[Ripper2860]

None, I'm afraid. The farthest afield I've gone with my 6SN7 amps is 7N7, 12AT/U7, ECC40, and 2C51s. Yeah -- I like to play it pretty safe.

 

[Isaacc7]

None, I'm afraid. The farthest afield I've gone with my 6SN7 amps is 7N7, 12AT/U7, ECC40, and 2C51s. Yeah -- I like to play it pretty safe.

I’ve thought about trying the 2c51 mostly because it’s the one chance I’ll ever have of using a Western Electric tube

 

[sam6550a]

None, I'm afraid. The farthest afield I've gone with my 6SN7 amps is 7N7, 12AT/U7, ECC40, and 2C51s. Yeah -- I like to play it pretty safe.

Amp designers pick the tubes that they want to use and design their topology around that tube's characteristics. When you substitute a different tube, with different electrical characteristics, you get different results from what the designer expected or obtained. Sometimes you think it sounds better [YRMV], sounds worse, or produces large volumes of smoke, none of which the designer expected. Unless you are an experienced designer, don't stick your finger in this tar baby. A little knowledge can be fatally dangerous.

 

[Isaacc7]

Amp designers pick the tubes that they want to use and design their topology around that tube's characteristics. When you substitute a different tube, with different electrical characteristics, you get different results from what the designer expected or obtained. Sometimes you think it sounds better [YRMV], sounds worse, or produces large volumes of smoke, none of which the designer expected. Unless you are an experienced designer, don't stick your finger in this tar baby. A little knowledge can be fatally dangerous.

It’s important to check to make sure your amp can handle whatever tube you are interested in trying, don’t go putting different tubes into your amp Willy nilly. You gotta stick with things that are close enough to not cause problems.

I do think you’re being a bit dramatic. This site is filled with threads about trying different tube types in different amps. Those same threads are also full of warnings about what specific amps can and can’t work with. Look at any thread about a tube amp on this site and you will get lots of chatter about the different tube types being tried. If someone else reports good results from a different tube type in an amp you have you can assume you’ll get a similar result.

While my preamp can only use 6/12sn7 and direct replacements like 7n7, 14n7, 6f8g, etc. my current amp is specifically designed to allow all sorts of different tube types to be used both for input and output. I have also ordered a custom amp that will allow the same flexibility. I’ve become a bit of a tube hobbyist in addition to an audiophile and I love trying out different kinds of tubes.

 

[sam6550a]

It’s important to check to make sure your amp can handle whatever tube you are interested in trying, don’t go putting different tubes into your amp Willy nilly. You gotta stick with things that are close enough to not cause problems.

I do think you’re being a bit dramatic. This site is filled with threads about trying different tube types in different amps. Those same threads are also full of warnings about what specific amps can and can’t work with. Look at any thread about a tube amp on this site and you will get lots of chatter about the different tube types being tried. If someone else reports good results from a different tube type in an amp you have you can assume you’ll get a similar result.

While my preamp can only use 6/12sn7 and direct replacements like 7n7, 14n7, 6f8g, etc. my current amp is specifically designed to allow all sorts of different tube types to be used both for input and output. I have also ordered a custom amp that will allow the same flexibility. I’ve become a bit of a tube hobbyist in addition to an audiophile and I love trying out different kinds of tubes.

Sorry, but I do not think that audiophiles that received their engineering training from the internet are qualified to make tube substitution recommendations, especially when you have no idea what the target amp schematic or operating conditions are. You may achieve some good results, but you are doing all of this by seat of the pants luck.

 

[Isaacc7]

Sorry, but I do not think that audiophiles that received their engineering training from the internet are qualified to make tube substitution recommendations, especially when you have no idea what the target amp schematic or operating conditions are. You may achieve some good results, but you are doing all of this by seat of the pants luck.

You may not like figuring out if a different tube works better for you in an amp but I'm not sure why you're so judgmental about other people having fun doing it. Once you figure out that a tube isn't harmful there's no harm in trying it out especially if others have done it before. There's no reason to be snide about people's "qualifications" to mess with their systems. Do due diligence about possible damage before swapping, there aren't any other rules!

 

[g0ldl10n]

Question for you guys.. so I purchased a 6CG7/6FQ7 to 6SN7 adapter and got a few 6CG7/6FQ7 tubes in, and for the most part, height wise, they're all fairly similar except for one. It seemed a bit different (taller) but has the 6CG7 stamp on it, but also has 'Cayin' (they make tube amps, among other things) stamped on it too. This tube was advertised as GE but I could not find any GE that looked anywhere close to this one.

Long story short, after some exstensive digging, it seems that Cayin was sending these out marked (i believe they put the 6CG7 stamp on it) as the stock "6CG7" tubes for one of their amps.

Here are comparison pictures and it looks exactly like a Russian 6N6P. Top photo is the one advertised as GE, the ones below it are the 6N6P.

First photo is advertised 6CG7 and the others below it are 6N6P tubes. So question is, which after the digging wasnt able to come to a conclusive answer, is it safe to run a 6N6P (which its datasheet shows it pulls 0.2 more amps than 6CG7) in a 6CG7 socket?

Here is where I found the info regarding Cayin sending these out marked as 6CG7.
https://forum.audiogon.com/discussions/drop-in-tube-replacement-6n6-v-6cg7

 

[jbua5150]

Ah, good information - will be interested in the rest of the testing, especially if it makes things significantly quieter, I would hop on that train!

After a little testing, I cannot say that the Woo Audio adapters are "significantly quieter" than my cheap-o's. I have a pair of 6C8G that have always made noise and are quite unusable. There was no improvement with the Woo adapters. The adapters do seem like they may be slightly quieter when I'm using them in conjunction with the USAF-596.

 

[TLO]

Question for you guys.. so I purchased a 6CG7/6FQ7 to 6SN7 adapter and got a few 6CG7/6FQ7 tubes in, and for the most part, height wise, they're all fairly similar except for one. It seemed a bit different (taller) but has the 6CG7 stamp on it, but also has 'Cayin' (they make tube amps, among other things) stamped on it too. This tube was advertised as GE but I could not find any GE that looked anywhere close to this one.

Long story short, after some exstensive digging, it seems that Cayin was sending these out marked (i believe they put the 6CG7 stamp on it) as the stock "6CG7" tubes for one of their amps.

Here are comparison pictures and it looks exactly like a Russian 6N6P. Top photo is the one advertised as GE, the ones below it are the 6N6P.

First photo is advertised 6CG7 and the others below it are 6N6P tubes. So question is, which after the digging wasnt able to come to a conclusive answer, is it safe to run a 6N6P (which its datasheet shows it pulls 0.2 more amps than 6CG7) in a 6CG7 socket?

Here is where I found the info regarding Cayin sending these out marked as 6CG7.
https://forum.audiogon.com/discussions/drop-in-tube-replacement-6n6-v-6cg7

I assume you are referring to the 6CG7 to 6SN7 adapter, no worry if it is well made with good quality wiring internally. Many ppl here are very happy with Mrs.X' s adapters from Ebay, including myself. I bet they use the same wire for all of their adapters, which some of them are for tubes, like BL63, draw more than 1 amp. It is the total heater current draw from your amp transformer you have to pay attention to.

 

[g0ldl10n]

I assume you are referring to the 6CG7 to 6SN7 adapter, no worry if it is well made with good quality wiring internally. Many ppl here are very happy with Mrs.X' s adapters from Ebay, including myself. I bet they use the same wire for all of their adapters, which some of them are for tubes, like BL63, draw more than 1 amp. It is the total heater current draw from your amp transformer you have to pay attention to.

Thanks for the info, and yep, Mrs.X' s 6CG7 to 6SN7 adapter indeed!

 

[Isaacc7]

I’ve been listening to the Sylvania “Bad Boys” in my preamp for the last couple of days. Because they have more treble emphasis than the Tungsol BGRP I found them fatiguing even though there was more detail coming through. Eventually I remembered that the tube combo I had in my amp (cv1102 and Cossor 807) was particularly open and detailed and so wasn’t a good pairing with these Sylvania tubes. I‘ve switched output tubes a couple of times. First 6ar6 and now e3375 and I find both of those a much better match. I totally get why people love these so much. The moral of the story is that it is all about the interactions between different parts of the system and/or tubes. It certainly helps to have a big selection to choose from on hand lol. Don’t write off a tube just because your initial impression isn’t favorable. I’ve found very tubes that always ruin sound, most can get you very good results.

 

[Isaacc7]

I mentioned a little while ago that I saw an RCA branded 6f8g with round plates. Had never seen that before and it was proceed decently so I bought it. Got it today and it is the spitting image of my National Union 6f8g. So happy to have a pair! Now I can try them in my preamp as well as my upcoming amp in the fall.

 

[DenverW]

Sorry, but I do not think that audiophiles that received their engineering training from the internet are qualified to make tube substitution recommendations, especially when you have no idea what the target amp schematic or operating conditions are. You may achieve some good results, but you are doing all of this by seat of the pants luck.

Even if you discount the people who ARE qualified and can speak well on the electrical characteristics, there are other people, like myself, who reach out to the manufacturer of the amp for an answer, and then share it. The builder usually has a pretty good idea of the schematics.

 

[Isaacc7]

I have now switched from the 12sn7 bad boys to 4x round plate Sylvania 12j5gt. I had mentioned that I thought they sounded similar and I was right. Except for one thing, the 12j5 are noticeably better across the board. Clearer, tighter bass, and smoother. If you haven't already I'd recommend checking out the 6j5 thread for a much cheaper alternative to 6sn7. Even the lowly metal versions have been getting rave reviews. If your amp can fit an adapter it is well worth trying. Alas, while my preamp can accommodate them no problem my amp just does not have enough space.

I'm still going to roll my Tungsol BGRP 6sn7 and my 6f8g as well but the single triodes are good to have in your rotation.

 

[bcowen]

Just ran across this on Ebay in case anyone is interested. Best price I've seen on these in a good while, and especially so for 1950's production. Note these are NOT 1578's, they are just the regular 6N8S but still very nice sounding tubes. Also, I just received some 6N6P's from a different seller in Ukraine. Arrived in 3 weeks, which IMO is pretty darn good considering the situation.

https://www.ebay.com/itm/2039998107...BSdghHRbKRSWBQ%3D%3D|ampid:PL_CLK|clp:2047675