What amp to match with Spatial Audio M3 Sapphire open back speakers

I should have added if you have a tube amp or a McIntosh tube or solid-state amp the 2,4,8-ohm outputs, the 4-ohm outputs make the Sapphire M3's sing like no other.

I suspect this is not correct. The reason is we have customers using our S-30 amp on this speaker and the S-30 has a rather high output impedance (and no 4 ohm taps as its an OTL). I've not heard this combo myself but Clayton (the designer) has- contact him to see what he thinks.

Thanks very much for your suggestions, even if the high and low order harmonics part kinda went over my head...

One of the differences you hear in all amplifiers is how they make distortion. Solid state tends to sound bright and harsh relative to tubes because the harmonic distortion they make is mostly higher ordered harmonics. The ear converts all distortion into a tonality- hence the brightness of solid state.

Tubes tend to make a lot more distortion but it tends to be lower ordered harmonics- the 2nd, 3rd and 4th. The ear is less sensitive to these (the higher orders are used to sense sound pressure, so the ear is keenly sensitive to them, please note that the brightness of solid state is caused by a very small amount of distortion) but the ear does treat the lower orders as a sort of 'warmth' or 'bloom'; these being the most common audiophile terms to describe lower ordered harmonics.


Some solid state people object to this coloration (thinking its caused by frequency response error, which it is not) and the most 'colored' in this regard are SETs. Much of this coloration can be removed if the tube amp is simply wired fully balanced from input to output; this causes the even ordered harmonics to be cancelled. This is desirable if getting closer to the music is your goal. SETs can be really neutral too, but to take advantage of them in this regard you need a very efficient speaker, typically over 100dB.

So I need to stay away from amps that are picky and will highlight lesser recordings to the point of making them very hard to listen to. In short, I need a high quality yet forgiving amplifier.

IOW an amp that does not editorialize when presented with a less than stellar recording! What you need is an amp that does not make much in the way of higher ordered harmonic distortion and keeps lower orders down as well. The only way I know to do this is to go with a tube amp that is fully differential and balanced from input to output and no feedback. In that way lower orders (2nd and 4th) are cancelled (leaving the 3rd, which is treated by the ear the same as the 2nd, which is to say its nearly inaudible) and the higher orders will be masked by what lower orders remain. To this end a triod amp would be a good place to start, but you need one with some power- 30-60 watts.

If you're on a budget, the suggestion of the Dyna ST-70 was a good one.