Tandberg 3012 - Hot fins

I was given a 3012A some years ago and as I live in a hot country I was also concerned about the heat from the transistors. I didn't want to modify anything permanently so I placed a small 12V computer cooling fan on the top of the case secured with soft gum and used the AC Out for the power supply. The air gets quite hot at medium volume. Whether the cooling does any good or not, it gives me peace of mind!

It is absolutely normal for that amp to run very warm - even at idle. My father purchased a new 3012a when I was a kid (I was probably about 10 years old) and it definitely ran very warm. I picked up a used 3012a (it's a great amp) for a bedroom system and it also runs warm. It seems like most of the older Tandberg amps (pre 303x series) ran very warm because they have a higher class A bias than most amps do. Either way, completely normal and nothing to worry about. Just don't stack anything on top of it - it needs the airflow!

Are you pulling my leg. How would you adjust bias on this S/S amp? Can this be done by anyone with technical skills or does it have to go to a repair shop with specialized test equipment?

sounds like the channel bias needs adjustment.

I did not want to take a chance and pulled the 3012 out of my system. I will try it again in the near future with more efficient speakers (vintage Dynaco A25) and see if it gets as hot.

I have a 3012 that I have not used in two years.Can they drive 4 ohm speakers or would there be a current problem. I used to use them on 8 ohm speakers. I have a pair Maggie 1.6's which I am using with crown 1983 amps and preamp .This site is amazing that Tandberg would pop up

The 3.8s are 8 ohms and 88 db in a reflex cabinet. I wouldn't call that a tough load.

I will go back to my CJ MV60SE amp tomorrow. I think that you are correct in that the 3.8's are a bit much for the 3012.

I had a 3012 and they normally run a little warm.
The 3.8 's are a tough load and if you like them loud they would sound better with a larger power amp.

It is a 3012, not a 3012A. Dust was cleaned out. Everything is balance and it sounds really good.

i sold tandberg retail and they did get hot. i also was concerned and just kept everything well ventilated and used a fan. i also had a music fidelity integrated that got so hot you could only touch the top for a second or two and it did finaly die. after 10 years. few things last forever especially electronics. i would get a fan and monitor the heat. and i would check out for dust if there is any.i am sure you have already done that but i just had a year old laptop fail and when i opened it up the amount of dust was impressive. i love my tandberg reel to reel and casette decks and we also sold nakamichi for what thats worth. thank you

I have owned a lot of Tandberg equipment over the years and some of their models can run quite warm. If it sounds good and the channels are balanced I wouldn't worry about it. Just make sure there is plenty of ventilation and you should be ok. The amplifier's protection includes a thermo trip, which will operate if the temperature inside the amplifier rises above normal operating value.

Is the amplifier a 3012 or 3012A?

I am using it with Proac 3.8 speakers at low levels (I hate loud music). This winter, I was using it for a couple weeks with Proac 2 speakers. I will be going back to my CJ MV60SE amp soon. I am just playing around with my equipment.

It would be helpful to know what speakers you are driving with this amplifier. If your Tandberg 3012 is running hot I doubt you are driving Klipsch speakers at a moderate level. So, tell us what your speakers are and how many pairs of speakers you are driving at the same time.

I would venture to say that if this is a dual mono amp, (having 4 transistors and an identical heat sink on the other side), and if the other channel's heatsink is not the same temperature, that you have a bias issue or a component failure somewhere.
If that heatsink is the only one and all O/P devices are on it, then it could be normal.

Nonetheless, if an amp is over 10 years old, bias current and DC Offset need to be measured before usage.