[mordy]

HI DL,
Just got a pair of Ken Rad VT-96/SN7 tubes today. They came in the original JAN boxes from 1944 and looked like they had not been opened for 74 years!
I made a shamelessly low offer and the seller counter offered with a price of $5 each.
(If anybody is interested in this source please PM me).
For some reason I paired them with a pair of Chatham 6080 and the initial impression is that they sound quite good.
So many choices!

 

[Johnnysound]

......

Anyway, mon ami, my excitement at your own findings mounts by the hour...these NOS ST-shaped CV1052 of mine are proving exceptional tubes. Last night I wasn't sure if they'd be able to match the EL3N and EL11, but as usual, I was much too premature in my judgment! Now they have nearly 20 hours on them, they are already nearly matching my (almost impossible to find) mesh-plated EL3NG and EL11...and at this rate will probably easily equal them...totally unexpected lol !

Hi again H1, quite interesting find (by CF I understand) of these CV 1052. After a quick search, the “straight” version, of high quality british tubes can be found quite cheap, but the ST ones are much rarer. And I (as you) do prefer the ST version of tubes. There are no adaptors available, so keep on giving your impressions. Of course, a comparison between straight and ST versions is eagerly expected (lol) !

Speaking of ST tubes, I become aware of Mordy’s preferences for the 6F8G as a top driver in the Euforia. Found that the tube is highly regarded in some amps, and not so in others. As you know, the same tube will sound very different depending on the amp. And the Euforia is particularly demanding. The TS 6F8G round plates, “holy grail” has become too expensive, but other similar tubes like vintage NOS Raytheons, National Union or RCA VT-99, are affordable. I would go for an offer of a nice pair of NOS black glass, mil spec RCA VT-99 from 42’ vintage, what do you think Mordy ?

 

[hypnos1]

Hi again H1, quite interesting find (by CF I understand) of these CV 1052. After a quick search, the “straight” version, of high quality british tubes can be found quite cheap, but the ST ones are much rarer. And I (as you) do prefer the ST version of tubes. There are no adaptors available, so keep on giving your impressions. Of course, a comparison between straight and ST versions is eagerly expected (lol) !

Indeed J..@connieflyer has the straight-sided tubes as well as the ST-type - both termed 'CV1052' - but I just love the 'shaped' tubes every time, as you have gathered!, so I've left it to him to be guinea pig with the straights...(and I'll be sick as a parrot if they perform to the same level lol!! ). And it will be interesting to see if my Pinnacle branded EL32s sound the same as my military CV1052...one Pinnacle having a brown base (which I also love in a British tube!), and both looking just as impressive...

Anyway, as you asked - along with @DecentLevi - I will give an update on how these tubes are sounding, with another 10+ hours on them...even though it's still early days for them!

Well, first of all I must admit they exceed all my expectations - was hoping for 'good', but they go way beyond that...in my system!...especially with EL12 Spezials as powers...(and DL, yes...I suspect the extra power of the 12s is preferable in that role!).

Last night it appeared I might have to get used to (quite a lot!) heavier bass and mids than I'm used to, with slightly less treble...but this morning they've toned down some (more to my taste, thankfully, and which often happens anyway). However, there is still a bit more in these areas than the EL11, which is no bad thing lol! Bass detail is still very good, with excellent control and 'tightness'.

Treble is very slightly down, but again has its own benefits - tracks that before could occasionally sound a little harsh at high listening levels are now more 'friendly', but without loss of detail and extension. This was borne out especially with Genesis's 'Duke' album, which has loads of treble, and can easily become tiring on the ears at higher levels! This also means that amp volume can be turned up, without the ears objecting so much...a good bonus IMHO.

Overall balance is very good, with the slightly more bass and mids reminiscent of the mighty ECC31 and FDD20, but without the high heat that goes with the former lol! It doesn't have the same treble 'sparkle' of the C3g, but as I said, is much better for longer term listening.

Again, like the EL11, the sound is beautifully clean and clear...a little less 'coloured' than the EL3N, and at least on a par with my mesh-plate EL3NG and Valvo EL11. In fact, at this rate, I suspect I will prefer these even to my rare mesh-plates - the Valvos giving the very slightest hum (in my system) that is unnoticeable while music is playing.

Another reason for this probable preference is that not only will they take even less power than the EL3N/EL11, but also something I only really noticed with Cassandra Wilson's 'Another Country' (HD Tracks 2013 sampler) - ie. slightly less echo due to the cross-feed implemented in our amps. This results in a tad less 'air', and a little more focus...you can't, by definition, have both lol!! Now that I've got used to the slight difference in sound this gives, I think I prefer a little less 'echo'! But this will also depend on the rest of one's gear/cables etc., of course...

Yet another aspect of the lower power draw/output of these tubes is that there's far less spike/'crack' when switching off the amp with the headphones still attached, which is another bonus. But later models than mine should have reduced spike anyway, and this doesn't really affect me as I always power everything down just from the soft on-and-off balanced mains & filter supply, plus mains regenerator (plenty of protection there also lol!!).

So all in all - as you may have gathered by now! - I am mightily impressed with this CV1052/EL32/VT25...the ST-shaped tube anyway...so far. I just hope I can get cf's adapters finished soon......

But again I must stress...in my system, and to my ears/preferences!...HAPPY LISTENING!...CJ

 

[Scutey]

Indeed J..@connieflyer has the straight-sided tubes as well as the ST-type - both termed 'CV1052' - but I just love the 'shaped' tubes every time, as you have gathered!, so I've left it to him to be guinea pig with the straights...(and I'll be sick as a parrot if they perform to the same level lol!! ). And it will be interesting to see if my Pinnacle branded EL32s sound the same as my military CV1052...one Pinnacle having a brown base (which I also love in a British tube!), and both looking just as impressive...

Anyway, as you asked - along with @DecentLevi - I will give an update on how these tubes are sounding, with another 10+ hours on them...even though it's still early days for them!

Well, first of all I must admit they exceed all my expectations - was hoping for 'good', but they go way beyond that...in my system!...especially with EL12 Spezials as powers...(and DL, yes...I suspect the extra power of the 12s is preferable in that role!).

Last night it appeared I might have to get used to (quite a lot!) heavier bass and mids than I'm used to, with slightly less treble...but this morning they've toned down some (more to my taste, thankfully, and which often happens anyway). However, there is still a bit more in these areas than the EL11, which is no bad thing lol! Bass detail is still very good, with excellent control and 'tightness'.

Treble is very slightly down, but again has its own benefits - tracks that before could occasionally sound a little harsh at high listening levels are now more 'friendly', but without loss of detail and extension. This was borne out especially with Genesis's 'Duke' album, which has loads of treble, and can easily become tiring on the ears at higher levels! This also means that amp volume can be turned up, without the ears objecting so much...a good bonus IMHO.

Overall balance is very good, with the slightly more bass and mids reminiscent of the mighty ECC31 and FDD20, but without the high heat that goes with the former lol! It doesn't have the same treble 'sparkle' of the C3g, but as I said, is much better for longer term listening.

Again, like the EL11, the sound is beautifully clean and clear...a little less 'coloured' than the EL3N, and at least on a par with my mesh-plate EL3NG and Valvo EL11. In fact, at this rate, I suspect I will prefer these even to my rare mesh-plates - the Valvos giving the very slightest hum (in my system) that is unnoticeable while music is playing.

Another reason for this probable preference is that not only will they take even less power than the EL3N/EL11, but also something I only really noticed with Cassandra Wilson's 'Another Country' (HD Tracks 2013 sampler) - ie. slightly less echo due to the cross-feed implemented in our amps. This results in a tad less 'air', and a little more focus...you can't, by definition, have both lol!! Now that I've got used to the slight difference in sound this gives, I think I prefer a little less 'echo'! But this will also depend on the rest of one's gear/cables etc., of course...

Yet another aspect of the lower power draw/output of these tubes is that there's far less spike/'crack' when switching off the amp with the headphones still attached, which is another bonus. But later models than mine should have reduced spike anyway, and this doesn't really affect me as I always power everything down just from the soft on-and-off balanced mains & filter supply, plus mains regenerator (plenty of protection there also lol!!).

So all in all - as you may have gathered by now! - I am mightily impressed with this CV1052/EL32/VT25...the ST-shaped tube anyway...so far. I just hope I can get cf's adapters finished soon......

But again I must stress...in my system, and to my ears/preferences!...HAPPY LISTENING!...CJ

Hi h1,

Sounds like an impressive tube, excellent description as always!, just when it might seem there are no more new gems to be found, it sounds like you might have discovered another winner, hope the burning in continues to go well!.

 

[connieflyer]

Glad to hear how well these cv1052 tubes are sounding. Nice to see that there are still discoveries to be made that enhance our amps even now. I thought I would give initial impressions of straight vs shoulder type tubes. These appear to be equally clean and free from defects in manufacture and storage. Well, that's about it! Seriously, because of the smaller size of the the tubes, compared with the likes of the 6N7 and El11 , the shoulder type is slightly less attractive for me. Still prefer it, but the proof is in the pudding as they say. It will be interesting to see how much, if any difference can be discerned between the two tube types and their performance.

 

[hypnos1]

Hi h1,

Sounds like an impressive tube, excellent description as always!, just when it might seem there are no more new gems to be found, it sounds like you might have discovered another winner, hope the burning in continues to go well!.

Thanks Scutey...I really do believe this is yet another (unorthodox!) tube that shines in our amps lol!! Will keep y'all informed as to progress...

Glad to hear how well these cv1052 tubes are sounding. Nice to see that there are still discoveries to be made that enhance our amps even now. I thought I would give initial impressions of straight vs shoulder type tubes. These appear to be equally clean and free from defects in manufacture and storage. Well, that's about it! Seriously, because of the smaller size of the the tubes, compared with the likes of the 6N7 and El11 , the shoulder type is slightly less attractive for me. Still prefer it, but the proof is in the pudding as they say. It will be interesting to see how much, if any difference can be discerned between the two tube types and their performance.

Hi cf...well, at least you've shown the difference between the 2 CV1052! Mind you, your EL32 does look a tiny bit different to mine...wonder if different factories also differ in sound!!! Really look forward to when you can compare straight-sided with ST type...

As to their appearance, hopefully a couple of photos (in low light, so no comparison with @SnapperMusicFan 's lovely pic please!! ) might put your mind at rest. To me, at least, they look fantastic...in front of the EL12 Spezials!



But more importantly...they sound tremendous!!

 

[mordy]

Hi again H1, quite interesting find (by CF I understand) of these CV 1052. After a quick search, the “straight” version, of high quality british tubes can be found quite cheap, but the ST ones are much rarer. And I (as you) do prefer the ST version of tubes. There are no adaptors available, so keep on giving your impressions. Of course, a comparison between straight and ST versions is eagerly expected (lol) !

Speaking of ST tubes, I become aware of Mordy’s preferences for the 6F8G as a top driver in the Euforia. Found that the tube is highly regarded in some amps, and not so in others. As you know, the same tube will sound very different depending on the amp. And the Euforia is particularly demanding. The TS 6F8G round plates, “holy grail” has become too expensive, but other similar tubes like vintage NOS Raytheons, National Union or RCA VT-99, are affordable. I would go for an offer of a nice pair of NOS black glass, mil spec RCA VT-99 from 42’ vintage, what do you think Mordy ?

Hi Johnnysound,
The main reason I became interested in the 6F8G tube is that the Tung Sol variant is supposed to sound the same as the TS 6SN7 black round plate tube which is very highly regarded and unfortunately very expensive. (There is a 12V version, the 12SN7GT BRP as well, but those are also high priced.)
The TS 6F8G comes as flat plate and round plate, but according to UT they sound the same. I found a lot of four 6F8G tubes with one Tung Sol, one Raytheon, one Philco (Sylvania) and an unknown brand Radiocoin. By looking at the pictures it seemed to me that the Radiocoin could be a rebranded TS, and when I received the tubes I confirmed that it was indeed a Tung Sol tube. Both are flat plate tubes.
The sound is unique and the best word I can think of to describe it is "creamy." Wide soundstage, very good detail, even FR and that smooth creamy presentation....
The Raytheon and Philco sound good as well. As always you need to find the right power tubes to pair them with. At the time of pairing I used the Cetron 6336B but was subsequently advised that they could harm my amp (even with external power and all cooling and ventilation precautions) so I stopped using them.
My advice on getting these tubes is to try to find an inexpensive pair (not necessarily TS) and try them out. You also need special adapters which adds to the expense.
There is another tube that is very similar but with higher gain (similar to 6SN7 vs 6SL7) - the 6C8G. Not 100% sure if it is compatible with the Elise/Euforia, but not that expensive. Here is an example:
https://www.ebay.com/itm/6C8G-6F8G-...109220&hash=item4b435fdbef:g:oRwAAOSw-0xYaUv2
I haven't tried it yet but may be a good possibility....
ATM trying another driver tube that also was a predecessor to the 6SN7 - the 6N7. It is a metal tube (I am told that there is a glass envelope inside). Since it does not have any visual appeal it is very inexpensive and you can get a WW2 NOS pair for $10 or less. Testing a Ken-Rad 1944 pair now.
These tubes need special adapters as well - ECC31 to 6SN7.
If you want the TS 6F8G be patient and keep on looking for rebranded ones such as ART and Radiocoin - I paid $84 for the four tubes including shipping.
Good luck!

 

[DecentLevi]

Hey guys, a little tip - here's a website I found that's supposed to search all eBay sites in one, so you don't have to go through a dozen individual eBay sites to find your rare tubes. I found some good ST CV1052 tubez from here:
https://www.geo-ship.com/

Also, any opinions on the 12SG7? (link here)

 

[mordy]

Hey guys, a little tip - here's a website I found that's supposed to search all eBay sites in one, so you don't have to go through a dozen individual eBay sites to find your rare tubes. I found some good ST CV1052 tubez from here:
https://www.geo-ship.com/

Also, any opinions on the 12SG7? (link here)

Hi DL,
The 12SG7 is a pentode - not suitable for the FA amp unless you have a special adapter made + external power.
https://www.radiomuseum.org/tubes/tube_12sg7.html

 

[Oskari]

The CV1052 is a 1969 Blackburn Mullard. Any codes on the EL32?

 

[connieflyer]

One has 1005 BOA and the other is unmarked. This is the Phillips MiniwattEL32.

 

[Oskari]

One has 1005 BOA and the other is unmarked. This is the Phillips MiniwattEL32.

Thanks. That's Mullard as well then, made before the 1955 switch to the Philips-style code.

 

[connieflyer]

Thanks for the information. Wondered if that was the case. As always, when in doubt, ask the expert!

 

[DecentLevi]

Hey guys, for anyone on the sidelines about the VT52 / CV1052 tubes due to no adapter availability - I'm in the process of contacting a few adapter vendors to ask if they can make one out of silver. So not to fret, hang on and I'll post if we get any offers. OTOH if someone already has something like this in the pipeline, let me know so I can cancel this.

Actually I would surmise an adapter made purely out of silver including the pins would be extravagantly costly and not to mention may be too pliable so maybe losing its' shape with insertion. So perhaps silver plated copper / brass would at least be a touch better than 'standard' adapters? (in addition to silver wiring everywhere else).

 

[DecentLevi]

I got this response from Xuling, who seems to actually have silver material. But I don't know how to answer, so will one of you, or possibly @Oskari or @2359glenn be able to post an answer to this?

Hi,thank your old friend, I can make it. But please tell me which using triode pin 1/2/3 or pin 4/5/6? the Elise amp last EL3N adatper octal triode pins are parallel connect. Because EL32 tube is pentode tube, if you know this i must redesign new board agaiin.
Thanks!

Above is the diagram she provided, and this is the tube specs sheet I found for it:
http://www.r-type.org/exhib/aaa0303.htm