Welcome, Guest. Please Login or Register
Decware Audio Forums
07/05/20 at 01:20:09 


       


Pages: 1
Send Topic Print
Roll Rachael Roll (Read 797 times)
imageflood
Verified Member
**




Posts: 16
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: 16
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: 16
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: 21
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: 16
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: 16
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: 21
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: 1729
Re: Roll Rachael Roll
Reply #7 - 05/30/20 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
imageflood
Verified Member
**




Posts: 16
Re: Roll Rachael Roll
Reply #8 - 06/01/20 at 02:55:53
 
Rivieraranch: You may indeed be right. I suspect the RCA's may not have been in the best condition. The adaptors are also suspect, obviously not fantastic craftsmanship. (I'm waiting for some Decware fanatic to build elite 807 adaptors... dare to dream.) If I find some NU's I'll take another look...

s3steve: The Winged C's are definitely gonna happen at some point. Have not tried KT66.
Back to top
 
 
  IP Logged
imageflood
Verified Member
**




Posts: 16
Re: Roll Rachael Roll
Reply #9 - 06/05/20 at 19:52:18
 
I pulled the 807s a few weeks back and replaced with the stock Tung Sol EL-34B's with which the unit arrived. These are not the freshest tubes, so take my impressions with a grain of salt. The amp is now over 6 years old, and the stock tubes got a decent amount of play before I started rolling them out.

The sense I got from them is that they are very "linear," neutral and straightforward. They don't get in the way of anything, so that you can get a baseline sense of what Rachael can do. It took several days for them to re-burn (since they hadn't been used in years), and once they did things started opening up and got a decent amount of power that I had been missing from the previous iterations you may have read about on this thread. I can totally see why they are used as stock tubes.

On the other hand, the Tung Sol's didn't add much to the mix. I'm happy I had them while I was waiting for a new set of Mullards to arrive. And I didn't miss them much once they had fulfilled their duty.
Back to top
 
 
  IP Logged
imageflood
Verified Member
**




Posts: 16
Re: Roll Rachael Roll
Reply #10 - 06/20/20 at 17:17:02
 
So, I received a matched pair of new-production Mullard EL34's and I'll just come out and say it: Along with the Mullard GZ34 rectifying the situation, this is my preferred configuration to date.

The Mullards appear to afford Rachael just slightly more power, or at least there seems to be more lift from the bottom-end. There is just a bit more warmth, and more crunch when you need to rock out. Without, however, losing the transparency and detail. I put on some Marisa Monte and re-discovered her voice -- like she was standing 6 feet in front of me.

My gripe with these new-production Mullards in the past is that they took so incredibly long to burn in and open up. Perhaps the production facilities in CCCP have been upgraded, but the new pair sounded very good right out of the box. For the first two hours or so they sounded amazing, and then dropped off noticeably thereafter. They were still quite listenable, though. The first set I had often produced a scratchy harshness that took 100+ hours to resolve fully. The new pair has been in the system for 50-75 hours now I would guess, and they are absolutely singing. I believe they're still on an upward trajectory too. I still can't believe these things ship for ~$30 a pop. (I think that says more about Decware than it does Mullard.)

I am still intrigued about trying Winged =C= EL34's, but I think I'll do that after the ZP3 arrives. The new phonostage is now "On Bench" so I have just enough time for my ears to adjust to a "benchmark" tube complement. I just popped in a new Mullard GZ34 about an hour ago, and as soon as that settles I have a new pair of military 62NP-EB's at the ready.

But all told, after how many years of persistent, near-manic, and quasi-obsessive tube rolling throughout my life as an audiophile, it feels weird to be one or two or zero steps away from the final configuration I'll ever want or need.
Back to top
 
 
  IP Logged
Rivieraranch
Seasoned Member
****




Posts: 1729
Re: Roll Rachael Roll
Reply #11 - 06/20/20 at 17:58:36
 
Now I am back to the 6V6 in my Mini. I did a side by side comparison; a 6V6 in the left amp and an 807 in the right side amp. I had a young girl serve as critic and she pointed out that the 6V6s gave more detail
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
imageflood
Verified Member
**




Posts: 16
Re: Roll Rachael Roll
Reply #12 - 06/22/20 at 22:46:27
 
Why don't I consider rectifier tubes more? Any time I want to change a sound I typically go to power or input. But I swapped in a new Mullard GZ34 over the weekend and, jinkies Scoob!, what a leap in quality. Everything is running way cleaner. The holography is a lot more holographic, images popping out a few feet in front of the speaker and receding a few feet behind it.

I just wish the GZ34 was a bit less stubby, a bit more pleasing to the eye. But for what this guy provides... I don't see any more need to roll other rectifiers into the slot.

A few more days with this configuration, then new 62NP's in the input in a few days, and I'll be done for now!
Back to top
 
 
  IP Logged
Steve Deckert
Administrator
*****


If the 1st watt
sucks why continue?

Posts: 4580
Re: Roll Rachael Roll
Reply #13 - 06/23/20 at 06:08:32
 

Some great feedback regarding quality tubes...  

The beauty of a tube amp is that you can change the tubes.  You can change the tubes when they grow tired and lazy sounding over time... or you can change the tubes when you grow bored or just want to take a different seat in the music hall so that you can hear the music from a different perspective. So this leads to tube rolling which leads to brands and types... and here is some of what I know that you should know:



Current production vs. New Old Stock. In my experience the only consistently solid tubes on the market today come from Russia. Brands like Mullard, Tungsol, Electro Harmonix, Sovtek, Svetlana. The rights to these brand names have been acquired over the years by New Sensor Corp in the USA, who is predominately a tube supplier for the music industry / guitar amps. They own or partially own factories in Russia.

Decware purchases it's Russian tubes direct from Russia in bulk with the exception of the larger output tubes (EL34/KT66/KT88) which are current production branded tubes imported into the USA. All of the the Russian tubes that we purchase direct from Russia are N.O.S. Russian Military Grade tubes. Many of them have Gold grids, thick glass, high G ratings for missile use, and longer life, in some cases 10,000 hours.  These are ultra-hi-end tubes in disguise and have always been.   To hear how good these tubes are you have to install an American New Old Stock rectifier tube.

My experience with Boutique Chinese brands is mixed. The sound is good, the reliability and or consistency is ridiculous. I have been purchasing samples of these fancy tubes as they come out over the past many years and I have an entire collection of crippled tubes. Even KT88's that cost $1600 a quad drifted out of usable tolerance within days and had to be replaced.

New Old Stock is the real deal. Those who like to push the envelope of what is possible with their amplifier will often go down this path with no regrets. For one thing, the tubes not only sound better, but often last longer, in some cases like with rectifier tubes up to 10 times longer.

Rectifiers are a subject all in their own. Russian rectifiers are acceptable, everything else is a no-go from a reliability standpoint with some rare exceptions that are very pricey. My advise to all Decware amplifier owners is to find yourself a New Old Stock 5U4 or a 5R4 that has never been used and comes in it's original un-molested box. Consider the current production rectifier tube we ship with the amp the best sounding and most attractive  option that will last long enough for you to find a real N.O.S. replacement.

Finding N.O.S. tubes is easy, even on eBay there are millions. Since you only need one or two you will have more to choose from than you know what to do with.  Finding quantity of these tubes is another story. If Decware could secure reliable inventory of 1000's of N.O.S. rectifiers, it is an investment we would gladly make but in 25 years is has yet to happen. Because we can't find N.O.S. tubes in large quantities, even batches of 100 would be gone in less than 30 days, we feel there is no point in even trying.  

For the customer it is easy, just find a N.O.S. 5U4 tube on eBay that is unused, and in it's original box for $40 and it could easily last for 10 years or more and sound better the entire time.

As an amplifier designer, it is possible to create circuits that baby the rectifier tube by limiting inrush current, using smaller capacitors, running higher voltages with a choke and so on.  Correctly done, this can make a Chinese rectifier tube last the full rated 500 hours or more.  The problem with this is that it changes the sound quality of the amplifier well outside what we find acceptable.  So, we have to make a choice, do we design tube amplifiers to baby the crappie rectifier tubes being made today, or do we design amplifiers to use REAL tubes.  Of course the answer has to be REAL tubes, because we make real amps.

Wink
Back to top
 
 
WWW   IP Logged
imageflood
Verified Member
**




Posts: 16
Re: Roll Rachael Roll
Reply #14 - 06/25/20 at 03:23:31
 
Steve, Wow! Thanks for the lengthy and super-interesting response. I have to agree with you re: Russian new production tubes. I'm under no illusion that the "Mullard" on the box means they are equal to the classic Britannic Mullards of the previous century. But the new Rooskies I've just rolled in are solidly made, and as I said in an earlier post, their quality out of the factory appears to have improved greatly over the past several years.

I've been trawling Ebay since reading your post, on the lookout for NOS 5U4's. I'm not likely to shell out $200, but $50-75 is totally doable for a NIB 50s era RCA. How can I not check them out after what you've said?

I'd eagerly follow another thread on rectifiers. Like probably everyone else, I've read plenty of forum discussions claiming they don't (or shouldn't) make a difference in sound quality. I suppose you can't account for a lack of discernment. Because all I can say is that nothing in this current wave of tube rolling has made such an immediate and dramatic difference. From 2 dimensions to 4, and all the fractals in between.

Thanks again for the post! A real honor and a treat to read.
Back to top
 
 
  IP Logged
imageflood
Verified Member
**




Posts: 16
Re: Roll Rachael Roll
Reply #15 - 06/25/20 at 03:51:07
 
One final note (for now): I mentioned in a previous post that the 6N2P's in the input were of unknown provenance. I went ahead and rolled in a verified pair of matched Soviet military 6N2P-EB's. On spec, they do not appear to be any different than the tubes I'm rolling out. But the new pair are acquitting themselves well. Just a tad more gain I would say, giving a boost of support to the imaging. The holography is all there, and an added sense of naturalness and transparency.

For preamp tubes in Rachael, I really can't imagine using anything but 6N1P or 6N2P as long as they're Soviet military grade. It's really just a matter of personal preference between them.

That's it for now! Future mods coming up once the ZP3 arrives: First, new power cords (both Decware!). At some point soon, I'll add an active preamp into the chain. I'll need an updated DAC as well. I'll have to see if my current turntable is up to the task of feeding the new phonostage. Along the way I'll probably get back to rolling: NOS 5U4 rectifier, Winged C's. And then at long last I'll be done. Until I realize I'm not done again. Or until my mind becomes a pool of limpid tranquility disturbed only ever so slightly by the sonic wisps of clouds that pass by as easily as the enter.... I may already be there in fact.
Back to top
 
 
  IP Logged
HockessinKid
Seasoned Member
****




Posts: 437
Re: Roll Rachael Roll
Reply #16 - 06/25/20 at 14:07:31
 
Wait until you hear 25th Anniversary mods on a Decware amplifier or preamplifier. They're mind bending.

HK
Back to top
 
 

Nottingham Interspace TT w/ Dynavector 20x2LO cart + Modwright PH 9.0 phono pre > ZROCK2-25th OR Modwright modified Cambridge CNX V2 > CSP3-25th preamp > ZMA-25th amp > PI Audio Group UberBUSS PC > Omega SAHO XRS or Caintuck Audio Lii 15 speakers > various cables.
  IP Logged
Ronald Wilkinson
Verified Member
**




Posts: 4
Re: Roll Rachael Roll
Reply #17 - 06/26/20 at 18:19:40
 
What is a 25th anniversary mod on a 341.5 "Rachel"?
Back to top
 
 
  IP Logged
HockessinKid
Seasoned Member
****




Posts: 437
Re: Roll Rachael Roll
Reply #18 - 06/26/20 at 18:35:52
 
The 25th anniversary mods include Jupiter Beeswax II caps and a Jupiter Cap bypass. You can also order Decware silver RCA jacks which provide additional signal transparency. if you pull up the item "additional information" order page it shows you all the options.

HK
Back to top
 
 

Nottingham Interspace TT w/ Dynavector 20x2LO cart + Modwright PH 9.0 phono pre > ZROCK2-25th OR Modwright modified Cambridge CNX V2 > CSP3-25th preamp > ZMA-25th amp > PI Audio Group UberBUSS PC > Omega SAHO XRS or Caintuck Audio Lii 15 speakers > various cables.
  IP Logged
Ronald Wilkinson
Verified Member
**




Posts: 4
Re: Roll Rachael Roll
Reply #19 - 06/26/20 at 19:21:29
 
Thanks!
Back to top
 
 
  IP Logged
Pages: 1
Send Topic Print