The Reference 6SN7 Thread

[BrainSalat]

Another thought is perhaps this particular tube is more sensitive to micro-vibration due to current flow. Do you hear a louder tapping sound when you tapped lightly on the glass with a pen or even your finger nail compared to other tubes you have? I have a couple of tubes that has this characteristic, you could say it is the early stage of becoming what we called microphonic. Anyway, all tubes have some levels of microphonic, the question is how much, will it affect the listening experience?
AFAIK, there is no solution to this problem. The best you can do is try it on different locations on the amp if your amp uses more than 1 6SN7 or on another amp.

Thanks for your tips again, I appreciate it.
Also not, they are in fact very little microphonic.
I have actually some very microphonic TS 5998 tubes that sometimes produce a hum that goes away after taping them gently with my fingers. The hum on the Melz is imperturbable.

 

[sam6550a]

Thanks @sam6550a for the info. I will transmit him your thoughts.
Actually the tubes came with this data sheet (in russian) and seems he, with the 8-9[mA], was referring to the anode current:
Using google translate:
- Heater Voltage: 6.3 V
- Filament current: 550-660 mA.
- Voltage Anode: 250 V.
- Grid Voltage: -8 V
- Anode current: 5-13 mA
- Gain: 18-25

I have a hard time believing that any competent amp designer would "over anode current" a tube. The parameters for a class A voltage amp are widely published, and if you draw load lines and operate the tube within max parameters, you achieve the best performance and minimum distortion. Although I do not speak German, in spite of a German name, one word does come to mind concerning this seller's argument--drek.

 

[bcowen]

Thanks @sam6550a for the info. I will transmit him your thoughts.
Actually the tubes came with this data sheet (in russian) and seems he, with the 8-9[mA], was referring to the anode current:
Using google translate:
- Heater Voltage: 6.3 V
- Filament current: 550-660 mA.
- Voltage Anode: 250 V.
- Grid Voltage: -8 V
- Anode current: 5-13 mA
- Gain: 18-25

I totally agree with @sam6550a 's assessment of drek in the seller's response. In addition to what he (Sam) pointed out, the amp doesn't determine the current draw. The amp only sets the voltage(s). The amp is not "powering current" it is powering voltage. So his statement that "The probable reason is the high filament current, 6n8s, like the full analog 6sn7, are powered by 8-9ma current..." is total hogwash, even if he is innocently interchanging the filament and anode.

 

[BrainSalat]

I have a hard time believing that any competent amp designer would "over anode current" a tube. The parameters for a class A voltage amp are widely published, and if you draw load lines and operate the tube within max parameters, you achieve the best performance and minimum distortion. Although I do not speak German, in spite of a German name, one word does come to mind concerning this seller's argument--drek.

Well said! thanks , just a tiny correction, if you allow me, for future quotes "Dreck". I also like how "Blödsinn" (nonsense/rubbish) sounds.

I totally agree with @sam6550a 's assessment of drek in the seller's response. In addition to what he (Sam) pointed out, the amp doesn't determine the current draw. The amp only sets the voltage(s). The amp is not "powering current" it is powering voltage. So his statement that "The probable reason is the high filament current, 6n8s, like the full analog 6sn7, are powered by 8-9ma current..." is total hogwash, even if he is innocently interchanging the filament and anode.

In the meantime I also asked Feliks Audio and they told me that these are some great tubes they know in practice and are used by many Envy/Euforia customers as driver tubes and that most likely in my case the tubes are faulty. But they also recognize is hard to obtain them in good conditions.

Thanks again @sam6550a and @bcowen for your explanation and support, now I can build some good arguments...

 

[BrainSalat]

Thanks again @sam6550a and @bcowen for your explanation and support, now I can build some good arguments...

The outcome: Without further argumentation, the seller will send me some replacement tubes.

 

[JTbbb]

The outcome: Without further argumentation, the seller will send me some replacement tubes.

I was going to suggest get your money back and buy some clear glass Brimar CV1988’s .

 

[Wes S]

I was going to suggest get your money back and buy some clear glass Brimar CV1988’s .

. . .or buy some adapters and ditch the 6SN7's all together.

The 7193, CV6, VR135, CV11135, 6C8C family of tubes with adapters, smoke any 6SN7 ever made.

Pictured below - Russian (Svetlana Factory) 6C8C and spoiler alert. . . they best the Melz 1578 in my opinion. They have weight, texture, detail and staging the 1578 just can't touch. The 1578 sound small and thin, compared to the 6C8C.

 

[JTbbb]

. . .or buy some adapters and ditch the 6SN7's all together.

The 7193, CV6, VR135, CV11135, 6C8C family of tubes with adapters, smoke any 6SN7 ever made.

Pictured below - Russian (Svetlana Factory) 6C8C and spoiler alert. . . they best the Melz 1578 in my opinion. They have weight, texture, detail and staging the 1578 just can't touch. The 1578 sound small and thin, compared to the 6C8C.

Haha, love it! I’ve only gone as far as 6J5GT’s with adapters. I don’t need anymore temptations thank you .

 

[Wes S]

Haha, love it! I’ve only gone as far as 6J5GT’s with adapters. I don’t need anymore temptations thank you .

I hate to do it to you, but take a look at the prices of the CV6, 6C8C, 7193 etc. . .

It's crazy how cheap they are compared to the more popular and hard to find 6SN7 and 6J5's.

 

[g0ldl10n]

I hate to do it to you, but take a look at the prices of the CV6, 6C8C, 7193 etc. . .

It's crazy how cheap they are compared to the more popular and hard to find 6SN7 and 6J5's.

Well where are you buying your 6C8C tubes at? I could've swore the last time I checked they were a LOT cheaper than what I am finding them for now. $89 and $99 a pop now, and need two, so when you factor that in they aren't much cheaper, unless you have a seller with a lot better prices. The CV6 and 7193 tubes are still cheaper, that is for sure.

However, I do agree ditching the 6SN7 family is the best route to go, but that can lead to an endless rabbit hole that actually ends up costing more money

I ditched the 6SN7 family for the most part, and yes, I have been able to stock up on lifetime supplies of tubes that I personally feel are better than any 6SN7 out there for average cost under $10 a piece, but it also turned into me building my own adapters when there wasn't one I needed available on the market, using external power supplies, and spending a whole lotta money on all of that stuff during my discoveries.

But I also now have my own personal tube museum, I kid you not

Tube fever is real, and if one is infected it's really difficult not to spend a whole lot of money no matter which route one goes.

 

[Wes S]

Well where are you buying your 6C8C tubes at? I could've swore the last time I checked they were a LOT cheaper than what I am finding them for now. $89 and $99 a pop now, and need two, so when you factor that in they aren't much cheaper, unless you have a seller with a lot better prices. The CV6 and 7193 tubes are still cheaper, that is for sure.

However, I do agree ditching the 6SN7 family is the best route to go, but that can lead to an endless rabbit hole that actually ends up costing more money

I ditched the 6SN7 family for the most part, and yes, I have been able to stock up on lifetime supplies of tubes that I personally feel are better than any 6SN7 out there for average cost under $10 a piece, but it also turned into me building my own adapters when there wasn't one I needed available on the market, using external power supplies, and spending a whole lotta money on all of that stuff during my discoveries.

But I also now have my own personal tube museum, I kid you not

Tube fever is real, and if one is infected it's really difficult not to spend a whole lot of money no matter which route one goes.

Those prices are for 2 tubes, so they still are way cheaper at about $50 a pop.

 

[g0ldl10n]

Those prices are for 2 tubes, so they still are way cheaper at about $50 a pop.

Ah, that makes more sense!

 

[Paladin79]

. . .or buy some adapters and ditch the 6SN7's all together.

The 7193, CV6, VR135, CV11135, 6C8C family of tubes with adapters, smoke any 6SN7 ever made.

Pictured below - Russian (Svetlana Factory) 6C8C and spoiler alert. . . they best the Melz 1578 in my opinion. They have weight, texture, detail and staging the 1578 just can't touch. The 1578 sound small and thin, compared to the 6C8C.

It depends on which Melz 1578 you are talking about, that series was made for four decades, I mostly run those from the mid fifties to the early sixties and own or have owned most all years and styles. Those from the 70's and 80's are very midrange forward IMHO. I have used many adapters for 6j5's, 7A4's (going from memory) and the like but I mostly run the Melz. We also tried several thousand 6sn7's and compatible tubes in a blind study friends and I did, the Melz finished quite well. We used a version that looks identical to most Melz except it had solid, shiny black plates. They are quite rare and I have them from three years. @sam6550a and a few others on here know that tube.

 

[UntilThen]

I was going to suggest get your money back and buy some clear glass Brimar CV1988’s .

A NOS Brimar CV1988 cost more than a ECC35.

I'm quite happy with a good 6a6 or 6n7g. Just bought a ECC31 (again) and next purchase will be a ECC35.

 

[Somatic]

Spoke with someone at WE today. They expect to release the new line of tubes including 6SN7 next year. :/