chrismercurio said:
Yes, I have seen several people do it with a battery. However, from what I have read, best results come from higher voltages and also form the toroidal transformer.. Less magnetic interference if I remember from physics.
juluska said:
cool, thanks for the reply. I will check out those rectifiers. I will also look into a buffer power supply. What I meant to ask is this.... is there a formula I need to know to to equate (match) the rectifier to the transformer. or will any combination work> I am not familiar with (Va- this must be some kind of power measurement?) and rectifier properties.
( I do have a basic understanding of how it manipulates the power supply from AC to a "rippled DC")
I contacted my professor, and he is willing to work out this first project with me, he remembered his first job working as an audio repair technician
at this point, I can't wait to start!
Kevlogg said:
Its not too surprising to see come around for the third or fourth time. At over 1000 replies, I don't get mad at people anymore for not reading the whole thread...
Don't use a battery. Use the biggest, best transformer you can afford.
Realistically, though, a 25VA or 35VA toroid with 2x12VAC will do the trick nicely. That one on ebay, or something similar from Digikey or wherever. It should be about $20, less if surplus.
Diodes: use a bridge rectifer, or two, bigger current is better, but anything above 1A and 100V is fine.
And don't forget the fuse.
12 VAC secondaries gets you about 17 V DC, 16 V if you use a bridge rectifier on both windings.
The simplest (VAC x 1.41) formula works quite well here, because the diode drop and ripple is compensated by the load regulation of the transformer. i.e. you lose about a volt to the diodes, but gain about a volt because the transformer is only lightly loaded.
/R
The simplest (VAC x 1.41) formula works quite well here, because the diode drop and ripple is compensated by the load regulation of the transformer. i.e. you lose about a volt to the diodes, but gain about a volt because the transformer is only lightly loaded.
/R
thanks AHAJA
Following your advices i changed the rectifier bridge for two schokky diodes rectifiers with parallel capacitors and added one 47uf and 100nf caps next to the opamp +v and -v. I am impressed how well it sounds now. Now i'm going to change the riaa network with your modifications. Can you explain with plain words hows this modifications can improve the sound?
ahaja said:
ahaja said:
Following your advices i changed the rectifier bridge for two schokky diodes rectifiers with parallel capacitors and added one 47uf and 100nf caps next to the opamp +v and -v. I am impressed how well it sounds now. Now i'm going to change the riaa network with your modifications. Can you explain with plain words hows this modifications can improve the sound?
Attachments
I know that it works.Thorsten wrote about it here: http://www.diyaudio.com/forums/showthread.php?postid=388315#post388315
Curently I'm working on these projects (pcb) on our polish audio forum, and it looks: http://www.audiostereo.pl/forum_wpisy.html?temat=48037&p=1#k
Two layer pcb.
Another mod is place on the top of opamp beetwen power legs cap 220-470nF. Wima MKS4 (raster/pcm=10mm).
Regards Krzysztof
ahaja said:
Thorsten wrote about it here: http://www.diyaudio.com/forums/showthread.php?postid=388315#post388315
Curently I'm working on these projects (pcb) on our polish audio forum, and it looks: http://www.audiostereo.pl/forum_wpisy.html?temat=48037&p=1#k
Two layer pcb.
Another mod is place on the top of opamp beetwen power legs cap 220-470nF. Wima MKS4 (raster/pcm=10mm).
Regards Krzysztof
Excuse my little knowledge in electronics. I guess the modified schedule for beginners is this:
Am I right?
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