#1
have a palomino crate v3212

when i first take it off standby and play (at approximately 1/3 volume), it sounds how i want it to sound. perfect. but after about a half hour of band practice, the sound kinda gets kinda, well, muddy. the distortion seems weaker, and the entire tone just seems different in general.


is something up with my amp,

or maybe it's my hearing getting ****ed up for the day?
#2
Could be your ears, but then I saw your amp...

I love them, but they are notorious for running too hot.

The cathode resistor can get so hot it can burn open, actually, or the chassis heat can wipe out pots on the control panel.

How warm does the control panel between the knobs feel when you hear this "tone change"?
#3
My tube amps sound better the longer they are on. Maybe your tubes need changing? how long have you had them in?
#4
well, it will sound different after the tubes warm up properly. Shouldn't take 30 minutes though.
#5
Yeah its probably just hearing fatigue.
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#6
Quote by Rutch
Could be your ears, but then I saw your amp...

I love them, but they are notorious for running too hot.

The cathode resistor can get so hot it can burn open, actually, or the chassis heat can wipe out pots on the control panel.

How warm does the control panel between the knobs feel when you hear this "tone change"?


it's always run quite hot since the day i bought it (about 10 months ago), but i just assumed that's how tube amps were.... i guess not? I used to use a small fan behind it, but didn't bring it with me to the practice spot where the amp is right now.
#7
See if a fan blowing full force straight into the back changes anything at all, like how long it takes to change, or the amount of change.

It might no affect anything much, since the cathode resistor is not really out in the open, but it's worth a shot.

A built in fan or upgrading that resistor are VERY common mods to this amp for a VERY good reason!
#8
it sounds like it is just your hearing. after a long time of playing, it seems like a proper reaction to pick apart your tone and find areas where it could sound better. Half hour seems a little short though. I can play my amp for several hours before i start to hear subtle things that could be changed, but overall i love the tone that my amp puts out. Usually after a couple hours i am just done playing; i don't pick my tone apart that much. I don't think i could ask for a better tone/amp.

Maybe the tone your getting from your amp isn't exactly what you are looking for. Maybe it is time to look into pedals or a different amp. That's just my opinion. Overall, i think it is just your hearing.

But then again, i could be wrong. There could be something with the tubes. But i am not a expert, so i can't give an accurate diagnosis if it is an electronics problem (but some day i will be able to).

Good Luck.
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#9
Quote by sexwithdolphins
it's always run quite hot since the day i bought it (about 10 months ago), but i just assumed that's how tube amps were.... i guess not? I used to use a small fan behind it, but didn't bring it with me to the practice spot where the amp is right now.



With the power tubes and power transformer there is plenty of heat generated in tube amps. The problem with the V32 is just bad ventilation. It still shouldn't affect your sound though. Especially after 30 min or so of playing. How long have those tubes been in there?
#10
Quote by Matt420740
With the power tubes and power transformer there is plenty of heat generated in tube amps. The problem with the V32 is just bad ventilation. It still shouldn't affect your sound though. Especially after 30 min or so of playing. How long have those tubes been in there?


same tubes since i bought it last december.

thanks for the good advice so far. i'll bring the fan next time and see what happens.
#11
Quote by sexwithdolphins
same tubes since i bought it last december.

thanks for the good advice so far. i'll bring the fan next time and see what happens.



If the fan doesn't help, you should consider changing your power tubes. Especially if you play a lot. There almost due for a change anyways if they been in there a year.

I like to change my power tubes every 6 months, and pre-amp tubes every year. But thats a little overkill.
#12
Quote by Matt420740
With the power tubes and power transformer there is plenty of heat generated in tube amps. The problem with the V32 is just bad ventilation. It still shouldn't affect your sound though. Especially after 30 min or so of playing. How long have those tubes been in there?


Nah, it's not just that, although that certainly doesn't help.

Those things run hot by design, it's part of their sound. Some tend to be okay, but others just eat tubes like they're goin' out of style.

Running two cathode r in parallel at twice the resistance will bring the heat down, especially if you use those fancy heat-sink ones and get them away from the board.

It's not the tubes that roast these things. Yeah, they run hotter than most, but the resistor can actually fry the board.
#13
Quote by Rutch
Nah, it's not just that, although that certainly doesn't help.

Those things run hot by design, it's part of their sound. Some tend to be okay, but others just eat tubes like they're goin' out of style.

Running two cathode r in parallel at twice the resistance will bring the heat down, especially if you use those fancy heat-sink ones and get them away from the board.

It's not the tubes that roast these things. Yeah, they run hotter than most, but the resistor can actually fry the board.


A resistor isn't going to put off enough heat to get the entire inside of the enclosure hot. I'm not familiar with the V32 circuit so your probably right about the resistor frying the board, but even if that little resistor was to get red hot, it would take hours for it to generate enough heat to get the whole enclosure hot. Power tubes generally run around 180-200 degrees, which is where the majority of the heat comes from. If there is a known problem with those resistors though, you should link him to some info or something on how to fix the problem.
Last edited by Matt420740 at Oct 16, 2009,
#14
I don't know of any links or anything, I doubt Crate ever owned up to a "problem", but I have seen a couple burnt boards, and it's always the same thing.

And the cathode resistor isn't some little guy, it's a big boy, and can get up to about 200 degrees. The value they use keeps it at (I think, IIRC, etc.) something like 13 to 15 watts idle dissipation.

You're right that tubes do get hot, and that's where most of the heat you feel is coming from, but I bet that control panel, and the board, are roasting, and they shouldn't be, tubes or not!

TS, I could walk you through it sometime if you're handy with a soldering iron, but I would at least try and cool things down with a fan to see if that helps first.
#15
Quote by Rutch
I don't know of any links or anything, I doubt Crate ever owned up to a "problem", but I have seen a couple burnt boards, and it's always the same thing.

And the cathode resistor isn't some little guy, it's a big boy, and can get up to about 200 degrees. The value they use keeps it at (I think, IIRC, etc.) something like 13 to 15 watts idle dissipation.

You're right that tubes do get hot, and that's where most of the heat you feel is coming from, but I bet that control panel, and the board, are roasting, and they shouldn't be, tubes or not!

TS, I could walk you through it sometime if you're handy with a soldering iron, but I would at least try and cool things down with a fan to see if that helps first.



Why do they have a 15 watt resistor in there? I've never seen a cathode resistor that big inside a tube amp before. Most use 2 watt or smaller.

Edit: I build tube amps for a hobby. I've been doing it for a while, but am still pretty novice. I haven't been inside of a V32 so I'm not doubting you at all or anything, just wondering why they would use such a large cathode resistor.
Last edited by Matt420740 at Oct 16, 2009,
#16
Nonono, the rating of the resistor isn't 15 watts, I don't remember what it is, it probably is 2.

But it's resistance value determines the dissipation wattage of the tubes, which really shouldn't be over 13 watts for el84s. (I'm sure there's a better way to say that, sorry, it's late! lol)

increasing the cathode resistor value would bring that down, but that would be biasing the amp "colder", and the amp probably wouldn't sound the same.

My suggestion is to use a heat-sink wire-wound resistor of the SAME resistance, and get it off the board. Those big resistors just happen to usually come in larger wattage ratings.

Another solution is to use two resistors of double the resistance, wired in parallel, so at least that way the heat is spread out a little.

Bleah, it's been a while since I've thought about cathode biasing, sorry if I'm getting any brains muddled! (beyond my own...)
#17
Quote by Rutch
Nonono, the rating of the resistor isn't 15 watts, I don't remember what it is, it probably is 2.

But it's resistance value determines the dissipation wattage of the tubes, which really shouldn't be over 13 watts for el84s. (I'm sure there's a better way to say that, sorry, it's late! lol)

increasing the cathode resistor value would bring that down, but that would be biasing the amp "colder", and the amp probably wouldn't sound the same.

My suggestion is to use a heat-sink wire-wound resistor of the SAME resistance, and get it off the board. Those big resistors just happen to usually come in larger wattage ratings.

Another solution is to use two resistors of double the resistance, wired in parallel, so at least that way the heat is spread out a little.

Bleah, it's been a while since I've thought about cathode biasing, sorry if I'm getting any brains muddled! (beyond my own...)


No problem If the resistors turn out to be his culprit your suggestions sound like they would work fine. He could also just use a resistor of the same value, but rated at higher wattage to cut down on heat. The wire-wound with heatsink should be a definite fix though.