random shutdown of my REF-75se

GreyMouse

GreyMouse

New member
Joined
Jan 11, 2016
Messages
34
Location
Denton, Texas
Last night, my REF-75se shut down unexpectedly after more than three hours of continuous play with no sonic issues. I have it connected to my ARC SP-20 preamp with a 12v trigger cable, so my first thought was I'd somehow pressed the power button on the remote, but the SP-20 was still on. Both units are 540 hours old. There have been no prior malfunctions except for a meter lamp on the amplifier which flickered intermittently between 250 and 350 hours then stopped.

I turned off the SP-20 manually and waited ten minutes.

I powered up both units again using the remote (which powers the SP-20 first and the REF-75 a second later) and they both came on. I played a few songs and then, after about 13 minutes, the amp shut down again, by itself. This time I noticed a soft pop when it powered off.

Somehow instead of screwing around with my amp all night I went to bed. This morning, I checked all connections to power and speakers and made an exhaustive examination of everything behind my gear. All was well. Then I removed the 12v trigger cable from both units, turned off the meter lights, and created more air space on the left side of the REF-75. It is open to the room on the right side and has about ten inches of clearance in the back. There's about eight inches clearance above (where the also tube-powered SP-20 rests on the upper shelf) and five or so inches clearance below. I turned on the ceiling fan.

When I powered up both units manually, they played fine. I played music for about ten minutes without a problem. Because of a previously scheduled event I was forced to shut down the components and leave. That's where we stand.

I'm out of my league here, but I'm hoping the unit overheated (somehow for the first time ever in my rack) and that the measures I've taken will address this. Or, perhaps there's something funky about the voltage in the trigger cable and my problem is there. If none of those, I fear a long chat with Kal and some boxes are in my future, which makes me sad.

Does anyone have any guesses other than what I came up with?
 
Sorry to read about the issues. Hopefully it's nothing serious but it's certainly frustrating.
 
That sounds frustrating. It would drive me crazy. Hopefully you have been able to resolve it.
 
Today I had friends over for Opening Day of the MLB season. Played music before we went to eat, thirty five or so minutes with no trouble. After the game we played vinyl for more than two hours and again, all was well. No sudden shutdown. Again, the main changes I made were to remove the trigger cable, switch off the meter lamps, and create more open space on the left side of the amp. If I can't use a trigger cable anymore, I can live with that, I suppose.


Sent from my iPhone using Tapatalk
 
That's great news, hopefully you'll be good for a while. I hope that's all it is, fingers crossed.
 
It sounds like you may have gotten it resolved. I certainly hope this is the case and good for you!
 
I was thinking that as well. I once tried using trigger cables on my amplifiers, but I have decided that I do not like them; I would rather turn each component on and off from it's own power control.
 
Great to hear - you can measure the temperature to confirm under 120 degrees. Seems you have quite a bit of space above though.
 
Randy Myers said:
I was thinking that as well. I once tried using trigger cables on my amplifiers, but I have decided that I do not like them; I would rather turn each component on and off from it's own power control.
Click to expand...

Can you guys tell me how a trigger cable works? Is there a one-time signal to power up the slave component and another to power off? Or a continuous signal?

I also feel comfortable switching each component individually. I can live without the cable.


Sent from my iPhone using Tapatalk
 
last time I had a valve amp [not arc] cut out after long playing , it proved to be it needed a bigger heatsink . had one fitted and all was fine . that was with a 6 year old amp but the 75se is a newish model so not sure what this is . keep us posted
 
hifinutt said:
last time I had a valve amp [not arc] cut out after long playing , it proved to be it needed a bigger heatsink . had one fitted and all was fine . that was with a 6 year old amp but the 75se is a newish model so not sure what this is . keep us posted
Click to expand...

I did a number of things to address the problem. I cleared more space around the amp for additional air flow, turned off the meter lamps (why not right?), and removed the trigger cable. For several weeks, the amp worked perfectly when powered up manually. I bought a new, shorter cable and finally installed it last week. So far it's worked perfectly, with no unexpected shutdowns. I don't know if it was the cable or not, but that seemed like a good guess.

It's possible the old cable was faulty somehow, or that it wasn't perfectly seated in the jack(s) previously.

I think the problem is resolved. Fingers crossed!
 
GreyMouse said:
I did a number of things to address the problem. I cleared more space around the amp for additional air flow, turned off the meter lamps (why not right?), and removed the trigger cable. For several weeks, the amp worked perfectly when powered up manually. I bought a new, shorter cable and finally installed it last week. So far it's worked perfectly, with no unexpected shutdowns. I don't know if it was the cable or not, but that seemed like a good guess.

It's possible the old cable was faulty somehow, or that it wasn't perfectly seated in the jack(s) previously.

I think the problem is resolved. Fingers crossed!
Click to expand...

One easy test to confirm is putting a food thermometer on top after a half hour - should be 120 degrees or less.
 
GreyMouse said:
I did a number of things to address the problem. I cleared more space around the amp for additional air flow, turned off the meter lamps (why not right?), and removed the trigger cable. For several weeks, the amp worked perfectly when powered up manually. I bought a new, shorter cable and finally installed it last week. So far it's worked perfectly, with no unexpected shutdowns. I don't know if it was the cable or not, but that seemed like a good guess.

It's possible the old cable was faulty somehow, or that it wasn't perfectly seated in the jack(s) previously.

I think the problem is resolved. Fingers crossed!
Click to expand...

brilliant , just might try a 75se sometime
 
joeinid said:
It's probably one of ARC's best amps. I'd like to play with one as well.
Click to expand...

There's no question the sound is unimpeachable. My only fear with the trigger cable quirk was I might be without this amazing amp for several weeks.


Sent from my iPad using Tapatalk
 
You must log in or register to reply here.
Back
Top