I need a advice on selecting new tubes for my 845 SET amp. I need to get 4 new small signal tube for the amp. The tubes that I use now is 6SN7 from Sophia Electric. I think the tubes are a bit pricey and would like to find some less expensive tube for replacement.
Now I really like the sound of the Sophia Electric, but maybe there is other alternatives, that I don't know about. I have been looking at the Shuguang Treasure CV181-Z, but it draws 900mA to the heating filament, wish is 50% more than a normal 6SN7.
Any advice will bee appreciate.
Now I really like the sound of the Sophia Electric, but maybe there is other alternatives, that I don't know about. I have been looking at the Shuguang Treasure CV181-Z, but it draws 900mA to the heating filament, wish is 50% more than a normal 6SN7.
Any advice will bee appreciate.
Hop on eBay and find some NOS tubes, although I may draw the scorn of the Snake Oil crowd, I really like the Russian equivalent tubes, well made, not microphonic unless under extremely high vibration conditions, but they are GT type, rather than GTA/GTB types, so watch the dissipation and make sure they will work in your circuit. They measure great, and sound excellent in a competent circuit.
GE or RCA are great over here in the US, and easy to find for sure.
I have had longevity and matching issues with most newer audiophile type tubes, and don't use Chinese tubes due to QC issues... NOS and/or Milspec only for me.
GE or RCA are great over here in the US, and easy to find for sure.
I have had longevity and matching issues with most newer audiophile type tubes, and don't use Chinese tubes due to QC issues... NOS and/or Milspec only for me.
If you're in the mood to modify your amp, the 2C22 is basically 1/2 of a 6SN7, with top caps for the grid and plate. They are very inexpensive ($5-10 per tube) and available NOS in legendary US brands such as RCA and Ken-Rad.
I find them to sound better than any 6SN7 I've ever heard. There are some reviews on the various audio sites - haven't heard a bad word about them.
I modded my Supratek preamp to use them in place of the stock 6SN7s with a nice improvement in clarity (see picture attached). I was able to get by with only one section since I didn't need the gain - for an amp you might need two per 6SN7 replaced.
I've since moved on to a DIY 26 preamp, but the Supratek sounded good too, though not is a league with the 26.
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New Sensor's "reissue" TungSol 6SN7 is good.
If you build or buy adapters made from Loctal Sockets and Octal plugs, 7N7s are an "affordable" alternative to costly NOS. With few exceptions, regardless of branding, Loctal tubes were made by Sylvania at Emporium, PA. NOS Sylvania 6SN7s are highly regarded and the same "cages" went into both the Octal and Loctal varieties.
If you build or buy adapters made from Loctal Sockets and Octal plugs, 7N7s are an "affordable" alternative to costly NOS. With few exceptions, regardless of branding, Loctal tubes were made by Sylvania at Emporium, PA. NOS Sylvania 6SN7s are highly regarded and the same "cages" went into both the Octal and Loctal varieties.
Hi Eli - do you know if sylvania vt-231's had the same internals as 7N7's?
Just curious - a few years back, I aquired a nice big lot if vt-231's for a decent price. They were my reference 6SN7's. Today they sell for too much though, and I really find the russians a seriously decent alternative.
Ian
Just curious - a few years back, I aquired a nice big lot if vt-231's for a decent price. They were my reference 6SN7's. Today they sell for too much though, and I really find the russians a seriously decent alternative.
Ian
Another tip is to look for 6sn7's in a 'coin' base. You can often get these super cheap, but they can be excellent. It seems that Audiophools shun coin base tubes. 😀
It depends on the time frame of manufacture. No way would Sylvania have used different "guts", if they were making VT-231s and 7N7s simultaneously. Profit has always mattered.
Chinese, cheap, and crap are all spelled starting with the letter "C".
NOS is probably your best bet. Many early televisions in the USA used the 6SN7 as a vertical amplifier...
Good luck..
crap. I just looked on that auction site and see that even NOS coin based 6sn7's are commanding real money.
Best bet is seriously with the Russian 6N8S...
Best bet is seriously with the Russian 6N8S...
JJ started producing 6SN7 tubes at reasonable price. I have no experience of them though....
Magz is spot on with the 2C22, best SN7 variant there is.
Eli is also spot on with the 7N7 which are cheap plentiful and use the same guts depending on time of manufacture as the Sylvania 6SN7. All are good if you clean the pins.
Another Loktal type is the 7AF7. Both this and the 7N7 are very good value and kick the snot out of any new production stuff. Just be sure to clean the pins properly, buy an adapter and good to go.
The Russian 6N8S is also pretty damn good. For the money I would go with these but if you have the skills to rewire the sockets and add another socket per SN7 then 2C22 and never look back.
Cheers
Matt
Eli is also spot on with the 7N7 which are cheap plentiful and use the same guts depending on time of manufacture as the Sylvania 6SN7. All are good if you clean the pins.
Another Loktal type is the 7AF7. Both this and the 7N7 are very good value and kick the snot out of any new production stuff. Just be sure to clean the pins properly, buy an adapter and good to go.
The Russian 6N8S is also pretty damn good. For the money I would go with these but if you have the skills to rewire the sockets and add another socket per SN7 then 2C22 and never look back.
Cheers
Matt
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At a previous employer, we used hundreds of Chinese 6SN7 (brown base) with excellent results. I believe most of the tubes we sourced were actually made in the late 80s or early 90s, for what that is worth.
I never cared much for the sound of the 'original' Russian (Reflector?) 6SN7, but they were stable. The later Russian EH 6SN7 (different construction) were a total nightmare - they had a serious failure rate which we ultimately assigned to cathode contamination during assembly. This was seriously for the suck, as they sounded really great +if+ and +when+ they were working correctly. But the dang things would arc-over and take out resistors etc.
As I understand it, that EH 6SN7 has been re-worked and is now a reliable tube. As to which "brand" it is currently sold under, if any, I cannot say. But when they were new, they were just total crap - asking for damage to your equipment.
For NOS USA stuff, the 80s production (black base, green / blue print) Phillips / Sylvania are excellent. USA RCA coin-base 6SN7 are fine in my view as well, despite some opinions. This is one of the great things about the 6SN7 - there are numerous choices out there, and don't be fooled, as there are still +plenty+ of NOS and used OS tubes out there. Common as a shoe.
I never cared much for the sound of the 'original' Russian (Reflector?) 6SN7, but they were stable. The later Russian EH 6SN7 (different construction) were a total nightmare - they had a serious failure rate which we ultimately assigned to cathode contamination during assembly. This was seriously for the suck, as they sounded really great +if+ and +when+ they were working correctly. But the dang things would arc-over and take out resistors etc.
As I understand it, that EH 6SN7 has been re-worked and is now a reliable tube. As to which "brand" it is currently sold under, if any, I cannot say. But when they were new, they were just total crap - asking for damage to your equipment.
For NOS USA stuff, the 80s production (black base, green / blue print) Phillips / Sylvania are excellent. USA RCA coin-base 6SN7 are fine in my view as well, despite some opinions. This is one of the great things about the 6SN7 - there are numerous choices out there, and don't be fooled, as there are still +plenty+ of NOS and used OS tubes out there. Common as a shoe.
My very limited experience of 6sn7 are both Chinese. One is the cheap tube that came with the tube, while not great, I wouldn't call it crap. Those are silver based.
However, my other more expensive tube, Psvane CV181 T mk2, is very very good, from top to bottom. Changing from the cheap Chinese tube to the Pvsane is feels like completely changing to a different much better preamp.
I will getting a B65 (suppose to be one of the best 6sn7 variant) from a friend later to compare to the Psvane.
Anyways, at least the Psvane packaging makes it feels like a premium tube (nothing to do with sound quality, of cause) . I attach an image of the cards with serial numbers.
However, my other more expensive tube, Psvane CV181 T mk2, is very very good, from top to bottom. Changing from the cheap Chinese tube to the Pvsane is feels like completely changing to a different much better preamp.
I will getting a B65 (suppose to be one of the best 6sn7 variant) from a friend later to compare to the Psvane.
Anyways, at least the Psvane packaging makes it feels like a premium tube (nothing to do with sound quality, of cause) . I attach an image of the cards with serial numbers.
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GE 6sn7gta tubes are one of my favorite low cost ones. They have 450v plate rating and controlled heater warm up too. In the vacuum tube valley 6sn7 shoot out they rated very high. They are still passed up by the public so at the price they usually go for still a good bargain.
Psvane= fancy box, fancy glass/base, better QC. Still Chinese and way overpriced compared to comparable quality NOS tubes, which will usually run 1/3~1/4 of the price.
Fancy certification and serial numbers don't change the origins...
I've played with Psvane tubes, and found them on par with most other current commercial offerings, but with worse THD measurements usually... Their 300B tend to be very variable and prone to runaway in my experience. The QC isn't any better, they don't always behave as they should, sections are often grossly mismatched, I wouldn't trust them long term in anything running near any reasonable dissipation...
Never again will I use Chinese tubes in any of my gear. Too much repair jobs and issues with them when I come across them. But, a fool and his money, or so they say 😱
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My experience with eastern 6SN7s is limited to the 90s, but similar to the observations of Legendre:
The Chinese version with the metal base is a great tube to replace. Whatever you replace it with, will be an approvement 🙄. It works, but sounds bland and boring.
The Sovtek that became available back then sounded quite better, although not on the same level as western NOS.
The big surprise was a (1) Chinese brown base 6SN7. That one was actually pretty good.
Since I have enough western 6SN7s and ECC32s for personal use, I haven't looked at recent production anymore.
If I needed to get a replacement now, I'd look for NOS equivalents like 7N7, 6CG7.
The Chinese version with the metal base is a great tube to replace. Whatever you replace it with, will be an approvement 🙄. It works, but sounds bland and boring.
The Sovtek that became available back then sounded quite better, although not on the same level as western NOS.
The big surprise was a (1) Chinese brown base 6SN7. That one was actually pretty good.
Since I have enough western 6SN7s and ECC32s for personal use, I haven't looked at recent production anymore.
If I needed to get a replacement now, I'd look for NOS equivalents like 7N7, 6CG7.
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