Taking Koss Portapro to the Limit (cool mods).
Feb 8, 2013 at 9:38 PM Post #62 of 143
Anyone consider these?
 
http://www.ebay.com/itm/Original-Sennheiser-HD25-1-black-velour-ear-pad-set-HD-25-c-HD25sp-HD25-13-sp-/130843674535?pt=UK_AudioVisualElectronics_HomeAudioHiFi_Headphones&hash=item1e76e407a7
 
I find the velour much easier and conforming than leather/pleather and a much better seal .
 
 
May 28, 2013 at 5:34 AM Post #64 of 143
I registered just to post in this thread, so this is all your faults. Been using my porta pros for a while when I misplaced them yesterday. There are two places for me to check before I buy a replacement tomorrow, but in the meantime, I'm keen on the mods that can be out the cabling and pads. Where do you find the custom pads? Cannibalizing seems to be the way of the leather, while the foam replacements are commonly sold. New cabling I have no clue about. The 75 ohm resistor I could probably find but I'm not sure about the why and how. Care to help get my ball rolling?
 
May 28, 2013 at 5:39 AM Post #65 of 143
Pads:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=171046931957#ht_4381wt_1077
75ohm:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=281110649388
 
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Jun 6, 2013 at 11:08 AM Post #67 of 143
How do you guys get the protective plate off? I see three small clips and one large one.  I started putting pressure on one of the smaller ones but the blue plastic housing discolored in that spot so I stopped to avoid breaking it.
 
Jun 6, 2013 at 11:12 AM Post #68 of 143
just "force" a little stanley knife in hair-thin gap between plate and driver housing.
then...lift it up
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my plate was slightly glued to the blue driver housing
others' aren't
no need for glue when you clip it back in place
 
Jun 6, 2013 at 11:21 AM Post #69 of 143
 
This is not a step by step guide but a collection of mods floating around head-fi tweaked for my own needs and taste. Some might find my impressions useful and get encouraged to perform their own.
The thing is that the portapro driver is awesome, but it can do much better if modded. Most ppl here perform the Kramer mod or the quarter hole mod(to release some detail and tighten the bass) and think they are pretty much done. Some add 75ohm resistors (to tame the highs and lows) and re cable their cans. But those are just tweaks.
Another mod is mounting reversed vintage Sennheiser Hd414 pads on the Koss driver. Pair this with the Kramer mod and the phones start to shine. That got me going for a while..

A year ago I purchased a vintage Koss SST/5 cans from another head-fier, which are sort off a Portapro's bigger brother. They were twice as big and.. twice as ugly
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 So I took em apart and grabbed their most valuable part- the ear cushions..
I had no clue that ear cushions can make so much difference! The hd414 are good, but not THAT good!
img0198bu4.jpg


First thing I noticed that the volume went up by a couple of notches with the SST/5 cushions. So i had to turn it down a bit. I guess what happens is that the cushion captures the sound and nothing is escaping so it goes directly to your ears. I assume that it didn't happen with the stock and hd141 cushions because they are made of foam.

Second major change was in the bass department. No more bloat! Just tight and punchy awesomeness
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 The beautiful thing is it's not less, just better.

Then comes the soundstage and instrument separation... Let's just say that those bad boys sound like a proper can now.

As for the highs, well, they can be a bit sharp. I guess it's because of the driver distance from the ears coupled with the Kramer mod [drilling holes in the driver grills (you can see that on the left side of the pic)].
It doesn't bother me much. Depends on the type of music.
What can be done to fix this is to put back a piece of the original foam
img0256bz9.jpg

One might ask- wouldn't that defeat the purpose of the Kramer mod?
IMHO it's better to go with the drill mod plus the foam (if the highs are to sharp for you) then going with the stock driver + foams with a quarter hole since plastic blocks more sound then foam. That way you get all the detail you want but with less dominant highs.

Here things went a little crazy..
img0159iv0.jpg

..mounted some unused hd212pro (lousy cans) ear caps on top of the sst/5 caps plus hd212pro headband cushion on top of the sst/5 leather stripe.
The main goal was comfort but then i discovered that the additional ear cushions widen the soundstage even more and tames the bass a bit. Which would suit classical music and ambient when you just wanna relax.

I encourage anyone who has the Portapro's/KSC75/35 to experiment with the mods. Those drivers are capable of so much more for so little money.

Post pics of your mods in here even if it's just a re cable.
img0240xk4.jpg

Kramer modded pp's with leather ear cushions, SPC recable and 75 ohm adapter awesomeness!
 
 

Do they still fold up?
 
Jul 2, 2013 at 8:24 PM Post #71 of 143
Bit of a thread resurrection, but is the resistance mod worth doing? Costs around £10, which is near enough 50% of what I payed for the PortaPros themselves! :p
 
If so, anyone got a UK source?
 
Jul 10, 2013 at 4:36 AM Post #72 of 143
Quote:
Pads:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=171046931957#ht_4381wt_1077

 
Do these pads fit well, and do you (or anyone else) have pictures of the porta pros with these earpads on? I'm curious to try them myself, as I find the stock earpads to be uncomfortable to wear when sweating, but I imagine that too large earpads would contradict the design of the drivers.
 
Jul 10, 2013 at 7:20 AM Post #75 of 143
I have them as well, and they get really sweaty. I take a picture for you later today before I put the stock pads back on.
 

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