but it still be decent.

Your comments on input capacitor stage seems to be a good explanation of this problem. It requires some knowledge/experience before getting into the GCPH box. Since my undergraduate degree on EE, I haven't touch measurement instruments which is a shame! In the other hand, I wouldn't spend too much money like twice of $gcph for cables. Unfortunately I am not as handy as you are to make changes as you did.

Right now I use AT440 and Shelter-201 which are not bad at all, maybe it is not as good as AT150 but the details and bass is pretty good. I thought instead of spending on more expensive cables just purchase more sophisticated MM cartridge. An alternative is to use only MM cartridges with MX135 where its quality is fantastic. and sell my MC cartridges+GCPH that I received as birthday presents!

Besides I am so tempted to replace MX135+gcph with a MC2300 which its quality is far superior. I need to think more seriously about this last option ...however I still hope to resolve the gcph problem ...

I set it first at 54db and volume knob to 3:00 - 4:00, the sound with MX135 was too compressed and not too much details. As a test I changed it to 66db @1:30-2 and sounds was much more open.

Without MX135, I used also the same combination and found more details on mid to high-frequency ranges compared to 54db @2:00.

If you ask me why? I am not sure about it...

Actually, I made a mistake on writing about gain setting!! I use only 48 and 54 db at 2:00 and mot 66db!

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 ...

Regarding Cables used in my system, I initially used AQ king Cobra, and switched to AQ Columbia, AQ Niagara and Nordost Heimdall. Of course there has been some improvement on sound quality when signal goes directly to AMP. The sound is pretty good and I like it very much so. This scenario is kind of not practical because when I want to listen to CDs I need to disconnect cables from GCPH-AMP and reconnect it again to my pre-amp(MX135)!

Unfortunately, the problem of sound degradation is being present once I use GCPH+pre-AMP+AMP. Even though using my AT33 cartridge, it sounds worse than a cheap cartridge as $20, no details at all on output sound ... I guess there is a mismatch (capacitor/impedance) between these two and I am very curious to find how?

Mr Rodman, I totally agree that cables play a huge role on sound quality, but I am afraid this case is not directly associated to cable issue. In case of upgrading cables to $4k cables only on phono stage, I would rather to buy a Manley Steelhead phono pre-amp, or the most practical option would be to upgrade to MC2300 where its phono stage is so phenomenal.

I read in these comments that you guy use gcph with some other pre-amps like parasound, TAcT and ... I was wondering whether how was your experience on using GCPH with pre-amp and how would you compare sound quality on GCPH+AMP and GCPH+pre-amp+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 …