Macworld Forums

Has anyone got or heard one of these ipod compatable amps. It's looks really good. I suspect the valves are just for the preamp stage of the amp. Also concerned how loud this little amp will be 13Watts x2. I know valve amps tend to be on the quiet side anyway.


Any feed back gratefully received.

pj1240,

the whole valve vs semiconductor argument has been going on for more than 40 years. As one who still has some valve equipment alongside everything through to the most modern digital stuff, I don't have a particularly strong feeling either way.

In terms of volume, if the valve is used as the power amplifier outputs stage, it's likely that it won't look very powerful as a specification on paper. But valves work in a subtly different way to transistors and a valve amplifier with a 10 W output will sound respectably loud - certainly room filling volume. Part of this is die to the way the amplifier works. Valve amplifiers usually use a configuration called Class A. The effect of this is that any distortion consists mostly of even harmonics, which are much more musical and therefore acceptable to the ears, so a valve amplifier can be pushed harder and still sound pleasing. Certain transistor amplifiers, particularly very early designs, used Class B, which produced odd harmonics when pushed towards distortion, which sound rather harsh.

But a modern high-quality semi-conductor amplifier won't produce distortion to any significant degree and such arguments are less relevant. Semiconductor systems usually offer a significantly better signal to noise ratio, that's more important with a digital source which could offer a 96dB dynamic range.

Generally speaking, valves are attributed with creating a 'warm' sound. Some would argue that a sound that isn't the same as the one fed into a device is wrong, but most things audio are very subjective and at the end of the day, it's down to what the individual likes.

If you're planning on using an iPod with any sort of high quality amplifier, don't forget that normal recordings will have been compressed using AAC and there will already be some loss of quality that can never be restored. On the other hand, if you rip CDs yourself via Apple's lossless codec, the quality can be superb and the limiting factors will mainly be the amplification system and speakers, together with whatever compromises were made during the recording at the studio and when mastering it to CD.

AlanAudio,

I don't disagree, but having lived with a Fatman iTube for some months, I would point out that even with an iPod packed with MP3s encoded at 192, the iTube gives beautiful, really pleasant, room-filling sound that knocks the Bose Companion series, the iPod Hi Fi, the Jamo i300 and the Monitor iDeck into the proverbial cocked hat.

And with John Lewis now knocking them out at £299, they really are a compelling bit of kit.