Recent News:

PV5 - Parts Connexion upgrade

The PV-1 to now...
Post Reply
Elan Vital
Beginner
Beginner
Posts: 2
Joined: Thu Jan 19, 2017 5:23 am

PV5 - Parts Connexion upgrade

Post by Elan Vital » Thu Jan 19, 2017 3:37 pm

I'm attempting to upgrade parts as per upgrade kit from parts connexion. I have identified all the parts which need to be replaced but am not sure if got them right - please advise.
Also - if anyone has any experience with this particular upgrade please chime in.
thanks
Attachments
conrad-johnson-pv5-preamplifier Parts connexion upgrade.jpg
conrad-johnson-pv5-preamplifier Parts connexion upgrade.jpg (509.14 KiB) Viewed 570 times
Last edited by Elan Vital on Sat Jan 21, 2017 12:37 am, edited 1 time in total.

User avatar
admin
Site Admin
Site Admin
Posts: 1121
Joined: Tue Jan 03, 2012 1:50 pm
Location: New Hampshire, USA
Contact:

Re: PV5 - Parts Connexion upgrade

Post by admin » Thu Jan 19, 2017 3:58 pm

Just wanted to welcome you to the site. I do not have personal experience with the PV5 but I think we have the schematic in our database so you may just want to look at that to confirm components. Let us know how your upgrade turns out!
-admin
Home Theater in Member Gallery
Conrad Johnson Owners.com Main Page

Current Conrad Johnson Equipment in System: Evolution 2000, PV-12L, and D/A-2b.

ronenash
Super Advanced
Super Advanced
Posts: 59
Joined: Sun Aug 05, 2012 2:19 pm

Re: PV5 - Parts Connexion upgrade

Post by ronenash » Tue Jan 31, 2017 7:15 am

Hi Elan,

In general CJ capacitors are better than most you will find. If the capacitor is labeled CJ I would not change it. The big blue caps don't look like originals to me. I have never seen them in any CJ equipment. I would start with upgrading all resistors in the signal path to Vishay Z201, expensive but they make a huge difference.
I would start with R9, R10, R19, R20 for the phono section and R26, R37 and R36 for the linestage.

Hope this helps.
ronenash
----
Power:CJ LP125m SE, Beard P100
Pre:CJ ACT2.1, Pr14, Pr15
Analog:VPI Classic/Falcon/Blackbird, Thorens TD125mk2/AT1005MK2/2M Mono, Lenco L75 rebuild
Digital:J.River-->AP2-->Chord Qude HD
Speakers:SF Amati Futura

cjlew
Beginner
Beginner
Posts: 2
Joined: Wed Feb 01, 2017 11:39 am

Re: PV5 - Parts Connexion upgrade

Post by cjlew » Wed Feb 01, 2017 11:42 am

The rectangular blue capacitors are definitely original to the PV5. If memory serves me, these are metalized polypropylene and the white CJD capacitors are film and foil with polystyrene film. Replacements for the latter, unless Teflon, are unlikely to be an improvement.

hi-fi
Regular
Regular
Posts: 5
Joined: Thu Jul 02, 2015 10:18 pm

Re: PV5 - Parts Connexion upgrade

Post by hi-fi » Mon Feb 20, 2017 4:48 am

Yes, this looks like a totally stock PV-5; all original. Resistors in the phono section are all 1%. Unless something is wrong with the unit, my (humble) opinion is you will change what is iconic about the sound, and perhaps the RIAA curve. The only thing my PV-5 has had changed was a power supply upgrade by C-J in 2006. The original silver storage capacitors, among a couple other changes, were changed to film caps. I have no desire to change anything in mine, but then again, I still love the reason I fell in love with it 34 years ago. Nothing has turned my head (or ear) since :). Good luck with your quest and hope all works out as you hope for.
Last edited by hi-fi on Sat Feb 25, 2017 4:44 am, edited 1 time in total.

jeffreybehr
Master Apprentice
Master Apprentice
Posts: 179
Joined: Mon Aug 06, 2012 1:10 pm
Location: Phoenix, Arizona USA

Re: PV5 - Parts Connexion upgrade

Post by jeffreybehr » Mon Feb 20, 2017 7:48 pm

cjlew wrote:
Wed Feb 01, 2017 11:42 am
The rectangular blue capacitors are definitely original to the PV5. If memory serves me, these are metalized polypropylene....
cjlew, are you really Lew Johnson? :-) WELCOME. I agree with Lew about the blue caps; they are indeed original (I've had my eyes in at least a half-dozen of these and was a c-j dealer in the early 1980s). They're ERO brand IIRC. And c-j's 'styrene-film-and-foil caps were and are excellent, but I think the current MultiCap RTX 'styrene-film-and-foils probably are better--but if you're staying with 'propylenes as the main piece in the section-output-cap-pairs, Lew is right--don't replace the 'styrene bypass caps.

I think it's more important to replace the high-Voltage 'lytics...
Image
...on the right in this pic. I used Solen metallized-'propylenes to replace them, with large 'propylene and small Teflon bypasses on the bottom of the board.
Image
This preamp, FWIW, is one I upgraded parts in a LONG time ago. :roll: :oops:

One more point--IMO these kinds of mods do NOT change the basic character of the device, they simply increase transparency and reduce edginess. So if you LOVE the sounds of your PV5 and use the fono section, by all means spend some money to improve it.
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."

hi-fi
Regular
Regular
Posts: 5
Joined: Thu Jul 02, 2015 10:18 pm

Re: PV5 - Parts Connexion upgrade

Post by hi-fi » Sat Feb 25, 2017 4:35 am

Hi Jeffrey, that's fascinating about Lew's feelings on the blue caps, I don't know anything about it! Any opinions about what's going on inside the PV-5, I'm all ears! BTW, beautiful work you did on the one in the photos, just gorgeous :)

My opinion was just a caveat that unless one is seeking a particular outcome rather than arbitrarily changing parts just to see (hear) if a difference might be found could possible disrupt a beautifully tuned architecture. I wish it was easy to do component swaps just for the experience and then safely return to base but one needs skills for that, which I don't have, nor the nerve, lol.

Thanks for the pictures and explanation of what you've done, it's a real thing of beauty to me. And if Lew had any insight you'd care to share in regards to hindsight on the PV-5 it certainly would be a pleasure to read about. Not being able to afford a Premier Three, it was my favorite from the classic c-j period prior to the PV-8. It seems the PV-8 forward was about the period when the specific differences between tubes and solid state products were crossing over, each trying to sound more like the other rather than as they were. I guess that's what I like about the sound of the 5. With no experience on parts upgrades I'm fearful not knowing what exactly would become different, but your insight seems to alleviate some of that. They say no guts no glory, though I've also heard (for cowards like me) ignorance is bliss, lol :P

Edit: I just realized you were referring to cjlew's post above my earlier one, I didn't catch that, but you did :)

jeffreybehr
Master Apprentice
Master Apprentice
Posts: 179
Joined: Mon Aug 06, 2012 1:10 pm
Location: Phoenix, Arizona USA

Re: PV5 - Parts Connexion upgrade

Post by jeffreybehr » Sat Feb 25, 2017 6:41 pm

hi-fi and all, just to clearly state my opinions and maybe help others make some decisions, here are some thoughts:
1. C-j's 'styrene-and-foil caps are indeed 5-star-quality caps, but I think the current MultiCap RTXs (also 'styrene-film-and-foil) are a little cleaner sounding.
2. In the PV5 (and most-any tubed preamp that used 'lytics as high-Voltage filter caps in its PS), the biggest improvement in sound quality will be gained by replacing the powersupply's high-Voltage 'lytics with metalized-'propylene caps and replacing whatever bypass caps originally installed with MultiCap RTXs. The entry-level caps here would be the basic, inexpensive Solens, but they too are a little edgy (but not nearly as bad as typical 'lytics).
3. Staying in the PV5, the next-biggest sonic improvement would come from replacing those blue Eros with good-to-very-good 'propylenes such as Sonic Craft's SoniCaps. If one did that, I too recommend leaving the original c-j 'styrene bypass caps on the board--those being Cs23/23 (fono-section-out) and Cs30/30 (line-section-out). If one doesn't use the fono section, don't change it. If it's not clear by now, the big blue Eros (in pairs) are fono-stage (Cs22) and line-stage (Cs29) output caps, bypassed by the adjacent c-j 'styrenes.

FWIW, the PV5 has lots of gain (70dB), split between fono (42dB at 1KHz) and 28db in the line stage. That 28dB is lots different than the 10 to 12dB that some modern line-stage preamps have. As a result of that, in most systems one will be running the gain control somewhere in the 8- to 10-o'clock position. If one's backend (poweramps and speakers) are more efficient than usual, preamp tube hiss may become audible. If one has that problem, a possible solution may be changing the two gain tubes in the line section (Vs 5 and 7, being 5751s) to lower-gain tubes, but I do not, offhand, know what might be suitable, lower-gain replacements. If I needed to do this, I suspect the lowest-gain tubes in the 12An7 series would work just finely.

TYVM for your positive comments on my long-ago mod work.
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."

cjlew
Beginner
Beginner
Posts: 2
Joined: Wed Feb 01, 2017 11:39 am

Re: PV5 - Parts Connexion upgrade

Post by cjlew » Mon Mar 13, 2017 12:46 pm

cjlew, are you really Lew Johnson? :-)

Guilty as charged.

Lew

Elan Vital
Beginner
Beginner
Posts: 2
Joined: Thu Jan 19, 2017 5:23 am

Re: PV5 - Parts Connexion upgrade

Post by Elan Vital » Tue Mar 28, 2017 3:35 am

Thanks for all the insights.
Please note that the initial photo was of a stock PV5 - mine has an upgraded power supply).

At this point most of the "Parts connexion" upgrades are now completed.

The only thing left to upgrade are the C7 C8 C9 and C11 caps
the upgrade calls to replace them with Solen 7.5uF 400V PB Series + Mulcap PPMFX 1.0uF 400V in parallel with the solen - does that seem like a correct thing to do?
attached is a photo of the upgrades thus far

also

cjlew is right - The lush PV5 sound signature has not changed but the transparency and cohesiveness has improved.
cjlew wrote:
Wed Feb 01, 2017 11:42 am

One more point--IMO these kinds of mods do NOT change the basic character of the device, they simply increase transparency and reduce edginess. So if you LOVE the sounds of your PV5 and use the fono section, by all means spend some money to improve it.
Attachments
IMG_0345.JPG
(985.99 KiB) Not downloaded yet
IMG_0344.JPG
(923.43 KiB) Not downloaded yet

Post Reply