Stubbed my toe on some distortion and when I kicked it over I found gold.

Having fun with a friend Bob Katz, who kindly offered to take the Lounge LCR MKIII through his own independent testing gear. Guess what? Distortion was a bit higher than I had measured in my lab earlier on in the project. So how can we reconcile the fact that the LCR MKIII had performed great at Kevin Grey’s studio with a higher distortion than anticipated? Well, the HP Spectrum Analyzer confirmed that the first two even harmonics are at equal amplitude. And so no wonder this was the case! I have seen equipment at $14000 with high distortion and $200 with very low distortion. Even if the distortion is within acceptable range, whatever that means, these numbers affect public perception. So, I will call my approach “Distortion Management”; forget conventional methodology. Boy!!! Funny to realize what can be done when there is hunger for perfection, breaking boundaries and following one’s ears.

Let’s rewind back to Sept of 2013. I went to Kevin Gray’s mastering facility, Cohearent Audio Labs, to do a little phono preamp shootout between the Lounge Audio LCR MKII and a tube preamp built by a friend of mine. The Lounge LCR MKII did well, but could not quite look eye to eye with the tube preamp in the top end richness department. The level of performance fell right in place with most of our preconceived notions of tube vs SS sonics. Everyone walked away with the audio technology hierarchy firmly in place in the cosmic machine of the audio universe.

After getting over the shock of hearing Kevin’s truly awe inspiring system I kept on evaluating every aspect of the choices I made on this phono preamp design. I kept on trying different components and listening over and over, each time, pushing the openness and perception of air within the treble range all
the while narrowing my preamp sound with the tube unit. All this was done by ear with only quick checks of noise and bandwidth.

So then, last week, I went back to Kevin’s place. Last time all the testing was done with a turntable my friend brought. This time I got the privilege of hooking up directly to Kevin’s cutting lathe. First, I had Kevin spin my thrift store copy of Supertramp Breakfast in America. Kevin listened for about 30 seconds and just said “everything just sounds right”. Then, he pulled his test pressing of a Donald Fagan LP and … that was it!!! It became obvious that the Lounge LCR MKIII had closed the high end resolution and openness gap.

Now a distortion reading of 0.15% had me a bit perplexed at Bob Katz’s lab. It got me thinking about a hidden aspect of distortion measurement: the harmonic distribution spectrum. This is a critical aspect of the static percentage of a THD number blindly spit out of an analyzer. Huge levels of low order, even harmonic distortion can be tolerated and even coveted by the listener. Conversely, relatively low levels of high order, odd harmonic distortion will cause the listener to perceive a brittle quality to the sound. This is where the Lounge LCR MKIII really showed a pot of gold under only marginally good distortion levels. The shock of my life was to see the signature distortion spectrum of what is usually reserved for those glowing little glass bottles. It was all 2nd and 4th harmonic distortion and nothing else.

Ahhh, it all falls into place now: the heightened feeling of drama with high transient sounds, the seemingly last drop of resolution with older recordings from the golden age and the stereo placement of instruments in a resolving space. It’s not like you have a choice to live with distortion or not. It will always be there no matter what! Distortion can seem like an enemy, but well managed it can be your best friend.

 

Two things:

1. I learn more in this forum than any other audio hardware forum
2. Apparently, I simply must have an LCR MKIII!

 

Interesting.

You offering upgrades from MKII?

 

G'day all, interesting. I can't say that I totally agree however I can understand how the harmonic structure of distortion can affect hearing perceptions of sonic 'goodness'.

Indeed one of my hi fi AM detectors has a slight 'hint' of distortion which actually sounds better than a lower distortion detector AM I have which can sound almost 'dull'.

Sometimes subtle distortion, in absolute terms can actually sound agreeable but in general terms I do think that all distortion in the hi fi context should be kept 'low' in principle. Regards, Felix.

 

Gee, I stubbed my toe and now I'm convinced my system sounds worse. Different toe, maybe?

 

I have no idea what's this thread about but the title is great