Differences Between Chinese and Russia 6AS7 Tubes

rhopkins

New Member
Apr 29, 2010
45
0
0
#1
Hi,

This one actually comes from another member of my listening group. He is comparing the current Chinese version to the Russian version of the 6AS7. He has noticed that the construction of the tubes varies slightly with a different base and other minor construction observations. He is currently testing a batch of them to see if one is different from the other and if any generalizations can be made.

Has anyone out there formed any opinions on the differences between the tubes? We have noticed that the pricing of the Russian tubes has been increasing. Not entirely sure why.

Any thoughts?
 

rhopkins

New Member
Apr 29, 2010
45
0
0
#3
I've heard that they are getting better and I've also heard that the price remains fixed whereas the Russian tubes fluctuate a bit more. Supply of Russian tubes is a little patchy too, at least locally.
 

rhopkins

New Member
Apr 29, 2010
45
0
0
#4
We have been doing some testing with both types of tubes and there is little difference. If anything, the Chinese tubes appear to be more consistent and therefore, may be of superior quality. They also sell for less money around here so I'm hard pressed to see a downside...
 

Detlof

Member Sponsor
Nov 5, 2015
307
0
0
#5
Five years have passed since the last entry, but here I go with my first post no less:

In my experience the Ruskies seem to last longer in spit of their inconsistencies mentioned above. Prices have varied in the last years, but with the Rouble being low can be found fairly cheaply on Ebay from Russia or the Ukraine.
 

ferrox

Well-Known Member
Jun 16, 2016
255
40
113
Jakarta, Indonesia
www.primes.asia
#6
I have just replaced all my Chinese tubes with Svetlana Wing C 6as7g..amazing in the only word for the new tubes..

Five years have passed since the last entry, but here I go with my first post no less:

In my experience the Ruskies seem to last longer in spit of their inconsistencies mentioned above. Prices have varied in the last years, but with the Rouble being low can be found fairly cheaply on Ebay from Russia or the Ukraine.
 
Dec 16, 2018
57
30
20
76
Phoenix, Arizona USA
#7
I have just replaced all my Chinese tubes with Svetlana Wing C 6as7g..amazing in the only word for the new tubes..
I've had my M-60/3.3s since 2016 and have 'always' used Russian Winged-C 6H13Cs in it.. When I bought the amps, I bought a carton (25 tubes) thru eBay from someone in a mddle-European country, the name of which I can't read on the return address; I still have 17 of those.. Speaking of prices going up, the per-tube price of that carton was only about $9 each!

A few days ago I bought a pair of MA-1/3.1s full of Chinese tubes, so I started looking at 6AS7s again.. I currently have enough Winged-Cs to equip the MA-1s, but one can never have too many vacuumtubes, huh! ;) Yesterday I bought about 20 from 4 sellers on eBay (for an average of around $14 each, delivered), so I'll have some spares.. I still have plenty of those gorgeous-sounding Tung-Sol oval-plate 6SN7GTs, so I'm well equipped.. The amps aren't predicted to arrive until Jan. 08; good thing my M-60s sound excellent. :)

With all dampers on_1500w.jpg
FWIW, I use Herbies tube dampers on three 'N7s and four output tubes (per amp) and will buy more output-tube dampers soon.. I also use Herbies GrungeBuster feet (the little white things) on my six VPI Magic Bricks and many plain-steel blocks...and also Herbies Tenderfoots under virtually all my equipment.
 
Last edited:
May 30, 2010
16,762
1,594
720
Portugal
#8
I've had my M-60/3.3s since 2016 and have 'always' used Russian Winged-C 6H13Cs in it.. When I bought the amps, I bought a carton (25 tubes) thru eBay from someone in a mddle-European country, the name of which I can't read on the return address; I still have 17 of those.. Speaking of prices going up, the per-tube price of that carton was only about $9 each!

A few days ago I bought a pair of MA-1/3.1s full of Chinese tubes, so I started looking at 6AS7s again.. I currently have enough Winged-Cs to equip the MA-1s, but one can never have too many vacuumtubes, huh! ;) Yesterday I bought about 20 from 4 sellers on eBay (for an average of around $25 each, delivered), so I'll have some spares.. I still have plenty of those gorgeous-sounding Tung-Sol oval-plate 6SN7GTs, so I'm well equipped.. The amps aren't predicted to arrive until Jan. 08; good thing my M-60s sound excellent. :)

View attachment 47120
FWIW, I use Herbies tube dampers on three 'N7s and four output tubes (per amp) and will buy more output-tube dampers soon.. I also use Herbies GrungeBuster feet (the little white things) on my six VPI Magic Bricks and many plain-steel blocks...and also Herbies Tenderfoots under virtually all my equipment.
Look for Ralph recommendations on 6AS7's - we should get only types that are self-fused.
 

tima

Industry Expert
Mar 4, 2014
1,792
1,291
390
the Upper Midwest
#10
As you may already know, the 6SN7 can make a genuine difference for Atma-Sphere amps and preamps. There are certain positions that make a bigger impact than others so you don't need every tube to be top notch - check with Ralph on which positions are more significant for the various models.

Compared to some, the Tungsols are okay and usually fairly quiet. NOS have been hard to find for a while, but the search can be worth it. Here are some that I liked most:
Ken-Rad VT-231 especially 1942 and '43.
Sylvania VT-231 especially 1952 vintage, 3-hole green labels
RCA VT-231 - grey glass
The real problem is once you hear the difference, it's hard to go back.

The best 6SN7 source for me was Andy Bowman at Vintage Tube Services in Michigan. His Web site is a wealth of information, but for selection and ordering you need to call him. Top quality tubes. I'd be v. v. cautious about e-bay.

I always used Svetlana 6SN7s.
 

Sablon Audio

Industry Expert, VIP Donor
May 22, 2015
898
508
283
#11
Over a decade ago, I already found the chinese Black Treasure ‘cv181’ to be sonically competitive with my smoked glass Sylvania and RCA VT231 / 6sn7. Am sure the Psvane options have improved a fair bit since that time whilst the cost and availability of the NOS will have become more challenging. The Russian Melz 1578 drilled plate is another great 6sn7 option.
 

Avidlistener

Well-Known Member
Feb 19, 2013
30
0
81
#12
I haven't replaced tubes in MY MA-1 for several years. How do I know if the 6sn7's need replacement . Some are vintage RCA - But if I wanted to retube - which do people suggest for new reasonably priced tubes.

HAs anyone tried the expensive CV181 ? A pair on Amazon is about $160.

Also anyone compared the 3.1 to the 3.3 revision ? I have the 3.1
 

Atmasphere

[Industry Expert]
May 4, 2010
949
157
455
St. Paul, MN
www.atma-sphere.com
#13
I haven't replaced tubes in MY MA-1 for several years. How do I know if the 6sn7's need replacement .
If the driver tube is getting weak you may find the DC offset drifts a bit as the amp warms up. It really should be pretty stable.

If the voltage amplifier tubes are getting weak the amp will start to sound a bit sleepy- less vivacious. Its a good idea to keep a known good tube on hand to swap in if a tube is suspected. You'll know right away if something's up.
 

ferrox

Well-Known Member
Jun 16, 2016
255
40
113
Jakarta, Indonesia
www.primes.asia
#14
Just make sure to correctly identify which are the input tubes. My MA-1 came with long chassis and before I started playing them, our local tech marked the position of these input tubes properly. I sent these pair to factory for an upgrade to mk3.3 version.

I then replaced the stock input tubes with NOS 6sn7 I purchased from Andy Bouwman. After about a year, the R channel tend to hum and I had to tap the 6sn7 tubes especially number 1 and 2 from the left.

I asked the local tech to check and fix the issue and voila! He found out that the position and number of input tubes have been changed. It was 2 tubes and now become 3. The position was on the 3rd and 4th, now become 1st, 2nd, and 3rd.

Luckily, I have just got newly arrived 6 Sylvania NOS and closely matched from Andy. Once I tried them on, it has very obvious improvement. So the point is, do try to understand which is the input tube and replace it with better 6sn7's.
 

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