[bcowen]

Well fortunately I did not seem to smoke the amp! I am familiar with Cyrillic but these letters seem Roman. I have attached a picture. Tubes are difficult to photograph!

The 6H7C has a different pinout than the 6SN7 (or 6N8S) which is why the tube didn't work at all. Glad nothing was fried!

 

[bcowen]

Fotons are the reason I started replacing the solder in 6sn7 tube pins. People claimed they needed a super long burn in and I thought that a little crazy so I conducted some experiments with the pins, new solder, and a long test cycle. To the best of my recollection @bcowen who is the resident Foton expert went back and checked some tubes that he had applied the long burn in time to and found they were still acting like they did prior to said burn in. Bill can answer this better but the best Fotons are from the fifties and have ribbed plates. 1952-1957 I think but Bill can answer that better than me.

1951 through (early) 1956 were the years of the ribbed plates. Sometime during 1956 they changed to the smooth plate which was carried forward from that point. I'm also assuming 1951 was the first year ('cause I have some), and I have yet to see anything dated 1950 or earlier.

 

[bcowen]

@Paladin79 @bcowen - Hi Tom & Bill, yes long time I know! I'm back and rolling tubes again in another SLP-98......LOL

What did I miss??

Welcome back! Another SLP-98, huh? I have to say that the '98 was my favorite of the (several) Cary preamps I owned. I never had a chance to hear an SLP-05 though...

 

[Paladin79]

1951 through (early) 1956 were the years of the ribbed plates. Sometime during 1956 they changed to the smooth plate which was carried forward from that point. I'm also assuming 1951 was the first year ('cause I have some), and I have yet to see anything dated 1950 or earlier.

I knew you would be able to answer that better than me. I pay less attention to Fotons.

 

[bcowen]

I knew you would be able to answer that better than me. I pay less attention to Fotons.

You're the Melz guru. I could never afford Melz.

 

[Paladin79]

You're the Melz guru. I could never afford Melz.

I saw one decent one on Ebay going for $250 lol, I got some rare ones for $35 or less before they disappeared. Hardly a day goes by that I am not turning down offers.

 

[g0ldl10n]

For arguments sake, let's assume the amp is able to handle the additional amperage.

Amp is 1x 6SN7 -> 1x 6AS7

What would be the effect if one made a dual 6SN7 adapter -> 1x 6SN7 and ran dual 6SN7s? Would this end up increasing the amplification factor to unsuitable levels, resulting in similiar undesirable effects on SQ when running a high mu tube in 6SN7 socket?

 

[Paladin79]

For arguments sake, let's assume the amp is able to handle the additional amperage.

Amp is 1x 6SN7 -> 1x 6AS7

What would be the effect if one made a dual 6SN7 adapter -> 1x 6SN7 and ran dual 6SN7s? Would this end up increasing the amplification factor to unsuitable levels, resulting in similiar undesirable effects on SQ when running a high mu tube in 6SN7 socket?

Now there’s a bad idea.

 

[g0ldl10n]

Now there’s a bad idea.

Okay, but what would happen, and why? I am not an expert, just someone willing to "adventure", and its been very rewarding so far.

Ive come across so much "that tube would certainly sound horrible running in place of 6SN7" across the web, but venturing out ive found many many tubes people discount, including strapping hexodes and beam tetrodes as triodes in that 6SN7 socket, that sound quite a bit better (and are far cheaper I might add) than any 6SN7 and even 5692 tubes ive heard.

 

[sam6550a]

Now there’s a bad idea.

Plus, the stage gain will not change.

 

[Mr Trev]

Okay, but what would happen, and why? I am not an expert, just someone willing to "adventure", and its been very rewarding so far.

Ive come across so much "that tube would certainly sound horrible running in place of 6SN7" across the web, but venturing out ive found many many tubes people discount, including strapping hexodes and beam tetrodes as triodes in that 6SN7 socket, that sound quite a bit better (and are far cheaper I might add) than any 6SN7 and even 5962 tubes ive heard.

Well, my first thought… and bear with me, I be drinking, is that the heater draw of 2 6sn7 is way higher than the amp design intended and would the power supply be able to handle it without going Chernobyl on you. Dual 6j5 on the other hand would be perfect - being ½ a 6sn7 in the first place

 

[Mr Trev]

1951 through (early) 1956 were the years of the ribbed plates. Sometime during 1956 they changed to the smooth plate which was carried forward from that point. I'm also assuming 1951 was the first year ('cause I have some), and I have yet to see anything dated 1950 or earlier.

Fun fact… 1956 was the year of Khrushchev's "we will bury you" speech. Coincidence????

 

[bcowen]

Fun fact… 1956 was the year of Khrushchev's "we will bury you" speech. Coincidence????

Well, I guess if the ribs were for pleasure, removing them was the first act of aggression.

 

[triod750]

For arguments sake, let's assume the amp is able to handle the additional amperage.

Amp is 1x 6SN7 -> 1x 6AS7

What would be the effect if one made a dual 6SN7 adapter -> 1x 6SN7 and ran dual 6SN7s? Would this end up increasing the amplification factor to unsuitable levels, resulting in similiar undesirable effects on SQ when running a high mu tube in 6SN7 socket?

This wild idea deserves a technical explanation to why it is bad, even if it is bad. This is a resourceful an helpful community. Unfortunately I'm not the right person to give this explanation. I would suggest using one 6N7 in adapter or a pair of 6C4/EC90/CV133. Or maybe a pair of EL42. But this lion is asking about 6SN7...

 

[g0ldl10n]

This wild idea deserves a technical explanation to why it is bad, even if it is bad. This is a resourceful an helpful community. Unfortunately I'm not the right person to give this explanation. I would suggest using one 6N7 in adapter or a pair of 6C4/EC90/CV133. Or maybe a pair of EL42. But this lion is asking about 6SN7...

I would very much appreciate a technical explanation as to the reason(s) (other than the additional amperage load) this would be a bad idea, and what might the results be. Also, was interested in the general pros/cons on a technical level, because I was thinking further into this in regards to other tubes, such as trying a dual 6922 -> 6SN7 which would only pull 0.6 amps total, as 6922 has a heater current of 0.3a each, which would be 100% safe as far as I know.

I guess I am just wondering if there would be any type of benefit to this - would dual 6922 in 6SN7 socket even sound different than just a single 6922 (assuming all tubes are same and matched) in the 6SN7 socket?

I think I am just gonna have to give these things a try and see what the outcome is.