My Headphone Amp (~1MB in Pics)

Discussion in 'OT Technology' started by eighteen_psi, Jul 14, 2003.

  1. eighteen_psi

    eighteen_psi Active Member

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    I mentioned in an OT thread that I had this amp and I figured at least Loudsystem would like to see it / get some details, so here goes. Amp was built buy the Head-Fi Member "Erix" and is somewhat 'famous' around those parts for its completely non DIY case. Regretably, the JB weld holding the rear panel gave out recently (thus the temporary epoxy now). I'm going to real-weld it soon. Its losely based on the popular/great META42 design making it a "custom multiloop" not a real META42 as I mentioned before. Specs are as follows:

    (2) BUF634T per channel in wide bandwidth mode
    (1) BUF634T virtual ground driver
    (2) AD823 opamps (1 is a buffer before the x-feed)
    Wima MKP10 caps through out the x-feed
    (4) 2200uF/16V Cerafine resevoir/filter caps
    (4) 1uF/63V local bypasses
    (1) 4-pole, 3-throw rotary switch for the crossfeed
    1% Metal Flim Resistors throughout
    Powered by 12V Regulated Wallwart.

    It has RCA in, mini in and a 1/4" headphone ouput. Locking jack was considered apparently but why would anyone want to disrupt the face of this thing with an ugly black/red jack?

    Currently in the works is an internal power supply to replace the wallwart but as is, it sounds incredible (better than all but the best META42's I've heard in terms of accuracy and near a sugden headmaster in terms of dynamicism and punch). 1/2 on the volume (from a relatively weak M-Audio 24/96 output) will cause PAIN with even hard to drive HD580s. My Grados were quite loud at 1/4. This amp has balls :cool:

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    Enjoy :wavey:

    EDIT: Case is all hand-build from brushed aluminum. Amp was aquired in a computer/hardware trade some time ago from the original owner. Also, that mini->RCA contraption is for my iRiver 350 until I buy a good mini->mini inteconnect.
     
  2. 04

    04 Guest

  3. eighteen_psi

    eighteen_psi Active Member

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    :) CMOYs are nice too. I had one of those as well as a CHA47-based micro-amp before I aquired my current one. Regardless, you built yours yourself and I've yet to make one that works properly so :bigthumb: good job!
     
  4. 04

    04 Guest

    How do you get your hands on so many DIY amps if you don't build them? :eek:

    What designs have you tried to build?
     
  5. eighteen_psi

    eighteen_psi Active Member

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    I've taken a couple cracks at making CHA47's. They're the easiest as far as I can tell. I actually got one to work with an external wallwart but my own psu's aren't working out too well (and I don't want to put one in the multiloop and have it fry). There are usually a few META42's, CHA47's, CMOY's and Gilmore's available FS on head-fi. A bunch of they guys there build them.
     
  6. Blindsight

    Blindsight Guest

    I would like to ask if anyone here would be interested in purchasing aluminum cases like that? I have an industrial CNC mill and could *easily* cut as many as there are demand for.
     
  7. 04

    04 Guest

    :eek: And... You live in Oklahoma...

    How much money are we talking?
     
  8. Blindsight

    Blindsight Guest

    It's hard to tell exactly how big those aluminum cases are, but I would guesstimate between $30 ~ $75 depending on whether or not you want them anodized and what quantity you want. We can also do very cool things like making the sides of the case heat sinks, etching logos and/or text into the case. Anodizing can be in many colors (including clear), and can be either a "cosmetic" anodize or a "hard" anodize which will yield much greater protection of the finish. All edges will be chamfered (an angle cut that makes them smooth to the touch).

    We only provide the absolute best quality, if you want a ton of cheap parts made at a chop shop, you should look elsewhere. ;) If you are REALLY serious, we can be very flexible on how we set up orders, if you want I can give you my phone number, and I'd be glad to talk about setting up a deal. :big grin:

    Edit: Price also depends somewhat on whether or not you have CAD files for the design you want. Since those cases are really simple, we would be very lax on how much we charge for doing the CAD files. Also note that the price for just ONE case will suck if you want it anodized, because it costs us like $200 for anodizing setup no matter how many parts we do. So its very advantageous to: 1) make your own CAD files, and 2) have us do a big batch per color of anodize to spread the setup cost out.
     
    Last edited by a moderator: Jul 15, 2003
  9. Blindsight

    Blindsight Guest

    And also, let me just add that I see alot of things with that case that range from "severe" to "minor" that we would change to make it a million times better :big grin:
     
  10. Blindsight

    Blindsight Guest

    No love for the aluminum case? :wtc:
     
  11. 04

    04 Guest

    Well, for 30 dollars, I would be more inclined to do it, but I dunno about 75...

    I also dont have any use for one right now, but in the future that could very easily change.
     
  12. Blindsight

    Blindsight Guest

    Hmm okay. The more I started thinking about it, the more I realized for just ONE case, it would actually be upwards of $100, probably even as high as $200, because there is some special tooling we would need to get to make things "just right"...

    I might look around and see how the market is for them though :dunno:
     
  13. eighteen_psi

    eighteen_psi Active Member

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    Something to consider is forging an alliance with an amp builder on head-fi.org's forums...people shell out large sums of money for good amps in basic plastic cases there all the time so eh...
     
  14. nt

    nt Guest

    18psi,

    what kind of pot are you using?
     
  15. Blindsight

    Blindsight Guest

    Good advice :cool:

    I've been looking around and I might go for it.... :x:
     

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