Tube drivin spring reverb question

[reincremated]

Hi, I have a crate vc 2110 r amp that Ive been messing with lately. I was curious what would happen if I connected the two rca cables that go through the reverb so i did it bypassing the reverb. It made it so when i turned up the reverb it acted as another gain/volume control. Im guessing that was because I was using the tube for reverb as a driver now? I wasnt sure if this would damage the amp so I quickly turned it off and hooked the reverb back up. My question is if this can anyway damage the amp? Is it a good idea or just a stupid downright horrible one.

Here is the amps manual with a rough schematic of the amp.VC2110R.pdf

Any and all responses would be very much appreciated.

[Enzo]

That is not a schamatic, that is a block diagram.

It won't hurt your amp. The amplifier stage that drives the reverb pan and the recovery stage have more gain than the 1M resistor they bypass, so it can add some loudness and tonal variation.

The grounds are common and the input and output are both protected by caps so no funny DC situations can result.

Here is the schematic.

[reincremated]

That is not a schamatic, that is a block diagram.

It won't hurt your amp. The amplifier stage that drives the reverb pan and the recovery stage have more gain than the 1M resistor they bypass, so it can add some loudness and tonal variation.

The grounds are common and the input and output are both protected by caps so no funny DC situations can result.

Here is the schematic.

Thanks tons. Also I was wonder how I would go about wiring a small computer fan to the amp to keep the tubes cooler. The amp has a horrible problem with overheating.

[Enzo]

Does the amp have an actual overheating problem? Or is it a matter of it gets hot and makes you uncomfortable? Tubes do naturally get quite hot. If tubes get red hot inside it is not for lack of a fan, it is from a lack of proper bias.

[reincremated]

Does the amp have an actual overheating problem? Or is it a matter of it gets hot and makes you uncomfortable? Tubes do naturally get quite hot. If tubes get red hot inside it is not for lack of a fan, it is from a lack of proper bias.

Well if you have ever seen any of those amps they have absoulutly no ventalation for the tubes. If i run the amp for longer than ten mins without a fan behind it something happens with the input jack and the guitars signal is reduced to almost nothing. Not to mention the face plate gets extremly hot. When I run a fan on it everything is fine except all of the electrical noise from the fan. So i figured I could just rig a small computer fan to the amp so when I turn the power on, the fan turns on. Im just not sure where i should wire a fan so it gets enough/too much voltage.
Thanks

[Enzo]

SO what kind of bias current is there flowing? These amps are not so poorly designed they cannot work on their own. If your amp gets that hot that fast, I'd bet my lunch money there is a bias WAY off, a faulty tube drawing way too much, or a failing power transformer trying to melt down.

Have you looked at the power tubes while this is happening to see if any are getting red hot inside? You should look.

You can put a fan on it, never hurts to cool things off, but if I were you, I'd also cure the underlying problem that causes this in the first place.

[mac1amps]

'just one more "2-cents" to add to this.....Don't make the mistake of using a fan that moves too much air (not to mention make a lot of noise), or place the fan "right on top" of the power tubes, or else you'll OVER-cool the tubes and sacrifice tone....otherwise, a fan is a good idea for most any tube amp......but you DO want to make sure that it's operating properly biased to begin with.

[reincremated]

The amp is cathode biased so it wouldt be the bias would it? The tubes are fine, glowing a orangish color. I actually retubed it all a few months back and it didnt make a difference. It might be the transformer but to me it seems like the problem is just that the only place for excess heat to go is directly into the chassis whick makes everything super hot. The face plate alone gets almost too hot to touch after a while.

[TD_Madden]

where is the glow centered...if the plates are glowing, that is BAD.

[Enzo]

Yeah, I am not concerned with the heater, I an concerned with the metal structure inside the tube, the thing the heater is in the center of. If that metal part starts to get a red hot area, then the tube is over-conducting.

CAthode bias circuits can fail. What if C15 were to get very leaky? What if coupling caps C13, 14 were to get leaky?

ANd what if a couple turns short in the power transformer. it would still work, but it would get real hot.

[reincremated]

Well I looked at the tubes and the plates werent glowing at all. Ive heard of other people having this same problem i figure its just a flaw in design. Is there anything else it could be?

[Steve A.]

Thanks tons. Also I was wonder how I would go about wiring a small computer fan to the amp to keep the tubes cooler. The amp has a horrible problem with overheating.

Computer fans typically run at 5vdc or 12vdc- were you going to build a separate power supply for it?

A lot of people have used a 230vac tubeaxial fan to cool down the tubes in their 120vac amp. Running it at 120vac reduces the speed and the noise. There has been much discussion of this topic here- or at least on the old AMPAGE forums. I always thought it was better to *pull* the heated air from the tubes rather than *pushing* the cool air at the tubes, although lots of people insisted that it shouldn't make a difference. Well, I'm a retired HVAC service tech (Ventilation is the V in HVAC) so I just thought it worked better that way. Or as my father used to say "Because I said so"...

Steve Ahola

P.S. Some modern amps do seem to run very hot, with the top panel getting very warm to the touch. Perhaps they missed something in R&D that allows the heat to build up like that...

It might be a good idea to have an amp tech take a quick look at the amp.

[reincremated]

Computer fans typically run at 5vdc or 12vdc- were you going to build a separate power supply for it?.

I was thinking I could hook up like a 9v stomp box wall wart to the amp and use that to power a 12vdc fan. Would that be a good idea? Is there any other way i could get power to the fan?

[Bruce / Mission Amps]

Here's what I use to cool hot combos down... a $15.00 small fan that stirs the air up and around the power tubes.
Bottom of this page:
http://www.missionamps.com/garage_sale.shtml

They run on 115vac-120vac and are very quiet.