quick valve question!?

[jibidy]

I just bought a Blackstar ht5 and I like it even though it needs repairs and the shop I bought it from are waiting for parts.

The valves are:

ECC83/12AX7 Pre-amp. Does that mean one or the other can be used or are they both the same?

12BH7 Am i write for saying that this valve cannot be changed?

What variaions of valves could I possibly have and what would the benifits be? If any of course.

At the moment its a bit dark/muddy. Could anything brighten it up?

Cheers

[Twinfan]

1)  They're both the same - European vs US name.
2)  Has to be the same
3)  Electro-Harmonix valves may brighten it up

[jibidy]

Ah i see cool. So different brands make different sounds/tones? Are electro harmonix the best for guitar amps or is it a matter of preference to which brand you lke?

[Twinfan]

Personal preference!  I like JJ preamp valves, and find E-H a bit brighter, so they may be better for you and your amp  :)

[jibidy]

cool cheers ill look into it.

[HTH AMPS]

12BH7 is similar to an ECC82, but it all depends how they're biasing the 12BH7 as to whether you could use an ECC82 in there.  they both have a maximum plate voltage of 300v but the 12BH7 has a maximum dissipation of 3.5w while the ECC82 is rated at 2.75w - you'd probably be ok.

you could safely use an ECC99 (jj currently make this valve) as it's similar to a 12BH7 but with a maximum plate voltage of 500v and a maximum dissipation of 5w.  it'll sound cleaner with this valve (more headroom).

you could mess with NOS 12BH7s too - I got some Sylvania ones that sound great but I haven't compared them to the current production (EH) 12BH7s yet.

[hamfist]

12BH7 is similar to an ECC82, but it all depends how they're biasing the 12BH7 as to whether you could use an ECC82 in there.  they both have a maximum plate voltage of 300v but the 12BH7 has a maximum dissipation of 3.5w while the ECC82 is rated at 2.75w - you'd probably be ok.

you could safely use an ECC99 (jj currently make this valve) as it's similar to a 12BH7 but with a maximum plate voltage of 500v and a maximum dissipation of 5w.  it'll sound cleaner with this valve (more headroom).

you could mess with NOS 12BH7s too - I got some Sylvania ones that sound great but I haven't compared them to the current production (EH) 12BH7s yet.

You're such a valve-nerd HTH ......... I love it !!

[HTH AMPS]

12BH7 is similar to an ECC82, but it all depends how they're biasing the 12BH7 as to whether you could use an ECC82 in there.  they both have a maximum plate voltage of 300v but the 12BH7 has a maximum dissipation of 3.5w while the ECC82 is rated at 2.75w - you'd probably be ok.

you could safely use an ECC99 (jj currently make this valve) as it's similar to a 12BH7 but with a maximum plate voltage of 500v and a maximum dissipation of 5w.  it'll sound cleaner with this valve (more headroom).

you could mess with NOS 12BH7s too - I got some Sylvania ones that sound great but I haven't compared them to the current production (EH) 12BH7s yet.

You're such a valve-nerd HTH ......... I love it !!

I know, it just fascinates me no end.  You could also try a 6FQ7 which is a beefed-up ECC82 and also exceeds 12BH7 specs.

I've got a few oddball valves here and more on the way - some small-signal pentodes and some 9-pin valves with a triode section and pentode section in the same envelope.  You can make some great amps with preamp valves other than ECC83s and the usual EL34/EL84/6V6/6L6/6550 etc. (y'know, the usual suspects)