Conrad Johnson PV10AL Tube & Polarity Questions?

You can contact CJ for a copy of the manual, they will be more than happy to answer any questions. But if I remember correctly the PV-10A does invert polarity which means if you have an odd number of invertions you must reverse your speaker leads. If the unit is line stage only which is designated by the (L) it has no phono stage then there are only two tubes inside. You can acquire access to the tubes by removing the top cover. If you go to the CJ web site there should be information there as to what type of tube is in the unit. Hope this helps

Chuck

It has a pair of 12AU7 tubes and does invert polarity.

Begin by taking out the screws that hold down the top plate. Be sure the unit is unplugged before you do this. To remove a tube, gently rock it a few degrees back and forth while pulling up. Some will tell you to wear gloves to keep oils off the tube but I don't think it makes any difference. The pins are not symmetrical so the tube can go back in only one way. Line up the pins in the holes and gently rock back and forth a few degrees while pushing down.

what tubes would anyone suggest to begin my first tube rolling experiment?

Hi Fishwater,
I have a pv10al that I bought new I do not recall seeing in the manual that it inverts polarity. I also own a premier 11a and it had a seperate paper the size of the manual warning of polarity inversion as well as a note in the manual. I will check to see again, but I'm sure it does not invert. I listen to a lot of types of music but I do prefer music that drives and has punch lower down. A friend lent me a pair of Mullard 12au7 tubes and that started my quest to purchase a pair. They sound a lot warmer than the standard philips tubes and seem to push the lower mids up a bit. I think this helps rock for two reasons one being that most rock tends to be poorly recorded and over prossesed and can sound harsh at best. Theese tubes are killer. Pay the extra bucks and you will I'm sure never regret the $$. Let me know what you think if you do it.

ps I have my pv10al for sale and I have a pair of tubes that are not even broken in yet as well as 3 other pairs. I have listed them all together as one pakage so if you are interested I will sell them.

Tthat is a great little pre amp and I'm not sure replacing mine is the best idea but when I get my new one (premier 14) I guess I'll know.

My pv10al owner's manual did come with the seperate sheet of paper (red, I believe) warning of phase inversion. Your dna does not invert phase, so swap the neg. and pos. leads on your speakers. As always, let your ears be the final judge. As for tubes, I've tried Phillips, Mullard, Amperex, and GE. Even within a brand name, there are variations (military spec, etc.) Even in my modest system, I can hear tube-related differences much more clearly than, for example, swapping different cables. Right now I'm running Mullards, but we probably like different things. My advice would be to buy a bunch of cheapo, used tubes from ebay until you find a set you like--then buy the same tubes from a reputable NOS tube dealer. And do unplug your pre before messing around with tubes.