Does that mean you sleep between building amps? 😀
I'd rather desolder something and have it work than have a mystery to chase down after it's constructed...
Just about got everything cabled. I'll finish off that tonight (10:30PM here) and the case will be in my hands tomorrow. We might have action tomorrow night with a bit of luck.
Michael
maf_au said:
Well, I try to sleep occasionally, but its hard to force myself. 😉
It would have worked, its just the taper would would have been in reverse, which would make adjusting the volume an interesting experiment(too much senistivity to rotation on the low end, too little on the high end).
I hope you have that thing working soon, it will be worth the trouble. 😀
Cheers!
Russ
Actually, this case is good.
Next time, I will construct the amp in the box, and fabricate my own heavier top and front rather than fight with constructing it on the base and having to leave enough spare wire to open and close it.
There is a larger size, 305 x 203 x 76mm Hammond cat 1444-24, that will be my next stereo chipamp case. Compared to constructing from scratch like I have with my Mauro, it's a lot cheaper and less hassle.
I guess you have to build a few of these to decide what works and what's the hard way of doing things.
Michael
Next time, I will construct the amp in the box, and fabricate my own heavier top and front rather than fight with constructing it on the base and having to leave enough spare wire to open and close it.
There is a larger size, 305 x 203 x 76mm Hammond cat 1444-24, that will be my next stereo chipamp case. Compared to constructing from scratch like I have with my Mauro, it's a lot cheaper and less hassle.
I guess you have to build a few of these to decide what works and what's the hard way of doing things.
Michael
Powersupply output voltage
Russ, I'm getting -13.5 +12.1 on the PS outputs.
Is that a problem?
At least it didn't blow 😀
Michael
Russ, I'm getting -13.5 +12.1 on the PS outputs.
Is that a problem?
At least it didn't blow 😀
Michael
maf_au said:
It is probably not a problem, but it could mean that your negative regulator(7912) is shot... It should still work, but I am wondering if you have a short of something... They should be very close, mine is exactly 12.1 and 12.1. Odd...
Nice work so far! She's a beauty! 😀
Cheers!
Russ
I think it's finished...
Ok. Before I connect it to source/amp, what should I check, and how should I check it?
Should I worry about the longer earth cable here drooping over the tranny when the case closes? (thinking about shorted turn)
Here is the case being closed...
Ok. Before I connect it to source/amp, what should I check, and how should I check it?
Should I worry about the longer earth cable here drooping over the tranny when the case closes? (thinking about shorted turn)
Here is the case being closed...
Attachments
Michael,
It looks very good!!! I really like the case for this project! Well done.
If I were you I would double check your rail voltages. If your negative rail is still >13V I would replace the LM7912, but nothing should blow up if you want to test it as it is.
Just test for DC offset prior to connecting it to anything other than a source.
Cheers!
Russ
It looks very good!!! I really like the case for this project! Well done.
If I were you I would double check your rail voltages. If your negative rail is still >13V I would replace the LM7912, but nothing should blow up if you want to test it as it is.
Just test for DC offset prior to connecting it to anything other than a source.
Cheers!
Russ
Thanks Russ, I've learnt a lot doing this, the next one should be smoother...
I'll check the rail volts again.
To test for DC, I just check each RCA (out) for mv between signal and it's gnd?
Should I leave the ource inputs open for this test?
Get back to you in 5 or so re the rail voltages, gotta open it up to do that, and I'll make a test lead to plug in while I'm at it.
Michael
I'll check the rail volts again.
To test for DC, I just check each RCA (out) for mv between signal and it's gnd?
Should I leave the ource inputs open for this test?
Get back to you in 5 or so re the rail voltages, gotta open it up to do that, and I'll make a test lead to plug in while I'm at it.
Michael
You can do two things when checking for DC offset, short the input, or connect to a source.maf_au said:
Then you do as you said and check for DC voltage (in mw hopefully 😉) between each channels output and OG. 🙂
Can't wait to see how it goes! 😀
Voltages
V+ to 0 = 11.96v (fluctuates 11.96 to 11.97)
V- to 0 = 14.12v (similar fluctuation range)
I'll pull the board out and look for shorts...
Michael
V+ to 0 = 11.96v (fluctuates 11.96 to 11.97)
V- to 0 = 14.12v (similar fluctuation range)
I'll pull the board out and look for shorts...
Michael
maf_au said:
Well V+ looks great, I would concentrate on the V- Side.
Also, if you don't find a short and you have another 7912 on hand I would simply replace it.
Hi Russ,
Heh. It looks like a parts shop here, but no, I don't have a spare 🙂
If I can't find a short, Jaycar has them I think...
Michael
Heh. It looks like a parts shop here, but no, I don't have a spare 🙂
If I can't find a short, Jaycar has them I think...
Michael
Could it be the LED? I just used one that was lying around. It works, but it isn't bright...
Safe to remove it and run without one for the moment?
Safe to remove it and run without one for the moment?
I may have to retire defeated...
I've checked and scored any close tracks, but they all seem clear. Removed the LED, resolderd anything that looks suspect, but no change.
No test I can do on the 7912 itself?
I've checked and scored any close tracks, but they all seem clear. Removed the LED, resolderd anything that looks suspect, but no change.
No test I can do on the 7912 itself?
maf_au said:
Well, the amps will run fine with the voltages you are getting out, so you could go ahead with your testing, but I would get a new 7912 when you can.
As far of testing the 7912 itself the testing you are doing now is basically the same as you would do in any case. 🙂
Sorry for the bit of bad luck...
Cheers!
Russ
No matter, maybe it was dud when I got it, or I fried it installing it or something.
Certainly replacement therapy will eliminate it as a source of the problem 🙂
Pushing on towards 1am here, I'll call it a night and test it tomorrow. So close.
Quite happy with how it turned out, I think I'll make a thick front plate for it to get that recessed volume control look.
Thanks for your help Russ! Hopefully have this puppy pumping out music tomorrow...
Regards,
Michael
Certainly replacement therapy will eliminate it as a source of the problem 🙂
Pushing on towards 1am here, I'll call it a night and test it tomorrow. So close.
Quite happy with how it turned out, I think I'll make a thick front plate for it to get that recessed volume control look.
Thanks for your help Russ! Hopefully have this puppy pumping out music tomorrow...
Regards,
Michael
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