D&R Triton console hot to the touch

[PJ Newman]

Hello all. I have a D&R Triton console that recently has been radiating quite a bit of surface heat. I feel it on the channel strips and on the master section. Lately, either L or R output drops out, sometimes to pop back in on its own or if I arc the channel.
Unfortunately, Boise does not have much in the way of pro level repair shops and/or techs. One, by my count and I don't know if he's still working or making studio calls. My preferred techs are either in Portland (7 hours) or Seattle (10 hours).
Does anybody have a guess what would cause the heat? Should I aim a fan at the rear of the desk?
Also, last year I purchased a huge load of channel and master strips, VU's and various other odds and ends from a studio in Atlanta (thanks to Ronan Chris Murphy for forwarding the info), so if it's a matter of swapping modules out, maybe I can give my hernia a break.
Thanks in advance.
pj

 

[pucho812]

heat means more current is pushing through. If this is not normal, some consoles normally produce a lot of heat, then we can assume something is a amiss. It might be as simple as needing new caps and due for a change out, it may be more serious.

 

[radardoug]

You imply that it wasn't hot to the touch before. Are you sure about that? If you are correct, the power usage in the desk has gone up. Are the supplies reading correct voltages?

 

[Newmarket]

Hi. What do you mean by "arc the channel" ? It's not a term I understand.

 

[living sounds]

The Triton uses mostly TL072 (and a couple NE5534) on the channel strips, no on-board regulation, so not much to get very hot in a console that size if run correctly. Check the power supply voltages first and adjust if necessary.

 

[JohnRoberts]

If it changed and now is running warmer, higher PS rail voltages could explain that.

If the console was hot rodded with faster and/or lower noise op amps substituted that could increase heat dissipation.

This would not explain L/R bus dropping out, that sounds like bad connections between strips and wiring harness.

JR

 

[abbey road d enfer]

Hello all. I have a D&R Triton console that recently has been radiating quite a bit of surface heat. I feel it on the channel strips and on the master section.

Do all channels radiate the same or are there hot spots?

Lately, either L or R output drops out, sometimes to pop back in on its own or if I arc the channel.

Has anything changed in your setup, like adding machines or outboard?

There is always the possibility of one of the rails (or both) going haywire and delivering too high a voltage, which would increase the dissipation of the opamps.
I've never seen the increase of current when the max voltage is exceeded documented in datasheets, but I suspect there is a point where it grows significantly, until the magic smoke is released.

 

[abbey road d enfer]

The Triton uses mostly TL072 (and a couple NE5534) on the channel strips, no on-board regulation, so not much to get very hot in a console that size if run correctly.

That's right, although I couldn't help noticing the huge regulators: 8x2N3055 in parallels! Talk about over engineering...

 

[living sounds]

That's right, although I couldn't help noticing the huge regulators: 8x2N3055 in parallels! Talk about over engineering...

But those are in the external PSU, right?

 

[abbey road d enfer]

But those are in the external PSU, right?

Yes, but I just wonder why they have so much current capability. Is it because they used the same PSU's for really huge mixers, or someone was paranoid about power transistors?

 

[dom]

First thing to check would be the power supply rails. The adjustment range appears to be about ±14.1 V - 19.4 V, so if both of the main rails are somewhere in there (likely 16V or so is the intended nominal voltage), then the supply is probably fine.

Do you have a kill-a-watt? Recommend picking one up if not, they're pretty cheap. You could check the overall power draw at the wall to see if the consumption is somewhere in the ballpark of the specified maximum power draw which should be labeled both in the documentation and printed on the console near the mains input.

Hard to think of too many things that would suddenly increase heat dissipation from the entire console at once other than the power supply rail voltages increasing substantially from where they were previously. That's not a very typical failure mode though, and I think in order for you to clearly notice an increase in overall power, the rails would probably have to have increased by at least 1.5x or so, which is probably enough to start frying components. So, this doesn't seem likely.

 

[JohnRoberts]

Yes, but I just wonder why they have so much current capability. Is it because they used the same PSU's for really huge mixers, or someone was paranoid about power transistors?

In my experience power supply design was mostly an after thought for some console designers. Some console only companies made rather poor choices wrt heat sinking and reliability. Manufacturers who also made power amplifiers generally had a better handle on thermal management and reliability. Even console only companies generally figured it out by second/third generation designs.

JR

 

[abbey road d enfer]

In my experience power supply design was mostly an after thought for some console designers. Some console only companies made rather poor choices wrt heat sinking and reliability. Manufacturers who also made power amplifiers generally had a better handle on thermal management and reliability. Even console only companies generally figured it out by second/third generation designs.

You're probably right.
I had a different trajectory. When I was hired by a console mfgr, my first task was designing PSU's for replacing the Philips PSU's they used at the time.
Daunting task for a wet-behind-the-ears newcomer, being challenged by the mighty Philips company.

 

[PJ Newman]

You imply that it wasn't hot to the touch before. Are you sure about that? If you are correct, the power usage in the desk has gone up. Are the supplies reading correct voltages?

It used to stay room temp. Now very very warm, hot in places.

 

[PJ Newman]

If it changed and now is running warmer, higher PS rail voltages could explain that.

If the console was hot rodded with faster and/or lower noise op amps substituted that could increase heat dissipation.

This would not explain L/R bus dropping out, that sounds like bad connections between strips and wiring harness.

JR

Actually, the PSU was serviced a year or 2 ago when I experienced a catastrophic event. The problem then was a wiring connection fused in the master section. Thanks for the tip. Really good place to start!

 

[PJ Newman]

Hi. What do you mean by "arc the channel" ? It's not a term I understand.

Pushing a fader up to 100% to try to get signal through. Usually works....sometimes....always good idea to mute monitors!

 

[abbey road d enfer]

Actually, the PSU was serviced a year or 2 ago when I experienced a catastrophic event. The problem then was a wiring connection fused in the master section. Thanks for the tip. Really good place to start!

Anyway, checking the rail voltages is a priority.

 

[PJ Newman]

Anyway, checking the rail voltages is a priority.

On it. Thank you.

 

[JohnRoberts]

Pushing a fader up to 100% to try to get signal through. Usually works....sometimes....always good idea to mute monitors!

That sounds like dirty jacks or switch contacts (oxidized, and higher voltage punches through thin oxide layer). I've seen this most often in inset jack switch contacts.

JR

 

[Newmarket]

Pushing a fader up to 100% to try to get signal through. Usually works....sometimes....always good idea to mute monitors!

Okay. Understood. See JR reply and my response to it.