old home amplifier has mood swings?

Question

well i got this old 4 channel amplifier and only 2 channels work and i got 2 alpine type s speakers hooked up on the left channel and 1 10 inch sub on the rite with 2 dome tweeters and it sounds great good clean sound good bass but at times the amp makes the left side crap out and give a big hiss over the music what do u think the problem is

Answer 1

Old audio equipment is easier to work on, nicer looking, and usually better sounding at the same price point as modern receivers. I collect them and fix them when I have the chance.

Now, to address your problem. I think part of the problem stems from you using the configuration you are using. I am familiar with the Alpine Type S series from my car audio days, and it sounds like you are driving the impedance too low with the Alpines connected up which might be killing that stereo channel. Check the wiring to make sure the combined load is no more than 8 ohms. You can technically put them in a 4 ohm configuration but the problem is that newer drivers have horrible impedance curves that usually drop a good 30%-40% below their nominal rating at times. This leads me to the next possible problem.

You could be overheating a component and have it developing/displaying a thermal defect. If it happens after being on for awhile then there is a good chance this is the problem. It isn't the easiest thing to isolate and replace the component, but it is worth it for someone who collects vintage amps.

However, it also might be something as simple as a dirty potentiometer. I have some dead spots on my volume and balance control that sometimes act up at random times. Some contact cleaner sprayed on the pots then worked into them usually does the trick temporarily. If you have access to some freon, it technically works better since it leaves no residue and just evaporates when done cleaning.

Bottom line is to not just throw the amp out. Sell it locally or on ebay to someone who can fix it if you need to buy something new. You'll make a few bucks and help make a tech like me happy.

Answer 2

Hi.I think it's on the way out.If only 2 channels work and one of those is faulty,sounds like its had its day !