TAS1020>AKM4584>LM722 http://snipurl.com/j48m There is more inside than what you think. BTW: AKM chips don't have bad specs at all

If you are looking for a more transparent sound why don't you try that: http://www6.head-fi.org/forums/showp...&postcount=653 I tried (with PPA v1.0, intersil buffers and HD580) and liked a lot. You have discrete buffers so it makes even more sense. It requires modding the amp but it's easy.

Thank you for your very interesting impressions. As I built a PPA 1.0 (with intersil's integrated buffers and now with ad744 bypassed output) and recently an M3 (more or less standard parts) I am also trying to discern sonical differences. I still haven't realized well but it seems to me that...

Yes, even with low impedence cans (MDR-V6) at full volume I can barely hear just a distant "somenthing" (thermal noise?). I though about lowering R1 (the att. is 10k) but with the actual performance I guess it is useless 'cause source noise is predominant anyway.

I cased the amp. No more buzz or hum. It's so silent I though it was broken I'd like to post pictures but I have no digital camera. It is a standard M3 anyway. The minor differences are the fixed BB, crossfed (Tangent board) with rotary switch in the back along with stepped att. and shaft...

I still listen to my PPA (my first DIY) and modding it. Recently installed AD744 with bypassed output and even with intersil buffers is a clear improvement. It's a great project and has a lot of options and "add-ons" to settle with an amp that fits your preferences. I finished an M3 yesterday...

Quote: Originally Posted by 00940 it depends of your model. Ladder, serie or shunt. Mine is a ladder but from this point of view it doesn't differ from a series. As I said it seems to me that the only thing that would occur is interrupting the signal from the source and I don't...

Quote: Originally Posted by ooheadsoo Basically, they say if it wasn't make before break, you'd be blowing your preamp up about now. I don't understand the point. Break before make, if I got it right, means that before making the next contact the switch interrupt the previous...

No, it is easy to turn and the knob has a good grip (and it is really massive). I am just complaining the clicking noise in the amp. I guess they use the wrong switch (bbm). Quote: Originally Posted by phobus You're talking about clicking noise in the amp right? I was just commenting...

I bought one of those but already done. It is noisy, it clicks when switching levels. I have tested it with clips (I am thinking of returning it) but I doubt the casing will solve the problem.

I retested the board and now the amp is working. No more problems with the ground channel (don't ask me why). I still have a little buzz, volume dependent, that magically disapper at full volume (no attenuation) but I guess casing and grounding the pot case will fix it. Just few minutes of...

Quote: Originally Posted by amb I recommend 33pF for the ground channel. You might not hear any anomaly with a smaller value cap, but the 33pF value was chosen with extensive testing and is optimized for best stability and bandwidth. Ops Now I realize i made the same mistake

Thank you Morsel for your suggestions. RMAA could fail but I hope my ears don't Building the PPA I had the same experience, casing the PCB the noise disappeared. This time is really huge. No wonder there is somenthig wrong in the grounding with all those clip wires I am using hanging...

DC specs. The "BP" is selected for better offset.

I have completed my M3 board and now I am testing it but something strange is happening. First, I hear a steady noise even with 300ohm cans, only with 600 ohm k240 is not clearly audible. RMAA tells me is a huge 50hz hum. I know that this sort of problems usually disappear with casing and proper...