I built it for a friend 18 months ago, I think it is excellent.
I have the Gerber files available on my hobby website (with links to this page) and they have been accessed over 1000 times, so I would say there are probably a fair few completed amps out there. Very few people come to this page asking for help which could suggest they haven't had any real problems with it.
It's relatively cheap to build, why not just send the files off and give it a go?
Thanks for confirming the drill size. My digital calipers aren't good enough (and probably aren't the right tool) to check them since I get a reading of 1.2x mm.
I was considering whether to solder wires directly to the board or use a terminal block. At the end of the day I suppose anything other than soldering (at least for my application) would just be a waste of time and money, as 18 AWG is more than enough for how much power I need out of these.
for the DC protect: https://www.diyaudio.com/forums/chip-amps/321922-source-layout-lm3886-13.html#post5606986
for the PSU: ok, a bom was here: An open source layout for LM3886? but it's not fully correct. Caps and resistors should be fine but the final version uses the bridges mentioned in post 63. The heatsink should rather be the Ohmite RA-T2X-38E
for the PSU: ok, a bom was here: An open source layout for LM3886? but it's not fully correct. Caps and resistors should be fine but the final version uses the bridges mentioned in post 63. The heatsink should rather be the Ohmite RA-T2X-38E
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I just realised I only posted my build to the main gallery thread & never actually contributed back to this thread. I finally finished it back in May this year, after starting in 2018.
It is a 3 channel build for a 2.1 setup, with two of the boards bridged via a Vigortronix VTX-101-007 audio transformer. There is a lot of empty space in the enclosure because I originally intended to house an active crossover & its power supply in the same enclosure, but in the end I stuck with my separate dbx crossover. I know my hand wound coils are bad, but I have to leave myself something to improve on next time.
I also built a 3U rack from some cheap plywood.
I am very happy with the results. I used my last gainclone for 8+ years & I now intend to use this one for 8+ more.
Attachments
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Are these files good to go to the forge?
First of all, many thanks... I've been looking for a project like this for so long...
I'm planning on printing the PCB's and make (another) an amp for myself
So... I have some questions:
Are these gerber the final version? Anything I should be worried about? Do you have a BOM's list? (found them, thanks)I don't want to mess it up
And thank you so much for all that work, it looks amazing by the way
First of all, many thanks... I've been looking for a project like this for so long...
I'm planning on printing the PCB's and make (another) an amp for myself
So... I have some questions:
Are these gerber the final version? Anything I should be worried about? Do you have a BOM's list? (found them, thanks)I don't want to mess it up
And thank you so much for all that work, it looks amazing by the way
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You have to search for Gaincard. Very interesting product and design style.
It might very well be that I messed up and never uploaded the gerbers but only the Eagle files
They haven't been very popular to start with so it's never been pointed out. I'll reinstall Eagle and generate gerbers.
My apologies
Gerbers
Thanks for this project, it looks like just what I've been looking for!
What version of Eagle are you running?
I tried to open the files, but my (quite old and in need of update) version of Eagle errored on them.
When you get a chance to do the PS and protection gerbers, it would be nice to have them.
Many thanks!
Adam
Thanks for this project, it looks like just what I've been looking for!
What version of Eagle are you running?
I tried to open the files, but my (quite old and in need of update) version of Eagle errored on them.
When you get a chance to do the PS and protection gerbers, it would be nice to have them.
Many thanks!
Adam
I just want to thank you for making this design public and available for everyone. This is really helpful to me as someone who is just getting into playing around with chipamps, and I think the difference between 0.001% and 0.000000001% THD is mostly academic and completely inaudible to human ears. So this amp design more than delivers on performance as compared to some of the other, composite LM3886 designs I've seen on this forum. Thank you so much for this design!
Changing Gain
Hi Guys,
A quick question.
I am about to build another pair of these but I want much lower gain this time round. Something like a gain of 13.
R5 is easy, I would simply change to 12k.
However I am uncertain what to do with the filter of R7 and C5.
Do I need to change R7 from 22k to 12k as well?
Hi Guys,
A quick question.
I am about to build another pair of these but I want much lower gain this time round. Something like a gain of 13.
R5 is easy, I would simply change to 12k.
However I am uncertain what to do with the filter of R7 and C5.
Do I need to change R7 from 22k to 12k as well?
That sort of stuff often happens if the FAB layer is missing. The FABrication drawing is basically the board outline and through-hole locations.
For a two-layer board with top silk screen, you need the following files:
- Top copper
- Bottom copper
- Top solder mask
- Bottom solder mask
- Top silk screen
- Echelon (X,Y) file for the through-holes
- Fabrication drawing
Your layout tool should be able to produce these in Gerber 2.74 format.
Tom
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I just finished my version of the Super Gain Clone stereo amp board. It places the rectifier and two channels on a single PCB.
GitHub - profdc9/SuperGainClone: A stereo layout of Bob Cordell's Super Gain Clone amplifier.
You can download the whole project, kicad, gerbers, and all using the Download button. I have a picture of my build below.
GitHub - profdc9/SuperGainClone: A stereo layout of Bob Cordell's Super Gain Clone amplifier.
You can download the whole project, kicad, gerbers, and all using the Download button. I have a picture of my build below.
