| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1484.1 | ex | VLNVAX::ALECLAIRE | | Mon Sep 18 1989 15:00 | 5 |
| I was told by a repair guy that the 7025's have greater frequency
response but more niose than 12ax7's.
This same guy also overlooked a resistor that had never been soldered
on one end at the factory and which subsequently fried my x-former.
Nonetheless, has anyone else more info on tube replacements?
|
| 1484.2 | GE says: 12AX7 = 7025 | SALEM::ABATELLI | Nouveau Blues Rocker | Mon Sep 18 1989 15:51 | 8 |
| I used to work alot on Fender amps and found that I could use
12AX7's instead of 7025's and also the other way around. I found
no large difference in noise with either when compared side by
side. At one point "GE" tubes were marked: 12AX7/7025
on each box. What does that tell ya? You should NOT replace a 7025
with a "12AT7", or a "12AT7" with a 7025/12AX7, but then you knew that.
Fred (who wants an old black face Deluxe Reverb)
|
| 1484.3 | 12AT7 = ECC81 | SQUID::GOODWIN | | Mon Sep 18 1989 16:35 | 4 |
|
I think 12AT7's are equivalent to ECC81's.
Where do the ECC83's and 12AX7A's fit into this puzzle?
|
| 1484.4 | yep... | VIDEO::BUSENBARK | | Mon Sep 18 1989 17:37 | 3 |
| I believe ECC refer's to european labeling's and there
american equiv's are as you mentioned
|
| 1484.5 | Tubes | CSC32::G_HOUSE | Does a bear wear a funny hat? | Tue Sep 19 1989 14:14 | 10 |
| 12AX7s are compatible replacements for ECC83s or 7025s. I was told by
two different techs that I trust that there should be no difference in
the sound or performance.
Now, I don't know about the 12AX7As though. I thought that this was
the "high performance" version of the 12AX7, so I'd expect it to change
your sound some. I *think* that it's electrically compatible though
(but I'd check before I put them in my amp).
Greg
|
| 1484.6 | | DNEAST::BOTTOM_DAVID | Rock and Roll doctor | Tue Sep 19 1989 14:52 | 8 |
| On the same topic, my Rivera will accept an number of power tubes, currently
it has EL34's which as I understand it are a warm sounding tube. Comparably
are 6550's a much sharper sounding tube?
fo anyone who was curious: Substitution requires re-biasing, a chart of values
and proceedure are part of the owner's manual....
dbii
|
| 1484.7 | | SQUID::GOODWIN | | Tue Sep 19 1989 15:13 | 10 |
| RE: .6
From what I've read 6550's are louder, harder and cleaner sounding.
6CA7's should interchange with the EL34's without the need to rebias.
I'm not sure about the 6550's though. Some amps that allow power
tubes to be interchanged have bias switches built in, which is a
very nice convenience (as long as you remember to throw the switch
when you replace your 6L6GC's with EL34's, otherwise, it's an
expensive pain in the rear end!)
|
| 1484.8 | | ASAHI::COOPER | Insert Flipper-type P-name here... | Wed Sep 20 1989 12:01 | 3 |
| 6CA7's are equivelent to the EL34's according to GT's Tube Amp Book.
jc
|