Any thoughts on the CD "trimmer"

Missti, ask Krell about how I discovered that overhead halogen lights, shining through the Plexiglas lid of their MD10 CD transport effected the bit stream to the D to A converter.

Stray light, bounced light and vibration are all real. The CD player must work harder to get the data correct when it meets these forms of interference. Yes, it still delivers good sound but there IS a difference and that's what most audiophiles are seeking.

So, if a tweak helps a little and the perfectionist can hear it (for instance Essentialaudio), they are availing themselves of better quality and passing along the experience to others that want to get that last bit of music.

If you can't hear it, be happy and don't spend the money.

Rlwainwright

That may be so, Albert, but the fact is that the VAST majority of CD players pull the disc inside the machine's case. So, please explain to me just how "stray" light is getting inside the player?

Obviously CD's pulled inside or otherwise blocked from stray light are exempt from that problem. The post by Missti indicated errors were impossible and I wanted to point out an absolutely clear example contrary to that statement.

My personal experience with this machine matches Sean's comments exactly. Perhaps others will remember the CES a couple of years ago where an Audiodesk was set up by the distributor. Attendees could get one or more of their CD's trimmed for free so they could hear the benefit.

Several people bought two brand new CD's from music vendors on the floor, had one trimmed, then proceeded to various rooms where both discs were played. Results were identical to what Sean outlines, I heard it myself as did other visitors in the room that had no idea what was going on.

Remember too, I am a fan of analog and seldom listen to CD's. However, I do support those who want the highest possible level of performance from their music systems and that includes tweaks to digital.

Albert: You say Krell confirmed your finding that "overhead halogen lights, shining through the Plexiglas lid of their MD10 CD transport, affected the bit stream to the D-to-A converter." This implies that they actually found a change in the measured datastream, and also that they controlled for any effect that such lighting fixtures may have on the powerline (presumably by measuring the data with the lights on, versus with the lights still on, but blocked from shining into the player).

One of our music night sessions I accidentally improved my Krells performance by resting a record album cover on it's top.

The CD was still playing and I was putting the LP on the turntable and we all heard the improvement. At first we all thought the tiny additional weight of the cardboard was somehow damping the chassis.

After repeated tests we determined the same effect could be had by holding any light blocking device above the player even when we were not touching the player or turning the lights off.

I told Krell about my experience and at first they did not believe me, later they acknowledged there was an effect and they treated the interior of the player with light absorbing material and added a heavily smoke colored tint to the Plexiglas.

Oddly enough, a guy my audio group has a very late model Krell player and while visiting him a month ago I ask for a magazine. He brought it in the room, we continued to listen and then I laid it on top, blocking his halogen room lighting.

There was an improvement and he was totally surprised. Not nearly as big as with my old Krell but audible enough that he cut a fancy piece of cardboard to fit the player and now keeps it handy when listening.

People love to make fun of tweaks but often it's just an improvement by accident that solves a problem nobody even knows exists.

Zaikes, I did not say Krell didn't measure the effect, I simply said they agreed there was a problem and fixed it. It does not matter that I didn't measure the effect, the change of blocking the light was enough of a problem that the manufacturer changed the design.

As for opaque cover, the transparent cover was a big part of the beauty and design of that piece. Swapping for a smoked version and darkening material inside increased performance without calling attention to the mods or admitting anything was wrong with the original. Frankly, this happens all the time in high end audio, it's just not brought to the attention of the consumer.