|
Post by imalive on Mar 3, 2015 7:53:55 GMT -7
Hello all, New to the forum, long time Z user. I picked up a used MAZ Jr w/reverb. I was pulling tubes to clean the pins with deoxit and the PI is a non LPS. Would this cause any issues? I have no idea how long the previous owner had it like that And am planning a full tube change but can I use it this way until the new tubes arrive?
|
|
|
Post by Mark (Basement Enthusiast) on Mar 3, 2015 8:04:06 GMT -7
No problem at all, man. Any 12AX7 would be fine; it's just that gearhead tone-obsession of ours where we all dictate that the PI must be a long-plate tube. You're 100% fine.
Many people say that long-plate (i.e., LPS) tubes have smoother-sounding characteristics, etc., but any tube that is built within reasonable 12AX7 specs is operationally fine. Honestly, you or I might not even tell a sonic difference. Some of Dr. Z's amps were actually designed with a slightly different tube, the 5751, intended for the PI spot--but the MAZ isn't one of those.
Also... welcome to the Z-Talk forum! Stick around awhile, it's a great place to be.
|
|
|
Post by imalive on Mar 3, 2015 9:36:41 GMT -7
Thanks Mark, much appreciated! Figured I do a full tube swap and get what came in the amp but glad I can use it safely until they get here....my day off today.
|
|
|
Post by headshrinker (Marc) on Mar 3, 2015 10:36:56 GMT -7
If you like the way the amp sounds now, DON'T do a full preamp tube swap! They last a really long time and don't tend to fade like power tubes. When they go you generally know it. All preamp tubes sound a little different, and if you change them all at once, the amp may not sound as good as it did before and you won't know which tube in which position screwed it up. If you feel you must change them, change them out one at a time, then listen to the amp. If it sounds better, leave it in. If it sounds the same, put the old one back in, mark the new one as to what position it sounded good in, and you have a spare. If it sounds worse, you have an emergency spare or try it in another position, as it may make things the same or better in another position. Changing preamp tubes in a good sounding amp is opening a can of worms. Power tubes are another story. My advice again is, swap a pair in, sounds better, you needed them. Doesn't sound better, old ones back, play it for another 10 - 15 hours, try again, unless you hear the amp sounding worse. Since they fade rather than go, it's possible to forget how the amp sounds with a new set.
|
|
|
Post by imalive on Mar 4, 2015 7:08:07 GMT -7
It's 2001 and it has a slight hum. I have No idea if the power tubes have ever been changeD so those will be swapped hoping that is the cause of the hum. After some reading a bit I found it has the correct pre amp tubes that would have came stock except the PI which is not a LPS so that will probably be the only one I change. I got it from an older gentleman that I don't think ever had it serviced. It looks like it sat covered(tuki cover) for a long time. Thanks Marc!
|
|
|
Post by imalive on Mar 4, 2015 19:28:49 GMT -7
I'm bummed...pulled v5 and still the hum. Replaced with new matched JJ'S and still the hum. Pulled v1,2 and 3 and still the hum. Pulled reverb tank cables and cleaned with deoxit and still the hum. There are actually two types of hum. One when the reverb is all the way down and and another when it gets turned up. There is also a lot of noise, hiss when the cut is turned up.
|
|