[mordy]

Audio output transformers are important and quality ones are quite expensive due to the core materials required. It takes quite a bit of engineering to make a transformer that has a frequency response of 20Hz - 20kHz with minimal output deviation across that range. The old rule of thumb is, the bigger the core the better the frequency response.
https://www.aikenamps.com/index.php/output-transformers-explained

Not quite the same for power transformers, as long as they can provide the voltage and current needed, it wouldn't make any difference. If the transformer is not up to spec or has too much of a requirement on it, then that would alter the sound due to all the voltages being off.

Thanks for the information. I don't understand that much about these things, but I do remember when I mentioned somewhere that I was using an old PC power supply for external power to tubes that I was told that some inexpensive power supplies can be noisy. If I understood correctly, even though the voltage and current are OK, electric noise can be introduced by a power supply.

 

[TrollDragon]

Thanks for the information. I don't understand that much about these things, but I do remember when I mentioned somewhere that I was using an old PC power supply for external power to tubes that I was told that some inexpensive power supplies can be noisy. If I understood correctly, even though the voltage and current are OK, electric noise can be introduced by a power supply.

Yes indeed, switching power supplies can be very noisy.

 

[lupoal]

need suggestion/help from very expertise people here ... I’ve recently bought a pair of Marconi 6SN7GT made in Canada... bad boys three holes black plates, togheter with 6HM5 gain 5 they sound marvellous to me

so I would like to buy a spare couple without paying a fortune (the Marconi costed me roughly 50 bucks) and without buying something that sound different (or is a fake)... so the problem of rebranding... here is a picture of my tubes, could you suggest me what looking for and what avoid? Thks a lot

 

[gibosi]

need suggestion/help from very expertise people here ... I’ve recently bought a pair of Marconi 6SN7GT made in Canada... bad boys three holes black plates, togheter with 6HM5 gain 5 they sound marvellous to me

so I would like to buy a spare couple without paying a fortune (the Marconi costed me roughly 50 bucks) and without buying something that sound different (or is a fake)... so the problem of rebranding... here is a picture of my tubes, could you suggest me what looking for and what avoid? Thks a lot

The most important thing to look for is "made in Canada" etched into the glass. And then, three holes, black plates.

However, only Sylvania manufactured the "Bad Boy", and they manufactured it in the US, not Canada. And if you were to purchase a Sylvania with three holes and black plates, it will likely sound different. But as I don't have the Canadian Marconi, I can't say for sure.

 

[mordy]

need suggestion/help from very expertise people here ... I’ve recently bought a pair of Marconi 6SN7GT made in Canada... bad boys three holes black plates, togheter with 6HM5 gain 5 they sound marvellous to me

so I would like to buy a spare couple without paying a fortune (the Marconi costed me roughly 50 bucks) and without buying something that sound different (or is a fake)... so the problem of rebranding... here is a picture of my tubes, could you suggest me what looking for and what avoid? Thks a lot

There is a possibility that these tubes were made by GE Canada for Marconi Canada. To get a better price you would have to look for a tube labelled GE with the identical construction, Made In Canada and try to find a private seller on eBay with a better price. Or look for the Marconi brand from a private seller.
There are several different Marconi versions from different countries and manufacturers so it is important to look for the identical one that you like.
PPO - patience pays off....
Found this seller in India that has Canadian GE labeled tubes that look similar to the Marconi Canada tubes you have but the price is too high....

https://www.ebay.com/itm/1MP-6SN7GT...068686?hash=item2f382f05ce:g:BAQAAOSw5PldsCBq

Possibly it is the same tube....

 

[mordy]

need suggestion/help from very expertise people here ... I’ve recently bought a pair of Marconi 6SN7GT made in Canada... bad boys three holes black plates, togheter with 6HM5 gain 5 they sound marvellous to me

so I would like to buy a spare couple without paying a fortune (the Marconi costed me roughly 50 bucks) and without buying something that sound different (or is a fake)... so the problem of rebranding... here is a picture of my tubes, could you suggest me what looking for and what avoid? Thks a lot

There is a possibility that these tubes were made by GE Canada for Marconi Canada. To get a better price you would have to look for a tube labelled GE with the identical construction, Made In Canada and try to find a private seller on eBay with a better price. Or look for the Marconi brand from a private seller.
There are several different Marconi versions from different countries and manufacturers so it is important to look for the identical one that you like.
PPO - patience pays off....
Found this seller in India that has Canadian GE labeled tubes that look similar to the Marconi Canada tubes you have but the price is too high....

https://www.ebay.com/itm/1MP-6SN7GT...068686?hash=item2f382f05ce:g:BAQAAOSw5PldsCBq

 

[lupoal]

@gibosi @mordy

thank you both

yes I tough the description “bad boy” was a fake description but... ok, I just tried and sound is very good so ok... what could be the right price level? I’ve found a couple of GE Canada (same as those in my hands) declared NOS from Italian dealer... but he ask 135$... quite expensive

 

[triod750]

@gibosi @mordy

thank you both

yes I tough the description “bad boy” was a fake description but... ok, I just tried and sound is very good so ok... what could be the right price level? I’ve found a couple of GE Canada (same as those in my hands) declared NOS from Italian dealer... but he ask 135$... quite expensive

If I want expensive tubes it seems as a good option to buy from Italy. That's my impression when looking at eBay.

 

[gibosi]

@gibosi @mordy

thank you both

yes I tough the description “bad boy” was a fake description but... ok, I just tried and sound is very good so ok... what could be the right price level? I’ve found a couple of GE Canada (same as those in my hands) declared NOS from Italian dealer... but he ask 135$... quite expensive

As you paid about $50 for yours, I think $50 or less would be a good price.

 

[mordy]

Can anybody tell me what is "bad" and "boy" about tubes? IMHO these are now just fictitious imaginations of unscrupulous sellers trying to jack up the prices. A whole plethora of fake "bad boys" seem to exist in addition to the original Sylvania one.
My theory is that to the average person tubes of the same category look pretty much the same. Sellers are seizing on obvious clues that make certain tubes easy to identify in order to drive up prices. Such examples are a red base, pinched waist, curved base, blacked out glass etc - these are things anybody can notice. And, obviously, the most expensive tubes sound the best...
On the flip side (and for us plus side) there are great sounding very inexpensive tubes that get no publicity such as certain US made all metal tubes because they are ugly, have no tube glow and oftentimes rust on them (which has no effect on the sound).
Anyhow - found an account how the term "Bad Boy" came about:

"The name "bad boy" was first applied to this particular vintage Sylvania 6SN7 by Robert Hutton back in 2001 or 2002. Just as the Tung Sol BGRP is possessed of certain special sonic characteristics that make it a highly sought after tube, so too the '52 Sylvania. It has a sonic presentation unlike any other Sylvania 6SN7. A substantial cache of US Navy surplus '52 bad boys was unearthed in Australia early in the past decade, and at first the gentleman that discovered the cache was selling them on eBay for $50/pair. Robert was among the first, if not the first, to write about their virtues. He dubbed them bad boys due mainly to their staggering ability to produce bass."

Another definition:
The "bad boy" designation signifies a tube that has a high market value, regardless of whether it actually has superior sonics.

And here is how you can determine if it is a real one:
1)3 hole black T plates
2)Bottom getter flashing 1/3 way up the tube
3)Shiny silver top and bottom rectangular mica. The top mica has three small triangular edges bent down on each side.
4)Copper grid posts
5) Date code of 2xx(or possibly 1xx or 3xx) were 1, 2 or 3 represent 1951, 1952 or 1953 and xx represents the week.
6)Full black bottom base with Sylvania or JAN-CHS-6SN7GT in green letters

(In short, only three hole plate JAN-CHS Sylvania tubes with green print from 1951-1953 qualify)


Buyer beware!

 

[triod750]

The true Bad Boys are the sellers .

 

[MIKELAP]

Can anybody tell me what is "bad" and "boy" about tubes? IMHO these are now just fictitious imaginations of unscrupulous sellers trying to jack up the prices. A whole plethora of fake "bad boys" seem to exist in addition to the original Sylvania one.
My theory is that to the average person tubes of the same category look pretty much the same. Sellers are seizing on obvious clues that make certain tubes easy to identify in order to drive up prices. Such examples are a red base, pinched waist, curved base, blacked out glass etc - these are things anybody can notice. And, obviously, the most expensive tubes sound the best...
On the flip side (and for us plus side) there are great sounding very inexpensive tubes that get no publicity such as certain US made all metal tubes because they are ugly, have no tube glow and oftentimes rust on them (which has no effect on the sound).
Anyhow - found an account how the term "Bad Boy" came about:

"The name "bad boy" was first applied to this particular vintage Sylvania 6SN7 by Robert Hutton back in 2001 or 2002. Just as the Tung Sol BGRP is possessed of certain special sonic characteristics that make it a highly sought after tube, so too the '52 Sylvania. It has a sonic presentation unlike any other Sylvania 6SN7. A substantial cache of US Navy surplus '52 bad boys was unearthed in Australia early in the past decade, and at first the gentleman that discovered the cache was selling them on eBay for $50/pair. Robert was among the first, if not the first, to write about their virtues. He dubbed them bad boys due mainly to their staggering ability to produce bass."

Another definition:
The "bad boy" designation signifies a tube that has a high market value, regardless of whether it actually has superior sonics.

And here is how you can determine if it is a real one:
1)3 hole black T plates
2)Bottom getter flashing 1/3 way up the tube
3)Shiny silver top and bottom rectangular mica. The top mica has three small triangular edges bent down on each side.
4)Copper grid posts
5) Date code of 2xx(or possibly 1xx or 3xx) were 1, 2 or 3 represent 1951, 1952 or 1953 and xx represents the week.
6)Full black bottom base with Sylvania or JAN-CHS-6SN7GT in green letters

(In short, only three hole plate JAN-CHS Sylvania tubes with green print from 1951-1953 qualify)


Buyer beware!

Am i rich mordy ?

 

[triod750]

Am i rich mordy ?

Can't answer for Mordy but that is a pretty good boy but in my opinion not as good as 6SN7W. But I prefer the tone in Melz 6H8C/6N8S. With the right synergy, that is.

 

[lupoal]

you know.., the problem with all these bad-good-what?-boy is that there are too many different versions of the same tube code... year ... manufacturer... bla bla bla... a nightmare...

ok many very useful info are inside this thread and many others inside the 6SN7 thread... but both together are more than 1000 pages and billions of words... here inside there are two very useful chart collecting all the info, it would be very useful something similar where, over the time, people add pictures with descriptions so when a rookie need to double-check to avoid surprise a place to go exist

 

[triod750]

MIKELAP, you showing your Sylvania 6SN7WGT made me visit them again. I now used them with C3g and external psu playing acoustical music. They were as I remembered them, a bit coloured. That might work well with some electrical music but to me they are like a somewhat dirty window. I changed to the Brimar pair I mentioned previously and the window immediately became clean and clear. In my setup, with my music. With my ears and gear, as Gibosi use to say.

Earlier today I tried RCA 6BX7GT coinbase with Mullard M8100 and CV4010. M8100 was also very colouring but CV4010 was not bad at all. If I had not heard C3g I might have been pretty satisfied with that combination. It needs external psu but is much cheaper than a lot of other combinations in this long and winding thread.

I've had a little mishap with my input adapter. When I am back on track I will try a Melz 6H8C with both 6SN7WGT and these Brimar to hear what change that will result in.