Conrad Johnson PV-5 Preamp

The PV-1 to now...
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Animal
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Conrad Johnson PV-5 Preamp

Post by Animal »

These preamps have a quite a following, and there's a reason for that. They personify the meaning of CJ's slogan: It Just Sounds Right.

I got this one via an estate sale, the original owner has passed from this earthly veil, but his PV-5 found a good home. It has been re-tubed since I acquired it with the new glass coming from CJ, other than that it is untouched. I took these pics right after it showed up.

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MylesBAstor
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Re: Conrad Johnson PV-5 Preamp

Post by MylesBAstor »

Sweet piece! That was my very first piece of cj gear back in the early '80s :)
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Re: Conrad Johnson PV-5 Preamp

Post by jeffreybehr »

I've had at least 2; this was a new product in the early '80s when I was a c-j dealer. Its 70dB of total gain is split 40 in the fono section and 30 in the line section. The latter certainly is high compared with contemporary linestages, but it still works well.

I rebuilt one for a friend, with MultiCap couplers, Siemens Styroflexes in the RIAA eq., Solen metalized 'propylenes replacing the PS 'lytics, and Teflon-film caps bypassing them. I was rather annoyed with myself for getting talked into this project and passed it along as soon as I verified it worked correctly. I'd use probably all MultiCap RTXs ('styrenes) for couplers and PS bypasses if I did it again.

I have pics!
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I think I still have a schematic if you're interested.
Tin-eared audiofool, large-scale-Classical-music lover, and damned-amateur fotografer.
William Bruce Cameron: "...not everything that can be counted counts, and not everything that counts can be counted."
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Animal
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Re: Conrad Johnson PV-5 Preamp

Post by Animal »

How would you describe the changes in audible terms?

I was considering sending mine to Bill Thalmann and have him do his modification package, but I gathered from reading multiple reviews that this process subtracted some of the "overwhelming lushness" that is an inherent part of the original design. This pre is by no means the most accurate out there, but it sure does mate up well with some other pieces and produce a truly lovely sound.

I compare the PV-5 to a Monet painting - not technically accurate but oh so lovely to experience.
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Re: Conrad Johnson PV-5 Preamp

Post by jeffreybehr »

Animal, first pls read my signature--I'm NOT a golden-eared audiofile capable of hearing all sorts of subtle differences between 2 pieces. I can distinguish some differences over days or weeks, and I have managed to put together a fabulous-sounding system.

As I wrote, I got rid of the rebuilt PV5 quickly. IME, while these kinds of upgrades never change the basic character of a piece, they do change it subtly. I eventually hear more detail and increased smoothness (less edginess). I suppose some of the old caps could have been warmer sounding than the MultiCaps I used; I simply don't remember and probably would not have been able to hear it in a hour or 2.

If you love the overall sounds of the preamp, have it improved. It might sound a little less 'golden-glowing', but it ought to sound better overall.
Last edited by jeffreybehr on Mon Aug 27, 2012 12:32 pm, edited 3 times in total.
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Re: Conrad Johnson PV-5 Preamp

Post by joeinid »

Jeffrey,

As usual, great photos and info. Thanks for posting.

Joe
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Re: Conrad Johnson PV-5 Preamp

Post by river251 »

Well I'd like to delete this msg, but there is no option to do so.




Animal wrote:These preamps have a quite a following, and there's a reason for that. They personify the meaning of CJ's slogan: It Just Sounds Right.

I got this one via an estate sale, the original owner has passed from this earthly veil, but his PV-5 found a good home. It has been re-tubed since I acquired it with the new glass coming from CJ, other than that it is untouched. I took these pics right after it showed up.

Image

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Well, first post in the first thread, and I find a picture of my preamp.

Animal was that you bumping around in my audio room a couple nights ago?

Loverly pics, good show. The only preamp I've ever owned, used with 8B and MC240 and MC30s. Accuracy? What accuracy? No such animal. There is only beautiful music

Jim
Last edited by river251 on Mon Aug 27, 2012 11:41 am, edited 1 time in total.
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Re: Conrad Johnson PV-5 Preamp

Post by river251 »

Well, first post in the first thread, and I find a picture of my preamp.

Animal was that you bumping around in my audio room a couple nights ago?

Loverly pics, good show. The only preamp I've ever owned, used with 8B and MC240 and MC30s. Accuracy? What accuracy? No such animal. There is only beautiful music

Jim
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Animal
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Re: Conrad Johnson PV-5 Preamp

Post by Animal »

river251 wrote:Animal was that you bumping around in my audio room a couple nights ago?
I'm sorry, the next time I'll try to keep the noise down.
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Re: Conrad Johnson PV-5 Preamp

Post by mmmalmberg »

Animal wrote:These preamps have a quite a following, and there's a reason for that. They personify the meaning of CJ's slogan: It Just Sounds Right.

I got this one via an estate sale, the original owner has passed from this earthly veil, but his PV-5 found a good home. It has been re-tubed since I acquired it with the new glass coming from CJ, other than that it is untouched. I took these pics right after it showed up.
Animal, I have same preamp but haven't used as it didn't sound so great and I assumed it needed recapped, haven't been able to afford Thalman ($650?), CJ quoted $1250 or something for a rebuild... Mine has all original caps which it looks like you have too, yes? How does it sound with new tubes and the original caps? Maybe that's all I really need to be using this thing... Or maybe new tubes and new p.s. caps to be safe...
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Re: Conrad Johnson PV-5 Preamp

Post by river251 »

Animal wrote:How would you describe the changes in audible terms?

I was considering sending mine to Bill Thalmann and have him do his modification package, but I gathered from reading multiple reviews that this process subtracted some of the "overwhelming lushness" that is an inherent part of the original design. This pre is by no means the most accurate out there, but it sure does mate up well with some other pieces and produce a truly lovely sound.

I compare the PV-5 to a Monet painting - not technically accurate but oh so lovely to experience.

Animal, I've been considering doing the same thing. Do you remember where you read those comments?
Thanks....
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Corben Dallas
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Re: Conrad Johnson PV-5 Preamp

Post by Corben Dallas »

Hello,
as on my PV9A, the man who did the upgrade had choose GE tubes... I've been told that those tubes was the best choice for the CJ's, does averyone agree with that ? and what about your AX7's ? are they GE too ? I was wondering if I could offer some Telefunken ECC83 NOS for my RIAA stage ? could it be better ? someone can give me an opinion ?
Thanks for your answer
cheers
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Re: Conrad Johnson PV-5 Preamp

Post by thefogf1 »

@ Jeffery.....
I'm working on a PV-5 and am having one heck of a time finding replacement caps.
The unit has power supply issues in the form of a 60Hz steady hum and a rhythmic 120Hz hum being output when the relay is energized.
Where did you get the caps to replace the old aluminum electrolytics from?
Any help would be greatly appreciated.
Thank you.
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Re: Conrad Johnson PV-5 Preamp

Post by jeffreybehr »

thefogf1 wrote:@ Jeffery.....
I'm working on a PV-5 and am having one heck of a time finding replacement caps.
The unit has power supply issues in the form of a 60Hz steady hum and a rhythmic 120Hz hum being output when the relay is energized.
Where did you get the caps to replace the old aluminum electrolytics from?
Any help would be greatly appreciated.
Thank you.
Replacing the main-PS caps is an opportunity to improve the sound. I used 400VDC Solen 'propylenes, fom Michael Percy. http://percyaudio.com/

I'd replace the PS-bypass caps with, probably, MultiCap RTXs.
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Re: Conrad Johnson PV-5 Preamp

Post by thefogf1 »

Thank you for your help.
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Re: Conrad Johnson PV-5 Preamp

Post by gregv »

Does anyone know the ohm load of the PV-5's phono section? Isn't it usually 100 ohms with most MM sections? I'm planning on installing my Benz Silver with .2mV output and 1 Kohm loading and I am considering a head amp (gave away my original). I am thinking about the Harmonious Audio Moving Coil Phono Cartridge Head Amplifier MPA-1b with 24dB gain. The 41.5 dB phono gain might be plenty… I may be over-thinking it.
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Re: Conrad Johnson PV-5 Preamp

Post by jeffreybehr »

gregv wrote:Does anyone know the ohm load of the PV-5's phono section? Isn't it usually 100 ohms with most MM sections? I'm planning on installing my Benz Silver with .2mV output and 1 Kohm loading and I am considering a head amp (gave away my original). I am thinking about the Harmonious Audio Moving Coil Phono Cartridge Head Amplifier MPA-1b with 24dB gain. The 41.5 dB phono gain might be plenty… I may be over-thinking it.
That 40dB-gain fono section is not for low-output MC cartridges; its input is 47K. I imagine about any headamp will work with the PV5. And the low input impedances for MC carts must occur in the first device the cart drives and NOT in the equalized fono section.
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Re: Conrad Johnson PV-5 Preamp

Post by amplifiersurgery »

I am currently restoring a PV5. This particular PV5 has Amperex tubes. The unit has a very well built layout and a very clean signal path. Here is a picture of the unit under work. Note the Mundorf EVO Silver-Gold-Oil capacitors in the signal path (these are the ultimate Mundorf signal path caps for Preamplifiers). The unit also has some new high-temperature power caps installed and some varied resistors replaced. There is also new silver-plated wiring installed to the input section. It is still work-in-progress, so yet to give it a listen post restoration.
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Conrad Johnson PV5 with Mundorf EVO Silver-Gold-Oil capacitors
Conrad Johnson PV5 with Mundorf EVO Silver-Gold-Oil capacitors
CJ PV5.jpg (209.35 KiB) Viewed 29123 times
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Re: Conrad Johnson PV-5 Preamp

Post by antaresbluespirit »

hi,

Great restoring of this "venerable" preamp...

I would like listen to the result as well!

Raymond
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Re: Conrad Johnson PV-5 Preamp

Post by amplifiersurgery »

Here is the unit playing post-restoration. Sounds incredibly detailed and has a fantastic bass definition too. Should be good for another lifetime.
http://youtu.be/51KLffksIx0
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