Conrad Johnson Owners.com

hello,
been working on my pv6, previously the phono sections sounded muted, like a wool blanket was over the speakers. i swapped tubes with no reaal differenc with the phone section, line stage sounded great..

so i updated the caps all the caps both poly and electrolytics.. preamp sounds much better but now the phono section pops with any amount of volume it pops.
any suggestions?
i've swapped out tubes with the same affect with the phone section.
any suggestions on where to start?

i'm using a rega rp1 with what i think is a higher output style MM cartridge.. is it possible that the pv6 is setup for a MC cartridge?

it also trips my mccormack DNA 1 protection curcuit on and off..

Not sure why it would trip a protection circuit on an amp unless some very unusual voltage/current was fed in via the inputs. Have you put a volt meter on the output RCA plugs of the PV6? Here is an article that may help in determining expected measurements: https://en.wikipedia.org/wiki/Line_level

If it's tripping your amp, then I have to assume there is some kind of unusual output from the PV6.

yes, it only trips the amp when i try to play the phono section with vol higher than 3, it'll pop.
everything else works great , just the phono has issues... The phono section was just muted prior to the cap upgrade..

i plan on looking into it further this weekend.
I'll check for bridges ( but i didn't see any before)
i did spray some detoxit on the board and tip it on its side, which made the detoxit run into the two little silver boxes right next to the phono rca jack.. i did spray some light air around everything, wonder if it did something to them.
thanks again for your help.. i miss it all ready!!

should prolly just buy a new tube set from CJ vs ebay ... too.

The tubes C-J now provides will likely be new production tubes. Not saying that's bad but the NOS they used to supply seem to no longer be available, which of course was inevitable. I only mention this not to dissuade you from what they have now, as I'm confident they verify the performance of their tube sets, but the manuals for the PV pre's, at least my PV-5, said the choice of NOS tubes they selected were chosen for the best fidelity regardless of price or pedigree. These were generally GE NOS tubes and that disclosure in the manual curbed any desire for me to try anything else, for awhile. I've not gone boutique with the popular euro tubes but have used a variety of '50's, '60's, '70's military and standard versions, triple mica's, and black plates from GE, Sylvania and RCA. It's too expensive to test all there are to try so I figured I'd learn the variety of sound with a selection of those three brands. The only "import" tube I've tried are a pair of ITT 12AX7's (7025's), which O believe are Toshiba's. What a great experience that has been, but exhaustive! The idea was to have a decent supply of NOS backups so I'd never be without, but it became kind of a compulsive activity! They all sound different and I was able to note each type's characteristics. I recorded a variety of the same LP's during the listening tests so I can always hear those tubes anytime in the future (I've done a similar project with five different cartridges but that's another episode).

The point I think I was trying to get to is you can by all means try the C-J tube set but you may want to explore NOS. As far as 12AX7's, I find the RCA varieties I've tried decidedly to my liking. The Various GE 5751's have all worked well as have the RCA's, and the 5965's seem to be affected least of the three so I just use NOS GE's there, though every change somewhere else opens up opportunity and potential for a synergy not noticed before, so it can be an endless excercise in playing musical tubes if you care to truly explore to that degree. All my tubes have come from eBay but based on careful discretion and following good intuition. Only one out of maybe twenty tubes was microphonic, and that had been a used one. It's easy to get gouged if you haven't learned the market and trends there but if you stay with sellers with 100% feedback that's a good start. Maybe try a pair of 12AX7's. I've spent up to $110 on a pair of NOS but also got fantastic ones at $35-$40 a pair.

Sorry to stretch this out, I was reliving my own musings as I was writing! Your preamp and system as well as taste will be unique, but from my experience I found more pleasure and variety out of mine as a result of branching out a little. I'm a firm believer in NOS. I won't elaborate with details but won't be buying any New Sensor tubes anymore. These preamps were designed with tubes long out of production, and the new ones are not the same, just like a 1965 GE or RCA are not the same, BUT, the RCA and GE will both be musically superior and manufactured better than any New Sensor tube made today (or tomorrow). That's just my opinion of course, but it stands as fact for me. Perhaps a new preamp or one of the Asian manufactured tube equipment may parlay fine with new production tubes, but then again, they aren't C-J's. And that's why we have C-J's . Good luck and happy listening whichever route you choose!

Did you get this sorted out? I would double check your cap work. I doubt a tube is responsible.