Welcome, Guest. Please Login or Register
Decware Audio Forums
05/31/20 at 20:26:21 


       


10% off your entire order until June 1st! Use coupon code: COVID19

Pages: 1
Send Topic Print
Roll Rachael Roll (Read 161 times)
imageflood
Verified Member
**




Posts: 10
Roll Rachael Roll
05/23/20 at 16:05:28
 
This thread will have some brief results of a tube rolling phase I've fallen into over the last week. I'll update on the various combinations as they emerge. But here's the context. The system:

Rachael (obvouslyi)
Kilpsch Cornwall II (circa 1978, updated caps 2010)
UTurn Orbit Turntable
Grant Fidelity TubeDAC-11 (fed by a Mac Powerbook)
Tisbury Audio Passive Preamp (this little baby deserves its own thread)
Anti Cable wires
Pluto Phono Preamp

You may notice that the last item is a weak link in the chain: either you've never heard of it, or know it to be a bargain basement and utterly undistinguished unit. So I finally cleared some budget space and ordered a ZP3 Zen Triode Phonostage.

So now I have, like, four months to get my ears adjusted to an optimal tube complement, so that I can accurately assess what the ZP3 will bring to the table. (Not complaining about the wait, btw. Perfection takes time, it's all part of the process.)

I had a stable tube complement for many years (more on this later on): 6N2P (non-military I believe), Mullard GZ34, a new production Mullard EL34. I started by rolling new preamp tubes in, mainly because I was never quite sure how high-quality the 6N2P's were -- results on the next post. Look forward to any questions or comments you may have.
Back to top
 
 
  IP Logged
imageflood
Verified Member
**




Posts: 10
Re: Roll Rachael Roll
Reply #1 - 05/23/20 at 16:32:36
 
For the first roll I replaced the 6N2P's with NOS Zaerix 7DJ8's. I've always loved this 7DJ8. It brings a certain detail and clarity, almost like a silvery light. I've set up my system to give the appearance of minimal interference from signal to speaker. (Every link in the chain interferes in some way of course, but you can still get the image of clarity.) Live recordings sound particularly live, as do female voices (especially if they're Brazilian).

At first glance, the 7DJ8's did the trick. Mid's and high's became crisper, and bass was tighter, if not as thunderous as before. Now that I'm working from home (thank you, coronavirus), the system is getting some fairly long workouts, at least 2-3 hours a day. The new tubes burned in pretty quickly.

After over a week, however, I found the sound to be less and less engaging. It was there, it sounded great, but it just wasn't engaging me anymore. I found I kept having to turn up the volume for the soundstage to get really 3-dimensional. Until I finally maxed out the volume, totally by accident since I hadn't really been paying attention. Under normal circumstances maxing the volume might cause my neighbors to call the cops on me. But now it was just kind of flat, and just not getting enough power to the drivers.

I eventually went back to the 6N2P (just ordered up some new Soviet military ones), but not before I noticed another issue which I'll get to next time I post. In the end, the Zaerix 7DJ8 brought some good characteristics to Rachael, but Rachael also tested them to their limits, and then crushed them. Just not a good fit.

Back to top
 
 
  IP Logged
imageflood
Verified Member
**




Posts: 10
Re: Roll Rachael Roll
Reply #2 - 05/24/20 at 17:40:46
 
After about a week with the 7DJ8's I noticed a considerable loss of power from Rachael, which I initially attributed to the new preamp tubes. Then I noticed the bias meters and, aha, the EL34's appeared to be dying. My usual configuration, with GZ34 rectifier, runs a bit "hot." The bias meters  go up to 56-58 millivolts. But now they were down to a bit under 50, which I'm just guessing was not a positive sign.

I have been using new production Mullard EL34 (not NOS, but new-new, made in Russia) and it will be really hard to move on from them. The mid's are so lush, ideally suited for the Cornwalls. They can get chunky and chewy when you need to rock out. And then sublimely natural, easy, and unobtrusive when you need some jazz (w/ or w/o vocals). If there is a classic tube sound, these give it in spades.

The only problem with them is that they require a great deal of patience. When they first arrived, they were one of the absolutely worst tubes I had ever heard. Dead, scratchy, cavernous, flat, you name it. I checked the forums to see if they were just defective, but no, this is par for the course. I don't know what it is, but the burn-in on these new Mullards is excruciating. One has to suffer 75-100 hours of sub-optimal performance (at best), cursing oneself for ever falling into this trap.

And then they finally open up and....

When they finally started to fade, it dawned on me that they had been in the system for well over 3 years, maybe closer to 4. Heavy usage, and loud. It's a real testament to Rachael and Decware that they lasted so damn long! Seriously, Rachael is so easy on output tubes that I didn't hear any diminution of soundstage or volume until the very end. Even now, I bet if I put them back in, they'd still sound way better than decent. Remarkable.

Now I have a new set of Mullards on the way. And it will be another summer of excruciating burn-in. Luckily the new ZP3 won't arrive for another 9-10 weeks or more, which will give my ears time to suffer, heal, and relax again. In the meantime, some more rolling to do with the power tubes, in another post.
Back to top
 
 
  IP Logged
s3steve
Verified Member
**




Posts: 18
Re: Roll Rachael Roll
Reply #3 - 05/25/20 at 14:55:24
 
Good review!

It's always nice to hear what other people are doing with there SE34I.5.

I run my Rachel with NOS Winged -C- EL34 power tubes and tried several different EL34's. Tung-Sol newer production Svetlana. The Winged -C- sound the best of the 3. I'll hold on to the others as back ups for now.

In the driver position I now have 6N2P-EV in but will often go back to 6N1P-EV or some old '50's version of the 6N1P. I also have a couple of Bugle Boy 6DJ8 that I will occasionally roll in. For the money you can't beat the 6N2P-EV and the 6N1P-EV!

I'd like to try some KT77's in it soon!
Back to top
 
 

CSP3
SE34I.5
Ariston RD11
PS Audio GCPH
Pioneer N-50 Network Player
Altec 605B's in a Model 17 Cabinet
  IP Logged
imageflood
Verified Member
**




Posts: 10
Re: Roll Rachael Roll
Reply #4 - 05/25/20 at 17:43:31
 
Thanks, s3steve! I'll have to try the Winged "C" some time soon. As to preamp tubes, it's hard to beat the 6N2P. I think you'd have to use a top-of-the-line 6DJ8 to work in the Rachael. But at that price-point, you could probably buy a whole case of 6N2P-EV's and never have to worry about it again.
Back to top
 
 
  IP Logged
imageflood
Verified Member
**




Posts: 10
Re: Roll Rachael Roll
Reply #5 - 05/28/20 at 01:05:44
 
So, while I'm waiting for a fresh set of Mullards to arrive, I put in a pair of RCA 807's I had bought a few year ago. These aren't NOS, but the seller said they tested well and I have no reason to discount that. I had another pair of 807s that were positively geriatric, and by comparison these RCA's are totally workable.

The positives are primarily visual. 807's look like the coolest tube on the block, and the adaptor/cap is appropriately Frankenstein-esque. Like, if you ever brought friends or potential love partners over to admire your supercool tube stereo concoction, these are the tubes you'd want to impress them. But the only thing is, I don't really bring friends over to have them compliment my gear, and the *vast* number of love partners I entertain show remarkably little interest. In my tube amplifier, that is.

As for what really matters, the sound, I'm underwhelmed. Now, it could very well be that one needs to shell out for truly NOS tubes, and have adaptors to match (the adaptors I have seem rather flimsy, maybe?). But these 807's are paper thin sonically speaking. Barely two-dimensional. Brought nothing to the dance, and they didn't last more than 48 hours in the system.

Oh, 807's, it's not you, really, it's me. But we're just not a good match!
Back to top
 
 
  IP Logged
s3steve
Verified Member
**




Posts: 18
Re: Roll Rachael Roll
Reply #6 - 05/28/20 at 17:04:28
 
I didn't mind the RCA 807's. You are right though I also found them a little thin. The issue I was having with them was more do to the adapter. I would have one meter reading 8-10 points above the other one. I swapped left to right and it followed the adapter so that's the bigger issue for me now.
So I,m back to the Winged -C- 's.

Have any of you tried KT66 power tubes?
If so What did you think?
Back to top
 
 

CSP3
SE34I.5
Ariston RD11
PS Audio GCPH
Pioneer N-50 Network Player
Altec 605B's in a Model 17 Cabinet
  IP Logged
Rivieraranch
Seasoned Member
****




Posts: 1726
Re: Roll Rachael Roll
Reply #7 - Yesterday at 11:14:15
 
That is strange that you all did not find the 807's engaging. Steve prefers this tube in the Rachel. It may be that those RCAs are different from Canadian Westinghouse or old National Unions. I noticed the difference between the RCAs and National Unions recently when I switched some 807's I was running in my Mini Tori. The 1970's RCAs were on the bright side, whereas the National Unions, 1951 manufacture had a more lush "old radio" sound.
Back to top
 
 

MINI TORII ANNIVERSARY MODIFIED; SE84UFO; ZSTAGE; MONOLITH SPEAKERS; TECHNICS SL1200MK2 KAB MODDED TT; ONKYO 6 DISC CD; MARANTZ 2226B; SCHIIT MULTIBIT DAC; SENNHEISER HD-580 headphones
55   IP Logged
Pages: 1
Send Topic Print