Review of the 12bz7 Tubes

faster100

Ok i bought these tubes from Early B, He tried them in his Jolida but decided to pass them along..

I'm not real good or techical on reviews..
These were used in the driver stage of my 6v6 push pull power amp

First off, I noticed a better defined lower end, I think they also have a higher gain then the standard 12ax7 tube as they seemed more powerful volume wise.. Its alittle lax on the top end and doesnt have as much sparkle as my EH 12ax7's.. they have a more defined overall sound as well. mid range is ok to me.. not the best but certainly better then some.

Its a chance trying these in place of the 12ax7.. I have a 50's /60's amp with old iron and the transformer doesnt get any warmer with these in..

I'm afraid to try them in my pas 3 pre as the transformer is pretty wimpy in that..

Over all i have left them in since yesterday and like them.. They came to me in NOS original boxes which is a big plus.. look mint/new

I'm running the Rt25i speakers with the tube pre by dynaco

Early B.

Cool. Glad you like the so far.

I may try them again one day. I e-mailed Jolida today about using them in my amp, and I'll pass along their response when (or if) I receive it.

madmax

My bet is the guys at Jolida will tell you not to use any tube except the original ones that shipped with your amp. I hear they are a little dickish. Let us know what they say though.
madmax

Early B.

madmax wrote:

My bet is the guys at Jolida will tell you not to use any tube except the original ones that shipped with your amp. I hear they are a little dickish. Let us know what they say though.
madmax

Got a reply yesterday. It simply said, "According to the tube substitution book, no."

Is that considered a dickish response?

madmax

Ha ha, maybe. If you aint buyin, we aint tryin... Good thing they make such a good product.
madmax

organ

Cool review Cliff. Glad you're enjoying them and that they're working out in your amp. So like it better than EH?

faster100

Yeah i think i do, they are more alive..