Well, well, well, now they're even cloning DIY amps. Who would've thought that? Headphone amplifier full kit w/ charger and chassis ! - eBay (item 220538377954 end time Feb-09-10 06:42:50 PST) There are also cloned Pass amps like B1 and F5.

I've recently bought a second hand E-mu 1212M after my 0404 broke down. It measures well, so I don't think it's anything wrong with it. It sounds more balanced than the 0404 which I found too forward and aggressive sounding. But... in spite of the state of the art CS4398 it doesn't sound any...

I finally got a new soundcard so I can play with RMAA again. Some time ago I had a discussion with other members in the sound science section about the drawbacks of 3.5 mm connectors. People had a hard time believe there was a measurable difference between different sizes of connectors. I wish I...

Help me make the 2009 Zero a better DAC! I've posted some possible problems in the analog/filter section and the headphone section before. I've done some preliminary tests, and I find the DAC to sound better with passive output than with either modded or standard filter/DAC. I've tried OPA627...

The only options I get are 16 bits and 32, 44.1 or 48 kHz. I thought it could be used 24/96 or even 24/192. Please help me out on this.

Why are there so many filtering caps? The simulated square wave looks really messed up. This is the the analog circuit of the 2009 Zero DAC. People in the FrankenZero thread worried about the 22 pF caps close to the output connectors and found it to seriously decrease treble

I wonder how they came up with something like this. The input capacitor to the second stage seems unnecessary. The input unity gain buffering stage seems unnecessary. The 100 uF cap from neg input to ground to reduce DC offset seems unnecessary and is probably a remnant of the days when they...

I just got my 2009 Zero DAC with OPA627 on the DAC output. I wonder what tricks I should use to make it better. 1. The "treble killing" capacitors in parallel with the output? Do they really affect the sound, and if so in a negative way? If they are 22 pF (maybe they're 2.2 nF) as claimed in...

After some arguing about active ground channel in this thread http://www.head-fi.org/forums/f6/how...inside-425711/, I ran some tests with opamps at unity gain, all of them supposed to be unity gain stable. The supply is +/- 6V There is a 3k3 input resistor, a 10k pot at the input and a ferrite...