Please help a Newbie with a PV9A

[jwahl411@gmail.com]

Hi Everyone, I was wondering if anyone can help me determine if a CJ PV9A preamp would be a good match for my Mcintosh MC225? I am new at all this and could use some help. I am worried about matching the components and don't have enough knowledge or experience to make the decision alone. The one thing I keep reading is that there may be a gain issue?? I want to make sure that I have good control of the volume range with sensitive and non-sensitive speakers. I want the flexibility to try many different types, from Magnepans to Harbeth, Klipsch, ZU and others. Please help I need to pull the trigger soon. Here are the specs of my MC225:

Power Output:
Stereo or twin amplifier: 25 watts continuous per channel
Monophonic: 50 watts continuous
Noise and Hum:
90 db or more below rated output

Input:
Input impedance: 250,000 ohms
Input sensitivity: 0.5 volts to 30 volts
through gain control. 2.0 volts with gain
control turned to dot indicator.


Output Impedance:
Stereo or Twin Amp:
(Center tap internally grounded) 600 ohms
(One side internally grounded) 4 ohms,
8 ohms, 16 ohms, 150 ohms, 200 ohms
Mono:
(Center tap internally grounded) 300 ohms
(One side internally grounded) 75 ohms,
100 ohms
Output Voltages: One side grounded
Stereo (or twin amplifier):
25 and 70.7 volts
Mono (single channel):
25 and 70.7 volts
Internal Impedance:
Less than 10% of rated load impedance

[roberto]

Hola jwahl411@gmail.com and welcome,

Any Conrad Johnson preamplifier will match any other hi-end brand. With a McIntosch, I don't see any problem. Those 25 watts of your McIntosch made to happen the honor of the brand's name on these days. If you use a very high sensitive speakers and over 90dB/2.83V/m or more, you are safe. This is a very important specs while paring the amp to the speakers. Never use the 70V tabs. This is for Public Address installations. (Profesional use only).

Understand that you have clean 25W/channel only. Magneplanar speakers are power hungry. So, all depends if you do not mind to play the music a moderate level. Same here for the Harbeths. Klipsch are easy to drive. You must find the right combination for the volume control. CJ will not harm your McIntosch power amp. It will make it to sound beautiful.

You should try it first, and then let your ears decide. They are your final judges.

Happy listening!

[admin]

Roberto is correct. Absolutely no issue with the PV9 in this system. It should complement the McIntosh very well. His 2nd point is also spot on. I run Magnepan speakers and they are highly inefficient. If you want to blast the music at very high levels, the 25 watts of the McIntosh will most likely not be enough. However, it should still be ok at low to moderate listening levels.

[jwahl411@gmail.com]

Awesome! Thank you so much, I'm going to give it a try. What do you think is a fair price for a PV9A with the phono in good condition? I would say 8 out of 10, I would like to be able to sell it fast if I end up not liking the CJ sound. I doubt it but who knows?

[jwahl411@gmail.com]

And what the heck is this? "Line Stage phase inverting, Phono Stage phase correct"

does anyone know how I should connect this? I have a Turntable and a DAC hooked to a Mac Mini running Roon and Tidal as my second source. Do I have to move speaker wires around if I change sources??

[roberto]

J,
If you use only the preamp with the phase inverting, then only reverse on both speaker the cables. That's all. The red goes to the - and the black goes to the +. Doing this the polarity is phase correct.

[jwahl411@gmail.com]

I'm confused, I am hooking up a turntable to the phono input and a DAC to the other input. How should I hook up the speaker wires?

[mgttr]

I'm confused, I am hooking up a turntable to the phono input and a DAC to the other input. How should I hook up the speaker wires?

All you need to do is reverse both of the speaker cables as Roberto instructed. You can do this at either the amp end or the speaker end, but don't do it on both! Since your phono stage is phase correct you will not need to take any additional steps when listening to LP. As long as you reverse your speaker cables your speakers will be phase correct regardless of the input source selected.

Jerry

[roberto]

Thanks mgttr,

J, understand this:

1) You have two speaker cables. One is for the right channel the the other is for the left channel. Each cable has two leads , right? One lead is + and the other is - (Red = + and black = -). Is this correct for you?

2) The CJ pre amp inverts the phase, this means, that you have a signal output at the preamp at 180º on both channels. To have the signal back to 0º,(desirable) you have to reverse the speaker cables only.

3) Just connect at the speaker binding post, the cables reversed, both cables on both speakers. This way, you have the 0º absolute phase.

4) Where you have the red biding post (+) connect the ground cable coming from the amp.

5) And at the black binding post (-) connect the red color cable (the one that comes from the 4 ohms or 8 ohms tab at the power amp).

I do not know the impedance of your speakers, you are the user, you should know this. if your speakers are 4 ohms or 8 ohms.

Is this now more clear for you? If you have more questions, do not worry to ask, we are here to help you out! Just follow the instructions.


Happy listening!

[antaresbluespirit]

PV9A,BeardC35,PV8 and MV 60SE

PV9a,C35,PV8,MV60SE.jpg (4.16 MiB) Viewed 1153 times

PV9A,BeardC35,PV8 and MV 60SE

PV9a,C35,PV8,MV60SE.jpg (4.16 MiB) Viewed 1153 times

PV9A,BeardC35,PV8 and MV 60SE

PV9a,C35,PV8,MV60SE.jpg (4.16 MiB) Viewed 1153 times

Hello Jewhall 411,

You are the lucky owner of two highly regarded classical unit designed by the end of 20th century!

The MC 225 is legend and the PV9A the most desirable CJ preamp fitted with phono stage ever....believe me...

THe PV9A phono stage is amazing and hard to find today (only the A version, the latest generation PV8 -PV9A had the specific high gain stage to be used with the any analogic phono input..

Their subjective and noticeable sound quality acknoledged by the fan and vinyl lovers was the "weight of the music,the matters and the strong dynamic"...
the PV 9A cicrcuit evolves from the fameous premier three who fix CJ gears among the top end of the preamp design since the end of seventies...

These qualities are also due to the high gain of their circuits not used anymore today within the majority of AUX input like CD,TAPE,TUNER ,DAc(similar sensivity for all of these except phono who include RIAA correction°

To complete the right recommandations given by Roberto:

All the input stage selection TUNER,CD,TAPE 1 & 2 are phase inverting

Only the PHONO stage is not phase inverting (the 180° are cancelled due to additionnal tube stage within the cicuit)


You 'll find below a couple of PV9A & MC 225 partenered (friend owner of me)

CJ PV 9A & MC225

CJ PV9A & MacIntosh MC225.JPG (168.88 KiB) Viewed 1494 times

Personnaly I own a PV10A,a PV8 & PV9A (all are fitted with the phono stage )

PV9A,BeardC35,PV8 and MV 60SE

PV9a,C35,PV8,MV60SE.jpg (4.16 MiB) Viewed 1153 times

My PV9A is partnered with a CJ MV 60SE; and the volume index is often to 9 o'clock in normal listening condition, you should get the same adjustment with the MC225 considering à 90 db of speaker efficiency.

Contingencies:

Among other end user having linked their PV9A with amp system including a 100 db speakers efficiency like Klipsh Horn and other guy having TAD compressed pavillon in these case the high gain ofthe PV9A would be unconvenient since the volume index would be limited between 8 to nine in usual listening .

So keep confident with these two lovely and desirable components, you are a really a lucky newbie!

Regards


Raymond

ps: i can transfer to you the french forum topic where we share PV9 A experiences but it is in french language...

[jwahl411@gmail.com]

Wow, thank you so much, guys! Can anyone chime in on a fair price to pay, I'm ready to pull the trigger on the PV9A based on the amazing people here. The condition is Very Good, not mint but nice enough to be proud of.

[jwahl411@gmail.com]

Thank you, Roberto, for the instruction on phase inversion. One question is about the two sources. So if I reverse the cables at the speakers I will be able to play my DAC and Turntable in polarity just by selecting the proper input on the Pre? That is my take away from the above, Did I get it right?

[admin]

Thank you, Roberto, for the instruction on phase inversion. One question is about the two sources. So if I reverse the cables at the speakers I will be able to play my DAC and Turntable in polarity just by selecting the proper input on the Pre? That is my take away from the above, Did I get it right?

Yes. One polarity switch by speaker wire is required for an odd number of polarity switching devices in the system.

[roberto]

J,
Admin is right!, you do not need anything else. All your system will be with at 0°.

Happy listening!