WOPL dual 500

grapplesaw

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#61
So the THD+N is very low .008 at 2.7 volts 005 at 5 volts which is great. The D.C. Offset is .2mv. Bias is very stable and changes by .025 mv from low rail to high rail voltage which is good.


will put the Meter board on next and then bring up the output.

got to look for those parasitic destortions in the 10-20k range. I hope not to find any.
 
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grapplesaw

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#63
tune time

Well after a good bench test it is playing now.

So it did not have any paristac oscillations up to 20k
bias is set at .350v
D.C. Offset is .2-.5 mv

output
565 watts at high rail
275 watts at low rail

117 line voltage
 

grapplesaw

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#73
May need to add a soft start

The amp plays beautifully. But I do have a problem.
Keeps blowing fuses. I had 10 amp in which is smaller than required. It wants 16 amp fast blow ABC style fuses. I up graded to 15 amp and worked fine till now and blew again. I have checked the outputs and no bad ones there that I can find.

I put in two 33,000uf main caps in this build. This maybe to big of a load for startup. I will get some 16 amp but do not think it will be a fix.

I will I'll run up on the dim bulb tester to confirm outputs being ok.
 

laatsch55

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#78
Fast blow's in the mains dont sound right, BECAUSE you have inrush, why would it be any different on a D-500 from a 700?
 

grapplesaw

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#79
Fast blow's in the mains dont sound right, BECAUSE you have inrush, why would it be any different on a D-500 from a 700?
I am with you.

I just ran it up with the DBT. Although at full power a 50 watt is not so dim all looked good. I powered it up slowly and after about 60 volts rail and got good sine wave.

The other 500's fire up good with fast blow but only have 15,000 uf caps where this has 33,000 caps

I will pick up some slow blow fuses and report back.
 
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