[mordy]

AFAIK the -ev extension means military grade i.e. manufactured to stricter specs and made to last longer.

Regular tubes are supposed to last 3000 hours; EV tubes 5000 hours and DR tubes 10000 hours. IR tubes have a shorter rated life span, but probably predicated on severe use in military applications. All the above designations only apply to Russian tubes.
For all practical purposes I doubt that anyone will wear out these tubes in their amps.

 

[sevenbrides]

I see plenty of 6j1p russian tubes available online for cheap price and they are voshkods. Then there is this 6j1p-ev tubes which are expensive. Are they same or two different tubes? They looks physically identical to me.

I not many used the Little Dot as a headphone amp, but as a buffer I can say that the 6j1 Chinese stock tubes are not bad but they have less bass with important mid-highs The Russian 6J1Ps improve the bass, the detail and the soundstage and finally the 6jP- EV, which have versions with richer platinum and gold grids (in traces ..), have a warmer and more full-bodied response with powerful bass, very natural voices and crystalline and airy highs, never harsh. Also soundstage and dynamics are very good. I thought they were the best tubes in the 6J1 family.
Audiofanboy and others put the 6J1P-EV in the A or B category. I'm curious to try the A +++ and A ++ category tubes I ordered.

 

[BreadFi]

I've owned a LD MKIII for many years now, and purchased a 1+ hybrid a couple of months ago to try some tubiness with my low impedance 32 ohm DT770 (and for some volume to my DT880s in the lounge room).
It's interesting how the tubes tone translates across both amps - seems kind of obvious, but it sounds how you'd expect a hybrid tube/solid state amp to.
I'm using my preferred GE JAN 5654 (fat sounding and gives rock snares a nice crack), the stock 6j1 sounded pretty good (clean, not so much bottom end though). I still don't like the Mullard 8100's with the Beyers (highs not so smooth).
I'm a bit disappointed with how it plays with the DT770's though, bass becomes very loose. Not sure if it's just the characteristic of the tube or if the amp is still too high impedance for them (doesn't seem particularly loose on the 250ohm '880's). Would anyone happen to know the output impedance of the 1+?

 

[cheungtsw]

I am torn between MK3 and Valhalla 2.
Seems Valhalla 2 has much less choices in tubes but some says Val 2 is a much better amp.

Any opinions?

ps. I am currently using the FX audio tube 3 with GE JAN5654W as tube buffer.

 

[sevenbrides]

A matched pair of GE 6AU6 (rank A ++ for this thread's experts) has arrived. 4 hours of burn and then spectacular sound!
Powerful and tight bass, high mid-range presence, very detailed highs, crystal clear and airy.
Excellent dynamics and soundstage. Absolutely awesome!
But after a bit of listening the voices also seem too forward and overbearing and the general tone is very engaging but sometimes too aggressive.
They are certainly the best for headphones (or amp + boxes) rather relaxed but with my components after a while a bit of listening effort comes.
Of course, they are NOS tubes never used and, after only 4 hours of burning, these are only my initial impressions.
If the GE 6AU6 (as I hope) will calm down a bit we are very close to the top, but for now I have decided to rest a bit by switching the output of my audio DVD player to other less aggressive buffers. Then I will resume the burning (with great pleasure).

 

[sevenbrides]

I am torn between MK3 and Valhalla 2.
Seems Valhalla 2 has much less choices in tubes but some says Val 2 is a much better amp.

Any opinions?

ps. I am currently using the FX audio tube 3 with GE JAN5654W as tube buffer.

Also have an FX tube 03 (with controls) and FX tube 01 in my buffer collection.
They sound pretty good, but to improve them I replaced the stock 6j1 Chinese tubes with the Russians 6j1P-EV
which in other buffers (including Little Dot MKii) work wonders.
Instead with both buffers FX did not change practically nothing.
So I put the stock tubes back!
If you want to buy an inexpensive but absolutely exceptional buffer I recommend the Matisse Guanzo by mounting two GE 5670 tubes.
It's a bomb with a sublime sound! Better than buffers that cost hundreds of euros (which I tried)!

 

[nofacemonster]

I not many used the Little Dot as a headphone amp, but as a buffer I can say that the 6j1 Chinese stock tubes are not bad but they have less bass with important mid-highs The Russian 6J1Ps improve the bass, the detail and the soundstage and finally the 6jP- EV, which have versions with richer platinum and gold grids (in traces ..), have a warmer and more full-bodied response with powerful bass, very natural voices and crystalline and airy highs, never harsh. Also soundstage and dynamics are very good. I thought they were the best tubes in the 6J1 family.
Audiofanboy and others put the 6J1P-EV in the A or B category. I'm curious to try the A +++ and A ++ category tubes I ordered.

Today I received the matched pair of Mullard CV8100 I ordered a couple of weeks back. I totally fell in love with the Mullard house sound within the first few minutes of listening. Probably the best sound I ever heard in my life. Laid back, warm, so smooth I haven't got the right words to describe it. Like many audiophiles and experts say the sound is something personal, it is different from person to person and I guess I just found the sound I am looking for.

Right now I am listening to "Gerry Mulligan - The Art of Gerry Mulligan (Final recordings)",

I think my journey to find the perfect sound that could please me 100% has come to an end with Mullards on the MKII.

 

[T3RIAD]

Does anyone know if the Little Dot 1+ and the MK III SE use the same tubes?

I'm currently using the 1+ with WE408A tubes and love the sound, but I'd like to upgrade to something with balanced output. The MK III SE is also a hybrid amp, so it looks like it might be what I need.

Would the same tubes work?

 

[BreadFi]

Does anyone know if the Little Dot 1+ and the MK III SE use the same tubes?

I'm currently using the 1+ with WE408A tubes and love the sound, but I'd like to upgrade to something with balanced output. The MK III SE is also a hybrid amp, so it looks like it might be what I need.

Would the same tubes work?

1+ (and regular OTL mk III) uses 7 pin 5654 etc, looks like the III "SE" uses 9 pin tubes.

 

[abman]

I see plenty of 6j1p russian tubes available online for cheap price and they are voshkods. Then there is this 6j1p-ev tubes which are expensive. Are they same or two different tubes? They looks physically identical to me.

Yes they are the "same" by the overall construction, but there are some differences:

The prefixes on the Russian tubes means (Google translate):
V (Cyrillic "B") - tubes of increased reliability and mechanical strength;
D (Cyrillic "Д") - tubes of special durability with guaranteed operating time of more than 10,000 hours;
E - tubes of increased durability with guaranteed operating time of more than 5000 hours;
I (Cyrillic "И") - the tubes intended for work in the pulse mode; characterized by increased emissivity of the cathode;
K - tubes with high vibration resistance;
R (Cyrillic "Р") - tubes of special reliability and mechanical strength;
So we can understand like:
- EV (Cyrillic "-ЕB") - tubes of increased reliability, mechanical strength and durability (5000 h);
- DR (Cyrillic "-ДР") - tubes of special reliability, mechanical strength and durability (10000 h).
...and so on

 

[nofacemonster]

Yes they are the "same" by the overall construction, but there are some differences:

The prefixes on the Russian tubes means (Google translate):
V (Cyrillic "B") - tubes of increased reliability and mechanical strength;
D (Cyrillic "Д") - tubes of special durability with guaranteed operating time of more than 10,000 hours;
E - tubes of increased durability with guaranteed operating time of more than 5000 hours;
I (Cyrillic "И") - the tubes intended for work in the pulse mode; characterized by increased emissivity of the cathode;
K - tubes with high vibration resistance;
R (Cyrillic "Р") - tubes of special reliability and mechanical strength;
So we can understand like:
- EV (Cyrillic "-ЕB") - tubes of increased reliability, mechanical strength and durability (5000 h);
- DR (Cyrillic "-ДР") - tubes of special reliability, mechanical strength and durability (10000 h).
...and so on

Thanks for the clarification. So it doesn't effect the sound quality right? Just longevity.

 

[abman]

Thanks for the clarification. So it doesn't effect the sound quality right? Just longevity.

I have not yet had the opportunity to compare directly, but I think there "may be" difference (thinking logically there should be some differences in construction, for example - cathode to provide 5,000 working hours (-EV version) instead of 2000 (original 6J1p)) - your ears will tell you exactly

 

[mordy]

The DR versions of the 6N6P (6H30P etc) are priced very high, and there are some differences in how they sound, but not justifying the high price IMHO.
The IR version of the 6N6P sounded the best of the less expensive ones.
For all practical purposes I can't remember wearing out a tube from use. I have heard of some people using other kinds of tubes for 10 years before they replaced them.
Some of the ratings regarding vibrations resistance etc applies to military applications (tanks, jets) and not the regular situation in somebody's home. But more support rods and more rugged construction could impact the sound - less microphonics etc.

 

[abman]

Hi DonLuca,

Please let us know if there is a difference with the gold 6J1p-EV compared to the non-gold variants once they arrive.
.......................................
Regarding the OTK symbol, this is what I found:

[size=medium]"The label OTK on the surface of the tube bulbe means that
it is a Russian tube was gone under a military test.
OTK is an abbreviation in Russian language.
It means: it was controlled by a Military organization.[/size]"

We have something similar on US made tubes made to military specifications: "JAN" which stands for "Joint Army and Navy". Sometimes US made tubes have a W after the designation, such as 6AK5W. The W stands for more rugged construction, although I do not know what this specification actually means.

Someone may have written about this before, but however I will clarify what I know from here, on this side of the iron curtain:
1) Inside the tubes is NOT a gold grid (!!!). An alloy of gold and platinum is applied to the grid. In the amount of 0.259 mg. Sorry guys that so not much
2) The fact described in clause 1. is part of the technological requirements of the production process of ALL AND ANY TUBE 6ZH1P-EV at all plants throughout the USSR. So it could not be produced these tubes WITH GOLD grids (!!!). THEY ALL HAVE GOLD AND PLATINUM ALLOY ON A GRID. And other options for these tubes simply can not be.
So forgive me guys, but it looks like you were wasting your time listening to tubes with a “golden grid” and “not a golden grid”.
Yes, there is certainly a difference in the sound, but perhaps for other reasons, independent of the grid material, since it is the same for everyone.
...as I know....
may be later I will add some

 

[mordy]

As far as I know GE was the inventor of the gold grid, but they never made any effort to use it in advertising. The amounts are minuscule.
My impression of the OTK stamp, which is always followed by a number, is that it a quality control stamp followed by an inspector number.