I mentioned last week that I would set up my ST-70 in place of my usual 200 WPC amp. I know, tube vs solid state adds one more variable, but at least it's in favor of the 35 watt amp. At any rate, my power hungry 4 ohm ADS M12 towers do sound great on the 'little' 35 WPC Dynaco. I could tell it was a different amp from the first few seconds of the first track that I played. But how was the power vs the much more powerful amp? In a few words, it was great, much of the time; other times, not so much. On vocals or other music with minimal bass and dynamics, it sounded fine.
When I switched to some with more bass and dynamics, I thought something was not quite right with the Dynaco. I checked the bias, as I know that I can get more distortion if it's not correct, and it was right on. I turned the volume down a bit, and it sounded good again. I suppose I was hearing distortion on the ST-70, which I must say was not as bad as SS distortion. It was like there was a jagged vs smooth sound, if that makes sense. This was on day one of using this amp, and I experienced the same on multiple occasions. It seemed to occur around 86-90dB or so... lower when there was more / louder bass. I know that the amp I normally use will go well over 105dB without distortion, and probably higher, if I pushed it.
I can repeat this with a 35 watt SS receiver, but I can't imagine that it'd fare any better. I also have a subwoofer in this setup, and the crossover is generally set at 42Hz. I raised it to 60 to allow the Dynaco to play louder without distortion. I was going to try it with the subwoofer bypassed, but I forgot to check that. Normally, the big ADS towers do fine without the sub; I use it since I have it and it's a decent one, and I find that I do get a bit more bass without it sounding overdone by using the sub with a really low crossover point.
My conclusion from a very causal 'test' is that a smaller amp can sound good, as I experienced. However, I have to balance the volume and material, as I cannot play much of what I listen to at levels I like with the smaller amp. The Parasound SS amp sounds really clear, effortless, and just slightly warm all the time, no matter what I play, at whatever levels I can reasonably handle. If I could use only one amp with my current speakers, I'd go with the higher powered one. If I listened to a different type of music, or had more efficient speakers, I'd likely be happy with the lower powered Dynaco. Since I don't have only one amp, and I can use both, I'll find a way to configure my setup to allow for easier switching between the two (if I can physically get them on the same shelf).
