#1
my power tube went microphonic so im getting new 12ax7's tomorrow. right now i have stock tubes in my amp Traynor YCV50 which are Sovtek 12ax7's. i like the marshall sound that the traynor gives me so i want to stay in the general area of marshall/classic sounding gain. what brand should i go with?
#4
Well i got the tungsol 12ax7's in my marshall and i still keep that british classic voicing. They are also pretty inexpensive tubes.
#5
Quote by PiperDawnsGate
Well i got the tungsol 12ax7's in my marshall and i still keep that british classic voicing. They are also pretty inexpensive tubes.


now what is exactly the dif between power and preamp tubes?
#6
Tung sols are the best sounding 12AX7s that I've come across...I A/B/C/D..etc a few Sovteks, tungsol, JJs, Ei, EH...

Tungsols sound the best, but experience has found that JJs are significantly more robust...if your amp is a combo, you might want to go w/ JJs so they don't get vibrated to pieces too soon.
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial
#7
Quote by culkid
now what is exactly the dif between power and preamp tubes?


preamp tubes are in the preamp and amplify the guitar signal to drive the poweramp tubes, poweramp tubes are in the power amp and drive the speaker(s).
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial
#8
Quote by DLrocket89
preamp tubes are in the preamp and amplify the guitar signal to drive the poweramp tubes, poweramp tubes are in the power amp and drive the speaker(s).



so if one of the tubes went microphonic, it would be the pre amp??????? whenever i turn the volume or gain past a certain point, there is always a loud screeching noise *not feedback*
#9
Quote by culkid
so if one of the tubes went microphonic, it would be the power amp??????? whenever i turn the volume or gain past a certain point, there is always a loud screeching noise *not feedback*


Your loud screeching noise is probably oscillation, which happens when someone doesn't know how to build/layout an amp, or when a tube mechanically starts to die. If it's high pitched, it's probably a preamp tube...but not necessarily.

When was the last time you replaced the tubes, how often do you play, and how hard are you driving it when you play?
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial
#10
Quote by DLrocket89
Your loud screeching noise is probably oscillation, which happens when someone doesn't know how to build/layout an amp, or when a tube mechanically starts to die. If it's high pitched, it's probably a preamp tube...but not necessarily.

When was the last time you replaced the tubes, how often do you play, and how hard are you driving it when you play?



i usually play in my room not at high volume, but when i jam with my buddies we play loud, i bought the amp used about 8 months ago and according to my knowledge the tubes have never been changed

the loud pitched screech is very recent, it did not used to do it.
#11
Quote by culkid
i usually play in my room not at high volume, but when i jam with my buddies we play loud, i bought the amp used about 8 months ago and according to my knowledge the tubes have never been changed


Probably time to refresh the whole thing, esp if the previous owner used it much.

I'd try replacing the preamp tubes...if that doesn't fix it, I'd replace the power tubes too.

....aaaand, I just read a review that says that the preamp tubes are internally mounted, which makes replacing them a pain. Bummer.

That amp has a pair of EL34s for output tubes. I'd replace those w/ JJ KT77s...better in pretty much every respect.
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial
#13
IF they are (maybe I was reading a review for a different year or something), you have to drop the whole chassis out to get to the tubes inside said chassis.

Go visit an amp tech, unless you've done this sort of thing before...
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial
#14
i have not done it before but id rather not pay some ridiculous price so the guy can show me how to remove a chassis
#15
Quote by culkid
i have not done it before but id rather not pay some ridiculous price so the guy can show me how to remove a chassis


I haven't worked on one so I don't know anything more than this:

1) remove chassis
2) find tubes
3) pull tubes out
4) put new tubes in
5) remount chassis

Sorry, not trying to be sarcastic...

In any case, if you do do it, *you've probably heard this before*, lethal voltage/amperage, don't touch anything, make sure capacitors are drained, etc, etc.

Do you have a volt meter to check and see if the caps are properly drained?
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial
#16
Quote by DLrocket89
I haven't worked on one so I don't know anything more than this:

1) remove chassis
2) find tubes
3) pull tubes out
4) put new tubes in
5) remount chassis

Sorry, not trying to be sarcastic...

In any case, if you do do it, *you've probably heard this before*, lethal voltage/amperage, don't touch anything, make sure capacitors are drained, etc, etc.

Do you have a volt meter to check and see if the caps are properly drained?


no. i dont even know what drained means.i watched a video on how to change tubes and all the guy did was pull them out and put a new one in. he never spoke of draining or voltage
#17
Quote by culkid
no. i dont even know what drained means.i watched a video on how to change tubes and all the guy did was pull them out and put a new one in. he never spoke of draining or voltage


thats because if the tubes are on the outside, the high/lethal voltages stay inside the chassis. If your tubes are on the inside, you have to go in by said lethal voltage to change tubes.

There are resistors that are supposed to drain the capacitors (think of caps as batteries that store charge and discharge very quickly and can retain charges for years). If the drain resistor is somehow bad or blown, the caps won't drain and unless you check it, you won't know it till you shock yourself and you're lying on the ground wondering why your heart isn't beating.

...sorry for the theatrics, that's why a lot of amp techs charge a crapton is if they screwup, they can die replacing the tubes in your amp. unlikely, yes, but possible.
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial
#18
Quote by DLrocket89
thats because if the tubes are on the outside, the high/lethal voltages stay inside the chassis. If your tubes are on the inside, you have to go in by said lethal voltage to change tubes.

There are resistors that are supposed to drain the capacitors (think of caps as batteries that store charge and discharge very quickly and can retain charges for years). If the drain resistor is somehow bad or blown, the caps won't drain and unless you check it, you won't know it till you shock yourself and you're lying on the ground wondering why your heart isn't beating.

...sorry for the theatrics, that's why a lot of amp techs charge a crapton is if they screwup, they can die replacing the tubes in your amp. unlikely, yes, but possible.


yea but you dont plug the amp into the wall while your putting in new tubes so i dont see how you can be shocked..
#19
Quote by culkid
yea but you dont plug the amp into the wall while your putting in new tubes so i dont see how you can be shocked..


the capacitors can store charge for years after you unplug the amp, if a particular resistor is blown or otherwise bad. and if said resistor is blown, you prolly wouldn't know it by listening to the amp.
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial
#20
Quote by DLrocket89
the capacitors can store charge for years after you unplug the amp, if a particular resistor is blown or otherwise bad. and if said resistor is blown, you prolly wouldn't know it by listening to the amp.


couldnt i wear something and be good?
#21
Quote by culkid
couldnt i wear something and be good?


Uh...no.

Do you know anyone w/ any sort of electronics background? It's not too hard, just need to have a voltmeter and know how to use the thing.
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial
#22
Quote by DLrocket89
Uh...no.

Do you know anyone w/ any sort of electronics background? It's not too hard, just need to have a voltmeter and know how to use the thing.


no lol
#23
Quote by culkid
no lol


hrm.

Well, take the chassis off, take a look, DON'T TOUCH ANYTHING. See if the tubes are easy to get to or not, etc...

BTW, quick sanity check, how many tubes do you see on the outside of the amp? Two big ones that are about the diameter of a half dollar and 4" tall or so...any (should be 3) smaller one maybe a nickel in diameter and 2" tall? They might be tubes or they might be hidden under metal shields that look like little metal cylinders...
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial
#24
Quote by DLrocket89
hrm.

Well, take the chassis off, take a look, DON'T TOUCH ANYTHING. See if the tubes are easy to get to or not, etc...

BTW, quick sanity check, how many tubes do you see on the outside of the amp? Two big ones that are about the diameter of a half dollar and 4" tall or so...any (should be 3) smaller one maybe a nickel in diameter and 2" tall? They might be tubes or they might be hidden under metal shields that look like little metal cylinders...

theres 2 in metal cages. just wondering.w hy do you ask?
Last edited by culkid at Feb 6, 2009,
#25
Quote by culkid
theres 2 in metal cages. just wondering.w hy do you ask?


doing a quick check to make sure that the preamp tubes are indeed inside the chassis. and they are indeed inside the chassis, if you only see 2 on the outside.

So, yeah, I'm going to bed. good luck w/ that..pull the chassis, be careful not to touch anything.
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial