Thanks for the reply. Leak shouldn't be problem because I am in a good distance from my colleagues. HD280 sometimes feels a bit to tight and can get too hot.

I just started a new job and is thinking about finding a good replacement for my HD280, because my new work place is very quiet. I am thinking about SR-60 because it does not require an amp. But I might also consider bring an amp to my office in case there is a big gain in sound quality...

That's normal among flat screen CRT monitors, if yours is of this type. The Dell (SONY Trinitron) and Mitsubishi I had used both have these two grill lines. It's perfectly normal and it's there because the whole screen can not be made in one part but three.

Cable: 16 AWG silver plated copper with teflon insulation, 2 strands for each signal line. Connector: gold plated RCA connectors Need a short cable to connect my PPA to my laptop and desktop in the office. This one sounds pretty nice, very detailed probably due to silver plated copper...

Quote: Originally Posted by eweitzman koladd, there will be clicks on turn-on and turn-off because of (1) contact bounce (2) load changes on the amp and (3) double load changes on the amp: the M³ has an active circuit on both hot and "ground" so you have two amps per channel being...

Quote: Originally Posted by eweitzman A 4P3T switch between amp and hp jack will introduce it's own turn-on/turn-off clicks and noises. And it will be in the circuit when the amp's in use, so it has to be a high quality switch. If you're switching the AC along with the output, you'll...

It remember the same problem occured to me before. With the HD580 I used to have, sometimes it gives unbalanced channels, pretty much depending on the Amp I use. I listened out of three amps with HD580, CMOY, Szerkerez and my Yamaha Compact Stereo at home. With the Yamaha, the channel problem is...

I guess I was wrong. The resistor rating should be RMS, so a transient probabily won't matter at all. But since during the switch off, the capacitors and 1 Ohm resistor from a R-C loop with initial voltage 24V due to the charge in capacitor, the peak power calculation would still be correct...

Quote: Originally Posted by JohnFerrier I = sqrt(P/R) = sqrt(0.25 W / 1 ohms) = 0.5A. This should work. It will only be a brief spike too... JF You're probably right. However, P_peak=U^2/R=24^2 V/1 ohm=576W. That's the peak power at the moment of switching. My concern is if this...

Quote: Originally Posted by morsel I suggest using a DPDT power switch, which connects the amp circuit either to the power source or a 1 Ohm resistor which rapidly discharges the onboard power caps, reducing or eliminating turn off noise. Sounds great, Morsel. This will totally...

Quote: Originally Posted by JohnFerrier You'll need to verify that between positions 2 and 3 that power doesn't turn off... Make before brake. JF JF, thanks for the suggestion. There're several "shorting" rotary switches available at Mouser, e.g. 10WA367 and 10WR046. For my PPA...

Quote: Originally Posted by amb We didn't design any pop-elimination scheme into the PCB, but you could always do whatever you want when you build the amp. Relays, switches, whatever. I find, though, on the M³ prototype and listening through the HD600, there is virtually no turn-on pop...

I just finished building PPA. And I'm really impressed with its improvement over my previous setup (CMoy and Szekeres). Thanks guys for your contribution. I'm considering taking a course next spring in analog IC design so I might be able contribute later to the society. I was excited to find...

Thanks for the reply. I placed an order at Tangentsoft.net. It seems like the only place that carries the POT.

It seems like that RS Components doesn't carry ALPS RK27 anymore. I got one from Mouser. But it turned out to be not the one that would work for PPA. I need help from folks here on where to find the ALPS POT's. If there're other alternatives that works as well as the ALPS, please also recommend...