Anyone know about the FOTON "1540" pre 6P3S-E pre Sovtek 5881/6L6WGC?

[Nigel]

The hierarchy is allegedly as follows:

1. Late 50's Foton "1540"
2. 60's Foton 6P3S-E
3. 70's & 80's Reflektor 6P3S-E
4. 90's Reflektor Silver letter Sovtek 5881 rebrands
5. Current black letter Sovtek 5881

I knabbed a NOS pair of the 1540's from Ukraine for my new Mofo #9. The thing is magic.

Anyone ever tried these 50's/60's early units? I've heard from a few sources that the 60's Foton are preferred in guitar amps. One enthusiast noticed "...more detailed attack with a sweeter decay."

60's Fotons:

NOS "1540" coming my way:

Figure they'll match the vibes of the late 50's Mullard long plates I love so much. Keep the Silver letter 5881's for a backup.

I get why Mark Cameron has to have 550v for the thing...that higher electrical "pressure" makes things more exciting. These "5881s" are just okay in most circuits, but man they open up with the higher plate voltage.

Anyways, anyone know about these commie war toys?

 

[Michiel Kemper]

The hierarchy is allegedly as follows:

1. Late 50's Foton "1540"
2. 60's Foton 6P3S-E
3. 70's & 80's Reflektor 6P3S-E
4. 90's Reflektor Silver letter Sovtek 5881 rebrands
5. Current black letter Sovtek 5881

I knabbed a NOS pair of the 1540's from Ukraine for my new Mofo #9. The thing is magic.

Anyone ever tried these 50's/60's early units? I've heard from a few sources that the 60's Foton are preferred in guitar amps. One enthusiast noticed "...more detailed attack with a sweeter decay."

60's Fotons:

View attachment 417541

NOS "1540" coming my way:

View attachment 417542
View attachment 417543

Figure they'll match the vibes of the late 50's Mullard long plates I love so much. Keep the Silver letter 5881's for a backup.

I get why Mark Cameron has to have 550v for the thing...that higher electrical "pressure" makes things more exciting. These "5881s" are just okay in most circuits, but man they open up with the higher plate voltage.

Anyways, anyone know about these commie war toys?

Sorry for the necro bump but I was wondering if they can be used in an evh 5150 100s safely as I read their max voltage is 250v but I’m other threads people say Mike Soldano used them in his Soldano’s and that they can easily handle 500+ Max plate voltage?

I tried them shortly in my evh 5150 100s biased at 27 mA and they sound superbe but I don’t want to fry anything.

 

[Nigel]

Sorry for the necro bump but I was wondering if they can be used in an evh 5150 100s safely as I read their max voltage is 250v but I’m other threads people say Mike Soldano used them in his Soldano’s and that they can easily handle 500+ Max plate voltage?

I tried them shortly in my evh 5150 100s biased at 27 mA and they sound superbe but I don’t want to fry anything.

Yes of course you can. So long as they’re within 10ma of each other you’re good. Some mismatch yields musical asymmetrical clipping & even order harmonics.

 

[Michiel Kemper]

Yes of course you can. So long as they’re within 10ma of each other you’re good. Some mismatch yields musical asymmetrical clipping & even order harmonics.

I have a quad that is within 3 mA of each other so well matched.
What is a safe value per tube on an evh 5150 100 s? I think the amp can run 480 plate voltage

 

[Alpha Stryke]

Modern amps [post 1985] you'd be better sticking with post 1980-ish + vacuum tubes.
1950's Soviet shit is dicey and not always as advertised.

 

[Nigel]

I have a quad that is within 3 mA of each other so well matched.
What is a safe value per tube on an evh 5150 100 s? I think the amp can run 480 plate voltage

The amps run low screen resistors (100 ohm) and low idle bias so they are more percussive in terms of right hand picking dynamics at volume.

40-70% of 25 watts is good.

Silver letter Sovteks are rebranded military production and better than the black letter ones. If you’re got the funds, get a box of them and find the lowest current draw (plate AND screen) as those will be the strongest. Matching is marketing.

Foton 1540 are the best, followed by Foton 6P3S-E, followed by Saratov (Reflektor) 6P3S-E which are silver letter Sovtek 5881/6L6WGC.

 

[Michiel Kemper]

I have the Saratov 6p3s-e’s and they sound really nice at 25 mA approx per tube. Not as bold as the JJ 6l6gc but much more mid details

 

[Michiel Kemper]

Modern amps [post 1985] you'd be better sticking with post 1980-ish + vacuum tubes.
1950's Soviet shit is dicey and not always as advertised.

I understand but I’ve read that Mike Soldano uses them in his SLO’s and I have seen them in Mesa boogie dual/triple rectifiers and read they are virtually indestructible and they sound really nice.
In this all the JJ 6l6gc’s sound a bit too bold and off for some reason to me (new matched quad)

 

[Alpha Stryke]

Modern 5881's aren't really true "5881's" at all.
M. Soldano retired in 2018. He's always ever used "Sovetek" brand tubes in his amps and thats what he "recommends".
Suit yourself.

 

[Nigel]

I have the Saratov 6p3s-e’s and they sound really nice at 25 mA approx per tube. Not as bold as the JJ 6l6gc but much more mid details

Bruce Zinky puts the Silver letter OG’s in his amps. They always sound better than the tig weld plate design of the New Sensor production version with the black letters.

A friend was the biggest Soldano dealer in the USA for a while and even he didn’t know about the difference. It’s stark, if not night and day. The Fotons are even better!

I love the JJ 6L6GC but they can be tubby. Their KT77 is the way up from Sovtek 5881’s if your PT can handle the heater current.