so i'm ready to give the chips some power, but the instructions were modified as of yesterday. no mention of J5 or J10. the PS is working fine. do i need to close both J5 and 10?
New kid on the block
so i'm ready to give the chips some power, but the instructions were modified as of yesterday. no mention of J5 or J10. the PS is working fine. do i need to close both J5 and 10?
New kid on the block
it's alive! i just need to finish the chassis and hook-up wire/switches. yes, my workbench is a mess.
Looking good fishski!
Looks like you have some parts on the shelf below to build more amps!
I think you will find this very addicting once you complete the first amp.
-=Tripath by 41Hz=-
When only the BEST will do
(beware of cheap imitations)
New kid on the block
yes, it's a PS done P2P with turrets and TX for a Pass F5, i just need to complete the DIY chassis work. Class A 25W with 12" tall heatsinks - Class D need not applyOriginally Posted by Scratchy
the pic is one channel
for the Amp4, i'm glad i had an easier SMD warm-up project to prep - this is a wonderful DAC that bests my DAC1: http://www.amb.org/audio/gamma2/. i needed a small and discrete amp capable of powering my uFonken speakers with Fostex FF85K drivers in the living room - a Tripath amp seemed like the most obvious choice and the Amp4 fit the bill. even out of my workbench speaks, i can tell this is an excellent amp. i might want to try some higher powered species to drive my piggy ATC SCM12 in the man-cave.
i have a ground loop with power GND connected to chassis and IEC safety ground. when left floating, no hum, but i still have some faint white noise from my 81dB bench-top speakers starting at about 1 ft. away from my ears with source connected - the soon-to-be partned speakers Fostex FF85K are 88dB. the PCB mounting holes are NOT connected to chassis. i haven't tied the shielded AC to ground yet, my hook-up/roach-clips wiring are all over the place, and the AC circuit powers a lot of "dirty" devices including my computer and halogen/fluorescent lights in the man-cave. from my experience, it sounds like RFI noise/sloppy wiring. i'll get the wiring soldered proper and shielded, and the chassis top mounted in the next couple of days - hopefully this will fix any residual white noise. if not, i'll reluctantly try re-ohming for a third time. i have a hard time believing this is a proximal TX issue.
Last edited by fishski13; 14-Feb-10 at 13:16.
Hi,
Nice work, what casing did you use for your amp4? I had to search quite a lot to find a casing that could contain the 50mm high amp 4.
/J
New kid on the block
thanks. the enclosure is a Hammond 1455T2202BK but it isn't tall enough. i misjudged it by 1mm or so. i also searched for other shorter caps that would fit the PCB, but no luck. i have loads of aluminum and various woods from other projects that i'll need to use to build a modified top. i have a few ideas kicking around.
Knight of the Solder Iron
Lots of fun stuff you've got going, fishski. My next serious project will be a Gamma-2 for the office, to really get the guys hooked on hifi. And I always have a soft spot for the Fostex FR sound.
New kid on the block
i'm still getting some faint white-noise that i can hear at about 10" away from the Fostex FF85K 88dB (no crossover) - no buzz or hummmm. it's totally inaudible beyond 10", but how quiet should this amp be? i had an all Naim Audio hi-fi that had a bit more hiss (normal for Naim), but this is DIY, and if i can fix it, i want to
QUOTE=krilli;27177]Lots of fun stuff you've got going, fishski. My next serious project will be a Gamma-2 for the office, to really get the guys hooked on hifi. And I always have a soft spot for the Fostex FR sound.[/QUOTE]
the y2 is a sweet little DAC. i prefer it to my Benchmark DAC1. for $250 with custom face-plates (don't cheap-out, they're beautiful in the flesh), you can't go wrong. i built an o11 PS to partner with it, but i think it sounds amazing powered via USB. i'm more of a headphone guy and have built other headphone amps from AMB: Mini3, CK2III (2 of them), M3, and B22. i'm currently listening to my y2/o11 and B22 as i type: http://images2e.snapfish.com/2323232...%3B55336nu0mrj.
Knight of the Solder Iron
Interesting poster on the wall. Got a Duc by any chance? ... I'm saving up for a Sport 1000 myself ...
New kid on the block
no, but i still dream about having one (my mid-life crisis is a few years off though). i used to ride and still have my old Yamaha. i have fond memories of riding with a friend who had a Duck back in my halcyon college days. i now work in the ICU and ER as a nurse
i plugged in my old Denon receiver and still get the same level of faint white noise out of the Fostex FF85K. i even took the Amp4 down to the man-cave where i have dedicated hi-fi AC circuit off the breaker box. i wonder if the noise insn't related to the crossoverless drivers? anyway, the noise is very faint at 10" and not an issue at normal listening distances. i'll leave it alone but may try plugging it into my ATC SCM12 next week.
the reason why i wanted to build a class D amp and the small Fostex speakers was for their small footprints and no thermal management issues to deal with. since my second child was born 6 weeks ago, i had to give up the dedicated hi-fi room. my wife and i still wanted to have music on the main floor in house though and the fire-place mantle was agreed to be the best place, hence the need for petite. i'm glad i built this amp because i had no idea that class D could sound so good. i'm really impressed with this amp. i've gone from a Krell powering ATCs to a Tripath paired with full-range speakers in a matter of a few weeks
i've finished the chassis and finalized the FPE face-plates - i'll post pics once i get the face-plate mounted and in situ over the fireplace. a BIG thnaks to everyone for the help and Jan!
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