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DIY High or Low Ouput Moving Coil Phono Stage

Thanks for that link. Interesting article. But I'd still be interested in your, (or anyone else's), opinion on the L-pad idea.
 
Artie said:
Thanks for that link. Interesting article. But I'd still be interested in your, (or anyone else's), opinion on the L-pad idea.
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It wouldn't work with the PhonoClone 3, it has to be moving coil to work with this design.
 
jimreeves said:
The LME49710/AD797 combo seems to me to be the most 'open' sounding, if at the expense of some 'warmth' or 'smoothness'. The Burr-Brown choices at the inputs combined with the AD797 at the outputs is a good compromise for added warmth.
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Just a curious luker on this thread - is the 797 chip single or dual channel?

Cheers,
Bob
 
HypnoToad said:
Unfortunately many have tried the AD797 in the input stage but it won't work, Richard Murdey the designer had this chip in mind but could not get it to work either. I haven't bothered but apparently there is no gain so it must be incompatible with this circuit.
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Interesting. The data sheet on Digikey listed the 27 as a higher noise equivalent. I wonder what the real difference is. If I recall correctly, it is better to have the lowest noise possible in the first gain stage. Thanks for the heads up.
 
Noob Tube said:
Interesting. The data sheet on Digikey listed the 27 as a higher noise equivalent. I wonder what the real difference is. If I recall correctly, it is better to have the lowest noise possible in the first gain stage. Thanks for the heads up.
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There is no noise using the OPA27GP in the first stage in the PhonoClone 3, it's a different design. I can crank up the volume and hear nothing coming from the speakers until the needle drops.

You're in Houston, you should drop by and have a listen.:yes:
 
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RCA jacks?

Want to source a good quality/affordable set of female panel-mount, insulated, female RCA jacks for the clone.
Redco Audio, Digi-Key, and Parts Express-nothing I/m finding, although PE has nice WTB 0210 jacks that would work @$51 and $29 ea NOT!!
Anybody?
 
pfcs49 said:
Want to source a good quality/affordable set of female panel-mount, insulated, female RCA jacks for the clone.
Redco Audio, Digi-Key, and Parts Express-nothing I/m finding, although PE has nice WTB 0210 jacks that would work @$51 and $29 ea NOT!!
Anybody?
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Here's firstly White then Red from Mouser, I found they are as good as any I have tried and the price is low.

http://www.mouser.com/Search/ProductDetail.aspx?R=NYS367-9virtualkey56810000virtualkey568-NYS367-9

http://www.mouser.com/Search/ProductDetail.aspx?R=NYS367-2virtualkey56810000virtualkey568-NYS367-2
 
pfcs49 said:
Want to source a good quality/affordable set of female panel-mount, insulated, female RCA jacks for the clone.
Redco Audio, Digi-Key, and Parts Express-nothing I/m finding, although PE has nice WTB 0210 jacks that would work @$51 and $29 ea NOT!!
Anybody?
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I have these on just about all my equipment. The system sounds pretty good and I have been at this a long time. As long as the connections are tight and clean these will sound 95% as good as $200 RCA Jacks. Insanely cheap at under $7/pr.

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=091-1120
 
HypnoToad said:
You're in Houston, you should drop by and have a listen.:yes:
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I may have to take you up on that. From some of the other threads I see you are getting into jazz. I have some blue note, both vintage and re-release you might like to hear. I would also like to see how this phono stage compares to my Musical Surroundings Phonomena 2. I like it very much, but I am always looking for more.
 
Power Supply Completed

I've finished my power supply. My first project of this type. I've used 50VA Amtek transformers at $17 each. The IEC connector incorporates a fuse and lighted switch to simplify my hole drilling and wiring. I have the IEC on what I plan to be the side for access. The umbilicals (or is that umbilici) exit the back. Comments and suggestions welcome.
Dave
 

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Dave,

Nice work! That should keep a lot of noise from the audio circuit. But... do you not plan any filtering outboard?

I put most of the major filtering outboard then some local energy supply on the audio circuit itself.

YMMV!
 
Grainger49 said:
Dave,

Nice work! That should keep a lot of noise from the audio circuit. But... do you not plan any filtering outboard?

I put most of the major filtering outboard then some local energy supply on the audio circuit itself.

YMMV!
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Yes fantastic work WntrMute2!

The construction guide for the Phonoclone 3 has the transformers and bridge rectifiers in one box then the X-Reg circuit is on the audio boards themselves.

http://phonoclone.com/diy-guide.html

The only question I have is do the bridge rectifiers need heat sinks?
 
Yup, that works too. One of the reasons for going to an outboard power supply is to remove all AC from the audio chassis. The results of Dave's power supply is DC, but the lumpiest DC possible.

I have built a few outboard power supplies. AC induced noise dissipates with the square of the radius. So a foot or three makes things a lot quieter. I put the Pi filter in the outboard AC box and put a hand full of good caps in the audio chassis.

It is just a suggestion.
 
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HypnoToad said:
Yes fantastic work WntrMute2!

The construction guide for the Phonoclone 3 has the transformers and bridge rectifiers in one box then the X-Reg circuit is on the audio boards themselves.

http://phonoclone.com/diy-guide.html

The only question I have is do the bridge rectifiers need heat sinks?
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I don't know about heay sinkage but they are bolted tightly to the aluminum case. Maybe I'll put some thermal grease under them and re-bolt them.
 
Unless you are drawing high current through the rectifiers you shouldn't need to heat sink them. Four UF4007 diodes would be safe with the current that the chips draw.

This is for the Phono Clone, right?
 
Where'd you source the transformers and swxd IEC? I just ordered a single 35VA from DigiKey for $43.10!! At that price I'd consider a do-over and let the 35 be a spare.
PS: very nice dual power supply-worth copying.
 
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