Another way to say this is… During a 'normal' turn on, the inrush current is usually much more then the normal run time current demand. So, slow blow fuses are usually chosen because they 'allow' (for short periods of time) greater current flow than their 'rating' would suggest. This also works...

It took me 200+hrs for my PurpFuse to 'sing'. And during the 'break-in' period, the SQ would shift all over the map, and in every possible way (dynamics, mids. bass, highs, soundstage etc.), and all of these shifts would mix and match (or not). I'd suggest a rematch well after 200hrs of playing...

Just curious as to how many hours of playing time are on these fuses? Thanks JJ

Yes, that should do the trick. You should also be able to find non medical grade transformers, which should cost less. And if you're handy with DIY, the core transformer can be found for well under $100. JJ

One possible solution for 'noisy' ac power is to use an isolation transformer or a much more expensive power conditioner. One advantage to using an isolation transformer is the output is 'balanced' (±60VAC) as this can also yield a SQ improvement in and of itself. JJ

Realistically only you will be able to determine where the greatest improvement will occur, and by how much etc. And it may not be that either one or the other will be the greatest improvement but that the accumulation of improvements could be the the greatest change and most gratifying. This is...

Can you hear any differences between the 3 gain settings at the same or nearly so, volume? If so, use the setting that sounds 'best'. If not, it doesn't matter. JJ

This 'trick' of making sure the clamp screws and the ends of the 12awg wire are optimally setup is a 'simple' tweak that in some cases can solve a whole mess of 'quirks'. All it takes is for someone (previous owner?), at sometime, to run a circuit, where the clamp screw was slightly loose, with...

Yes, I saw Caelin's videos and white papers as well. So I purchased an ASCC (Available Short Circuit Current) tester and performed several experiments using several types of power delivery and several different cables and duplex receptacles, and then measured the actual current draw into a 'test...

I have looked into these and other related issues and have written up my findings, if interested, look at my sigline and follow the link(s). Bottom line is, it's not the voltage fluctuations that are really important, as it is the ability to deliver current in small regularly timed pulses that...

AKA Deep, weekend long, Cryogenic treatment… 😎 JJ

One of the more plausible 'explanations' for why fuses can make a difference is… As ALL of the power that is used by our audio devices is channeled into a single 'short' chunk of wire or 'fuseable link', it will change it's operational characteristics. As our devices demand current be drawn...

The frequency response measurement itself is still a 'static' measurement, which is unlike music. We are talking subtle nuances of phase and other circuitry response characteristics (slew rate, overall phase response, as well as possible impedance mismatches etc), due to the constantly changing...

Just an added thought to consider. The fuse direction that you use, if 'backwards' will take additional time to 'undo' before the fuse will reach optimal SQ. This comes from experience. JJ

Have you accumulated close to 200+hrs yet? If not, I'd use the 'go with the flow' technique. That being, the current should flow thru the fuse in the direction of the wording on the fuse itself. Then decide… JJ

Making the assumption that a static or simple based resistance measurement is directly related to SQ is, in my experience and understanding, misleading at best and at worst completely irrelevant. Why? Because we are talking about listening to music which is not a simple, nor static, nor easily...

Depending upon your budget of course, I'd start with the power amp then move to the dac and ddc last. Why? Because the power draw from the amp is the most dynamic while the digital devices use a more consistent amount of ac power. These 'tweako' fuses tend to 'favor' the changing demands for...

There are a variety of cables that are an 'improvement' over the stock cable. Which cable is dependent upon your budget and requirements (length, if it is to be hardwired, or not, etc.) I myself use a SAA (Stephan Audio Arts) cable and also a Jena Wire cable, both of which are hardwired into 2...

One thing that can help, is to dampen the 'trapazoid' area (next to the headband to earcup mounting screws). These 'early reflections' can 'mess with' the overall SQ and in a number of ways. As for micro and macro dynamics, I have found that a better cable, and hardwiring said cable, can do...

I will respond in more detail to your 'sound proof room mods'… hahahahahahahahahaha Since this is a very interesting subject that has multiple facets all of which help in our enjoyment of our audio pursuits. It will be interesting to hear your observations on the 88.2 vs 44.1SR shift… JJ

I dealt with this many years ago. I have the Rok on ≈ 1.5" risers insulated with wood, sitting on top of my Jggy dac, and added a very slow speed/cfm fan sucking air out from the top vent holes as well. This dropped the temperature of the case from 5-20°F (depending on where it's measured) and...

do you have a direct link to their test? It is a russian site and while I can translate it there is no direct access to that test. Also when I use my trusty fluke 289 it measures the 2 channels as 52Ω and 47Ω JJ

Yeah that is 'interesting that there are so many different 'measurements'. I tend to trust Inner Fidelity since that is based upon an actual measurement from his test setup. And I did try and find an actual genuine HiFiMan data/spec sheet but none showed up in my searches. And this is kinda...

I guess we both are incorrect because according to the inner fidelity test they measured as 47Ω. Thanks for pointing this out. JJ

I've been at the audio 'hobby' for many decades and have always enjoyed learning the details of what is and isn't significant. No, when I was in school, audio was not on most schools curriculum, so it was my own research and study that 'paved the way' so to speak. My HD800's are on the 6th (and...