Mark Levinson 23.5

I was at my local dealer yesterday because I am considering purchasing some cables down the line. He gave me 2 brand new sets to audition and told me since they are brand new they would sound best after the burn in of about 30 hours or so. I plugged them in to my Mark Levinson 23,5 and its been on playing all day (about 10 hours) at a normal to lower volume. My thought is, I'll just keep the system on and audition the sound periodically in between. I don't know if I've ever had my amp on this long. It seems to be getting very hot. Everything sounds absolutely fine. Does anyone know if these amps normally run hot after extended hours of play. It's not even being driven hard. I'm concerned because I just got the amp out of the shop last week after being in there 4 weeks the first time and then 9 weeks the second time. When I received it back the first time, I received it back with a noise issue. Nothing has changed impedance wise. Any thoughts out there?
luvrockin, I have a no.334 dual mono. I’ve had it for a very long time. Actually I bought it new when the no. 334, 335, 336 series was released. I leave my amp on for extended periods. Days- weeks even. Unplug when it rains or to switch equipment or cables. Mine only gets warm to the touch even when I push it.

No way would I leave my 23.5 on 24/7.  I would connect those cables to something else to burn in, or,  I would burn them in while listening.  If you had a tubed REF 6 pre-amp brand new would you leave that on constantly for 600 hours while burning it in?  I definitely wouldn't. Most people suffer to the slowing bettering sound of their new equipment while burning it in.

Also, the cables shouldn't sound bad while burning in anyway, and it is interesting to hear the sound get better over time.

My recommendation, is you are asking for trouble leaving a 23.5 on.


I use an old Oppo DVD player to burn in new cables. I run the Ayre IBE disc and a stereophile test CD for the most part. I normally don't  like the sound of new cables initially. If the cable is used, it goes into the system immediately.

However my Levinson normally stays powered up most of the time. 

I owned a Classe' CP35 and a CP60 Preamp and they did not have a power switch.

I wonder if the bias was changed when it was in for service.
The 23.5 runs in Class AB and there is enough idle bias which results in the amp being warm, not hot.  Former 23.5 owner.
Guys, thanks for your input. I actually turned off the amp last night. After a couple hours after this post I felt it's running way too hot, not warm for comfort. Years back, I burned in cables leaving the amp on most of the day and I don't remember anything like this. They must have done something. My dealer is closed today but I will definitely be calling them tomorrow morning.
Good luck, keep us posted in your 23.5.

Yes Woobie, will do. Its going back in Saturday. I just hope they didn't screw it up on me. I'll be really pissed because this is an awesome piece, age and all. We'll see!