kevin gilmore 1,435 Posted December 10, 2011 Report Share Posted December 10, 2011 (edited) So it turns out that the lme49830 is pretty much a dynafet on a chip, with diamond buffers driving the fets. SO... combine with the semelab-tt lateral audio mosfets, and the result is something super sweet, and easy to build, about $50 in parts per channel. Combine 4 channels with my balanced preamp, and have one serious kickass thing guaranteed to drive anything, he6's and k1000's included. At about 2 orders of magnitude less distortion than that other thing. And more than 10 times the available output current. at... 20hz to 20khz... .1mw .05% thd (most of which is noise) 1mw .01% thd 100mw .005% thd 1w .0003% thd many watts <.0001% thd http://gilmore.chem....u/blackhole.jpg Works great at +/- 30 volt supplies, But also works all the way up to +/-100 volt supplies. 30 volt supplies highly recommended especially balanced, because lets face it, enough is enough. Suitable for driving say ten thousand pairs of sr-009 at the same time (400 volts peak to peak) A bit more work to do, but getting close now. 3.2 x 3.6 inches plus required external heatsinks. Edited December 10, 2011 by kevin gilmore Quote Link to post Share on other sites
n3rdling 79 Posted December 10, 2011 Report Share Posted December 10, 2011 Small and powerful like a blackhole Would this be suitable to drive speakers? Quote Link to post Share on other sites
spritzer 2,546 Posted December 10, 2011 Report Share Posted December 10, 2011 (edited) Well pretty much anything can drive speakers (M3 even) but yeah, it can. This thing can swing 400V P-P into a 8ohm load with a massive PSU to match. Edited December 10, 2011 by spritzer Quote Link to post Share on other sites
cobra_kai 2 Posted December 10, 2011 Report Share Posted December 10, 2011 Well pretty much anything can drive speakers (M3 even) but yeah, it can. This thing can swing 400V P-P into a 8ohm load with a massive PSU to match. Lol, that's 2500 watts or so. Absurd. So it can swing pretty much all the way to voltage rails and isn't current limited into low impedances? In that case even a +/-40V or so power supply for 4 channels would drive almost any speaker pretty well. Quote Link to post Share on other sites
ujamerstand 19 Posted December 10, 2011 Report Share Posted December 10, 2011 Very cool. How does mute work? Quote Link to post Share on other sites
justin 1,705 Posted December 10, 2011 Report Share Posted December 10, 2011 Very cool. How does mute work? darkstar mute function, turn it up until you're deaf: mute. Quote Link to post Share on other sites
spritzer 2,546 Posted December 11, 2011 Report Share Posted December 11, 2011 Ehh on this one I believe you just short to ground and the chip shuts off the output. Most chip amps have something like this. Quote Link to post Share on other sites
Shaman 10 Posted December 11, 2011 Report Share Posted December 11, 2011 At about 2 orders of magnitude less distortion than that other thing. Erm, does that other thing happen to be group buy material at that other place? Quote Link to post Share on other sites
chinsettawong 213 Posted December 11, 2011 Report Share Posted December 11, 2011 Looking forward to spending more money. Wachara C. Quote Link to post Share on other sites
slwiser 0 Posted December 11, 2011 Report Share Posted December 11, 2011 Sorry for my lack of technical understanding but is this to be another Electrostatic amp or an amp that can power any headphone depending on its power supply? Thanks Quote Link to post Share on other sites
spritzer 2,546 Posted December 11, 2011 Report Share Posted December 11, 2011 Erm, does that other thing happen to be group buy material at that other place? No, that would be a certain commercial amp designed to explode your headphones. I think that is the only thing that explains that crap design... Sorry for my lack of technical understanding but is this to be another Electrostatic amp or an amp that can power any headphone depending on its power supply? Thanks This is for dynamic and magneto planar headphones and a way of getting close to a balanced Dynafet performance for not a whole lot of money. So while this can in theory swing enough to drive electrostatics nobody would build it like that (save for somebody wanting to upstage Krell). Recommended PSU is +/-30V. Quote Link to post Share on other sites
n_maher 11,547 Posted December 11, 2011 Report Share Posted December 11, 2011 Kevin, Any plans for an accompanying, simple bipolar PS? Quote Link to post Share on other sites
kevin gilmore 1,435 Posted December 11, 2011 Author Report Share Posted December 11, 2011 The new dynahi power supply seems simple enough. Most of the size is due to the electrolytics anyway. If you really want to use this as an integrated amp, a much more massive power supply is going to be required. And then the size is mostly capacitors and the transformer anyway. This thing actually works just fine on a completely unregulated power supply which is what i'm testing it on now, because i don't have a regulated supply that puts out 5 amps. Quote Link to post Share on other sites
skullguise 4,439 Posted December 11, 2011 Report Share Posted December 11, 2011 This sounds exciting.....I'd be in....errr....to buy one that someone talented can build Quote Link to post Share on other sites
luvdunhill 3,265 Posted December 16, 2011 Report Share Posted December 16, 2011 darkstar mute function, turn it up until you're deaf: mute. I think I've found a market for the Dorkstar. It's mil-spec, of course: http://www.google.com/patents?id=UZzxAQAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false Quote Link to post Share on other sites
kevin gilmore 1,435 Posted December 16, 2011 Author Report Share Posted December 16, 2011 That has already been patented before in slightly different forms. The army had a version that did very low frequency at obscene volume levels, guaranteed to make you think you drank a few gallons of dulcolax. That version was not portable however. Quote Link to post Share on other sites
bhjazz 55 Posted December 16, 2011 Report Share Posted December 16, 2011 (edited) dynafet + black hole = DynaHole I'm in once I get through my current top-shelf builds. Cool stuff, Kevin! Edited December 16, 2011 by bhjazz Quote Link to post Share on other sites
Mister X 110 Posted December 16, 2011 Report Share Posted December 16, 2011 Mute has me scratching my head as well. The datasheet sez: If there is between 130 μA and 2mA of current flowing into the MUTE pin, the part will be in ‘play’ mode. Must be one of those "A bit more work to do" things? Quote Link to post Share on other sites
kevin gilmore 1,435 Posted December 16, 2011 Author Report Share Posted December 16, 2011 (edited) Like i said, its not done yet. resistor and zener to turn off the mute. And a better way to get the output off the board. etc... Plus you can tie all the mutes together and wire it to the protection board. Edited December 16, 2011 by kevin gilmore Quote Link to post Share on other sites
justin 1,705 Posted December 17, 2011 Report Share Posted December 17, 2011 does it play the brown noise? Quote Link to post Share on other sites
kevin gilmore 1,435 Posted December 17, 2011 Author Report Share Posted December 17, 2011 it plays the full spectrum of noise. i'm not really happy with the 530101b00150 heatsink, need to find something else. Quote Link to post Share on other sites
Mister X 110 Posted December 17, 2011 Report Share Posted December 17, 2011 How about the Ohmite R series? http://www.ohmite.com/catalog/pdf/f-r-sink.pdf or Mouser page 2078 http://www.mouser.com/catalog/catalogUSD/644/2078.pdf Quote Link to post Share on other sites
kevin gilmore 1,435 Posted December 17, 2011 Author Report Share Posted December 17, 2011 Need to get rid of about 1 watt max. Width of chip is .75 inch. Would like a single sided thing with circuit board mount pins that is about 1.5 inches wide, .5 deep and 1.5 inches high. Quote Link to post Share on other sites
n_maher 11,547 Posted December 17, 2011 Report Share Posted December 17, 2011 We could always mill down stock heat sinks. Quote Link to post Share on other sites
Mister X 110 Posted December 17, 2011 Report Share Posted December 17, 2011 The Ohmite C series is pretty close to what you have described but they have a spring loaded, cam lockable, clip deal. http://www.ohmite.com/catalog/pdf/c-sink.pdf Digi-Key # C247-025-1AE-ND ( http://search.digikey.com/scripts/dksearch/dksus.dll?vendor=0&keywords=C247-025-1AE-ND ) Quote Link to post Share on other sites
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