The Fostex T50RP as envisioned by Zach Mehrbach

With an overwhelmingly positive review, it kind of sounds like shilling this for free stuff, doesn’t it? Nope, these headphones were loaners that I’ve already returned. But the ZMF mod impressed me so much that I bought one. Well, I bought the mod. For the sake of reviewing purposes, I removed the jack and hardwired them to see if there’d be any significant difference. I think I did the experimental process wrong because I bought Alpha pads for them, which changes the sound significantly enough for an entirely separate review.


*I am finally getting back to this review after two months. Zach was kind enough to loan me a pair of the painted and recabled Bass to compare to my maxed out pair. The main differences is that my pair has Alpha pads and Canare Star Quad cable. The loaner has HM5 pads with an extra piece of distancing foam, a new jack (which I was told makes a significant difference), and Mini-Star Quad. Consider this ZMF Review Part 2, but considerably shorter because the differences are minor at best.*


The bass with the thicker pads is a little less impactful, but more diffused, enveloping even. I noticed that there’s a little more body with the Alpha pads, which may be a result of the much thicker padding and now-angled pads and larger volume between the driver and my ear.

Alpha Pads on the left, HM5 pads on the right
Alpha Pads on the left, HM5 pads on the right

Comparing the bass to that of the loaners shows that there is definitely more impact with the thinner HM5 pads, but I noticed that I sorely miss the extra warmth the Alpha pads give to the upper bass and lower mids.

The mids are a bit less prominent in the Alpha padded version due to the warmer sound, but it makes all the difference to my issue with the upper mids being a bit too sizzly. Vocals are definitely more to my tastes (which, of course, may be different from the reader’s) with the more intimate, yet paradoxically larger, sound.

From memory, I think the upgrades Zach gave this particular Bass pair a slight boost in clarity and cleaned up a little of the upper mid grain. Otherwise, I don’t think the upgrades have drastically changed the sound. Compared to my pair, the Bass sounds a little shrill due to the still-wonky upper mids, but vocals and instruments are notably more forward.

The Alpha pads make for a slight dip in the treble compared to the regular versions, but it adds to the linearity of the sound. I don’t really miss the treble, but I wish it extended a little more.

The Bass pair I have on hand has better treble extension than the previous pairs I had, but still isn’t what I would consider bright. I did notice the harmonics are a little bit cleaner than I remember from the previous pairs. Whether it’s the cable or new modifications that create this change I’m unsure, but I’m liking it.

Soundstage is very much larger with the Alpha pads, but as Zach mentioned in his own website, it can sound artificial due to the significant angling of the pads. It’s definitely a unique take on the typical warm sound, since it’s both intimate and spacious at the same time, but may not be for everyone.

All in all, it’s pretty easy for me to recommend the Alpha pads as an upgrade, but with the caveat saying that the Alpha pads most certainly push the ZMF away from neutral and make them more of a chill-out headphone than a dissection tool, which the ZMF shouldn’t be used for anyway. But I can definitely see the appeal in the more mid-forward sound of the HM5 pads, as it makes for a very nice all-arounder, especially with the new modifications.


Speaking of the modifications, Zach was quite excited when he told me about the rejacking options, and now I can see where he was coming from. While the difference isn’t night and day, I almost immediately noticed that there was slight improvement in the sound all around. I’m not sure if I can trust my ears completely, but, to me, the sound was cleaned up to make them fight even more above their price tag. But $60/$75 is a significant amount of money, until the fact that the original jack is pretty mediocre is considered. With the Classic and Bass, I had to use DeOxIt at least once weekly, with the continual fear that the jack will prematurely wear out. If the ZMF is to be considered a headphone to keep for the long haul, I unabashedly recommend getting a new jack. The version I have on hand now is the balanced jack, and for $15 more, it’s hard to say no because it adds the possibility of using an entire new sect of amps (even vintage receiver speaker outputs, which I sorely wish I had the opportunity to try with these).

I’ve now been a ZMF owner for two months and I’m being completely honest in saying that my search for a closed headphone has come to an end. While I still have pangs for a JVC DX1000 at times, it’s hard to argue with the package the ZMF provides. It sounds fantastic, is usable from DAPs (of course not to their fullest potential though), is incredibly durable (I’ve just jammed these in my backpack without a care), and is comfortable. While my Audio Technica ESW9 still gets some use when I don’t want to lug around such a large headphone, I haven’t really been searching for my next upgrade. The ZMF may just be my final upgrade…until Stax are attainable.

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