Just listened to some Fostex T50RPs today... WOW!

[ambchang]

I used the ALO Rx MkII, RSA Tomahawk, and CMOY amp on my modded T-50RP, and I have to say the only one that really drives the cans well is the RX MKII.  Tomahawk is more of an IEM amp, and CMOY struggles in the sense that it feeds too much extra noise to it.
 
I don't have a desktop amp, but I would love to see if anyone tried the Matrix M-stage on these babies.  I always wanted to get the M-stage, and was wondering if they work with my cans.
 
BTW guys, if I am putting a direct cable, does the position of the drilled holes for the cables make a difference?  Is there an ideal spot for the cables?

 

[BotByte]

From:
 

 
To:
 

 
Conducting tests at the moment. In Mono with one side modded.
 
 
Right side is modded
 
 
The Airborne Toxic Event, Welcome to your Wedding Day:
it seems that the right side, I don't want to say more full, more wore is there. But the highs are sharper.
 
The Beatles, Come Together - FLAC, 2729kbps 96000hz
Left side gets the mids more, right has more highs,
 
John Martyn, Solid Air - my favorite with the T50RP
The bass has a slight more impact on the right
 
Frank Sinatra, Glad to be unhappy
More reverb on right More bass impact on right
 
Diana Krall, A Case of You
More reverb on right, harper highs
 
I see that removing the material on the back of the driver gives the sound more action for soundstage and reverb, a little bit more impact of the bass and looses the highs.
 
To call it a better mod, I guess you couldn't. But maybe it will let me mod more better and allow the mods to make more of a change. I'll update when I find what's another upgrade. Maybe dense foam will be nice.

 

[BotByte]

Quote:

 
BTW guys, if I am putting a direct cable, does the position of the drilled holes for the cables make a difference?  Is there an ideal spot for the cables?

 
I haven't recabled but have thought about it hard enough
 
Placement won't matter. But it would be cool to put a detachable off side one.
 
Has anyone tried sending a cable off through the headbands?
 
If you face the drivers down, drill right under the square shaped backing. Then the cable will face down and shoot up to the driver. Off side or on the diagonal might cause problems

 

[BotByte]

Another update:
 
I've tested and tested, for about three hours. Pics will show:
 

 
The best mod I found, next to my Blutak sheet. Sounds just like the blutak sheet. So if you can't get blutak and have some high density foam around, go a head.
 
I made a Blutak monster. RAWR!!!
 

 
This was to test the effectiveness of mods period. I stuffed pennies into the blutak sheet. The sound, was less, as if the blutak wasn't there at all. Maybe there was some bad reverb kick also, but only on some recordings.
I added the dampening dot to the naked driver vent and this helps.
 
 
So, what did I find was the best?
 
My blutak sheet. I just took three strips and rolled them out into a sheet. Pressed in and cut the center dot and vent out.
 
 
Last impression:
 
All I did do, in the end, was cut the backing off. Now, the bass impact was drained a bit. But everything seems a little more clear. Symbalance is more on high now, but that adds to the clarity. Vocals sound more defined and the bass sounds more natural.
 
I do think the back removal is a good mod, 4/5 stars. But if you want more bass, keep it and stuff the entire cup with blutak and drill a hole under the driver to vent.

 

[Katun]

That thing looks creepy.

 

[mrspeakers]

Quote:

My comment about the amp is up to 250ohms. I said that because a low impedance amp would he horrible to the T50RP
 
And fine, I'll replace the felt on the drivers. Now where was that again? Thunderpants thread?

Can't agree on the impedance comment...  Low impedance amps are fine with the T50.  
 
In general, having higher output impedance in an amp than the load is not a good thing.   This is because the circuit is really a voltage divider and when the load has nonlinear impedance, this will cause an increase in bass response, and other anomalies of 1-3dB (or more) throughout the spectrum as the load impedance peaks and dips.  
 
A good rule of thumb is actually that the ratio of headphone impedance to amp output impedance should be at least 4:1 to avoid artificially boosting bass.  Interestingly, orthos are a bit of an exception due to their flat impedance curve which will make them actually pretty independent of output impedance compared to other driver types).  All my amps are 1 to 10ohms, and they are all excellent with the T50.  They are OK on my receiver, which has higher output impedance, but it does not sound as good to my ears as my dedicated headphone amps. 
 
For the felt, there's a lot of discussion in this thread.  I think Sachu started it way back, it's also detailed in the Rastapants (and some other mods, I think joelpierce and leeperry).  
 
I'm sorry if you think I'm trying to push you to take off the white felt.  You have a sound you like and if you're happy, it may not improve on it and it is a one-way mod (I do feel it's worth it, but with your pads, I truly can't predict the outcome).  For me, the sound I ended with was very flat and extended and I never looked back.  I only mentioned it because in my case, it had a bigger effect than the pads and the combo of mods ended up way exceeding my personal expectations...  If you live in SoCal, maybe we could arrange a mini-meet to listen and compare.  I got some good feedback from Turimbar when we had a meet, he's the one who turned me on to the 840 pads.
 
 

 

[BotByte]

Quote:

Can't agree on the impedance comment...  Low impedance amps are fine with the T50.  
 
In general, having higher output impedance in an amp than the load is not a good thing.   This is because the circuit is really a voltage divider and when the load has nonlinear impedance, this will cause an increase in bass response, and other anomalies of 1-3dB (or more) throughout the spectrum as the load impedance peaks and dips.  
 
A good rule of thumb is actually that the ratio of headphone impedance to amp output impedance should be at least 4:1 to avoid artificially boosting bass.  Interestingly, orthos are a bit of an exception due to their flat impedance curve which will make them actually pretty independent of output impedance compared to other driver types).  All my amps are 1 to 10ohms, and they are all excellent with the T50.  They are OK on my receiver, which has higher output impedance, but it does not sound as good to my ears as my dedicated headphone amps. 
 
For the felt, there's a lot of discussion in this thread.  I think Sachu started it way back, it's also detailed in the Rastapants (and some other mods, I think joelpierce and leeperry).  
 
I'm sorry if you think I'm trying to push you to take off the white felt.  You have a sound you like and if you're happy, it may not improve on it and it is a one-way mod (I do feel it's worth it, but with your pads, I truly can't predict the outcome).  For me, the sound I ended with was very flat and extended and I never looked back.  I only mentioned it because in my case, it had a bigger effect than the pads and the combo of mods ended up way exceeding my personal expectations...  If you live in SoCal, maybe we could arrange a mini-meet to listen and compare.  I got some good feedback from Turimbar when we had a meet, he's the one who turned me on to the 840 pads.
 
 

Well, to note I've modded my receiver to power into three different loads. No idea how much power if coming out of each, but the first goes for 32-60ohms, the second 100-300ohms and the last all the way up past 600ohms to almost 6 watts. I still don't really understand what I did to my receiver. I get into doing something and I learn how to do it without someone teaching me. Maybe if I had a pro check my receiver out he could tell me what I did. I've done the same thing with a mustang before. I fixed it up and didn't know what I did.
 
I see if you want to go ortho, don't go by the Ohms. T50Rp is 56ohms (?) but then pulls like a 160ohms. The Hifiman orthos pull at like 36ohms and need a bunch of juice to push.
 
I tried the felt, $0.60 for a yard, and it did bloat the bass for me.
 
I'm kinda happy I did the backing, but then not. I guess I just have to used to it. What surprises me most is the vocals. Listening to Beck (which he's not so clear) I can hear further into his tone. The bass loss is a downturn, but then I added more blutak and gained the bass back. Overall it was a +
 
I don't like in california.
 
Now the mod inside the cup are small little addons to me. First you need a amp, then pads, a good burn and then you dive inside. Everything adds up over time and after 200+ hours of you ears burning in, you start to love these.
 
My homemade pads are the ones that absolutely boosted everything. I need to make a second set.

 

[ccklone]

Quote:

BTW guys, if I am putting a direct cable, does the position of the drilled holes for the cables make a difference?  Is there an ideal spot for the cables?

Hey Now,
 
Here is my pair of T40v.1 that I re-cabled balanced with CAT6 ethernet:
 

 
I just used a solder iron to poke some holes in each cup. I have since sheathed the multi-colored ethernet with techflex.
 
I put the holes somewhat rearward on the bottom of the squarish part of the cup housing. Worked fine. The T50RP should be similar enough, although the driver assembly in the T40v.1 is round and not rectangular like the T50RP. Easy enough to do. Just use caution soldering the headphone cable leads to the driver pads. 
 
--
Finest kind,
Chris

 

[proid]

Quote:

Hey Now,
 
Here is my pair of T40v.1 that I re-cabled balanced with CAT6 ethernet:
 

 
I just used a solder iron to poke some holes in each cup. I have since sheathed the multi-colored ethernet with techflex.
 
I put the holes somewhat rearward on the bottom of the squarish part of the cup housing. Worked fine. The T50RP should be similar enough, although the driver assembly in the T40v.1 is round and not rectangular like the T50RP. Easy enough to do. Just use caution soldering the headphone cable leads to the driver pads. 
 
--
Finest kind,
Chris

 
How does it compare with stock? I recabled my Superlux 668B with cat5e and it make huge improvement. Then i use some thin buffalo cat6 which is very soft and the conductor must be about 1/2 compare to cat5e to recable and its worse than cat5e.

 

[keanex]

With the ease of installing a cable on these I hope that there becomes a variety of other options. I don't believe in cables effecting sounds, but man some cables look really nice!

 

[BotByte]

Quote:

With the ease of installing a cable on these I hope that there becomes a variety of other options. I don't believe in cables effecting sounds, but man some cables look really nice!

I might do a re-cable. But i would have to do a detachable one sided cable.

 

[mrspeakers]

Quote:

I'm kinda happy I did the backing, but then not. I guess I just have to used to it. What surprises me most is the vocals. Listening to Beck (which he's not so clear) I can hear further into his tone. The bass loss is a downturn, but then I added more blutak and gained the bass back. Overall it was a +
 

The bass can also be adjusted by using tape to cover the vent to varying degrees.  With most of my pads, I ended up almost closing off the port and bass became tight, powerful and deep.  Since BluTak has changed your cup volume, your results, and the effect of the port, will be different....  But once you find a solution that balances things out, the whole spectrum becomes as clear and nice as the mids (it is amazing how good the mids sounded once that felt was out.  Really, I don't know why Fostex chose to use it except to hot-up the treble).
 

 

[fishski13]

Quote:

The bass can also be adjusted by using tape to cover the vent to varying degrees.  With most of my pads, I ended up almost closing off the port and bass became tight, powerful and deep.  Since BluTak has changed your cup volume, your results, and the effect of the port, will be different....  But once you find a solution that balances things out, the whole spectrum becomes as clear and nice as the mids (it is amazing how good the mids sounded once that felt was out.  Really, I don't know why Fostex chose to use it except to hot-up the treble).
 

 
what vent are you referring to?  are people removing the plastic covering the top vent?  sorry, i'm still trying to read through the thread from the beginning.
 
 

 

[micmacmo]

Quote:

What are people using to drive these 'phones? Do they require amping?

I'm happily using a KICAS Caliente to drive them. I've also tried an MP-301 tube amp and wasn't as satisfied. Note that, aside from replacement pads, my cans are stock. 
 

 

[bluemonkeyflyer]

Quote:

 
what vent are you referring to?  are people removing the plastic covering the top vent?  sorry, i'm still trying to read through the thread from the beginning.
 
 

 
I am not aware of anyone on this forum opening the top (false) vent in the cups.  Various people have modded the bottom cup vents in many different ways in an effort to tune the bass after making other mods such as adding Paxmate to the cups, plasticine to the baffles, and felt over back side of drivers...and many more.