Brian, very nice pcb job indeed. I like look the "professional" look. Maybe you can offer your services to Sakura Systems ?
The PSRR of the LM3875 is ~100-120db at 50Hz, at 100Khz it has dropped to ~30db. Spikes and other noice on the mains are mainly composed of Highfrequencies and are not supressed enough.
One way to get rid of that. Is to use a mainsfilter. If the noice source is indentifiable you might want to mount the filter there rather than on the gainclone, (since its smal Psu caps it´s also sensitive against high impedances on the mains.)
/ Micke
One way to get rid of that. Is to use a mainsfilter. If the noice source is indentifiable you might want to mount the filter there rather than on the gainclone, (since its smal Psu caps it´s also sensitive against high impedances on the mains.)
/ Micke
There are many of us who have not built a GC, or any device beyond a crossover, and don't have a parts box filled with many of the bits and parts we'll need to even start, let alone complete this project.
Does anyone have a list of the additional parts we should be shopping for, before the "instruction manual" becomes available? I understand many choices might be personal preferences, but a list of needed parts, with some recommendations would be very helpful.
Might this be a topic for a new thread? The GONG list for complete novices?
Does anyone have a list of the additional parts we should be shopping for, before the "instruction manual" becomes available? I understand many choices might be personal preferences, but a list of needed parts, with some recommendations would be very helpful.
Might this be a topic for a new thread? The GONG list for complete novices?
x. onasis said:
Don't worry too much about this. I will have a complete instruction manual, and guide. I spent a few hours today putting together an amplifier with the kit, taking lots of pictures during the process. The manual will be available soon, and I will continue to update it as new questions come in. I will be providing it in PDF format, as I don't want to mail out a 10 page document to everyone, wasting paper and increasing shipping costs.
If you do find that there are issues not discussed in the manual, you can let me know and I will update the manual, as I am sure that others will need the same issues addressed.
Stay tuned for the manual soon.
(I took 139 pictures so far today of the build, taking each shot a few times with different exposure settings)
I attached a picture of the current amplifier build process. It is mostly done. I had the chassis done from my last gainclone, which I gutted, and managed to get the boards stuffed and the wiring done in about 3 hours, while taking lots of pictures. I also taught my fiance how to solder during this time, and she stuffed 4 channels today, and is working on a power supply board now.
Good news for those who just ordered PCB sets, as I will include a set of standard resistors to go along with each pcb set (4 x 22.1k compact metal film, 2 x 221 ohm compact metal and 2 x 680 ohm carbon film) See a picture here of the resistors that will be included with the pcb sets:
http://www.diyaudio.com/forums/showthread.php?postid=347814#post347814
--
Brian
Attachments
Here is a closeup of how the board is wired up.
On the previous picture, ignore the extra wires coming out of the transformer, as they were originally there for a fully integrated solution with a digital volume control, but I scaled this down to a simple passive solution, and they are un-used windings.
--
Brian
On the previous picture, ignore the extra wires coming out of the transformer, as they were originally there for a fully integrated solution with a digital volume control, but I scaled this down to a simple passive solution, and they are un-used windings.
--
Brian
Attachments
my first audio project
Brian says that I should post pictures of the boards that I soldered today. I have no clue what they do but they look cool. Brian is really cheap, he gave me the five cent components instead of the expensive ones. You think I would be getting better stuff since I am filling out all his envelopes for him for the group order! Maybe I should have taken circuits in college.
-meredith
Brian says that I should post pictures of the boards that I soldered today. I have no clue what they do but they look cool. Brian is really cheap, he gave me the five cent components instead of the expensive ones. You think I would be getting better stuff since I am filling out all his envelopes for him for the group order! Maybe I should have taken circuits in college.
-meredith
Attachments
S.C said:Do you have any sources except Mouser->Alpha Wire.... They are expensive..... 300ft = $79.xx
The stuff that I used today was Carol stranded 18ga cable, with the thicker insulation. It came from Digikey, and costs a little over $15 for 100ft.
Here is the digikey catalog page, the secont table down, C2103......
http://dkc3.digikey.com/pdf/T041/1032.pdf
I got it from the school, as I only needed a few feet.
ApexJr sells silver coated copper with teflon insulation for $0.13 a foot, in different colors. I ordered 20ft each of several different colors a while back:
http://www.apexjr.com/wire.html
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Brian
I finally got around to hooking up the amplifier with the new boards that I put together earlier today, and it works great, and sounds good. I will do some more listening tests tommorrow.
Everything works great, with no problems at all. This sure simplifies the building process for a gainclone.
Here is a picture of the working amp (same as earlier picture, but hooked up my cdpro2.
The part that I like most about this amp, is that there are few places to mess up. I am working on the instruction manual now, to make it super clear on how to put this thing together, even for the beginner.
(stuff on the floor, since table is being actively used for part of the kitting and packaging process)
--
Brian
Everything works great, with no problems at all. This sure simplifies the building process for a gainclone.
Here is a picture of the working amp (same as earlier picture, but hooked up my cdpro2.
The part that I like most about this amp, is that there are few places to mess up. I am working on the instruction manual now, to make it super clear on how to put this thing together, even for the beginner.
(stuff on the floor, since table is being actively used for part of the kitting and packaging process)
--
Brian
Attachments
Bas Horneman said:
I mean the rest of your married life ofcourse.
Regards,
Bas
...of course
. I forgot to congratulate you and Brian on your wedding. I wish you both the best of luck and hope you have a happy life together. Oh well, I'm derailing the thread. Meredith, try not to get too mad about Brian's projects. After all, look how many innocent people would suffer. 
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