The Reference 6SN7 Thread

[mordy]

From aviation control, but with a different connotation:

Google has more prosaic explanations…
BTW, people often speak of going down the rabbit hole in connection with tubes.

 

[TLO]

That was a costly fumble.

Yeah, I have to go on Ebay to look at tubes to get my heart pumping again ..lol

 

[UntilThen]

longer than all of us

But some of us lives to 100.

 

[bcowen]

But some of us lives to 100.

Quit bragging. What month this year is your 101st birthday? I want to send a card.

 

[UntilThen]

Quit bragging. What month this year is your 101st birthday? I want to send a card.

Just send the original Western Electric 300b tubes will do. Tyvm.

 

[g0ldl10n]

So, something I came across that I was not aware of, was that Raytheon manufactured tubes designated specifically to the "Amateur", at least by these pieces of paper that came with a few NOS tubes I picked up seem to indicate.

I thought the two pieces of paper were cool enough to put in a frame showing the front and back

Surprisingly, the Amateur tubes of this type (at least in my amp/setup) sound better than the Military 'JAN-CRP' version of the same tube type (different internals as well).

 

[Isaacc7]

So, something I came across that I was not aware of, was that Raytheon manufactured tubes designated specifically to the "Amateur", at least by these pieces of paper that came with a few NOS tubes I picked up seem to indicate.

​

I thought the two pieces of paper were cool enough to put in a frame showing the front and back




Surprisingly, the Amateur tubes of this type (at least in my amp/setup) sound better than the Military 'JAN-CRP' version of the same tube type (different internals as well).

I have heard similar things about Bendix tubes. They were made to exacting standards and are super rugged. And that might translate into being able to be abused in guitar amps it seems like their hifi reputation is much more mixed.

 

[mordy]

So, something I came across that I was not aware of, was that Raytheon manufactured tubes designated specifically to the "Amateur", at least by these pieces of paper that came with a few NOS tubes I picked up seem to indicate.

​

I thought the two pieces of paper were cool enough to put in a frame showing the front and back




Surprisingly, the Amateur tubes of this type (at least in my amp/setup) sound better than the Military 'JAN-CRP' version of the same tube type (different internals as well).

When is says "Amateur", it appears to refer to ham radio. Seems to me that the emphasis would be on clarity of speech.

Amateur Radio

Amateur Radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communications.

 

[mordy]

I have heard similar things about Bendix tubes. They were made to exacting standards and are super rugged. And that might translate into being able to be abused in guitar amps it seems like their hifi reputation is much more mixed.

Many of the Bendix tubes were intended for ballistic weapons as can be seen from the spec sheets with ratings for 60,000 feet.
Usually the military versions of tubes are more rugged, but that feature may not always correspond to better sound. However, it seems to me that tubes developed for low microphonics have an impact on the sound.

 

[Isaacc7]

Many of the Bendix tubes were intended for ballistic weapons as can be seen from the spec sheets with ratings for 60,000 feet.
Usually the military versions of tubes are more rugged, but that feature may not always correspond to better sound. However, it seems to me that tubes developed for low microphonics have an impact on the sound.

Yeah, a shop around here that makes custom gear told me that he thinks that audiophiles tend to prefer tubes with some micro phonics. His most popular preamp uses a WE tube that rings like a bell if you bump the table it is on. On the other hand I have found the c3m tube a revelation as a driver tube. Mind you while some sources claim that the tube was designed for low microphonics some people claim they are highly microphonic so who knows? Lol

 

[mordy]

Yeah, a shop around here that makes custom gear told me that he thinks that audiophiles tend to prefer tubes with some micro phonics. His most popular preamp uses a WE tube that rings like a bell if you bump the table it is on. On the other hand I have found the c3m tube a revelation as a driver tube. Mind you while some sources claim that the tube was designed for low microphonics some people claim they are highly microphonic so who knows? Lol

I don't have the C3m tubes but I have the C3g tubes which I believe are similar in function but 6.3V instead of 20V.
These tubes were made for trans-atlantic telephone transmissions and a lot of research and resources went into them and they cost a lot of money to make. Although very linear my impression is that they were made for clarity of speech. -Did not find the C3g microphonic but a little too bright in my amp.

 

[triod750]

-Did not find the C3g microphonic but a little too bright in my amp.

And here is the difference between Siemens and Lorenz made C3g, the latter not very bright. I agree to the theory of 'clarity of speech'. Maybe that's the reason to why Lorenz sourced most of their tubes from Siemens?

 

[Isaacc7]

I don't have the C3m tubes but I have the C3g tubes which I believe are similar in function but 6.3V instead of 20V.
These tubes were made for trans-atlantic telephone transmissions and a lot of research and resources went into them and they cost a lot of money to make. Although very linear my impression is that they were made for clarity of speech. -Did not find the C3g microphonic but a little too bright in my amp.

The c3g tubes have twice the Mu of the c3m so they aren’t quite equivalent. Think the C3o are the 6v version of the c3m but hardly ever hear about them.

 

[mordy]

The c3g tubes have twice the Mu of the c3m so they aren’t quite equivalent. Think the C3o are the 6v version of the c3m but hardly ever hear about them.

I never bothered with the other versions of the C3g because of the different pin outs and voltages, but I once researched the different versions and found at least 6-7 versions. There is even at least two GEC versions but of course with still different pin outs.

 

[Isaacc7]

I never bothered with the other versions of the C3g because of the different pin outs and voltages, but I once researched the different versions and found at least 6-7 versions. There is even at least two GEC versions but of course with still different pin outs.

So, uh, do you remember what the GEC version was called? I know about the 5a/152m from STC but unaware of other versions.