Hi. I rectly upgraded my phonostage from an ART DJ Pre II to a Vincent PHO 701. Well i can't tell you how much of an upgrade its been. MY TT has come alive, biger soundstage, 3D like depth, more warmth. And its louder than the ART DJ pre II, which means i don't have to turn the amp that high, while it's not completly silent like i thought it would be (at the volume i listen to is OK, got no problem with it), there's a little buzz/hum when i put my ear into the speakers at a high volume), i'll work around that later. My question is, i've read that changing the stock chinese tubes 12AU7 with a NOS tube or better tube improves the phonostage, if so in what way or by how far? Thanks in advance
I just purchased this myself. I’ve only heard one other comment about the hum/buzzing. As for switching out the tubes, no idea. I would probably keep what it comes with until a desire arises to switch out.
I'd suggest you play around with the positions of the stage and power supply to reduce or eliminate the hum. I have a Vincent Pho 8 and had the same issues until I found the right spot for them in relation to my amp, once I did no buzz/hum at all and nice and quiet.. These phono stages are definitely sensitive to their position relative to the amp. As for the 12AU7 I would definitely swap that out for a quality NOS tube. It won''t cost much, and you only need one correct? Look up some up on Brent Jesse Recording.
I'm no tube expert, but if you choose from Telefunken, Amperex, Mullard, or RCA you will do fine. Read through Brent Jessee's page on the 12AU7, he gives detailed descriptions of the sound qualities of these tubes, I've no doubt you'll find something in your budget. I've purchased NOS RCA 12AX7 Black Plates from him for use in my tube CD player. I've also purchase RCA Grey Plates that were recommended by a Forum member who found an Ebay Seller offering a large quantity cheaply. I used two in my Icon Audio all tube phono stage.
I always go for the platinum grade no cryo... The Tungsram has good imiging and focus a real good all around well balanced tube.
I know some say tubes do not need break in time but you may want to wait abot 100 hours before doing any critical listening. Please let us know what you think after the tube has time to settle in. I also upgraded my PHO-700 power cord the fuse and 9 pin cord 24 AWG.
That's the same cord I use for all my gear even the TV. Here is the 9 pin cord I upgraded to... 9-Pin (DB9) LSZH Low Smoke D-Sub Cable - Double Shielded + EMI Cage - Male / Male
Note: the printing on the tube is easily rubbed off, try to avoid touching the printing. I know because I was not carful and rubbed off most the printing when inserting the tube.
Just got the tube. I can hear the difference with the stock chinese tube. More depth soundstage is bigger According to the documentation that came with the tube you need 75 hours break in time.
How many hours on the tube so far? I also have the French Cifte it's a very nice 3D sounding tube though not as warm as the Tungsram. All depends on the listeners preference. Tubes I've rolled in the PHO700 Psvane 12AU7-TII NOS Mullard ECC82 NOS Cifte 12AU7 NOS Tungsram ECC82 NOS Brimar Long Plate CV4003 (Special CJ Test Grade)...currently in preamp now. All are great sounding valves. The Brimar is my favorite thus far. Tube rolling is fun.
The Psvane to me sounded the same as the original Chinese tube that came with the phono stage...fancy box, high price same sound.
The Psvane sound is clearer. I guess what I'm saying is, the tone sounds the same as any new production Chinese tube. It's not bad in any way its just does not have the tone, imaging and soundstage that NOS tubes offer.
Quality tubes to the likes of RCA black plates and gray plates, Amperex Bugle Boys, Mullard, and Telefunken will noticeably improve the sound in your phono stage. You can find quality tubes to fit your budget from the 1950s through the 1970s and all of them will outperform the crap coming out of China and Russia made today, in my opinion. I've owned the 701 for almost 5 months and have purchased several tubes from Brent Jessee's site. Nice selection of quality tubes there and, as another member in this thread points out, Jessee gives you great background history and the applications the tubes were/ are used in. So even if one is new to tube rolling (as I still consider myself as still being new to it), an informed decision can be made to help you with your tube purchase. From the technical aspect, 12AU7s are quiet but you take a gain hit (like 20% less gain than that of a 12AX7). I switched from 12AU7 to 12AX7 because of that reason. Been rolling various 12AX7s from the 50s, 60s, and 70s to see which sounds best. The 1960s Mullard 12AX7 sounds the best in the 701 in my setup so far. I can say I have not had any noticeable hum but I am running my phono stage through Panamax power conditioning.
