[gibosi]

Today I have tried the pair of 6H13C first with Ken-Rad 6SN7GTA with a less favoured outcome and now with a Brimar 6SN7GT (marked with a P over a 4 to the left and 1 over a 4 to the right of the 'BRIMAR' on the socket. @gibosi will probably tell you what that means). This combination has a lot going for it. So much so that I don't want to make any changes for a while. I can't say that it is better than 804 with 6N12S but somewhat different. More agile maybe. More bite, but not overly so, at least not with this jazz quintet. (Yes, I will listen to something else too). But if you want to, you can find 'West of the moon' with Bosse Broberg, Gosta Rundqvist, Joakim Milder, Thomas Lofgren and, not least, Red Mitchell on Spotify. My version is better than that. I listen to CD. Semi-old school.

Unfortunately, those characters (P414) don't appear to conform to a normal Brimar production code, and I have no idea how to interpret them.

http://www.g8hqp.me.uk/audio/brimarcodes.html

 

[mordy]

Unfortunately, those characters (P414) don't appear to conform to a normal Brimar production code, and I have no idea how to interpret them.

http://www.g8hqp.me.uk/audio/brimarcodes.html

Add to this that towards the end of the tube era Brimar imported many tubes from Eastern Europe and put their name on them.
A wild guess: P
4
could mean March 1964

 

[triod750]

But...there are a lot of pics in this thread. My posts are worthless due to losing my Kodak Instamatic more than forty or maybe fifty years ago. Neither me nor my phone is smart. But I am clever - I save my money for tubes.

 

[triod750]

Unfortunately, those characters (P414) don't appear to conform to a normal Brimar production code, and I have no idea how to interpret them.

http://www.g8hqp.me.uk/audio/brimarcodes.html

They look like this, the tubes I mean, but you don't see the codes on this photo: http://www.tangotubes.com/bilder/0608/Brimar6SN7GT(2).jpg

 

[triod750]

Add to this that towards the end of the tube era Brimar imported many tubes from Eastern Europe and put their name on them.
A wild guess: P
4
could mean March 1964

And: 1
4
could mean one for you?

 

[gibosi]

They look like this, the tubes I mean, but you don't see the codes on this photo: http://www.tangotubes.com/bilder/0608/Brimar6SN7GT(2).jpg

Yes, I have a similar tube with 12 and 3 on the right. And I am inclined to guess it is December, 1953, but this is just a guess. And so yours, with 1 and 4 might be January, 1954. But again, this is just a WAG. And I have no idea what P and 4 might indicate. Mine has only one digit on the left, a 3.

 

[triod750]

Yes, I have a similar tube with 12 and 3 on the right. And I am inclined to guess it is December, 1953, but this is just a guess. And so yours, with 1 and 4 might be January, 1954. But again, this is just a WAG. And I have no idea what P and 4 might indicate. Mine has only one digit on the left, a 3.

Sounds reasonable. I was told they were from the early fiftees. They can also be seen here: https://www.head-fi.org/threads/the-reference-6sn7-thread.117677/page-46
The P 4 might mean peace for you? Or maybe they have to be two or more to mean that. (Sorry, just pulling Mordy's leg. Didn't want to mention pee. Won't mention pee).

 

[mordy]

And: 1
4
could mean one for you?

Based on the picture it is a Brimar made 6SN7GT - somewhat pricey today with people asking over $300 for a single.
However, it looks like I found a bargain - a G.E.C 6SN7GT for GBP 40 ($54) and free shipping!
Too good to be true? Well, let's find out...
https://www.ebay.com/itm/G-E-C-6SN7...572316?hash=item1aa7fdb75c:g:UOAAAOSw9wVfmb6e
So here we have a rebranded Eico American made GE 6SN7GT that you can buy for $10.
The free shipping is only GBP 23 ($30).
Since I recently dealt with a different unpleasant British seller that repairs TVs and seeing that this seller is into vintage radios I have to draw the conclusion that some British people are strange. The other guy claimed that he has 60 years experience and knows everything about date codes, but then he was unable to explain a Mazda date code. And yes, he said that all tubes sound the same.....
Caveat emptor!

 

[triod750]

Based on the picture it is a Brimar made 6SN7GT - somewhat pricey today with people asking over $300 for a single.
However, it looks like I found a bargain - a G.E.C 6SN7GT for GBP 40 ($54) and free shipping!
Too good to be true? Well, let's find out...
https://www.ebay.com/itm/G-E-C-6SN7...572316?hash=item1aa7fdb75c:g:UOAAAOSw9wVfmb6e
So here we have a rebranded Eico American made GE 6SN7GT that you can buy for $10.
The free shipping is only GBP 23 ($30).
Since I recently dealt with a different unpleasant British seller that repairs TVs and seeing that this seller is into vintage radios I have to draw the conclusion that some British people are strange. The other guy claimed that he has 60 years experience and knows everything about date codes, but then he was unable to explain a Mazda date code. And yes, he said that all tubes sound the same.....
Caveat emptor!

If only I had known about the price I would have paid much more. My pair cost me about $23, measuring almost NOS from a reliable seller.

 

[mordy]

If only I had known about the price I would have paid much more. My pair cost me about $23, measuring almost NOS from a reliable seller.

I have the 25V version (13D1) of the Brimar 6SN7and paid $10....

 

[mordy]

I have the 25V version (13D1) of the Brimar 6SN7and paid $10....

Triod750 inspired me to dig out my Brimar 25SN7 AKA 13D1. It is rebranded Haltron and from 1962. The 25V tubes were intended for aircraft use. There is a US made tube 1633 that is a similar 25V tube.
The obligatory picture:

This tube has a nice, mellow sound. It is one of the favorites of amp builder Glenn and the reason my amp has a 25V switch.

 

[triod750]

Mellow is good to make biting behave!!

 

[Arro]

Today I have tried the pair of 6H13C first with Ken-Rad 6SN7GTA with a less favoured outcome and now with a Brimar 6SN7GT (marked with a P over a 4 to the left and 1 over a 4 to the right of the 'BRIMAR' on the socket. @gibosi will probably tell you what that means). This combination has a lot going for it. So much so that I don't want to make any changes for a while. I can't say that it is better than 804 with 6N12S but somewhat different. More agile maybe. More bite, but not overly so, at least not with this jazz quintet. (Yes, I will listen to something else too). But if you want to, you can find 'West of the moon' with Bosse Broberg, Gosta Rundqvist, Joakim Milder, Thomas Lofgren and, not least, Red Mitchell on Spotify. My version is better than that. I listen to CD. Semi-old school.

With British made tubes with an indecipherable factory code, it can be useful to look up images of the CV equivalent and see if there are any tubes resembling the ones that you have. It's not exact but if you also factor in the suspected date of your tubes it should give you a hint as to what factory had the equipment to manufacture that type of tube at the time. The clear glass Brimar CV1988s with the scalloped top mica and 50s date codes have the factory code FB which is Foots Cray.

 

[triod750]

Last night I listened to 6H13C with Yugo 6HM5 as drivers. In this combination 6HM5 were elevated to a new level. But in the long run I experienced a nagging grating feeling. Today I changed drivers to Philips 5654SQ. The listening became much more relaxed. I will have to wait with a comparison. It is almost ridiculous to look at the amp. These 5654 are soo small compared to the big bottles. It's a pity I lost that Instamatic since this is a sight to be seen.

 

[triod750]

Forgot to mention that the amp seems to be as warm with these monster tubes as with 6N6P. No measurements, just touching it with my fingers. The 6080 tubes generates much more heat. I guess the adapter and socket saver with heater inlet isolates a lot of generated heat from getting into the amp.