Onix A-120MKII Gets hot fast.

Hey All,

Need some advice on what to do with this integrated amp. When I turn it up and I don't mean wall shaking loud it gets very hot to touch after one CD and then the protection shuts her down. I am pushing PSB 6T's. I think have it bi-wired correctly and it doesn't do this with headphones. What's up Goners? THX
I'm not familiar with your speakers but it sounds like your amp is going into protect mode. Reading a review here

they had some problems driving Theil 2.2's. It may just be reaching it's power limit? A higher current amp may be necessary? Someone else may be more familiar with your speakers and know for sure? Remember the watt rating of your amp is not really important. It's the current it can provide to the speakers that's important. "amps power supply"
Did it just start doing this? How old is the integrated amp? How old are your speakers?
Thanks for responding. Not real sure about the age of the amp. I picked it up in March from Audiogon. My guess is 10 years. The speakers are about 12 years. It has run very warm since I got it and the problem has been happening the whole time. It's fine at normal levels, just very warm to touch. I have no idea how to check the current.
Current capability isn't something you can check per-say. A good indication of an amp's current capability is how much power it has at 8 ohm's say 200watt and close to 400 watts into 4ohms. This is not an exact way of checking but it is a good indication of the amps power supply. The closer it comes to doubling it's power the better.

If you have another pair of speakers that are smaller and less demanding give them a try. If the only time the amp over-heats and goes into protect mode is when your pushing it. I would guess it's just running out of gas.
There could be many reasons why your amp is over heating. The idea of using a different pair of less demanding speakers is a good one. Without taking it in to have someone check the idling current of the output transistors, it's really just a guessing game at this point as to what the problem is. Make sure the heatsinks are not being covered and there is plenty of room above and below the heatsinks for convection cooling.

It sits open with a cable box and cd player on top. I am more attached to the speakers then this unit so I may start shopping for a replacement. Only paid $400 for it so it's not a huge deal. I may look around here for a shop to check it out, depending on the price. It replaced a finally dead 25 yo Rotel RA-870 60w integrated that never clipped and sounded better for a pedestrian amp from the 80's. I'd bet the Onix would sing with the right speakers. THX!
I would suggest you not place anything on top of the amp. Having anything digital placed on top of a piece of analogue equipment or vice verse is a really bad idea from a sonic perspective. Digital noise is pervasive. Put your digital equipment off to the side and try not to stack anything on top of each other.
How far apart should they be?
what kind of speaker wire are you using?
6-8 inches is sufficient. Just not on top of each other....
Speaker wire is just some old bi-wire no name stuff with thicks and thins for each side. Rather stiff. I have thought these old wires might be the cause, too much resistance but I don't know. Never a problem with the old Rotel so I didn't buy new wires to see. The amp does sound bass heavy at lower volume. Kicks butt when I turn it up.
Looking at a picture of the integrated, it appears that there are no external heat sinks and only a small slotted area on the top of the case for convective cooling. If your stacked equipment covers those slots then you are almost certainly going to have a cooling problem. I also note that the amp does not double down from 8 - 4 ohms, and that even though the nominal impedance is 8 ohms, the minimum is spec'ed at 4 ohms. So my guess is that the amp may be struggling a little to make the necessary power into the 4 ohm portion of speaker's impedance which causes it to run a little hot and then the stacking of the cases is making it worse. And of course the component on top is also releasing heat, some of which is radiating downward to the amp.

This problem of stacking will be fixed asap. I live in SWFL so it's very warm inside because I don't mind the heat all that much. I keep the AC around 82 for me which may be too hot for a hot running amp. As far as 8 to 4 ohms there isn't much I can do with this unit. I sure appreciate all the advice folks. JJones
Let us know, but I bet you will see an improvement if you make sure the amp gets adequate ventilation. If its also got slots on the bottom, you may get some additional improvement by raising the unit up off the shelf w blocks under the feet.

There are now four inches clearance on the bottom and eight inches above the amp so we shall see if it can stay cool. Can't turn her up unless I am home when the crabby old lady across the street isn't. Not a SRV fan.
She still runs pretty hot but hasn't shut down yet. Sounds a bit better with the digital units further away from the amp. I may now keep this thing for a while longer. Thanks very much for all the help! JJones
My Pleasure....Enjoy.