Conrad Johnson premier 14 Pre

[lonergan2468]

I managed to get a Conrad Johnson P14 pre amp to day. Waiting for it to arrive.
Just wondering if anyone here has any reviews or experience of this unit.
thanks

 

[Scumurculum]

If by that you mean the PV14. Then that is a really nice sounding preamp.

A friend had one his system for a while and it was a really enjoyable to listen to.

Not the ultimate in the highs and lows, but it has a wonderful midrange.

 

[Cherian]

I had a CJ PV14LS for about a year and loved it. It is very smooth and detailed. As I recall the PV14LS is a zero feedback single stage triode amplifier design using one 6C4 tube per channel. I think you will find this is a very good preamp and will match well with most amplifiers.

EDIT: I see you are talking about the CJ Premier 14. ML member TrumpetDoug has the CJ Premier 14 you may want to PM him. I know he is very happy with his. See his system http://www.martinloganowners.com/forum/showthread.php?t=6157&page=2

 

[lonergan2468]

Thanks
I need to find out about this phase invertion stuff as I believe that the P14 is.

 

[Cherian]

Most CJ gear inverts the phase. It is an easy thing to fix. If you have an odd number of phase inversions in your system all you need to do is swap the "+" "-" connection at the speaker. IE hook the - lead to the + post and the + lead to the - post of the speaker. This will correct the inverted phasing. If you have an even number of phase inversions in your system you do not need to do anything. Just wire as normal.

What I ffind is when the phase is inverted everything sounds out of focus.

 

[lonergan2468]

Crikey! OK I am not TEC dude. I dont know about the rest of the system
I am using a spark Cayin CD, Krell KST100 power, Project RPM 10 turntable Trichord dino and power supply. Geting confused here LOL

 

[Cherian]

The user manual for all the equipment would state if they are phase inverting. If they don’t then they are not. Most equipment are not phase inverting. I think you will need to invert the phase at the speaker if you use the CJ premier 14 pre. Because once you put the CJ pre in line you will have an odd number of phase iversions (1).

 

[Kruppy]

Most CJ gear inverts the phase.

Please excuse my ignorance here, but why would they do this?

 

[Jeff Zaret]

Kruppy,
From CJ
"Why is my conrad-johnson component phase inverting?
A. Each active voltage gain stage in a circuit inverts phase once. In pursuit of ultimate purity in music reproduction, recent conrad-johnson preamplifiers have been designed for the absolute minimum number of gain stages – one. One stage, one inversion, hence these components invert phase. By the nature of its design, the Premier 350, which also has a single voltage gain stage, is phase inverting."

I hope this it just a little clearer.

Jeff

 

[tonepub]

They do it because if you use a CJ power amp, which also inverts phase, then it's all ok....


A quick email to the relative manufacturers will tell you what's what.

It gets more confusing, because some RECORDINGS invert phase and some do not. Just when you thought it was going to be easy!

If you don't want to bother with any of this, just hook your system up. When you are used to how it sounds for a little while, try reversing your speakers polarity (both the same).

If your system is in correct phase, it will sound slightly more closed in when you reverse the wires. If it is not, it will sound slightly more open and dynamic.

Nothing to lose sleep about!

Enjoy.

 

[lonergan2468]

Yes CJ sent me the manual in e mail. I will phase invert the cables at the speaker terminals, have a good listen using some good material that I use on a regular basis such as Patricide Barber's nightclub on CD, and jazz at the pawnshop on vinyl. After a few days I will change them back to normal input. I am still waiting on this amp. Looks like my Audiolab 8000Q pre and the four 8000M should go up on E Bay later if my camera is working!

 

[SundayNiagara]

Yes CJ sent me the manual in e mail. I will phase invert the cables at the speaker terminals, have a good listen using some good material that I use on a regular basis such as Patricide Barber's nightclub on CD, and jazz at the pawnshop on vinyl. After a few days I will change them back to normal input. I am still waiting on this amp. Looks like my Audiolab 8000Q pre and the four 8000M should go up on E Bay later if my camera is working!

Invert the cables at the amp end, so the positive signal travels thru the positive part of the cable, as it is designed to do.

 

[Cherian]

Invert the cables at the amp end, so the positive signal travels thru the positive part of the cable, as it is designed to do.

HUH?? WHAT??? I don't get it?

 

[FISH_MAN]

If your system is in correct phase, it will sound slightly more closed in when you reverse the wires. If it is not, it will sound slightly more open and dynamic.

Nothing to lose sleep about!

Enjoy.

this is very interesting TonePub maybe you could elaborate further about why this is if you have any more info on this

 

[Gordon Gray]

HUH?? WHAT??? I don't get it?

Hi Cherian,

I have been told the same thing by two different individuals and that's what I do with my CJ.

Don't know why but it is supposed to be the better way to do it.

May have something to do with the positive lead, inverted at the amp end, connecting to the postive terminal on the speaker.

Maybe Sunday can elaborate a bit more.

GG

 

[SundayNiagara]

Hi Cherian,

I have been told the same thing by two different individuals and that's what I do with my CJ.

Don't know why but it is supposed to be the better way to do it.

May have something to do with the positive lead, inverted at the amp end, connecting to the postive terminal on the speaker.

Maybe Sunday can elaborate a bit more.

GG

Self explanatory!

 

[MiTT]

Self explanatory!

I guess I'm missing something too. How is it self explanitory?

If I have the + terminal on the + speaker cable and the - terminal on the - speaker cable at the amp end and then invert them at the speaker how is that any different than having them connected "in phase" at the speaker and inverting them at the amp?

In either case net effect will be realized at the speaker. The amp only passes the signal either in or out of phase depending on it's gain stages and /or those of the equipment that preceeds it. It does not sense polarity, it only processes a signal regardless of polarity.

I don't see how either of your posts make an argument for the requirement of one attachment sequence over another self evident; can you explain in more detail?

 

[Cherian]

I agree with Tim. If the phase inversion is done at the speaker or the amp what is the difference??? I'm still very confused.

 

[kach22i]

My Graaf WFB One pre-amp (tube) is also phase inverted, I think I have it inverted at the preamp. This only gets confusing when cleaning the connections and then having to remember why it looks hooked up wrong.

 

[SundayNiagara]

Invert at the amp. Then the positive signal travels down the positive side of the speaker cable, just as it is designed to do.