Pretty much the same. I don't know whether 230V makes ground loops worse or not, but regardless, the improvement would not be any less significant.
I would not go under 22mH, and not much more because larger chokes tend to have parasitics that worsen performance.
We're not using a line bypass capacitor because we're using the choke on the signal line, not the mains.
Okay, got it. I am ordering it soon. Digikey has the Schaffner 27mH.
I have a most annoying ground loop where I can here my computer mouse moving in the speakers. I can only hear it with the tube amplifier, and never with the DIY Firstwatt F5 solid state mosfet amplifier. My $5 ground loop isolation transformer fixes the problem, except treble sound quality is 5% worse with the transformer than without. Unacceptable! 😛 If this does not work as advertised, I will go for the Made in Sweden Lundahl isolation transformer. Thanks for the help!
I have a most annoying ground loop where I can here my computer mouse moving in the speakers. I can only hear it with the tube amplifier, and never with the DIY Firstwatt F5 solid state mosfet amplifier. My $5 ground loop isolation transformer fixes the problem, except treble sound quality is 5% worse with the transformer than without. Unacceptable! 😛 If this does not work as advertised, I will go for the Made in Sweden Lundahl isolation transformer. Thanks for the help!
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Nope, still living with a pretty poor subwoofer isolation transformer for the mids and tweeters.
Just the way it was shown earlier in this thread. You don't have to though if you don't want to. 😀
I think what deterred me from trying was that I did not fully understand how to connect it. I am thinking I should use it on the minidsp and the tube amplifier. On the minidsp digital active crossover I think I must make an external circuit, because the thing costs €700 and still has warranty. Could anyone make a schematic for me including the 27mH choke and the line bypass capacitors described in the datasheet:
"Common-mode suppression chokes together
with line bypass capacitors building an AC
EMI suppression filter device."
"Common-mode suppression chokes together
with line bypass capacitors building an AC
EMI suppression filter device."
The schematic is here:
http://www.diyaudio.com/forums/construction-tips/251996-ground-loops.html#post3845378
It doesn't go on the mains, it goes on your RCA input in the same place as your signal trafo. And there's no line bypass capacitor because we're not using it for mains.
http://www.diyaudio.com/forums/construction-tips/251996-ground-loops.html#post3845378
It doesn't go on the mains, it goes on your RCA input in the same place as your signal trafo. And there's no line bypass capacitor because we're not using it for mains.
Your schematic if anyone else is curious: http://www.diyaudio.com/forums/atta...94172232-ground-loops-groundfaultrejector.png
Thanks, I remember now. I will go ahead and try it out. Do you think it will do a better job than an isolation transformer for the tweeter? Maybe it is the same thing. http://forums.prosoundweb.com/index.php?action=dlattach;topic=139588.0;attach=5785;image
Thanks, I remember now. I will go ahead and try it out. Do you think it will do a better job than an isolation transformer for the tweeter? Maybe it is the same thing. http://forums.prosoundweb.com/index.php?action=dlattach;topic=139588.0;attach=5785;image
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It could be, but it would be a break in habit to use anything other than an isolation transformer in that position.
I solved most of the problem I think. It has annoyed me that the firstwatt F-5 that I built with star ground to the PSU-board has no noise, and the tube amp did. So I firstwattified the tube amp with a thermistor, in the same fashion as in the F5. I also moved the tube PSU ground to the chassie ground with the CL-60 thermister in between, instead of it being connected to the chassie at two separate points - one at the power connection and one in the middle, separated by 15cm. All I can say it helped a lot. I can still here some buzz when I stick my head in the horn. I will test the choke like you said in a week when I get the parts.
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I tried the X-something cap in parallel to the power connector and it was even more quiet until the tube amp started to oscillate, and then it was less quiet. But the thermistor+star ground worked out great.
The choke worked like a charm. Now there is only a faint hiss, but no scratchy RF noise. The cure was a choke and connecting the grounding more similar to a Firstwatt F5. Thanks!
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