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October 16, 2017 - 8:21am
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4 ohm Speakers with 8 ohm Amp Cause Distortion?
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As it states that the minimum load is 2 ohms, the distortion should not be caused by your speakers. The high damping factor also indicates that the actual output impedance of the amp is less than one ohm, which is exactly what you want.
Also; even IF the speakers were causing it, it would not overheat to the extent you describe.
I suspect that the problem is a poor ground where your RCA cables connect to the source or amplifier.
This can cause the amplifier to go into oscillation at ultrasonic frequencies, which causes excessive power to be produced at the ultrasonic frequencies, which overheats the amplifier. This also causes distortion, because the amp is clipping at the ultrasonic frequencies. To verify this, you need an oscilloscope, which will show the clipping and distortion at the speaker terminals. You will not hear the ultrasonic clipping, because it is...duhh...ultrasonic.
This is a very common problem. It is the first thing I look for when I am checking an amp that is overheating.
Many of the RCA cables have thick heavy leaves on the outer grounding part of the plug connector. These LOOK good, but they may not be springy enough to make a tight ground contact on the jack.
Cables with thinner springier contacts often make a better ground contact.
No RCA plugs. Was using Airplay or USB computer to amp connection.
I recall now that at volume ~75-80/100 I was getting popping sounds too. This was on a Grateful Dead bootleg so I thought recording artifact but no pops when volume lowered below 70/100.
Speaking with others many suggest a bad match and a 60W 8 ohm amp not ideal.
Is it possible to damage the amp and not know? I mean even if I swap to 8 ohm speakers down the line have issues from pushing it a few times.
I must admit I had it over 90/100 several times for over a minute and over 80/100 for extended jams....
The dealer is taking responsibility about selling the mis match and willing to swap out. I don't want to do this unduly and cost a good store for no reason.
Consider getting the Musical Fidelity M6si integrated amplifier.
It is second to none in sound quality, and has the power to drive ANYTHING with no strain (hundreds of watts).