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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 196

post #2926 of 8048
Quote:
Originally Posted by kvtaco17 View Post
 

Got a pair of OPA627's yesterday... very similiar to the TI OPA2107, but withe much improved channel seperation, slightly bigger soundstage, better insturment seperation... so far  it sounds kinda like a hybrid love child of the OPA2107 and LME49990... I like it a lot!

 

 

I also receieved the GE 6DT6 (grey plates and ribbed) Svetlana 6A2P (looks a lot different in construction vs other heptodes I've deal with) AND a new to me AD2000X (amazing cans I must say!)

 

 

 

 

 

 

 

You should try the OPA1611 and the LME49720 also, Also i very much like the warmness of the AD797.

 

These are all from my SS iBasso amp though.

post #2927 of 8048
Quote:
Originally Posted by mab1376 View Post
 

 

You should try the OPA1611 and the LME49720 also, Also i very much like the warmness of the AD797.

 

These are all from my SS iBasso amp though.

I will get around to it eventually, I really like the Burr Brown/TI sound it seems... So for now I will enjoy what I have lol

post #2928 of 8048

From what I am reading, it appears the the mysteries of two mystery tubes have been solved:

 

1) Siemens "Foreign" seems to be a Japanese Matshushiita/(Hitachi ?) tube, also available as Haltron 6CS6. (Paid $2 for a pair, but got hit with $8.50 shipping from Canada). Under what other brand names and designations is this tube available? Zaerix?

 

2) Pinnacle 6AV6 seems to be a RCA black plate rebranded side getter tube. What is the difference between the side getter 6AV6 and 6AT6 if any? What about 6AQ6, which looks different than the 6AT6/6AV6, although I saw a Westinghouse 6AQ6 that looked like a side getter tube as well? Under what other brand names and designations is this tube available? CGE?, NEC?, Raytheon?

Seems that the 6AV6 and 6AT6 is available as a top getter from the same brands that made the side getter tube. Is there a difference in sound?

 

Would appreciate your help with the above.


Edited by mordy - 9/13/13 at 7:42am
post #2929 of 8048
Quote:
Originally Posted by mordy View Post
 

From what I am reading, it appears the the mysteries of two mystery tubes have been solved:

 

1) Siemens "Foreign" seems to be a Japanese Matshushiita/(Hitachi ?) tube, also available as Haltron 6CS6. (Paid $2 for a pair, but got hit with $8.50 shipping from Canada). Under what other brand names and designations is this tube available? Zaerix?

 

2) Pinnacle 6AV6 seems to be a RCA black plate rebranded side getter tube. What is the difference between the side getter 6AV6 and 6AT6 if any? What about 6AQ6, which looks different than the 6AT6/6AV6, although I saw a Westinghouse 6AQ6 that looked like a side getter tube as well? Under what other brand names and designations is this tube available? GCE?, NEC?, Raytheon?

Seems that the 6AV6 and 6AT6 is available as a top getter from the same brands that made the side getter tube. Is there a difference in sound?

 

Would appreciate your help with the above.

 

1) Yes, this tube has been marketed under the Zaeix label. However, as Zaerix was a rebrander, one cannot assume that all Zaerix EH90/6CS6 are equal to the Siemens "Foreign".

 

2) The 6AQ6 has .15 amp heaters and a gain of 70. The 6AT6 has .3 amp heaters and a gain of 70. And the 6AV6 has .3 amp heaters and a gain of 100. In my experience, at least with Sylvania, these three sound essentially the same. However, the 6AV6, with higher gain and improved separation between the diode and triode circuits, was considered to be the best.

 

Regarding side getters and top getters, I don't think it makes any difference...  The 1950s GE tubes had top D-getters... and then side D-getters in the 1970s ... and then, top O-getters by around 1980. In my experience the 1950s GE with top D-getters sound the best. However, I can't say anything about other brands..

post #2930 of 8048

Did anybody compare the Pinnacle style side getter 6AV6 with the GE 6AV6 top getter?

post #2931 of 8048
Quote:
Originally Posted by mordy View Post
 

From what I am reading, it appears the the mysteries of two mystery tubes have been solved:

 

1) Siemens "Foreign" seems to be a Japanese Matshushiita/(Hitachi ?) tube

 

Toshiba. On the other hand...

 

Quote:
Originally Posted by gibosi View Post
 

1) Yes, this tube has been marketed under the Zaeix label. However, as Zaerix was a rebrander, one cannot assume that all Zaerix EH90/6CS6 are equal to the Siemens "Foreign".

 

In this case, Siemens was a rebrander as well! In the same vein, we shouldn't assume that all Siemens "Foreign" tubes were made by Toshiba.

 

I'm fairly convinced that the Canadian side-getters were made by RVC, Radio Valve Company of Canada Ltd.

post #2932 of 8048
Quote:
Originally Posted by mordy View Post
 

Did anybody compare the Pinnacle style side getter 6AV6 with the GE 6AV6 top getter?

 

I have not directly compared these, but my general feeling is that the RCAs are a bit more forward and bright.

 

And I can provide a little more guidance regarding which GEs to purchase....

 

GE 6AV6

 

Currently, my go-to tube is the 1958 GE 6AV6. It has superb clarity and transparency, sweet mids and a punchy, detailed bass. Actually, I have had this tube for some time now, but initially felt that it wasn't all that great, so had put it aside. When I received the FIVRE and Toshiba tubes, I noticed how similar the construction of these tubes were to the GE and pulled it out for comparison. In the meantime, I had purchased new headphones and upgraded my op amp, and boy was I surprised when I heard these again! Finding an overlooked treasure in my "not good enough pile" was very sweet. :)

 

However, the fact that Audiofanboy reported that he was not all that impressed by his GE 6AV6 was somewhat disconcerting. And further, I have seen several versions of this tube on eBay that look quite different. So in an attempt to get to the buttom of this, I ordered two more GE 6AV6, each with different internal construction.  (And I should point out that that there also exist RCA and Sylvania manufactured tubes with GE paint. Typically, the classic sandblasted GE pattern with the tube number and dots is conspicuously missing on these tubes.)

 

1958 GE 6AV6

 

 

1974 GE JAN 6AV6. The metal box-like structure on the top mica is gone. It has a side-mounted square getter, located above the top mica. Compared to the 1958 GEs, it is as if the bass has been sucked out, leaving a rather shrill presentation. Not good.

 

 

1980 GE JAN 6AV6. Halo getter, top mounted. But sound is similar to the 1974 GE with a rather shrill presentation. Not good.

 

 

The specific changes in these newer tubes that make them sound like crap are likely undetectable to the naked untrained eye, but they appear to coincide with the removal of the box-like structure located on the top mica. So my recommendation is that if a GE 6AV6 doesn't have a metal box-like structure on the top mica, do not buy it.

 

But there is more....  Apparently, the 1950s GE 6AV6 design was adopted and implemented by a number of other manufacturers, such as FIVRE and Toshiba (Multivox) below. Notice that both of these have the metal box-like structure on the top mica and diodes that resemble GE's plates with a rather steep peak. And more importantly, the sound of the FIVRE and Toshiba tubes is indistinguishable from my 1958 GEs. So if you see a 6AV6 that looks like a 1950s GE with peaky diodes and a box on top of the mica, there is likely a very good chance it will sound like a 1950s GE. And that is a good thing. :)

 

FIVRE 6AT6/EBC90 (1950s)

 

 

Toshiba (Multivox) 6AV6/EBC91 (1970s)

 

post #2933 of 8048
Quote:
Originally Posted by Oskari View Post
 

I'm fairly convinced that the Canadian side-getters were made by RVC, Radio Valve Company of Canada Ltd.

 

This seems reasonable to me. Further, I would speculate that in this instance, RVC simply licensed RCA's technology to enable them to manufacture what are essentially RCA 6AT6 and 6AV6 tubes.

post #2934 of 8048

Created with GIMP

The Early Development of Radio in Canada, 1901-1930 (Second Column)

Probably some in there as well about how RCA fir into the picture...


Edited by TrollDragon - 9/13/13 at 11:27am
post #2935 of 8048

These are my favorite 6AV6

 

http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/2385#post_9709904

 

Very detailed but not too much and clean punchy bass

post #2936 of 8048

Ok a few impressions for you guys...

 

GE 6DT6 (USA)

 

700

 

Svetlana 6A2P

 

700

 

Test chain FLAC>ODAC>LD MK1+> PS500/ AD2000x/Magnum V5

 

Epica - Blank Infinity

 

 

(I used the version on "The Classical Conspiracy Live" I used the studio version here because I couldn't find a decent version on youtube)

 

Svetlana 6A2P

 

The Svetlana's generally are warm sounding similar to an EH90 with less treble extension and air. They are full bodied and precise, great on intimate recordings, not so great here. Simone's voice is presented in a very small, narrow, odd,  direct manner... Adding a 1/7 strap helps add some air and space BUT I still didn't care much for these tubes here...

 

GE 6DT6

 

Open and airy with great detail and dynamics (should just label every 6DT6 this way it seems) These are great on this track, HOWEVER they have less bass extension and sound stage then the Sylvania and RCA 6DT6A's that Ive tested... think of it as a more focused 6DT6 (this is in both EF95 and 1/7) I like this tube BUT not as much as the other 2 6DT6's I've sampled. Everything is presented well, awesome airy vocals, good mid and treble detail... bass seems less textured and detailed then the other 6DT6's...

 

Rachel Sermanni - The Fog

 

 

Svetlana 6A2P

 

Ok now I see what these are good for! They eat this track up and sound intimate and awesome! Great dynamics, detail and sense of space (a small but detailed space)

 

GE 6DT6

 

Well, I personally love the presentation here... although the size of the sound stage and seem somewhat artificial because of how simple the track is... Most of you will probably prefer the Svetlana's above... Dynamics are a little on the soft size vs the 6A2P.

 

Pantera - Cemetery Gates

 

 

Svetlana 6A2P

 

No... just no... congested but detailed... flat... where did the instrument separation go?

 

GE 6DT6

 

Decent... a little diffuse vs the RCA/Sylvania  6DT6A and Valvo/Ediswan/Mullard EH90... average really... left me feeling indifferent...

 

Yo-Yo Ma, Stuart Duncan, Edgar Meyer, Chris Thile - Quarter Chicken Dark

 

 

Svetlana 6A2P

 

Detailed but lacking air and space, very good sense of dynamics, fun. Good instrument separation and texture to the strings.

 

GE 6DT6

 

OK, but somewhat blurred... dynamics are flatter then I'd like... (in comparison to other tubes it is average, similar to the Siemens 6AK5W) Strings take on an odd tonality... I really can't describe it... nasally maybe?

post #2937 of 8048
Quote:
Originally Posted by mab1376 View Post
 

 

You should try the OPA1611 and the LME49720 also, Also i very much like the warmness of the AD797.

 

These are all from my SS iBasso amp though.

 

 Quote:

Originally Posted by kvtaco17 View Post
 

Got a pair of OPA627's yesterday... very similar to the TI OPA2107, but with much improved channel separation, slightly bigger sound stage, better instrument separation... so far  it sounds kinda like a hybrid love child of the OPA2107 and LME49990... I like it a lot!

 

 

I also received the GE 6DT6 (grey plates and ribbed) Svetlana 6A2P (looks a lot different in construction vs other heptodes I've deal with) AND a new to me AD2000X (amazing cans I must say!)

 

 

 

What op amps do you recommend for the 

Tung-Sol 6AK5, Sylvania Gold Brand 5654,Voshkod 6ZH1P-EV and the Mullard M8100 / CV4010?

 

 

I want the op amps to bring out the best of each individual tube, without changing or altering the distinct characteristics of each tube. I've noticed that certain op amps do not go together well with other tubes.

 

Does anyone have any suggestions?

post #2938 of 8048

i'm wondering if 12AU7 will work with LD mk III.

post #2939 of 8048
Quote:
Originally Posted by Sony Slave View Post
 

What op amps do you recommend for the 

Tung-Sol 6AK5, Sylvania Gold Brand 5654,Voshkod 6ZH1P-EV and the Mullard M8100 / CV4010?

 

 

I want the op amps to bring out the best of each individual tube, without changing or altering the distinct characteristics of each tube. I've noticed that certain op amps do not go together well with other tubes.

 

Does anyone have any suggestions?

 

I find the LME49990 to be a very neutral op amp:

 

http://www.ebay.com/itm/DUAL-SOIC-LME49990-DIP8-ADAPTER/190897295927?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D17396%26meid%3D1289909108227033573%26pid%3D100011%26prg%3D8093%26rk%3D1%26rkt%3D5%26sd%3D190888281070%26

post #2940 of 8048
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