Intelligent Power Amp

We decided after trying several speakers to use the ATC SCM100. This speaker is famously easy to drive, presenting a nominal 8 ohms load even at low frequencies. Therefore the voltage part of power amplification will be very well tested. This is also important since we know that it’s possible for an amplifier to be good at driving current without being able to control voltage equally well in which case load dependent anomalies would be apparent. The ATCs can also play at high sound pressure levels without distortion such as you might hear in a live performance, so we looked forward to that part of the evaluation as doing so requires sufficient current – the ATCs would reveal any limitations at those higher sound pressure levels.

At about the same time as receiving the new Linn amps, we took delivery of our 2-channel demo pair of ATC C4 Mk2 sub-woofers. We had already installed these sub-woofers in several home theater applications where we drove them with the single LFE (low frequency effects) channel, however this would be the first system we had set up with two C4 Mk2 subs in a stereo configuration, that is one for left and one for right. The full evaluation of these sub woofers is a subject for another planned review. Apart from the overall system performance elevation that we found during our initial listening tests, we felt it would be important to add the sub-woofers to make use of the convenient balanced output XLR provided on the rear panel of the Linn Solo 800s. This is relevant because it fits into ATC’s recommendation to leave the main speakers with their natural, non-resonant low frequency roll-off and place the sub-woofer roll-on at a somewhat low frequency (in our case 50Hz) to retain an overall response free of frequency peaks and limit any phase distortion. Note that this also places demand on the amplifier and is a very good test – we see that some amplifier manufacturers recommend passing the full bandwidth signal from the preamplifier or source firstly to the sub-woofer, then from the sub-woofer to the main amps, thereby rolling off the main amps when used with sub-woofers to reduce the load on the amps at low frequencies and improve mid and upper bass control. We are deliberately doing the opposite as provided for by Linn with no need for “Y-cables” or additional first order “stability filters” that can only increase phase distortion which would be the enemy of successful sub-woofer driver and dedicated amplifier integration between the main speakers and Solo 800s.

How does it sound?

The very first track we listened to was the Infernal Dance of the King from Stravinsky: Firebird Suite (1919 Version), a live Bavarian Radio Symphony Orchestra recording with Mariss Janson, released in 2019 on  BR-Klassik – 24 bit/48kHz FLAC. No system gets a second chance to make a first impression and what a first impression. We were unprepared for the attack of the very first note. Or we should say, the lack of attack. The sound made by the first massive, complex and dramatic tutti and fff chord actually starts before you register the timpani mallet has struck and a fast release reveals the response of the concert hall long after, during the rests in the remainder of the first bar, sounding as only live music possibly can – even the harpist is playing their very own eight note chord, four of them accidentals. Can anyone hear every individual note in the chord? We believe not. Based on this one chord, we could end the review here, as it really tells us everything we need to know about this system and the ability to exactly capture such a huge musical event.

Next up: The Gap Band, Yearning For Your Love from their 1980 album on Mercury Records 16 bit/44.1kHz. This band is an everlasting reminder of Black Wall Street in Tulsa, Oklahoma, spelling as it does the three main streets Greenwood, Archer and Pine of that neighborhood where the Wilson brothers forming the band are from. The signature hooks at the start of the track and incredibly catchy tunes and bass grooves the band is famous for, give way to beautiful harmonies and guitar solos that are simply enthralling. All of this is depicted as a four minute masterpiece by the pair of Linn Solo 800s. How many times have we heard this track as background music in grocery stores, on the radio or streaming without being able to wonder at the the whole song and all of its parts.

Conclusion

We can say with certainty that with this system and particularly with the Linn Solo 800s we have found stereochemistry, and at Basil Audio, achieved a truly reference level of musical performance far beyond our expectations using for the first time mono bloc amps with passive speakers and sub-woofers.