[Sonido]

http://www.bottlehead.com/store.php/products/bottleheadphone-kit
 
DIY headphones?!?!
 
Ok it looks like a mod on the Monoprice headphones. I'm a big Bottlehead fan, but idk if this is worth getting since I'm used to higher end headphones like HD800. Also interestingly, the Monoprice 8323 is a low impedance headphones, but this modded version is designed for use with the Crack, an OTL amp. The description doesn't sound like the mod affects the impedance of the headphone though.
 
More info and impressions:
http://www.bottlehead.com/smf/index.php/topic,5721.0.html
http://www.bottlehead.com/smf/index.php/topic,5609.0.html

 

[jodgey4]

Just saw this too, the page says "And there is a little extra surprise in the cable that allows the headphone to work so well with Crack." I'd love to try this out for myself, after some reviews are out, I'm a DIY kinda guy.

 

[bdr529]

Yeah I am not so sure about this one, but who knows. It sounds like the cable has some kind of impedance adapter built in.

 

[Sonido]

I recently got an impedance adapter to use my KEF M500 with my Schiit Vali, which has a high noise floor with sensitive headphones. While it sounds great to me, and the noise issues are gone,another head-fier who knows more about the technical side of things told me there could be problems with the damping factor and it would affect the bass. Another issue would be the frequency response would get all messed up, but luckily my M500 has a flat impedance curve. So if they simply add a resistor like impedance adapters do, it could face the same problems. Here was the discussion: http://www.head-fi.org/t/685162/new-vali-schiit-amp/3405#post_10258180

 

[Armaegis]

The 8323 impedance plot is relatively flat, so there won't be much of a change in frequency response due to output impedance. Damping factor will be pooched, but that can be finagled with an L-pad or something similar in the cable.

 

[Sonido]

  The 8323 impedance plot is relatively flat, so there won't be much of a change in frequency response due to output impedance. Damping factor will be pooched, but that can be finagled with an L-pad or something similar in the cable.

Actually it looks like they didn't change the impedance. They even said it will clip at high volumes with the Crack. I'll probably wait for more impressions before jumping in.

 

[kramer5150]

From the description it *sounds* exactly like they have added resistors in line.  Which increases resistance but not impedance.  KSC75 modders have been doing this for almost a decade to help smooth out the midrange and mid-bass bloat a little when running them amped.

 

[Sonido]

Well the goal is to compete with the likes of HD600 and DT880. While it's hard to imagine a $30 being able to compete with a $300 headphones, the T50RP is only $100, but mods such as the Alpha Dogs are $600. Driver is not everything. It's mentioned they wanted something that works well with Crack that's cheaper than a used HD600 or DT880.

 

[btrancho]

Doc has been very specific that this project is NOT to compete with the likes of the HD600 and DT880, but to provide an inexpensive closed back alternative that is carefully tailored to run off the Crack.  He specifically says "Not saying it will stomp HD600s, but so far I'm pretty happy with our experiments and one nice advantage is the design has a closed back."
 
Once they start shipping and some users have put their's together we should hear what they think.

 

[Doc B.]

Yes the end result was to use series resistors. That was after trying an Lpad to preserve the damping factor. While the Lpad may look like a good approach on paper, unfortunately in practice it sucked. So much power gets lost through all the resistors that the amp was driven into clipping just to get the listening level loud enough. And yes, even with the series approach if you play very dense complex music and drive the cans to levels that are really not that healthy for your ears you may hear the amp clip. The mechanical damping and the different cable both have quite an influence on the sound. The changes are not just related to tonal balance, there are temporal differences too, i.e., the transients are better defined.
 
So I hope that it will be understood that the kit is a combination of mods, not just series resistors. And I hope it will be understood that these mods were developed solely with the Crack amp in mind. 
 
If one is hesitant to purchase I think there should be some commentary not long after we ship the first run. About 1/3 of our planned initial run has been promised since announcing the release last night.

 

[Mahdi8]

  Doc has been very specific that this project is NOT to compete with the likes of the HD600 and DT880, but to provide an inexpensive closed back alternative that is carefully tailored to run off the Crack.  He specifically says "Not saying it will stomp HD600s, but so far I'm pretty happy with our experiments and one nice advantage is the design has a closed back."
 
Once they start shipping and some users have put their's together we should hear what they think.

I wonder will it be better than a DT770 600 Ohm.

 

[ssrock64]

I just saw this on the BH site. Color me interested. Is there a new thread for the Bottleheadphones, or has this one just gone dead?

 

[btrancho]

It will be another couple of weeks before the new kits start shipping so there really isn't much to say at this point.  Once the kits go out and folks start assembling them you should start to hear more.

 

[Doc B.]

The guys were shooting the last part of the kit assembly yesterday. It took us three tries to find a 3mm TRS plug that fit over the cable I spec'd (What? it's not that big!) and that plug arrived yesterday. Josh will need about a week to pull all of the documentation together and then we can ship the first orders.

 

[btrancho]

Thanks for the update, Doc.  I'm looking forward to receiving mine.