So I got the the B version of the Pi and the compatible Wolfson Dac board. I also have a 12V 7" TFT that I’ll plug to the analogue video out because I didn’t find any hdmi TFT around my area. Besides that I have a shitty keyboard and a mouse for my laptop that I might … Continue reading Raspberry Pi and some thoughts.
Sometimes I really hate living in Portugal, If I want to buy some JRC4556 for my low impedance headphone amp I must pay 18€ of shipment doesn’t matter if it’s 1 or 30 op-amps, if the purchase doesn’t go above 65€ the shipment must be paid. I get people must get paid to make my shipment but 18€ … Continue reading JRC4556, shipment prices and other rants.
Don’t get me wrong I love to build stuff but I draw my limit on selling clones, one thing is to sell a Cmoy amp the other is selling a RA-1 clone and actually using the Grado name to do it. I know that people need to make money but stealing a layout and making … Continue reading Not Selling DIY Grado RA-1 clones.
I need to revise my cmoy headphone amp because that DC offset still bugs me a lot. I want to know what I did wrong or at least reduce the offset to an acceptable voltage 20mv to 25mv max. After some light reading my conclusion is that the problem can be from: A bad ground plane, a bad … Continue reading Revision to my headphone amplifier.
My Philips SHE3590 mod…100% tangle free garanted!
I think I’ll need another box, a volume controler and a input selector (not really a pre-amp but similar in use)
I only need some connectors to have all the stuff I need to build this : http://diyaudioprojects.com/Chip/DIY-TDA2050-Hi-Fi-Chip-Amplifier/ I don’t actually need this amp because I have a nice one already but I want to have some fun. Chiisai Fukurou It’s a pleasure to share stuff, one of the few joys of the internet.
Some audiophile remove dc filtering caps from their source devices saying that they degrade the sound of their setups, usually I read stuff like electrolytic caps suck, bass gets cut off, my (insert device name here) does not have any dc problems, my preamp already has filtering and the list goes on. My questions to … Continue reading Some thoughts about AC coupling.
Solve for -3 db Frequency Solve for Capacitor Value Load Input Impedance (Ohms): 32 Capacitor Value (µF): 680 -3db Frequency (Hz):7.31 Optimal low frequency response (Hz):73.14 After some “study” I went for the 680uf caps. 32 Ohms are the base impedance of my grados. People say electrolytics color the sound, I must be deaf because I … Continue reading My DC coupling caps.
My 9V dual rail cmoy with the Jan Meier Crossfeed (2 positions & bypass). The plastic box is lined with aluminium tape and the perfboards rest on pcb cooper boards, it’s a fully modular project. Opamp made by Burr-Brown (2132PA), I’m using the original ones still made by Burr-Brown if that stuff actually matters to … Continue reading 9V dual rail cmoy.
My Cmoy looks like this right now. The Sigma25s will be in the cmoy box because I don’t want noise to get in the regulated 9V cables and the AC-DC primary will be on a separated box that is shielded inside. The front of the cmoy will also have that wood imitation look, in my … Continue reading Cmoy update.
I’ll drop the virtual ground and go for a true dual rail PSU design.The V ground will be used to test amp boards.Note on dual TLE2426, it’s a bad idea to use 2 voltage references because they will “fight” for the voltage center, so I dropped one of the TLEs.
I need to get them outside my country and they get expensive, I do have 5 little ones for portable use but at 20€ for case you get why I didn’t buy a big one. I could actually shield all the case with that aluminium tape but I’ll just shield the amplifier board & crossfeed … Continue reading Hey! I like your opamp pictures, really great :). Why didn’t you buy a steel or aluminium case for shielding?
Half of the simple shielding I’ll do in the amp case and the Jan Meier Crossfeed.
Cmoy board using a darn Burr-Brown 2132PA. The JRC’s that I got need at least 9V in each rail to work fine…darn. Next crossfeed section from Jan Meier. I really need to shield these boards.