i used a pre-sensitized PCB. a bit expensive, but it worked well for me. I printed the PCB layout on a transparency X4, make a sandwich like this: glass plate, transparency X 4, pcb. then hold the sandwich together with one of those black paper clip things. expose with low wavelength UV...

thanks apheared! i do definitely need a larger case. from what vendor are you getting these prices? (e.g., $4 for Pana caps, etc)

I had bought a fixed-speed Dremel, I think 10,000 rpm. Is it safe to use a lamp light taper to slow down the drill? I know Dremel sells speed pedal or whatever, but it's expensive. thanks

Elna sounds tempting, but where can I get some of these? Wellborne is the only Elna source I know, and it only carries small values only. I was going to build a low profile PS and amp, so that it'd fit on a 1/2 U rack case, but I might just get a new enclosure.

hi, the photos can be found here: http://homepage.mac.com/hyungsongnam/PhotoAlbum4.html i'm sorry about the blurry close-up images. the camera cannot focus well at such range. as you can see, i never quite finished it--was never drilled a hole for the headphone jack, etc...

thanks! i'll look into those one more general question: let's say i build a PSU with two or three 5-10k caps before the regulators. Is it necessary/beneficial to put another set of caps before the power goes into the amplifier circuit? like so...

I'm looking for high capacitance (at least 5000), high voltage (at least 35 V) electrolytic capacitors. Digikey lists Panasonic ECG series. Are these good? What are some other _reasonable_ alternatives? Thanks!

oh no, i had used a dremel to drill all the holes, i took about 10-15 min to drill that board, as you point out. the only problem was that drilling ruined all my drill bits ($$$) (pcb was fiberglass or somethng and the drill was steel something from digikey). what drill bit do you...

ppl, hsnam = "hanson" you always called me that for some reason. anyway, the 5 files in the directory above are indeed in .doc, ie, MS Word, format. because of iDisk software, it's encoded into .binhex.hqx format. what you need to do is go to www.aladdin.com, and download StuffIt...

PPL's schematics _ARE_ in Word format.

sorry, i can't do it anytime soon. mainly because the holes are very small and it's a pain to drill them. (i ruined all my drill bits on one board!) i can etch them and sell you that, but drilling holes is too much.

yeah, ambitious, i hear that word a lot about my attitude. Budgie: next weekend, i will post some pics of the amp. then you can decide if you want it. anyway, the reason i'm selling the old one is, i want to make a (cosmetically) better version of the amp and also add KGilmore's...

hi, could somebody answer my silly question: what do you use to drill holes thru steel and also aluminum enclosures? i had used a Dremel at high speed, in order to drill thru a RadioShack aluminum case, and the bit was all destroyed by the time i finished... thanks!

i'm still alive, but busy. here are the schematics *http://homepage.mac.com/hyungsongnam/ skip the first page, click on "Downloads" on top of the screen, choose the folder named "PPL designs". they are all in there.

hi everyone, it's been a while--first year in med school leaves little time to tinker with anything! anyway, this summer i had built --with much help from everyone here--an amp based on Kevin Gilmore's design, using good components, e.g., hand-matched vishaydale resistors, wima caps, nobel...

ppl, i don't have time to build one, but you can email the schematics to the following address, and i'll put it up my iDisk: hyn2001@med.cornell.edu

i'm tempted to pick up some Goldpoint attenuators. Some of their old-modl series-type attenuators are priced quite reasonable now (40-60USD, don't remember exactly.). my question is, is this "better" than a similarly priced pots, noble, alps, whatever? i plan to get the kit, and as much as i...

ok, i get it. so i presume the DC servo isn't necessary if a good PS, like your design, is used?

hi kevin, could you elaborate a little on making headphones dual mono? damn, i wish i had a little free time...

hi, is there a napster-like service through which one can exchange entire CD's in WAV format (uncompressed digital audio)??? thanks

hi all, I have recently built a +/-16V power supply to use with Kevin Gilmore's discrete dynamic headphone amp. It utilizes LM317 and 337 to regulate down from a 24VDC, ~0.8 A supply. When the volume is low, the amp sounds fine, but if i play it too loudly, then the power supply seems to shut...

HERE

hi all, I currently own an AKG240M, and I'm thinking about upgrading to either AKG501 or Senn600. I listen to mostly classical (piano concertos/sonatas mostly) and jazz, but I also listen to "pop". Since I don't think my dealer carries both, I can't listen to them at the moment. Could people...

first, with good headphones, you will always (OK, more or less) be able to distinguish between CDs and MP3s. with that in mind, if you're at home or at work with all your CDs around, listen to the CDs for the best musical experience. if you listen to MP3s because you don't like the hassle...

so is your EMI problem gone now? i don't think Al is that good of a conductor. how about sheets of steel? and yes, the shielding should be connected to GND.