Fostex T50RP Mods Compendium

This is amazing work, thank you, @DEATHxMACHINE . I recently ended up with a Dekoni Blue nearly on accident and while I overall agree with your assessment, I heard enough potential in them that I'm now fiending for a proper mod. Any chance you'll be getting your hands on Argon Mk3 to add to the comparisons?

 

@Climber my nomenclature is wrong. Argon mk refers to driver mk not mod iteration. I refer to mk1 and mk2 in this list but it should be mk2 and mk3. So to be clear, mk1 on my list is the argon mk2 and mk2 on my list is the argon mk3.

 

Ahhhh, very helpful. Will go back and re-read with that in mind.

 

@DEATHxMACHINE,

Thanks for the comparisons of all the Fostex T50RP mods. Really helpful to get an idea of the differences between the many mods.

Have you tried a T60-based Argon? Based on your impressions of the T60 and of the T50 Argon Mk 3, the T60 Argon-modded could be another good choice. I wonder if Modhouse could achieve the same T50 Argon Mk3 soundstage you describe with the sound signature of the T60?

 

Came across this while looking for t50rp mods. Has anyone tried the Mayflower Audio mods?

Also wanted to see if @rhythmdevils has any recommendations for mods since you seem to have experience with them.

 

Mild thread necro just to post this curious thing I stumbled on:
https://www.3m.com/3M/en_US/p/d/b5005089018/
https://multimedia.3m.com/mws/media/1693093O/3m-engineered-damping-materials-edm1000-series-tds.pdf

CLD is nothing new and has been used with Dynamat and all its brethren for ages, but the nubbly bits looks new to me (article says 2019, not sure if that's when this stuff was made or just the revision of the material).

 

There's a $150 price difference between the mk3 and mk4. Why?

I know a lot of mods end up making the headphones cost much more. So does the mk4 just incorporate these mods?

 

New driver with more magnets & tighter windings - scroll down for a diagram:

https://www.fostex.jp/en/products/t50rpmk4/

Lower impedance, higher efficiency vs the MKII/MKIII. Also balanced connector wiring OOTB (but you have to buy the balanced cable as an extra). The pads look better, too.

 

Those original pads were terrible, so it wouldn't take much to improve on that.

I'm curious about that lower impedance. I would have assumed tighter thinner traces to be higher impedance, though I suppose they could have easily paralleled a couple traces to drop it back down. Higher sensitivity may come from a better/stronger magnet structure.

 

Some random links from the Head-Fi Mk4 thread:

Driver differences

Smaller front baffle foams

Looks like the front baffle structure from the Mk3 is retained (separate plate with venting around the sides).

Looks like the same paper behind the driver as the Mk3 (thicker than Mk2). The new driver backs have different venting structure than the older ones (slots vs holes).

Seems the Mk4 still has a hump in the middle mids; need more rear damping, pads...