crippledchicken 0 Report post Posted November 9, 2005 hi, i'm new here and would like some advice on what would be a good budget priced headphone amp to build or, kit i could use with my adcom gfp 565 home preamp with three sets of outputs. i have a set of Koss UR40 headphones with 60 ohm impeadance and don't drive too well as is from the preamp. thanks for any help. Share this post Link to post Share on other sites
Kippei 0 Report post Posted November 9, 2005 It depend on the budget. Most likely you can try the Cmoy2 Share this post Link to post Share on other sites
squalle 0 Report post Posted November 9, 2005 yup see how much ur budget is then can work on from there cmoy is simple amp but I can suggest PA2v2 that's quite famous out there. and yes, you can DIY that easily Share this post Link to post Share on other sites
crippledchicken 0 Report post Posted November 9, 2005 hi and thanks for the help fellas, i plan to try building the amp aroung the first of the new year with a budget of $100-150 Share this post Link to post Share on other sites
Kippei 0 Report post Posted November 9, 2005 Pimeta is within ...... Share this post Link to post Share on other sites
neutralzz 0 Report post Posted November 9, 2005 haha or you could conceptualized a buffered cmoy2 Share this post Link to post Share on other sites
neutralzz 0 Report post Posted November 9, 2005 btw ever thought of modifying your adcom gfa 565?? you could ask mr ts lim to look into this and modify/improve the headphone out.... that pre-amp costed probably 1.5k in 1988? or 1990 if you've stripped the amp like i had done b4.. the parts inside are.. quite superior.. except if your headphone's too high sensitivity there's a slight hiss sound.. but you've got the treble/bass/mid knobs, you could try switching on the filters and all.. Share this post Link to post Share on other sites
crippledchicken 0 Report post Posted November 9, 2005 hi and thanks for thje replys. i have thought of modifiying the adcom preamp headphone section as i have pretty well upgraded everything else in the unit including replacing silicon rects. with schottys, increases ps capacitance, replaced line level op amps with opa627bps. i've got some lt1010, and buf634t buffers as well as numerous other op amps, i might be able to implement some how. i think i will check things futher as i do have the service manual. all advice welcome, and thanks abunch! crippledchicken Share this post Link to post Share on other sites
Northern Oak 0 Report post Posted November 21, 2005 hi crippledchicken, have you tried putting a contant current diode across the Vout and V- of the OPA627? It's one of the method documented in Tangent Audio about biasing the amp into class A. I'd performed that mod to good effect. It's about 3 plus per piece at Farnell. Share this post Link to post Share on other sites
