Srajan, your colleague Dawid just published a review of the icOn 4PRO you like so much. There's one paragraph I wanted to ask you about.
"The icOn 4PRO as described above relied solely on the PSU provided by its maker, but I couldn't resist investigating its responsiveness to any changes on this front. I'm glad that I didn't, Pál's product scaled well with a higher-tiered 5V feed. Its stock charger replaced with iFi audio's iPower resulted in a mild boost to imaging specificity and bass control, however tissue complexity and tonal weight remained intact and that was unusual. The more potent noise rejection is, the more these two aspects lean towards darker heftier sonics. This aside, the small performance increase with the iPower on duty was perceptible enough to appreciate it, especially considering how much iFi charges for this PSU, but ISOL-8's Prometheus did substantially more. It also didn't touch the passive pre's tonal balance and saturation, but produced more slamming, powerful and tighter bass that clearly spelled out noticeable improvements. Backdrop behind instruments and voices also became blacker to effectively outline these virtual shapes even finer than before, and land more orderly posher general view. Although listed changes weren't drastic in the grand scheme, their easily audible thoroughly beneficial nature was more than enough to justify the linear expense. This report's stout performer surely deserves such a treatment."
Here is my question. I thought this was a passive preamp. Isn't the wall wart just to power the MCU which handles the remote functions? How could that have any effect on the sound? Have you noticed the same thing with your unit? I'm just trying to understand an apparent impossibility. Fred Roma
It frankly hadn't even occurred to me to try this; not that I have another suitable outboard power supply on hand in the first place. Like you, I view the wall wart as just the power behind the remote-control and display throne. Since Dawid heard differences with his better PSU, we must assume that perhaps the micro-processor part of the circuit isn't 100% isolated from the autoformer signal path despite actual switches being at work? Even if so, I can't see how swapping in a beefier PSU could improve the bass response. How do the passive autoformers even see the wall wart? It would be best to ask the designer about that. It's not anything I've looked into, considered or understand. But there's always more to learn. So ask Pál Nagy? Srajan
PS: Because I'm curious, I just asked Pál myself. "The linear power supply is one of the variants of concern of the subjective audiophile virus which has infected a big part of the well-informed audiophile community. Because 50-20 years ago and occasionally still today, the old-school linear power supplies had some advantages, the infected guys without any real knowledge, investigation or experience with this matter believe that all SMPS are shit and the expensive analogue PSU the holy grail. So several icOn customers have immediately replaced my original wall wart, my HK dealer offers the Model 4 with an expensive Plixir supply and so forth. I spent several 100 hours on just different power supply possibilities out of the more than 10'000 hours of icOn development and production. I tried batteries in lead acid, lithium-ion, alkaline, Ni-Cd, zinc and more, dozens of different ultra low-noise linear supplies and several dozen more smps measuring them all with an FFT analyzer and listening to them in blind A/B." From that I glean that I'll happily continue to use the stock wall wart; and that others will upgrade theirs in ways which satisfy them.
Srajan, thanks for getting back to me and Pál involved. Did your man just imagine it then? Fred Roma
Not for me to say. I wasn't there. I've not done his experiment and I'm not inclined to pursue an outboard power supply just to follow up. Should I review one again like the Ferrum Hypsos which I wrote up with our active desktop speakers but never considered to then strap onto my icOn 4Pro SE… I might just try it if I remember to. I owned a Tap X from John Chapman back when and never was concerned about its wall wart either. For me it's still a non-issue. But as Pál explained, even some of his dealers feel different so everyone must trust their own ears. Srajan
It's not the first time that theory and reality aren't the same. Dawid Grzyb
