[rawrster]

Quote:

You may have missed the post a few pages back. I don't remember who told me how to do this. It works every time without stressing the pad flaps and without frustration and litany of expletives. Turn the 840 pad flaps inside out, position the pad against the baffle, and roll the flaps back over the cups. Hold the sections you've rolled over onto the cups in place as you work your way around.
 

 
I did not notice that but i will try it later. Do these pads get easier to put on over time or will it always be this difficult? I do plan on doing mods on them since they are pretty much stock outside of me removing the double sided tape on one side. I'm going to do the other side later when I get home.
 
 

 

[Questhate]

 
Quote:

Anyone else on this thread who's getting the O2amp?

 
I just built mine on Tuesday. It powers the T50RP just fine. Still haven't given it a very thorough listening (only a couple of songs to test that it works), but there's definitely enough volume. It's a thin-sounding amp, though. It doesn't pair well with my K701, as the highs get very strident which is an obvious side effect when I run that headphone through under-powered sources (ie. directly from iPod headphone jack or a Fiio E11). 
 
Quote:

Awaiting the enclosure and panel from the DIYaudio group buy. Got my batteries yesterday. Just need to find a few alternative options for some sold-out components then I'll place my order with Mouser.
 
BooYAH I'm getting an 02 amp! (Providing I don't botch up my first DIY electronics project )  
 

 
I ordered everything about a week ago, and was able to find alternatives on Mouser for all the OOS parts except for the volume knob. I got the volume knob at Digikey and it's much nicer than the cheap plastic ones at Mouser. If you look in the comments section of the BOM, he lists the part numbers for alternatives.
 
And this was my first DIY project as well and I was surprised at how easy it was especially considering I have no background in electronics. You should have no problem. Feel free to PM me of you need any advice on the build. 
 
Quote:

I'm in on the group buy for the O2 amp.. board and front panels should be on the way.. I'm not trying to get off topic here, so a PM would be appreciated for the answer: what are people getting for the rest of the enclosure?

Which front panel did you buy? If you got the B2 panel, then it'll fit the B2-080 enclosure. If you got the B3 then get the B3-080. Unless you were going to fabricate your own....
 

 

[mrspeakers]

Quote:

FWIW,
 
I re-tested the "Less is More?" mod with different amounts of 100% cotton added to the cups ranging from 1/2 to 1 Jumbo cotton ball teased apart vs no cotton filler. To my ears, cotton added no benefits and actually muffled the sound proportional to the amount used.
 
You can increase the bass quantity by adding more tungsten putty. I know, it sounds counter-intuitive but that's what I hear.
 
The components are as follows:
 
1. Tungsten Putty around the driver and up to the edge of the driver perimeter, sort of like a 1/2" wall of putty. Again, add more if you want more bass.
2. Paxmate Plus in the cup bottom with the stock bass port felt in place and uncovered; and the central compartment uncovered.
3. Dynamat surrounding the driver on the ear side after first removing the dust cover and adhesive; I left the dust cover in place over the drivers.
4. Stock driver felt or 1.5 layers of Transpore over the drivers.
5. Stock ear pads with a "rope" of Kleenex rolled up and about 4 or 5 inches long, placed under the rear side of the ear pads. Shure 840 pads are optional and may change the sound.
6. Plasticine or Paxmate in the cup outer rims.
 
I found that tungsten putty flush mass loaded filling all the baffle compartments also works and sounds similar to the above. I medium mass loaded another set, all other things being equal, and got more bass quantity. None of these configurations caused bass bleeding into the mids and treble remained unaffected, too.
 
May be placebo, but I believe the combination of tungsten putty and dynamat around the ear side of the drivers improves SQ, and I like what I hear. YMMV, etc.
 


 

I have measured this and posted test results, I believe.  Pure cotton significantly reduces certain resonances and makes the transient response better, but it is not sufficient by itself.
 

 

[mrspeakers]

Quote:

 
I did not notice that but i will try it later. Do these pads get easier to put on over time or will it always be this difficult? I do plan on doing mods on them since they are pretty much stock outside of me removing the double sided tape on one side. I'm going to do the other side later when I get home.
 
 

You just get better as you do it a few times.  First time or two was a bear for me, takes 10s now.
 

 

[wdahm519]

Nevermind, saw Mrspeakers post.

 

[Lurkumaural]

Lessens reflections and creates the same effect as having a larger cup.  I believe you can fine-tune cotton to remove some very specific frequency bumps.

 

[drexman]

cotton gauze pad worked better for me than cotton balls. cotton balls changed entirely the sound signature. it made the mids unnaturaly thin and the bass non-existent. cotton gauze pad made the sound just slightly brighter and clearer.

 

[wdahm519]

Quote:

cotton gauze pad worked better for me than cotton balls. cotton balls changed entirely the sound signature. it made the mids unnaturaly thin and the bass non-existent. cotton gauze pad made the sound just slightly brighter and clearer.

 
Sounds like you put in too much cotton.  The cotton balls do thin out the mids a bit but I feel like it really makes the sound more open-sounding.  Bass should be decreased but still there.
 
I'm going to try and remove the cotton and see how I like the sound, and then try BMF's set up with the transpore.

 

[nsk1]

 
Quote:

 
 
I just built mine on Tuesday. It powers the T50RP just fine. Still haven't given it a very thorough listening (only a couple of songs to test that it works), but there's definitely enough volume. It's a thin-sounding amp, though. It doesn't pair well with my K701, as the highs get very strident which is an obvious side effect when I run that headphone through under-powered sources (ie. directly from iPod headphone jack or a Fiio E11). 
 
 
I ordered everything about a week ago, and was able to find alternatives on Mouser for all the OOS parts except for the volume knob. I got the volume knob at Digikey and it's much nicer than the cheap plastic ones at Mouser. If you look in the comments section of the BOM, he lists the part numbers for alternatives.
 
And this was my first DIY project as well and I was surprised at how easy it was especially considering I have no background in electronics. You should have no problem. Feel free to PM me of you need any advice on the build. 
 

Which front panel did you buy? If you got the B2 panel, then it'll fit the B2-080 enclosure. If you got the B3 then get the B3-080. Unless you were going to fabricate your own....
 

Any comparisions against FiiO or... just an amp ?
 
bluemonkeyflyer, what about Kryston tungsten putty, did you get it?

 

[bluemonkeyflyer]

Shipped yesterday. Delivery date unknown.
 
Quote:

bluemonkeyflyer, what about Kryston tungsten putty, did you get it?

 

 

[drexman]

i stretched the cotton balls in the cup just like BMF 6v3, only the density was more even and it was covering also the cup "walls" not just the bottom cup.

 
when you say the sound is more open you mean it has more treble? because i didn't notice any difference in soundstage.
Quote:

 
Sounds like you put in too much cotton.  The cotton balls do thin out the mids a bit but I feel like it really makes the sound more open-sounding.  Bass should be decreased but still there.
 
I'm going to try and remove the cotton and see how I like the sound, and then try BMF's set up with the transpore.

 

 

[wdahm519]

Quote:

i stretched the cotton balls in the cup just like BMF 6v3, only the density was more even and it was covering also the cup "walls" not just the bottom cup.
 
 
when you say the sound is more open you mean it has more treble? because i didn't notice any difference in soundstage.


 

 
Nope, I meant it had more airiness to it and a slightly larger perceived soundstage (small, but noticeable).  Treble was pretty well balanced with the rest of the spectrum.  The thing was, I think it had an airiness quality because of the thinner mids and highs.
 
 
EDIT:
 
Now having tried both Mrspeakers Cotton mod with electrical tape reflex dot, and BMF's idea of putting 1.5 layers of Transpore down with the "half walls" of tungsten (I used plasticine, and I also have the baffles loaded with plasticine) (I used FatMat instead of Dynamat too), I feel as though I prefer BMF's version more.  Mrspeakers version sound very open due to the thin mids and weaker bass.  While I think Mrspeakers mod brings out a lot of the great qualities in the highs the fact that the highs roll off so early with the T50RP's it kind of leaves it empty sounding.  BMF's version gives me the natural mids that I always liked with a healthy amount of bass (that I may need to decrease in the future if its too heavy) with highs that sparkle. 
 
In the end, Mrspeakers cotton idea end up sounding a lot like a thin dynamic driver that boosts highs and airy sound, while BMF's mods give a more full sound, thick sound.  What you like more is up to you.
 
 
EDIT 2:  Here's what my current set up is:
 
- SilverStone acoustic foam in cups, no foam on headband hanger
- 1.5 layers of Transpore tape on driver back
- Plasticine "half walls" around driver, in driver holes, and baffle holes (all the spaces you can fit it without overdoing it)
- Plasticine in the edges of the cups to give a good seal
- Stock bass port fabric, didn't mess with porting yet -- don't see a huge need to, no bleed.
- FatMat on ear side of baffles, covered with acoustic foam residue from when I removed it (there's not actually acoustic foam on there)
- Shure 840 Pads with one triple sized cotton ball rolled into a hot dog shoved in the back of the pad for angle

 

[HDMan]

Instead of cotton wool in the rear end of the pads, I have now tried bending the Fostex pads in half and stuffing them into the backs of the 840 pads, seems to work nicely. I have modified my 840 pads, so stock 840 pads may not work.

 

[wdahm519]

I can't even begin to understand how that would fit without popping off the 840 pads from the cups...  The cotton works really well to shove behind the earpads so I probably won't try your idea, but I'm assuming it wouldn't work for "stock" 840 pads.  
 
What exactly did you do to modify your 840 pads?

 

[drexman]

did you measure the cotton's effect on the frequency response? was there more treble / less lower mids and bass like i heard?
 
Quote:

I have measured this and posted test results, I believe.  Pure cotton significantly reduces certain resonances and makes the transient response better, but it is not sufficient by itself.