Here my setup !
For the levels :
Low gain ZF : 9 hrs to 10 hrs for listening level with LCD-5
Low gain SS : About 1 hrs or 1.25 hrs higher
High gain ZF : About 8.5 hrs
High gain SS : About 8 hrs (ZF or SS is far more subtle in levels in high gain).
My short review
HeadAmp GS-X Mini vs HeadAmp CFA3 semi-deluxe:
Highs:
The GS-X Mini has more pronounced and raw highs. The plucking of the strings has greater impact.
The CFA3is definitely smoother in this regard—more refined, with greater extension. It captures finer details and nuances.
I notice the reverbs extending, while on the GS-X Mini, the plucking of the strings is more lively and i capture less the reverb cues.
The GS-X Mini is not aggressive at all in the highs. The CFA3 seems a bit more restrained in comparison, but with headphones, you don't want needles in your ears as it quickly becomes unbearable.
Bass:
The bass is firmer and better damped on the CFA3 compared to the GS-X Mini. It feels like moving from a 50WPC amplifier to a 200WPC one with speakers.
Soundstage:
The soundstage is something very important to me.
I don't want a rendering where you're stuck close to the music.
I want some distance so the illusion feels more realistic and less like hearing music on either side of the head.
The soundstage is wider / envelopping on the CFA3, and the music feels more distanced from the head.
It's not too distant to feel dull, nor too close.
The GS-X Mini is slightly closer to the head (not by much), but the soundstage doesn't extend as much as it does with the CFA3.
Listening experience:
The CFA3's rendering is organic, very fluid, and musical.
When listening, the focus isn't directed towards the high frequencies but rather towards the melody.
With complex music, one can appreciate the CFA3's ability to deliver all the nuances and micro details, whereas with the GS-X Mini, it might seem a bit grainier and harder to listen to.
Heat:
The CFA3 is hot! I can keep my hand on it, but it's uncomfortable.
The GS-X Mini is pleasantly warm to the touch, like a heated floor.
AC Cable:
I tested the stock power cord against my Aliexpress Nordost Odin II on furutech copper outlet.
The "nordost" is firmer, wider, more impact ... no question for me ... the "big stiff powercord" stay there.
Summary:
For me, it's clear that the CFA3 surpasses the GS-X Mini in every criterion, even with an easy-to-drive headphone like the Audeze LCD-5.
Update: 2025-03-10 : HD650 on CFA3
On my Sennheiser HD650 wired with the Stefan Audio Arts Equinox (XLR) balanced cable, it's truly excellent, as you would expect.
For criteria, it's pretty much the same as with my LCD5.
Is the GS-X MINI better with the LCD-5 or the CFA3 with the HD650? Hard pick !
I appreciate the HD650 for being able to handle everything without anything becoming irritating. It’s precise enough to delve into the mix and has enough soundstage to provide a great experience. The LCD-5 is more capable; it’s more precise, the bass is sharper, the soundstage is larger with more apparent spacing, but it’s more sensitive to recordings. With pop/rock, it can feel a bit too thin in the midrange, and the details can dominate a bit too much.
You either go for an all-rounder or choose something that can go further but might be less enjoyable on certain recordings.
The CFA3 brings very notable improvements to the HD650. For example, a broader and more immersive soundstage, more distance from the music, finer details with smoothness, and greater nuances.
For sure, HD650 will stay in my ultimate headphone station without hesitations and same for LCD-5 (not have the $$$ for susvara 8-/ )
I put a AC Infinity AIRCOM S7 to help for the heat.