The Accidental Tweak


Recently I turned my system on as usual and started listening to an album I know pretty much by heart. Halfway into it, a small voice in the back of my head started saying the system sounds really good today.

And it did sound fine. Maybe even... better than usual? No way I thought, I haven’t done anything to it. I must just be in a good mood.

It was not a life-changing improvement; just a bit more airiness, a tad more definition.

My Krell preamplifier made a world of difference when I introduced it to my system. I bought it in a still-working but near-death condition, and I started a regimen of fixing problems, listening for a couple of weeks, taking measurements, troubleshooting, fixing more stuff, all the while keeping tabs on bias and temps and DC offset.

The inside of this pre is gorgeous - all discrete, top-shelf components, not an IC in sight, the PCB laid out as if by a choreographer; it harks back to Krell’s long-gone heyday.

The cover was off during that process, ostensibly so I could check on stuff, but honestly I didn’t mind admiring the beautiful audio craftsmanship inside. Eventually its maladies were cured and I screwed the cover back on, I figured better before I spill a cup of coffee over the PCB.

Then it hit me: something did change, the cover went back on. Presumably that’s what I was hearing: it must have completed a Faraday cage around the pre’s sensitive single-ended circuitry, restoring shielding it probably needed because it sits inches from a pair of large, EMI-spewing monoblocks. The cover blocked the EMI / noise and that’s what I was hearing - or rather, not hearing.

But the true beauty in this is that I made this tweak completely unbeknownst of myself. In my mind I was putting a lid back on, not completing a Faraday cage, thus my brains never had a chance to develop the smallest expectation. To the opposite, I was trying to convince myself that I could not possibly be hearing anything (even though I was hearing something), because I had done nothing to my system.

So I know for sure that the sound improvement I heard, albeit subtle, was real, and that I believe is a rather unusual treat in this hobby.

Would love to hear similarly unintended improvements that happened to you guys.

 

devinplombier

There is an English company DNM Design (initials of the founder Dennis Moorecroft), that goes through extreme measures to reduce adverse effects of electromagnetic interactions.  These measures include a non-metallic case for their components.  Perhaps going topless is helping in that respect.

It’s dust…. Open up your solid state or tube gear and  blow some canned air in there and voila !!! No more noise.

i replaced my SS (Class D) amp lid with a cutting board. +1  dusting out the inside

@tweak1 ”l replaced my…amp lid with a cutting board”

I have a suggestion that may add some synergy to your amp tweak. Have you ever thought of trying the “cutting board” trick along with the latest reincarnated Leak “Sandwich” 250 speakers?

Food for thought?

Larry, There is also the American made preamplifier that uses a plastic chassis. However, in either case, wouldn't you think the complete lack of shielding would make these units MORE susceptible to EMI, rather than less?