[Clayton SF]

Karo,
When searching for great sounding 6c33c-b (6s33s-v--or the like) power tubes what does one look for? What are the identifying marks that may be on the tube that would help tell me that this is the tube to get. Any idea? I've been cruising fleabay and there are many different types of 6c33c-b tubes out there and I just don't know which to pick. I also visited the Dutch site and it seems that they are out of that tube. Thanks!

 

[Karo]

Hilarious.  What I've been wanting to say ..... I don't think any of us even realize how important this thread is.  The idea that these ultra-modern amps are being built to unleash these "tube spirits" from 50 years ago,  it's just stunning.   It's really a testament to the Zana, the sensitivity of the unit.
 
Clayton, for a moment I thought you were the guy in the east-bay.  Go back early in this thread, he's got a dozen power tubes (the wings).  It would seem that the guys up north snagged a-lot of the first run.  Being a former inhabitor (!?)  of the east-bay and other parts ... I can certainly appreciate that. 
 

 

 
The Zana is the Bomb.  Nearly 2 years now on the partsconnexion tubes, ran fine.  As Eddie says.... if they last 48 hrs. they're good.
 
Also just finished mahogany base #2, for the DAC this time. Should post in the owner thread.  The depth, the harmonies !!!  Wow.

 

[40Hz]

Quote:

What are the identifying marks that may be on the tube that would help tell me that this is the tube to get. Any idea?

There are (were) only two manufacturers - Ulyanovsk and Svetlana.  As I understand it, the earlier version was the 6C18C but a more robust tube was wanted, so the 6C33C was developed.  I have pairs of each type (hopefully shown below, if the picture loads), and left to right they are:
 

1. 1961 Svetlana 6C18C, which I am using at the moment with a Mullard ECC35;
2. 1967 Ulyanovsk 6C18C;
3. 1969 Svetlana 6C33C (the most expensive of the 6C33C / 6C18Cs around - generally $100 / pair);
4. 1974 'early' Ulyanovsk 6C33C - a really nice tube; and
5. 1987 'current' Ulyanovsk 6C33C - the stock tube shipped with the Zana.

 

 
Hope that helps...
 

 

[Clayton SF]

40Hz,
Thanks. Great photo. One of them, the middle one, is incognito--a spy tube perhaps, yes?

I notice the earlier ones have no "horns" and the latter ones do. I wonder why.
And a Tung-Sol 6SL7 black glass no doubt--score.
This information and photo is very helpful. Thanks!

 

[BobMajor]

The center one is as 40hz says the most expensive. An early Svetlanov "winged C" tube.

 

[40Hz]

Quote:

40Hz,
Thanks. Great photo. One of them, the middle one, is incognito--a spy tube perhaps, yes?

I notice the earlier ones have no "horns" and the latter ones do. I wonder why.
And a Tung-Sol 6SL7 black glass no doubt--score.
This information and photo is very helpful. Thanks!

No problem.  The middle one is in a sealed bag, purportedly because these tubes can be susceptible to oxidisation on the pins (not something I've seen on any to date, however). 
 
From what I have been able to determine, the 6C33C's have the support rods all the way through the tube (forming the 'horns') in order to make them more rigid, and therefore more reliable...
 
I have way too many 6SL7 variants, but frankly I see my Zana as a lifetime amp (or my wife does, anyway!) so a few spares and options won't hurt.  The Tung-Sol black glass tube is definitely one of my favourites.
 

 

[Clayton SF]

Quote:

No problem.  The middle one is in a sealed bag, purportedly because these tubes can be susceptible to oxidisation on the pins (not something I've seen on any to date, however). 
 
From what I have been able to determine, the 6C33C's have the support rods all the way through the tube (forming the 'horns') in order to make them more rigid, and therefore more reliable...
 
I have way too many 6SL7 variants, but frankly I see my Zana as a lifetime amp (or my wife does, anyway!) so a few spares and options won't hurt.  The Tung-Sol black glass tube is definitely one of my favourites.
 

This is wonderful. I am on the May run for my Zana Deux SE and I expect delivery to be some time later this month or early next. Anticipation has definitely heightened. As I understand it the ZD, depending on the vintage, has different rectifiers. Does anyone know why Eddie Current made the alteration. I am sure both versions sound spectacular.

 

[40Hz]

Congrats on your order, Clayton, definitely something to look forward to!
 
I think that the rectifier tube change was due to the fact that matched tubes are needed, and matching the previous tubes was proving more difficult because there was nothing in current production.  The 6D22S tubes used now are (1) readily available, and (2) cheap, so you can buy a bunch and swap them in and out until you have a match - they're all over ebay for example.  Maybe someone with a longer institutional memory than me will jump in and confirm or clarify...  (edit - see http://www.head-fi.org/forum/thread/193868/eddie-current-zana-deux-owners/440#post_3683127).
 
Note too that by contrast the big power tunes do not need to be matched - one less thing to worry about. 
 
What the differences in sound are, I have no idea, but like you I expect that both iterations of the amp sound wonderful.  I think I read somewhere that Craig himself did not expect the choice of rectifiers to have a noticeable impact on sound, but Karo is the resident roller of rectifier tubes, and his experience is that there can in fact be quite a difference.  I have stayed with the stock tubes to date, as if anything there is a lot of exploring to do just with the 6SL7 options. 
 
Keep us posted when yours comes to stay.

 

[Clayton SF]

40Hz--Thank you very much for the insightful information and link. I will certainly stay with the stock tubes for awhile until the ZD burns in and I become accustomed to its sound signature. Although I will certainly spring for the coveted tubes if and when the opportunity arises to procure any of them.

 

[Karo]

The Spy Network.
 
 

 


 

 

[Clayton SF]

I've noticed that the wire to your grid cap is black and the rectifier looks taller than a 6D22S. Did you have that black wire custom made to accommodate the taller rectifier?
 
Great photos and the plates on that 6C33C-B are THICK!

 

[Karo]

Quote:

I've noticed that the wire to your grid cap is black and the rectifier looks taller than a 6D22S. Did you have that black wire custom made to accommodate the taller rectifier?
 
Great photos and the plates on that 6C33C-B are THICK!

 
Thanks man. Yes they are thick.  The first thing I noticed when I finally got the photo from them was the glass itself.  It seemed to have a different quality to it.  I've worked with glass since I was 11, so .....   Anyway.
 
My cable buddy says red is for high voltage.  Yes, when I blew a rectifier ... that's when Craig told me about the 6D22 variants. It was funny when Electro-Harmonix refused to sell to me without a wholesale account.  Actually what was funny was Craig's response. He wasn't very happy about it.
 
So he recommended some on eBay from a guy who was a very fast sender, which were the taller variants. As cable guy says ..... larger envelope, less heat, better performance.  He built me the extended cap-wire set. Then Mattijs came through with the tubes.
 
Voila !  

 

 

[nghows]

Good Grief this thread is still alive and kicking! Strange to see an ancient post of mine quoted as well.... btw, my ZD is #45.
 
I've been super happy with the tall glass rectifiers. It made a surprising amount of difference. Thanks Karo for the heads up on that one!
 
I've been happily rolling 6sl7s from my stash. Been tempted a few times on fleabay to add to the collection but stopped myself... Spending on other bits of audio instead. My goodness, how prices of 6sl7s have increased.

Back to the tunes. Enjoy your ZDs people whatever the iteration. Craig is a genius. And a nice one at that!
Quote:

 Maybe someone with a longer institutional memory than me will jump in and confirm or clarify...  (edit - see http://www.head-fi.org/forum/thread/193868/eddie-current-zana-deux-owners/440#post_3683127).  
Note too that by contrast the big power tunes do not need to be matched - one less thing to worry about. 
 
What the differences in sound are, I have no idea, but like you I expect that both iterations of the amp sound wonderful.  I think I read somewhere that Craig himself did not expect the choice of rectifiers to have a noticeable impact on sound, but Karo is the resident roller of rectifier tubes, and his experience is that there can in fact be quite a difference.  I have stayed with the stock tubes to date, as if anything there is a lot of exploring to do just with the 6SL7 options. 
 
Keep us posted when yours comes to stay.

 

[AppleheadMay]

Shaking up an old thread ...
I didn't read this whole thread yet but will do so tonight. There are some questions I have as a tube newbie that keep my mind occupied though.
 
 
Why do I see only tube rolling with the driver tube and not with the power- and rectifier tubes? What is each type of tube for by the way?
 
When I roll tubes, do I need to "bias" them, whatever that is? Or is the Zana auto-bias?
 
Is there any way to know what effect you will get with a certain brand/kind of tube before you try it?
 
Can you recommend me tubes for the following cans? LA7000, W5000, W3000ANV, L3000, HD800? (With the Zana of course)
 
 
 
Thanks for any answers you can give me!

 

[Blackmore]

Well, you should read the thread first, imo. You will find there enough info about rolling and not driver tube only, however the most influence on the sound  comes from the driver, I believe.