Quote: Avro, are you skilled enough to show that it is possible to etch the board at home?   :)

Thanks for your help MisterX. It seems that I am so frustrated that I cannot think , when I noticed the hissing I had thought that I had finished the amp.

OK now I see the logic. But what about that hissing?

I managed finally to implement that gain switch. I used R3  2.2K + 4.3K  and R4 10K , then I have switchable gain from 5.5 to 2.5. But I just cannot seem to figure out what causes constant hissing. I have it in default metal case and input grounds are tied to it. Output ground is isolated.  ...

hmm there is a problem still... Now I have short between VDD and GND. I have managed to pinpoint it to either one of the top side ICs. I checked DAC datasheet and it should have any short related to VDD and GND because there one pin between those. But PCM2706 has. I think my PCB has damaged...

I think I managed to get the previously mentioned GrubDAC working. I hope it stays that way. I am relieved for now.

akgfan , don't worry about it. GrubDAC tests abnormally low on RMAA for some reason. Maybe it starts to oscillate or something. And, if it outputs 2V, then it would need attentuation before going to soundcard IMO   Could somebody help me with my problem? The chip is possibly OK, because it...

I have problems with my latest GrubDAC. It gets recognized sometimes, but mostly it is an unknown device. I lifted one or two pads in the pin 31 and scratched to the first layer in 25 and 26.  I just wonder, that when those are only ground connections, do I have other problems in there or should...

Quote: I try to implement it, thanks! I will put a strip socket in place of R4, so that changing gain is easy. I think 6k is fine but the lower gain needs to be 2k. The headphones are Denon AH-D2000, and sometimes high impedance devices.

Quote: I will need bass boost too so this doesn't work :) Good advice though!

Quote: I have hard time figuring out the correct way to use the switch. Could you draw a schematic for it? It would help a lot. I know, if there is open loop, DC offset gets very high and headphones can burn.  

Hmm I need a switchable gain. How should I do it? I have no experience on it. I guess I will use dtdp and two R4s. But how to implement it on the PPA v2 board?

Hi! I have three boards which I am building. I have first bent most of the resistors to the circuit. Next I solder them.   I need to build these pretty fast. Any suggestions for quick completion techniques?

Now testing Ready-to-use NiMH batteries and I must say that Pimeta v2 excels so well in producing purest sound for a battery powered device!

oh people have got their boards? PM me then.

I need some boards

Avro_Arrow can you share your regulator layouts eagle files?

2 for me then also

Oh It has a headphone amplifier too. I would have expressed my interest if I had noticed that before.   

Hi!   I wanted to try a little bit more difficult things after I completed the LM317 regulator circuit which was my first PCB and etching job.   I designed an adapter for single MSOP to dual DIP with ExpressPCB.     The traces are 0.25 mm wide. The MSOP op amps are only about 3...

I would like to have one board. Do I have to pay something for it?

OK. I browsed the Internet and found many helpful advices and instructions. I was pretty sure my layout was correct so I decided to proceed. I used Press n Peel blue for toner transfer. Here is the printed layout and prepared copper clad.   I filed the edges and used kitchen scrubber...

Thanks to 00940 I made this:     ExpressPCB: http://dl.dropbox.com/u/7337908/highendLM317.pcb   Could anybody help me and do a very good SIP8 to DIP8 adapter that would be ready to print, for a single sided board? I need to remove some sip8 op amps from a amplifier and use the...

OK!   How do you find such nice looking layouts? What is the technique?

Amazing workmanship in here!