12bh7 valve help

[Sondekker]

I currently have an unmarked 12bh7 valve in the line stage of my Croft 25R (which was modded by Glenn to better drive a low impedance s/s power amp) and would like to try a 'better' version of this particular valve.

I cannot find much info on the web about the relative merits/sound quality of different versions of this particular valve and wondered if anyone here can offer any thoughts/guidance.

There are a number of different versions of a 17mm Brimar 12bh7 currently on ebay being offered by the same seller with different prices/construction/codes etc but unfortunately, the seller was unable to offer any explanation of the differences between them. Does anyone have any experience of Brimar 12bh7's....?

Thanks for any help/advice.

John

[walpurgis]

My inclination would be to leave it alone if it sounds as it should. If you don't know what brand/spec valve you have, there's no way of telling if an alternative will sound 'better'. Unless of course you buy one. :)

[Jimbo]

I currently have an unmarked 12bh7 valve in the line stage of my Croft 25R (which was modded by Glenn to better drive a low impedance s/s power amp) and would like to try a 'better' version of this particular valve.

I cannot find much info on the web about the relative merits/sound quality of different versions of this particular valve and wondered if anyone here can offer any thoughts/guidance.

There are a number of different versions of a 17mm Brimar 12bh7 currently on ebay being offered by the same seller with different prices/construction/codes etc but unfortunately, the seller was unable to offer any explanation of the differences between them. Does anyone have any experience of Brimar 12bh7's....?

Thanks for any help/advice.

John

Hi John, I have a NOS RCA 12BH7a in my Croft 25R linestage and have tried a GE NOS 12BH7a but this did not sound quite as good. Never heard a Brimar but I have seen a few fitted in the Croft 25RS linestage, I presume these would be NOS. As with all 12BH7 valves I would suggest those NOS from the 60'or earlier sound the best so I would look into old versions of Brimar valves.

[anthonyTD]

Hi John,
I have some original new old stock Black plate Brimar's if you need any.
I currently have an unmarked 12bh7 valve in the line stage of my Croft 25R (which was modded by Glenn to better drive a low impedance s/s power amp) and would like to try a 'better' version of this particular valve.

I cannot find much info on the web about the relative merits/sound quality of different versions of this particular valve and wondered if anyone here can offer any thoughts/guidance.

There are a number of different versions of a 17mm Brimar 12bh7 currently on ebay being offered by the same seller with different prices/construction/codes etc but unfortunately, the seller was unable to offer any explanation of the differences between them. Does anyone have any experience of Brimar 12bh7's....?

Thanks for any help/advice.

John

[basnas]

Hi
The 12bh7a Tung-sol is very good :-)

[Sondekker]

Thanks to those that have been kind enough to respond to my request, any other contributions would still be appreciated.

I did find one brief review of a small number of different 12bh7 valves and interestingly the reviewer concluded that a Brimar version sounded best to him in his system. I think the fact Jimbo has seen Brimar versions in the 25RS lends further support to one of these being a likely good option to try in my 25R.

As such, I'd be very interested to hear more from anthonyTD with regard to the Brimars he mentioned.......

Thanks

John