I see Crate's Problem with the Palomino V32

[bnwitt]

Wow! This thread is now over 5 years old!

[Tone Meister]

I chose to use the 50-watter for no defensible reason other than 1) 50 is greater than ten, 2) the size of the 50-watter was still quite small, and 3) the price was only $5.00 plus shipping. I mounted it off the board, yes, and it eliminated the excessive heat from the controls. The sound wasn't adversely affected either, and I expect the tubes to last a bit longer.

[Tone Meister]

[g1]

My only concern here would be whether you are adding to the heat that the transformers must dissipate. I don't think you would want to mount it directly above the transformer, I'm not sure if that is the case here.

[Tone Meister]

My only concern here would be whether you are adding to the heat that the transformers must dissipate. I don't think you would want to mount it directly above the transformer, I'm not sure if that is the case here.

Good point. When I initially assessed the problem, the majority of the heat seemed to be generated in the vicinity of the cathode R in the center of the board. With the much larger 50-watt resistor now mounted off the board and using the chassis as a heat sink, there seems to be less overall heat inside the chassis, and the control panel is certainly much cooler than before. There doesn't seem to be excessive heat being generated in the PT area although I cannot quantify that with actual temperature readings.

[Enzo]

That resistor dissipates what Ohm's Law tells it to. The resistance and the current through it do that. The resistor generates the exact same amount of heat whether it is a 1 watt or a 50 watt part. The only difference is whether that heat is concentrated into a tiny 1 watt space or spread out in a large 50 watt case.

A resistor on the circuit board creates a local hot spot there. When you mount the resistor on the chassis in the heat sink package, then the heat is spread out and coupled to the chassis. It is the same amount of heat, but it now radiates away by the heat sink action of the chassis.

[Tone Meister]

That resistor dissipates what Ohm's Law tells it to. The resistance and the current through it do that. The resistor generates the exact same amount of heat whether it is a 1 watt or a 50 watt part. The only difference is whether that heat is concentrated into a tiny 1 watt space or spread out in a large 50 watt case.

A resistor on the circuit board creates a local hot spot there. When you mount the resistor on the chassis in the heat sink package, then the heat is spread out and coupled to the chassis. It is the same amount of heat, but it now radiates away by the heat sink action of the chassis.

Absolutely, and a 75-ohm resistor dissipates more than a 60-ohm resistor will, which means the power tubes don't have to dissipate as much. Mounting it on the chassis was by design for exactly the reason you pointed out. Overall, no matter what components are dissipating heat to what extent, the end result was favorable and the amp internals just don't seem to emit as much heat as before, for whatever reason. Maybe the heat just isn't as concentrated in a single area as before.

[lsiden]

This thread has more longevity than some bands! Now I can see that these V32's have a real following. I bought mine at Guitar Center when I was just beginning to play. I didn't know zilch about guitars or amps but I got lucky with both. I found out much later on these forums that these amps were dumped by Crate because of the heat issues, and Guitar Center dumped them on customers like me who didn't know what they were getting into.

Anyway, I took mine to Dean Zink in Keego Harbor, MI, a real amp doctor, who happens to live near my mom, and he did more or less what respondents on this forum have been suggesting. He replaced the resistor with one that runs much cooler (I got the info from this thread or another and ordered it myself) and it made a huge difference. I was able to stop putting a little fan inside it that I bought.

It had another problem in clean-channel mode that if I just touched the clean-channel knob past #2, it would roar. Since I use it mostly at home I wanted something that would give me a little more control and allow me to dial my guitar pickup volumes higher to get a little more tone. So he swapped out some tubes for a different model number that aren't quite so "hot" volume-wise. I think he said that this might sacrifice a little tone, but give me more control, so I think it was a trade-off I could live with. I think they were in the pre-amp section, but I can't remember. My experience with electronics is pretty much limited to changing a light bulb.

These Palominos are like diamonds in the rough. They have "tempers" but treat them right and you'll learn to love and appreciate them. Kind of like some women I've known!

[snowfall]

Hi -
First post here, and on a 6+year old thread, too I'm posting because I have a V32, had heat issues similar to others who posted, and performed both the resistor mod, and the addition of a fan. I did the resistor mod first. it seemed to bring the temps down a bit (from skin-frying to just uncomfortable), but not down as much as I'd hoped for. I noticed after running the amp for a while that the tube sockets are huge sources of heat (no surprise there, I guess). Also, the chassis is vented at the bottom, but nowhere else. So, basically the heat has no place to go. So, I added a fan, as per the link mentioned above:
Installing a fan in vintage Fender amps
I didn't do it quite like that guy. Instead, I installed it on the bottom of the chassis, so that is draws air out the bottom, rather than blowing on the tubes directly.
The fan makes no noise, and *really* brought the temperature down, to where its just about at room temperature, after being on for about almost an hour. So, to others out there who have a heat problem with this, or any other amp, you might want to try just the fan mod before anything else. It's cheap, and non-invasive. You can easily remove it if you don't like it, without having disturbed the original circuitry. Not really sorry that I did the resistor mode, because, well, who doesn't like to fool around with high-voltage electronics, but if there is a next time/amp, I'll be doing the fan mod first.

[The Dude]

Welcome to the forum and thanks for joining just to post this. Old thread or not, it's good information to have and nice to hear "real world" experience.

[bnwitt]

Snowfall,
Welcome aboard. I think you may have set your goal for optimal amplifier temperature a bit to low. Your goal shouldn't be to get your vacuum tube amplifier down to room temperature but rather to a level where surrounding components are not damaged by the heat from heat generating components or simply stated normal tube amp operating temperature. Remember that vacuum tubes operate via a principal known as thermionic emission. The have a filament inside for the purpose of heating the tubes up. They need heat. Of course we don't want that heat being absorbed by surrounding components to the point they exceed they're design operating temps, but components for vacuum tube amplifiers are selected to operate at higher temperatures. So most amplifiers (with exceptions like the old AC30s and the amp in this thread) run for years and years at fairly high temperatures without any collateral damage. Don't forget the tubes will lose heat to the surrounding air and the cooler that air the higher the transfer rate. This Crate amp put a high power dissipating resistor right under some variable resistors which couldn't take it. The original amp that came across my bench when run for a while made the control knobs hot enough to burn your hand. Now that just ain't right. Warm to the touch is ok though. This is why the resistor and the original fan suggested by another poster which brought the temperature around the amp chassis controls down some 30 degrees is just what the doctor order. With the internal chassis temp around 100° instead of 135° we are in a pretty normal tube amp operating zone.

[Steve A.]

I didn't do it quite like that guy. Instead, I installed it on the bottom of the chassis, so that is draws air out the bottom, rather than blowing on the tubes directly.
The fan makes no noise, and *really* brought the temperature down, to where its just about at room temperature, after being on for about almost an hour.

I like your idea of mounting the fan on the bottom of the cabinet. I've seen pictures of Peavey Classic 30's with a fan mounted very precariously. So does your fan draw in air through a hole (or holes) you drilled in the bottom of the cab?

I created a downloadable PDF file of the excellent article linked in your post about adding a fan to a BF/SF Fender amp complete with dimensions for a fan bracket the mounts under existing transformer bolts and bias pot nut- very clever.

www-blueglow-de.pdf
("Don't shoot me- I'm just the librarian!" )

Steve Ahola

[snowfall]

So I just measured some of the internal & external temps, after running the amp (guitar plugged in, but not playing) for about 30 minutes. The temp gun says that the max temp for the top panel is 95F (ambient temp for room is 73F). I put the gun into the cab and tried to slowly scan it across the housing containing the tubes. There, the max reading is 260F. Then, I removed the back panel and scanned a few components. The power tube sockets read about 150-160F, the preamp tube sockets at around 130-140F, and the new resistors at 99F. everything else seemed to be in the 120-130F or less range. So, I *think* I'm ok. I didn't measure the temps last night, so when I said "room temperature", I guess it just felt that way, relative to the hotplate that it felt like before the mods. I wish now that I'd measured the internal temps initially, with the original resistor in place before I'd done the mods, but its too late for that...

[snowfall]

I like your idea of mounting the fan on the bottom of the cabinet. I've seen pictures of Peavey Classic 30's with a fan mounted very precariously. So does your fan draw in air through a hole (or holes) you drilled in the bottom of the cab?

At the risk of inciting a thousand face-palms, here's a pic of the fan. It's drawing air downward, mostly from the main part of the cabinet, but also some from inside the chassis, through the bottom vent holes. no additional holes drilled, just using a couple of machine screws through the chassis vent holes And yes, I do plan to clean it up - the placement, attachment, and wire routing are all just a tad sketchy

[Jazz P Bass]

I really do not understand the post about the amp being too cold.
(Caution: do not use amplifier in Alaska.)

I think you have a winner.