Ch precision...p1

[byrdparis]

I’m sorry if this question has been asked before: is there any downside, except for increased electricity bill, to have P1 and L1 permanently switched on?
Also, can I use both XLR and RCA outputs at the same time and connect them to L1?

Thanks in advance.

i have a full CH PRECISION system (all of it in my signature) i am always switched ON 24\7 356 days!
never turned it off. my system is always warm and ready.
the only time that i turned them off is for tiding up the system if somethiing new is coming or if i am out for a few days....

also you can connect both way, no problem.

BR
aviad.

 

[abeidrov]

i have a full CH PRECISION system (all of it in my signature) i am always switched ON 24\7 356 days!
never turned it off. my system is always warm and ready.
the only time that i turned them off is for tiding up the system if somethiing new is coming or if i am out for a few days....

also you can connect both way, no problem.

BR
aviad.

Thank you, byrdparis. The only possible issue with keeping them on 24/7 is display burn-in, but I figured, that if I keep the displays on 10% dimmed setting, that is very unlikely to happen.

As for simultaneously connecting both XLR and RCA out, I am not so sure. The P1 manual states: “We recommend that the output stage doesn't get loaded with an impedance lower than 10 kOhms (the input impedance of the unit connected to the P1 should be greater than 10 kOhms). “ Does the loading change when you connect both outputs at the same time, and can it somehow affect the sound?

 

[iaxel]

Thank you, byrdparis. The only possible issue with keeping them on 24/7 is display burn-in, but I figured, that if I keep the displays on 10% dimmed setting, that is very unlikely to happen.

You can have the display off, as well as the CH LED.

 

[byrdparis]

Thank you, byrdparis. The only possible issue with keeping them on 24/7 is display burn-in, but I figured, that if I keep the displays on 10% dimmed setting, that is very unlikely to happen.

As for simultaneously connecting both XLR and RCA out, I am not so sure. The P1 manual states: “We recommend that the output stage doesn't get loaded with an impedance lower than 10 kOhms (the input impedance of the unit connected to the P1 should be greater than 10 kOhms). “ Does the loading change when you connect both outputs at the same time, and can it somehow affect the sound?

you can dim or close the display all together and still keep them ON,

for connection, you asked if it will work and it does, how it will sound, i dont know, but i thought yyou uwanted to do AB test and figuure what best for you,. try and decide.
there is no reason to have them both connected unless you have two amps system...

 

[abeidrov]

I use Gryphon VIP XLR and Kubala-Sosna Elation RCA and can’t decide which one is better, I keep switching between the two cables and it drives me crazy)

 

[byrdparis]

I use Gryphon VIP XLR and Kubala-Sosna Elation RCA and can’t decide which one is better, I keep switching between the two cables and it drives me crazy)

I have a solution for you
Sale them both and buy VYDA xlr cable.
done and dusted! Forever.
You would not believe what it will do for your P1. You will thank me later .
A

 

[Bonesy Jonesy]

You can have the display off, as well as the CH LED.

Word on the street.... that the P1 sounds better with the display off....going to try it (with the X1 that already has the display off permanently) this weekend to see if I can hear any difference to the sound with my headphone system.

 

[byrdparis]

Word on the street.... that the P1 sounds better with the display off....going to try it (with the X1 that already has the display off permanently) this weekend to see if I can hear any difference to the sound with my headphone system.

i tried that some, many years ago, didn't notice for such a difference, i like to see the displays, even if they a little dimmed.

 

[mtemur]

I have a solution for you
Sale them both and buy VYDA xlr cable.
done and dusted! Forever.

Looks like a good plan but it’s almost impossible to sell cables unless you’re pricing dirt cheap. I’m sure many audiophiles have a bunch of cables waiting to be sold, especially power cords. Another bunch waiting to be sold is tweaks.

 

[Bonesy Jonesy]

i tried that some, many years ago, didn't notice for such a difference, i like to see the displays, even if they a little dimmed.

Agree with you 'byrdparis' i.e. listening with my headphone system, to my ears, I couldn't hear any difference with the P1 LED display on or off with playing different genres of music with different quality of LP pressings etc. for a good hour or so !

However, going forward, I have decided to now keep the P1 LED display off at all times (along with my X1) as I am now operating the P1 through the CH Precision App via my Samsung Galaxy Tab A8 Pad / Tablet so I don't need to see the P1 on-board LED display.
This CH App is great as I have also been experimenting with RIAA curves, subsonic filter, gain values etc. on-the-fly that has allowed me to dial-in the ideal sound for my ears.

 

[Bonesy Jonesy]

Has anybody upgraded to two P1's and two X1's from one P1 and one X1 ?
If so, was it a big difference in the sound and if so what had changed ?

p.s. Have read numerous online reviews from professional Reviewers over the last year or so, but I want to hear from people who are not professional Reviewers and have taken the plunge to purchase two P1s and two X1's themselves and to hear their own personal experiences !

p.p.s have also read how great the P10 is over two P1s and two X1s from online professional reviews but I am not in the market for a new or used P10 at the moment (maybe in 5+ years from now !)

 

[mtemur]

Dear @Bonesy Jonesy I heard two P1s and two L1s supported by X1s in different setups. Yes there is an improvement over single P1 but IMHO it’s not huge. Or maybe it’s because CH is not my thing.

 

[Bonesy Jonesy]

Dear @Bonesy Jonesy I heard two P1s and two L1s supported by X1s in different setups. Yes there is an improvement over single P1 but IMHO it’s not huge. Or maybe it’s because CH is not my thing.

Thank you for the feedback on your experience 'mtemur'. Much appreciated.

 

[metei]

I recently acquired a CH P1 to replace accuphase C-47.

I am wondering whether adding a X1 or P1 next makes a bigger improvement?

Hi there. From Your signature it seems like You still have the P1. I am also considering the same move (from C-47 to P-1). Would You care to compare the two?

 

[jsec]

Hi CH P1 Owners,
Have two questions regarding the earth connections on the P1 and the transportation bolt(s) underneath the P1 that should be removed after being transported / delivered before being installed in the P1's resting and operating place.

Reason I am asking these questions is I have (and always have since installing my P1 last November (bought used), hear some hum through my Hifiman EF1000 Headphone Speaker Amp and Susvara Headphones when the volume gets to around 50% onwards. Through the speakers it is much harder to hear the hum but it is still there.
Therefore I am wondering if
I have disconnected the tonearm lead (currently connected to the MC1 / current input of the P1) and the hum does reduce but is still there. So I know it is not the cartridge or the tonearm cables from my Kuzma 4Point 11" (connected to my Kuzma XL DC).

Earth Connections on P1
On my P1 there are three earth connections (for banana connections) at the back of the P1 i.e. the two upper ones in black and the lower third one in yellow.
I am using the yellow connection as the earth with an earth wire (green & yellow) going to a mains power supply hub earth connection.
And I am using one of the black connections (top one) for my black tonearm earth cable connection i.e.;

View attachment 104627

When I disconnect the earth connection from the P1 that is wired to the mains power supply hub earth connection the hum is louder.
When I disconnect the tonearm cable from the P1, the hum is louder.
Can anybody give me information as to whether my current earth connections are correct / optimal in reducing any hum from the P1 that may be due to earthing of the P1 as much as possible.

Transportation Locking Bolt(s) for P1 (or not in my case with my P1).
When I read version V1.1 of the P1 Manual it talks about in Section 4 to unscrew a transportation locking bolt from the P1 that locks the Transformer in place during transportation and unlocks it when removed.
When I read version V2.2 of the P1 Manual (most current version on the CH Precision website) it doesn't mention at all about unscrewing a transportation locking bolt to release the P1's Transformer.
When I look underneath my P1, it doesn't have such a transportation locking bolt like is shown in the V1.1 P1 manual, however I do see four smallish domed head allen key bolts arranged in a square pattern i.e. ;

View attachment 104628

I am therefore assuming that my version of the P1 (manufactured late 2019 (possibly Nov 2019) has no such transportation locking bolts to remove before siting and operating the P1, hence no information on such transportation locking bolts in the V2.2 version of the P1's manual.
Can anybody give me any information / reassurance on this for my P1 ?

Thank you WBF Members in advance for any help / advice you can give me to make sure I am using my P1 optimally to reduce hum as much as possible.

I'm wondering the same thing. I have 4point 9 with RCA connectors plugged in to P1 (no X1 in the system yet) MC1 and ground cable is on the P1's yellow connector. There is hissing sound, but not audible through speakers. If I switch to MM/MC connectors on P1 the humming is significant and easily audible through speakers. The ground connection doesn't seem to impact the humming at all. I would appreciate if anyone has experience on dealing with humming with P1. Would XLR terminated cables help?

 

[metei]

So after more than a year, coming back with many comments;
I have purchased the P1 and also life gave me a chance to keep Accuphase C-47. Bottom line P1 is better than C-47. How much? Is it worth x3 price? Depends on personal preferences. P1 is more, neutral, more detailed and has way lower noise level. Once set-up to best with test record and ear (I personally prefer, at least 1, sometimes 2 +5 dB low on P1 and more volume on my pre-amplifier) P1 is as good as it gets. If You have a C-47 but a P1 is out of Your budget are You missing too much? Personally no, keep listening and be happy with C-47, it is a wonderful phono pre especially for its price. I also have L1 and X1. Since I would have and keep them, didn't do A/B/C tests (P1/L1/X1 one or both connected etc. variations) but, I had to separate P1 and L1 so kept X1 with L1. I can't say with and without X1, the difference is day or night, I'm not missing the X1, but that's me. Now I also have C1.2 (dac) and even when my two systems merge, I'm planning to use my X1 on C1.2 and L1 and not buy another X1 for my P1 but use it with its internal power supply.
As for @jsec 's issue above along with @Bonesy Jonesy 's; I have had similar problem but not with my P1 and my Kuzma 4pt 11 and ClearAudio Goldfinger on it. Although every case is its own; what I realized on my system is; there is a noise source (in my case it was an LED lamp with wireless phone charging base unit too close to my analog layout) and a weak link prone to RF noise (in my case it was my step-up-transformer) which in Your cases may be cartridge body itself and / or any cable on the way). I've had no issue with my Kuzma -> P1 connected on my MC1 input. Even after I got rid of the noisy lamp, my SUT still picks up some RF noise (environment noise, wireless, phone, etc.). Someday, I will built a simple Faraday cage for it and try again. You can always try a basic Faraday cage Yourself (although hard to apply on cartridge): just tear simple kitchen aluminum foil and cover to a closed box / ball / tube to the best You can around the device and have a go. As I said, although not the perfect cage, it shall cut noise enough (i.e. 20 - 30 dB instead of a perfect 50 - 60 dB) to eliminate most noise. For cartridge You can make a ball of aluminum leaving the bottom open and put it on the cartridge even without using (i.e. playing music) and caring for the VTF if You use. In these cases of phono noise, grounding naturally decreases the hum / buzz noise but in my case no matter what combination of grounding used (phono, pre, even grounding to the radiator etc.) didn't kill the noise completely. In P1, the signal ground and chassis ground are separate. In general, in a regular phono pre they are connected (i.e. one). So connecting the phono ground cable to one or the other grounding post or even more, connecting the two ground posts with another cable should yield no technical danger / harm but may decrease, increase or not change at all the noise.
In most phono cables, if it is built as a phono cable, the left common cable is also a grounding cable and additionally there is a grounding cable to connect to the grounding post of the phono pre, or an additional grounding cable to connect the phono pre grounding post to pre-amplifier grounding post. In most XLR phono cables, due to the nature of the process, there are three grounding cables, one for left channel, one for right channel and one for general coming out of Your cartridge. Would this yield a better grounding? Yes definitely. Would this solve Your case? Most probably not. If the noise is generated by Your cartridge or arm cables, this would decrease the noise, not solve completely. You shall eliminate the noise source, or if not able to eliminate, find a solution (as a Faraday cage etc.).

 

[iaxel]

I do not own (or owned) a Kuzma 4P tonearm. However, I have heard issues with using the 4P and the P1. Something concerning the capacitance of the 4P cable itself, specifically when using it with the current inputs of the P1 (and with low impedance cartridges).
I would try to ask/contact Franc.

 

[metei]

I do not own (or owned) a Kuzma 4P tonearm. However, I have heard issues with using the 4P and the P1. Something concerning the capacitance of the 4P cable itself, specifically when using it with the current inputs of the P1 (and with low impedance cartridges).
I would try to ask/contact Franc.

By the way, my Kuzma 4p is Kondo internal cabling with rca connectors.

 

[iaxel]

By the way, my Kuzma 4p is Kondo internal cabling with rca connectors.

I have no idea if the Kondo wiring resolve the issue.

 

[jsec]

So after more than a year, coming back with many comments;
I have purchased the P1 and also life gave me a chance to keep Accuphase C-47. Bottom line P1 is better than C-47. How much? Is it worth x3 price? Depends on personal preferences. P1 is more, neutral, more detailed and has way lower noise level. Once set-up to best with test record and ear (I personally prefer, at least 1, sometimes 2 +5 dB low on P1 and more volume on my pre-amplifier) P1 is as good as it gets. If You have a C-47 but a P1 is out of Your budget are You missing too much? Personally no, keep listening and be happy with C-47, it is a wonderful phono pre especially for its price. I also have L1 and X1. Since I would have and keep them, didn't do A/B/C tests (P1/L1/X1 one or both connected etc. variations) but, I had to separate P1 and L1 so kept X1 with L1. I can't say with and without X1, the difference is day or night, I'm not missing the X1, but that's me. Now I also have C1.2 (dac) and even when my two systems merge, I'm planning to use my X1 on C1.2 and L1 and not buy another X1 for my P1 but use it with its internal power supply.
As for @jsec 's issue above along with @Bonesy Jonesy 's; I have had similar problem but not with my P1 and my Kuzma 4pt 11 and ClearAudio Goldfinger on it. Although every case is its own; what I realized on my system is; there is a noise source (in my case it was an LED lamp with wireless phone charging base unit too close to my analog layout) and a weak link prone to RF noise (in my case it was my step-up-transformer) which in Your cases may be cartridge body itself and / or any cable on the way). I've had no issue with my Kuzma -> P1 connected on my MC1 input. Even after I got rid of the noisy lamp, my SUT still picks up some RF noise (environment noise, wireless, phone, etc.). Someday, I will built a simple Faraday cage for it and try again. You can always try a basic Faraday cage Yourself (although hard to apply on cartridge): just tear simple kitchen aluminum foil and cover to a closed box / ball / tube to the best You can around the device and have a go. As I said, although not the perfect cage, it shall cut noise enough (i.e. 20 - 30 dB instead of a perfect 50 - 60 dB) to eliminate most noise. For cartridge You can make a ball of aluminum leaving the bottom open and put it on the cartridge even without using (i.e. playing music) and caring for the VTF if You use. In these cases of phono noise, grounding naturally decreases the hum / buzz noise but in my case no matter what combination of grounding used (phono, pre, even grounding to the radiator etc.) didn't kill the noise completely. In P1, the signal ground and chassis ground are separate. In general, in a regular phono pre they are connected (i.e. one). So connecting the phono ground cable to one or the other grounding post or even more, connecting the two ground posts with another cable should yield no technical danger / harm but may decrease, increase or not change at all the noise.
In most phono cables, if it is built as a phono cable, the left common cable is also a grounding cable and additionally there is a grounding cable to connect to the grounding post of the phono pre, or an additional grounding cable to connect the phono pre grounding post to pre-amplifier grounding post. In most XLR phono cables, due to the nature of the process, there are three grounding cables, one for left channel, one for right channel and one for general coming out of Your cartridge. Would this yield a better grounding? Yes definitely. Would this solve Your case? Most probably not. If the noise is generated by Your cartridge or arm cables, this would decrease the noise, not solve completely. You shall eliminate the noise source, or if not able to eliminate, find a solution (as a Faraday cage etc.).

Thanks @metei for the suggestions. I will troubleshoot this further. One important think I forget from my previous message - I have used Accuphase E800 with phono add-on cart (66db gain) with any humming problems.