Balanced Phono Preamp?

[richidoo]

What are the 4 pins that come out of the phono cartridge? Do they connect to each end of two coils in the cartridge?

Thanks

[BobM]

Here's a page full of pictures, some of which might help:

https://www.google.com/search?q=phono+cartridge+construction+diagram&espv=2&biw=1208&bih=769&source=lnms&tbm=isch&sa=X&ei=8JXkVJirFMinNrzbg8AM&ved=0CAYQ_AUoAQ#imgdii=_

[richidoo]

Thanks Bob.

I found a tube based balanced phono-pre design from Broskie.

[rollo]

Thanks Bob.

I found a tube based balanced phono-pre design from Broskie.

   Build it they will come. BTW love your "but the Crusades" very clever stealth message. Eh eh eh.

charles

[sleepyguy24]

Thanks Bob.

I found a tube based balanced phono-pre design from Broskie.

Morning Professor,

Is this the design you will be building?

http://www.tubecad.com/2009/10/blog0175.htm

http://glass-ware.stores.yahoo.net/tetrasansps.html

Seems pretty cool. I wish there was one already pre-built so I could give it a try.

[richidoo]

Dean,  that Tetra is a single ended circuit, because the input ground connects to the output ground and chassis. Balanced (differential) circuit has separate + leg and - leg that are both signal.

I was looking at this one: http://www.tubecad.com/2007/09/blog0120.htm
No step up for MM, so cart floats with grids!   
Only 1 cap in signal path, super simple. Is there really RIAA EQ in there?

Because a phono cart is a magnetic coil, AC voltage is seen at both ends, despite one of its pins traditionally called "ground." Normally one pin is attached to ground to make a single ended signal as in Tetra, but with a coil as signal source why not make a balanced preamp? I have balanced amps now so I am looking at converting my single ended sources to balanced.

[richidoo]

Seems pretty cool. I wish there was one already pre-built so I could give it a try.

DIY Dean! It is a lot easier than you think when you use good design and a good PCB or kit.
http://glass-ware.stores.yahoo.net/tetrasansps.html
http://glass-ware.stores.yahoo.net/hiposu.html

[richidoo]

Another Broskie balanced tube phono pre from 1999

http://www.tubecad.com/july99/page9.html

[rollo]

Dean,  that Tetra is a single ended circuit, because the input ground connects to the output ground and chassis. Balanced (differential) circuit has separate + leg and - leg that are both signal.

I was looking at this one: http://www.tubecad.com/2007/09/blog0120.htm
No step up for MM, so cart floats with grids!   
Only 1 cap in signal path, super simple. Is there really RIAA EQ in there?

Because a phono cart is a magnetic coil, AC voltage is seen at both ends, despite one of its pins traditionally called "ground." Normally one pin is attached to ground to make a single ended signal as in Tetra, but with a coil as signal source why not make a balanced preamp? I have balanced amps now so I am looking at converting my single ended sources to balanced.

   Excellent idea. Balanced dual mono oh my !


charles

[BobM]

My understanding of a phono cartridge is that it is inherently balanced, just by its design. It's the phono stage that typically makes it common ground. My phono stage is also balanced, by design (Hagerman Trumpet) and you can actually order it that way with balanced output to your pre-amp if you like. But that is not typical of most designs.