7189's in a Tiny Terror

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Abstract
Posts: 150
Joined: Wed Apr 23, 2008 1:47 am

7189's in a Tiny Terror

Post by Abstract » Sun Feb 08, 2009 10:38 pm

A friend of mine has one of these and is looking for more headroom. I suggested 7189's and a 12ay(t)7 in V1.

Anything else? Idea's?


Can I get conformation that 7189's won't wreck his OT or PT? I know there are some inconsistencies between these and el84's...but I'm not 100%


Thanks y'all!

pinkmarkos
Posts: 78
Joined: Sat Dec 13, 2008 7:33 am
Location: portland, or

Re: 7189's in a Tiny Terror

Post by pinkmarkos » Sun Feb 15, 2009 6:35 am

using 7189s in a tiny terror won't have any effect on the transformers because they are cathode biased, which means more or less that they bias themselves. the difference is the max plate voltage(400 volts for the 7189 vs. 300 for the el84/6bq5). if the amp were made for 7189's then you would have a problem using el84's, but no problem subbing 7189's for el84's. i measured the plate voltage on my TT and it was well below 300v. however in regards to clean headroom, you might get away with using a 12at7/12ay7 for one or both preamp tubes to achieve that , but IMO this amp is made for that sludgy/stoner rock kind of vibe. i actually like the chinese 12ax7's that come stock with it. i run some RCA 7189's in the power section and it sounds awesome. hope that helps- MP
R.Y.N.O.

andrew4566
Posts: 11
Joined: Thu Oct 19, 2006 3:24 pm

Re: 7189's in a Tiny Terror

Post by andrew4566 » Sun Feb 15, 2009 4:29 pm

If they are 7189a's there is a pin difference, but 7189(no a) will be a direct replacement.

-Andy
-Andy

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