[timind]

Hey all,
Recently picked up a Unison Unico which arrived with a noisy tube. The noisy tube is a Mullard 12AU7 driver tube, it makes a phht phht sound. It may quiet down after an hour or so, but not completely. I already replaced both tubes with a very nice sounding pair of NOS GE tubes.
My question is, has anyone tried new tubes (12AU7) made by JJ Telsa or PSvane? I really like this amp and thinking of getting a pair of new tubes and not worry about swapping them for the long haul. Any recommendations are appreciated.

[geowak]

Yes JJ NEW. But I like RCA and NOS BEST.

[timind]

Thanks. Should've said I'm not really a tube guy, but this little amp sounds very good in my little system.
 

[borism]

Hi,
I have used NOS Mullard CV 4003 the military version of the 12AU7 bought from Upscale Audio in my amplifier for years. Wonderful tubes, never any problem. Upscale is now selling NOS Mazda/CIFTE another military version of the 12AU7 at a reasonable price. Kevin Deal seems very enthused but I haven't heard them.
Boris

[rollo]

   Either Brimar, RCA cleartops or Mullard NOS would be a wondefull choice. They will cost a bunch though. For new Harmonix "gold pin" 12AU7 are VG. Have not tried the Pavane to date.
   Why not contact Unison and ask them for a recco. A stock tubed Unico really does not leave much to be changed. They sound great as is.  Remember what is good for one system may not be for another. No one size fits all.

charles

[rpf]

It's all, of course, gear dependent but I actually like the regular Shuguang 12AU7 over the Psavne. The latter sounds overly smooth in my Rogue Cronus Magnum. I also like the JJ Tesla as drivers in the Rogue. I found the EH (regular or gold pin) muddy sounding.

NOS Mullard, Tungsram, RCA or Raytheon black plates, and GE or CBS Hytron 5814 (if suitable) are all good sounding. Not a fan of the RCA clear-top unless the unit is very dark sounding, like some vintage tube gear.

[SET Man]

Hey!

   My Audio Note M1 pre use 12AU7 for the line stage.

   So far my favorite is the Mullard CV4003. A bit pricey but I found them to have the best sound when is come to overall tonality wise, the sense of space and got that emotionally feel to it of which is very important to me. The down side is the bass is a bit loose and a bit bloomy.

   I also tried RCA Clear Top. Great extension both end and tight bottom. Better sense of speed than the 4003. Very clear and detailed. But can sound edgy and thin sometime.

     And since I'm on this for the fun of it. I swapped out a pair of JJ ECC803s that I bought awhile back for a second listening. Well, now I remembered why I never use them. The sound is well balanced with tight bass and good high with good separation and good detail. But overall sound a bit flat and restricted, lack the emotional level feel to me. Oh! And they are a bit noisy too through my 94dB speakers.

     So, that is my experience with 12AU7 tubes in my own system of which consisted of Single driver speakers, SET amps, NOS DAC and turntable. So YMMV with your system.

    Talking about new production 12AU7. Had anyone here tried the new Gold Lion? I'm curious about how theses sound.

Take care,
Buddy 

   

[rpf]

     And since I'm on this for the fun of it. I swapped out a pair of JJ ECC803s that I bought awhile back for a second listening. Well, now I remembered why I never use them. The sound is well balanced with tight bass and good high with good separation and good detail. But overall sound a bit flat and restricted, lack the emotional level feel to me. Oh! And they are a bit noisy too through my 94dB speakers.


Take care,
Buddy 

 

I should have stated that the JJs I've tried are the short plates not the long plates as in the ECC803s.

[timind]

Hey!

   My Audio Note M1 pre use 12AU7 for the line stage.

   So far my favorite is the Mullard CV4003. A bit pricey but I found them to have the best sound when is come to overall tonality wise, the sense of space and got that emotionally feel to it of which is very important to me. The down side is the bass is a bit loose and a bit bloomy.

Take care,
Buddy 

 

The CV4003 is what was in the amp when I received it. My initial reaction was "wow, this sounds wonderful." Then I got up close to the speakers and checked for noise. That's when I discovered the phht ffft sound coming form one channel. The GE tubes are much quieter but don't seem as thrilling to listen to.
I appreciate all of the input, very helpful.

[SET Man]

The CV4003 is what was in the amp when I received it. My initial reaction was "wow, this sounds wonderful." Then I got up close to the speakers and checked for noise. That's when I discovered the phht ffft sound coming form one channel. The GE tubes are much quieter but don't seem as thrilling to listen to.
I appreciate all of the input, very helpful.

Hey!

   I see.... look like you've got a bad tube or old tube that starting to show sign of age.

   That's part of using tube NOS or new pro. Sometime you get a dud. 

   If you like the CV4003 than why not stick with it?  I'm actually on my second pair now. I used the first pair for about 9-10 years I think.

   Anyway, as for new-pro tube the Gold Lion 12AU7 and 12AX7 will be something I would like to try someday. Would be nice to find some new-pro that sound as good as NOS CV4003.

Take care,
Buddy

[borism]

I agree with SET man. Tubes can become noisy. I like Upscale Audio because they offer different grading on all their tubes, new or NOS, ranging from "platinum", which is best = best matched triodes and lowest noise, to "driver grade". I have always bought the slightly more expensive "platinum" grade but have had long term enjoyment.
Boris

[timind]

Checked Upscale Audio. A bit pricey but as we all know, you get what you pay for. I will go for a "platinum" set of tubes if I purchase there. It would be worth the extra few $$ to know the tubes are premium and I shouldn't need to change them for a while.

[Gopher]

As a cheap experiment try CBS Hytron 5814As.  I preferred it in some circuits to my 1950s Mullard Long Plates.

[timind]

Received the Sylvania 12AU7WAs today and have them playing now. They sound very clear and clean, just what I am looking for. I think I'll give them until the weekend to make the decision but the lid will probably go back on the amp Sunday.
Pretty sure these tubes had never been used. They came in the boxes pictured below.

If any of you were in the military in the late sixties/early seventies and worked in communications maintenance the boxes will look familiar. Actually took me for a trip down memory lane. I was in the USAF in communications maintenance and was very familiar with the boxes. The numbers 5960 in the top right corner designate the Federal Stock Class for tubes. The FSC for solid state devices was 5961 I believe. What a treat to see these boxes.
Thanks for all the help guys.