[MWALK]

Anyone recently receive a new ZD?

 

[ironbut]

I spoke to Craig at the Nor-Cal meet on Saturday ( very cool and funny guy!), and he said that the Zana's were being assembled now. He didn't say when they started and when mine was built, I think it took 2 weeks for assembly and a couple of days to be checked before shipping. Did he do another lot of 10 this time?

 

[Zuerst]

My Zana Deux is ready to ship.

I have a choice of going with a newer gen Tung Sol 6SL7 vs an older gen Tung Sol 6SL7.

Anyone know if there is any advantages or disadvantages going with the newer vs the older gen. The newer gen cost $15 more.

Thanks.

 

[greggf]

Mine will be shipped in two weeks. Anxiously awaiting.

My only concern is its function as a space heater . . . but I live in the snow belt, so many months of the year I hope that that will be an advantage.

 

[ironbut]

Quote:

Originally Posted by Zuerst /img/forum/go_quote.gif My Zana Deux is ready to ship. I have a choice of going with a newer gen Tung Sol 6SL7 vs an older gen Tung Sol 6SL7. Anyone know if there is any advantages or disadvantages going with the newer vs the older gen. The newer gen cost $15 more. Thanks.

The best 6SL7 tubes I've used are all 1940's-early 1950's. The low noise/closely matched balance tubes like the 6SU7 were produced for WWll.

 

[Zuerst]

Quote:

Originally Posted by ironbut /img/forum/go_quote.gif The best 6SL7 tubes I've used are all 1940's-early 1950's. The low noise/closely matched balance tubes like the 6SU7 were produced for WWll.

Are the 6SL7 and 6SU7 interchangable? What else can be used in place of the 6SL7 for the Zana Deux???

And it looks like the lastest run of Zana Deux now comes with plate caps.

Craig sent me the following image:

They now come with 6D22S rectifiers instead of 6DM4A

EDIT: looks like the big feet are gone too... I kinda like the big feet...

 

[greggf]

Any thoughts on the changes? What are plate caps/why plate caps? This is how dumb I am..............

 

[granodemostasa]

um... makes me want to get mine modified....

 

[ironbut]

The 6SU7 is a selected VT229/6SL7 so it's actually the same. Sound wise, the earlier the better. Other names for these tubes are 5691 like the RCA special red base tube I did in my comparison. Here's a comparison I copied a while ago from Chimera Labs


There appears to be a more noticeable difference in sound performance in these high gain tubes like the 6SL7 than in the low gain types like the 6SN7.

It also points out that the current produced 6SL7 & 6SN7 types don't sound very good at all. This is not surprising because current tube production improvements, outside of the 300B, have focused on the tubes used in guitar amps. It's considered a more important market. So there are some very good 12AX7s, 6L6GCs and EL-34s. In my opinion, the latest Sovtek 12AX7LP & 12AX7LPS are superb. Svetlana makes very good EL-34s and 6L6GCs. The fact that these tubes are so good is why we used these tubes in the design of our ACE 8 Watt Single Ended Amplifier.

So here is the list. Notice the early 1940s VT-229s are the best. Just like the VT-231s for the 6SN7GT. All the early 1940s commercial types have the same construction as the Mil-Spec types. In the ones I have tested, the sections and tubes do not match each other as well as the military types.

The 6SL7 types that used a round plate structure fared much better than the flat plate structures. Didn't notice much a difference between graphite coated versus no coating, but there may be an impact on reliability, service life or specific applications. Don't see any negatives with graphite coating. Stay with the black plate tubes or consider the "nickel" plates if your system sounds too soft.

VT-229 Tung-sol Brown Base, Black Round Plates, Graphite Coating - You got to love the early Tung-sols they do everything right, no weaknesses, just bring you closer to the music.

VT-229 Tung-sol Black Base, Black Round Plates, Graphite Coating - Same as above, in my samples maybe a little less focused.

VT-229 Sylvania Black Base, White/Green Label, Black Round Plates, no coating - Front row center, very immediate with big sound stage. Not quite the low level detail resolution and accuracy of the Tung-Sols.

VT-229 Raytheon - Black Base, Black Round Plates, no coating - Sound very much like the Tung-Sol, but not quite as clean or immediate, very musical, its like sitting in the middle of the hall.

VT-229 RCA - Black Base, Black Round Plates, graphite coating - If your system sounds a little too analytical, harsh or electronic this may be your favorite tube, very rich harmonic structure.

VT-229 National Union - Black Base, Black Round Plates, very dark graphite coating - Maybe a little bass shy, excellent high frequency and wonderful midrange, amazing on vocals.

VT-229 KEN-RAD - Black Base, Black Round Plate, no coating - Nice pace and drive, big sound, very clean and low distortion, does not have the rich harmonic textures of the other VT-229s.

C series Military Tubes - Many VT tubes also had a C series identification. KEN-RAD was CKR, National Union was CNU, Raytheon was CRP, RCA was CRC and Sylvania was CHS. Many VT-229s had C__-6SL7GT on the tube base. To my knowledge all the C-series tubes are identical to the VT series. Same
performance same rankings.

Commercial versions of the VT-229s - All the tube manufacturers manufactured their early commercial tubes exactly like their VT-229s. Both RCA (the silver labels up to early orange labels) and Sylvania(up to green labels) were manufactured with exactly the same parts as the VT-229s. Some of the RCA silver labels were graphite coated.

CKR-6SL7GT KEN-RAD, Black Base, Round Nickel Plate, tall bottle - Don't know if KEN-RAD started as a division of General Electric but it ended up that way for most of its life. The commercial KEN-Rads of this era constructed the same way. Sound - very alive and musical, in the right system could be very effective. Later G.E. tubes had the same construction, but don’t sound as good.

6SL7GT Sylvania - Black Base, Black Round Plate, through Green Label, Same general sound characteristics as the VT-229, not as clean and detailed. I think the quality slipped. The sections don't match as well, the reduced low level detail resolution may be due to a softer vacuum or less rigorous material specifications.

6SL7GT RCA - Black Base, Black Round Plate, silver and at least some orange label - same basic sound as the VT-229s, once again just not as good, probably for the same reasons stated in the Sylvanias.

6SL7GT Raytheon - Black Base, Round Black Plates, Top Getter, Yellow Label - Great driver tube, super in guitar amps, wide bandwidth and very low distortion, sounds very clean, may be a little light on harmonics.

6SL7GT General Electric - Black Base, Round Nickel Plate, red through white label - A nice tube if you can't get the ones listed above, should be able to get them at very good prices.

Black Flat Plate 6SL7 Types including the 5691 - I am sure I have not listened to all of them, I have listened to all the 5691 types. They suffer from reduced bandwidth, poorer low level detail resolution, they sound unfocused and electronic in comparison to the round plates. Just an opinion, but try the ones listed before you get back to me to tell me how wrong I am.

I'm not sure what gear was being used so YMMV. There was also a similar one on Audio Kharma. Both are pretty biased,.. but aren't we all.

 

[Zuerst]

Sweet! just got my Zana Deux!!! There are some scratches but I guess that's probably likely with all the extensive tests the amp goes through before being mailed out to owners.

Anyways, the things looks awesome! Can't wait for the tubes to warm up and start listening to this puppy.

 

[MWALK]

Mine is ready for sipment!!!!!

 

[Absorbine_Sr]

Welcome to a fine little club! You will enjoy your amps.

A_Sr.

 

[mach46]

isnt that the best of news, the wait has come to its end.

quick question for the existing zana owners, what cans and tube you do you enjoy best with your zana?

 

[Absorbine_Sr]

Quote:

Originally Posted by mach46 /img/forum/go_quote.gif isnt that the best of news, the wait has come to its end. quick question for the existing zana owners, what cans and tube you do you enjoy best with your zana?

My fav combo so far is a 1940's Brimar 6SL7GT (all other tubes stock) powering MS2i's. A marriage made in heaven for most of the music I listen to.

A_Sr.

 

[Dr.J]

I have a pair of AKG 701's, driven by my ZD. Craig suggests I try a 6SL7, instead of the 6135 I currently have. After reading this thread, I'm nearly completely confused.

Can anyone recommend an ideal tube for the K701's?

thanks,

John