[ljordan]

Wow.

I removed the compensation network.

Screw off the wire cover over the magnets(ccw ~1/12 of a turn,pull). You want to open the 220ohm smd resistor. Cut the trace going to the pad on left side of the glue spot (this is where the coil leads attach).

I also jumped the 1 ohm resistor.

Also the advertised Litz wire is only the jumper(over the head). The cord is not Litz. I I used teflon silver plated 24ga in a twist.

I think this network is needed if you use anything but a power amp.

I use a quasi Meta42 with a opa637 and 5 buf634s per ch.

 

[Music Fanatic]

Quote:

Originally posted by ljordan Wow. I removed the compensation network. Screw off the wire cover over the magnets(ccw ~1/12 of a turn,pull). You want to open the 220ohm smd resistor. Cut the trace going to the pad on left side of the glue spot (this is where the coil leads attach). I also jumped the 1 ohm resistor. Also the advertised Litz wire is only the jumper(over the head). The cord is not Litz. I I used teflon silver plated 24ga in a twist. I think this network is needed if you use anything but a power amp. I use a quasi Meta42 with a opa637 and 5 buf634s per ch.

Interesting. Want to post photos? What happened to the sound?

 

[ljordan]

I is more dynamic. I did all three at the same time. I would rather have copper wire but I did not want PBJ -Kimber pulling with too much weight. The 24g is too bright I think being silver plate. But the detail transmission is much better.

Lewis

 

[ppl]

ljordan. Thanks for the tim I will do thid to my f1's and report back. I asume that each ear cup has these two resistors so each wire mesh screen will have to be removed

 

[Budgie]

Interesting. Can't wait to hear ppl's opinion.

 

[ppl]

This mod works great I removed both resistors and jumper the 1.5 ohm one. The DC resistance measured at the Phone Plug was 16.5 ohms per channel now it is 30 something ohms. The most noticeable improvement is tighter more extended Bass. The F1’s are still not a Bass friendly headphone however improved over what it was. The overall sound also improved with more Dynamics and better micro-dynamics. The headphones are now more responsive to the Amplifier driving them where as before using different amps would result in slight barely noticeable improvements prior to the Mod. IMHO what is the reason to obtain a High End set of Headphones only to have your best amp sound as compressed and non involving as the amp inside your Portable CDP, This just made no since to me at all. after the Mod the headphones are real sensitive to the amp driving them and while the sound out of even a portable is a lot better than it was going to a better amp really improves things as opposed to just getting louder.

If one has a pair of F1’s I recommend this mod. It is good and I thank ljordan for posting about this mod. It is kind of nice to have someone new to the Forums post about doing something to enhance the Enjoyment of other community members and this is what ljordan has done and I for one am thankful he did as my enjoyment of my F1’s are now greatly improved and I might just give up my quest for that elusive $5,000 Tube amp to drive them with.

This mod in no way turns the F1’s into CD3000’s however the difference is no longer embarrassing. What this mod dose is make for a better F1 presentation. Now users of the F1’s may have noted how the sound changes with anything placed to the rear behind the screen. I think some constructive dampening could go a long way hear. Also placing a Button over on the center of the rear screen like grados do with the logo might also offer some sonic change I tried that with some stick on paper from some Rubber feet and slight forward upper mids similar to grados was noted however this is not the type of sound I want.

 

[Budgie]

Looks like my F1's are going under the knife next week.

Thanks for the mod, ljordan! And for the review, ppl.

 

[Joe Bloggs]

If it even sounds better out of a portable now what the hell was Sony doing with the network in the first place

There must have been SOME reason for the network to be there, unless the engineers at Sony are a bunch of monkeys

 

[ppl]

Quote:

Originally posted by Joe Bloggs If it even sounds better out of a portable now what the hell was Sony doing with the network in the first place There must have been SOME reason for the network to be there, unless the engineers at Sony are a bunch of monkeys

Just because something has a plausible technical explanation is in no way to indicate that it is the best sounding or performing solution. This network will swamp the low output impedance of the driving Amp if the Amps output impedance is less than a fraction of an ohm and thus allow the Driver damping to be determined by the resistor network. if the Driving Amps output impedance is over 1 ohms and allot are then the network is no longer the controlling element and the Amps output impedance now has a far greater effect upon performance.

Normally these types of networks are used to reduce the input voltage, however that is not the intent hear. Such a network is intended to prevent an over dampened condition by presenting the Driver with a Minimum source impedance and often times this will prevent the Bass from sounding Thin when the Headphones are driven from Amps with ultra low output impedance. The 220 ohm resistor is intended to prevent an under dampened condition when Amps having a high output impedance are the source.

As wonderful as this sounds on the surface or shall we say in the Marketing Ad copy reality is seldom so well defined and this seemingly perfect solution now becomes a liability under some situations.

When assessing the performance abilities of a technology one must also keep in mind that it is marketing people that write these things and not the designers. Anyway this mod works and has improved the sound of My F1’s on every source by about 25% and that’s ok by me.

 

[Joe Bloggs]

Can someone post a schematic of this impedance compensator circuit so that I can start trying to figure out what this is all about?

 

[ppl]

Hear it is see attached

 

[Budgie]

Nice mod!! The F1's seem to drive better from portable sources, too, now. Thanks ljordan!

(this may get me back into headphone listening again. Most of my listening time has been with speakers

lately.)

 

[greyhorse]

I finally decided to go thru with this mod, but am finding it very difficult to remove the mesh. Has anyone else had a similar problem? If it helps, I bought the headphones while I was living in Japan.

 

[SK138]

Instead of creating my own thread regarding modding F1 as noted above and adding a balanced cabling, I just decided to bump this (VERY) old thread to respect those who started it.

I really appreciate revival of Sony F1 interest in this new thread: http://www.head-fi.org/forums/f4/son...s-pics-284563/ It is this thread that pointed me to this old thread to really change the sound quality to be more open and dynamic.

WARNING: DO NOT PERFORM THIS MOD IF YOU ARE NOT COMFORTABLE WITH BASIC SOLDERING SKILLS.

It seems that Sony has decided to GLUE the screen in place at three lip/slide points. To loosen the glue's grip I used a 2mm flat tip screw driver. Insert it between the screen and metal housing as deep as you can put it without too much force then lift gently until you see the screen shifting little bit. Do this all around about 1cm apart. You might have to go around the screen 2x-3x before you can twisted open or they will just pop open. Once it's loosen you will NEVER-EVER have to use this method since the glue's seal will be broken permanently.

Once the screen is completely open, you will notice a notch. On the left cup that notch is pointing south and on the right cup the notch will be pointing north when you have to put it back. Placing everything back is easy...just place the notch along respective position for left and right cups and just twist clockwise.

Here is picture of left driver exposed: (yes, I cut the wires already)

Here is picture of right driver exposed:

Further optional modd to increase dynamic and clarity (IMO):
I removed the driver housing and took off the silver coat around the inside of the housing facing the ears. It just peels off easy with rubber tension around the lips.

I noticed there is paper screen around the rim of the driver housing. I decided to remove it to put less restriction from the drivers as well as more air-flow inside the driver chamber. (At lease it sounds like a good idea at the time and it did work out better in the end). IMPORTANT: YOU MUST PUT THE SILVER COAT BACK ON OR YOU WILL HEAR ALL TREBLE.

For the final balancing act:

The positive terminal is the soldering connection immediate left of the puddy like substance in the mid section and the negative terminal is immediate right of the puddy like substance. As you can see from this close-up...I totally obliterated the comp network by scoring the single trace and removing the two registers around the two + and - poles.

After this...you just wire it to your balanced standard (two 3pin XLRs or like me, 4pin XLR).

 

[statica]

Hi! That looks like an interesting mod. BUT - can you please help me? I need to know how to replace the earpads on my NDR-F1's. I have a nice pair of pads from SA5000s and they look like a perfect fit. Please let me know. THANK YOU!
 
DONE! Did it myself.
It worked. You just have to be careful! VERY!