Hi Cousinbilly, all ...
Well, I just received delivery of my Atma-Sphere MP-1, and made the balanced conversion on my Tri-Planar tonearm yesterday.
I documented the process with photos and procedural hints in this web page in the Tri-Planar section of my website:
http://www.galibierdesign.com/prd_triplanar_xlr_build.html
The photographic quality is only o.k., but it gets the point across.
Note, that since the ground is common to both channels, you need solder pin-1 to the braided shield connection in only one channel.
I opted to solder the pin-1 connections in both channels and risk a ground loop. My reasoning was, that I could recover gracefully by lifting the connection to one of the shield connections inside the black junction box.
Inside the junction box, you'll find three wires soldered together: (a) the black ground wire used for single ended operation (b) and two yellow wires - with one going to the shield of each channel.
Strictly speaking, you don't have to open up the black junction box to do this job. You can clip off the black ground wire flush with the outside of the box and be done with it (or, alternatively leave it hanging free).
I tidied up the installation and made it more reversible by pulling the black ground wire back into the junction box, coiling it up, and tucking it into the box.
As an aside, your MP-1 will sound a bit soft (Ralph calls it "dead") for the first 20 hours, so don't let this alarm you.
I was a bit surprised that any metal film resistor (Caddock upgrade) along with Teflon capacitor (V-cap upgrade) could start out life sounding soft.
Ralph tells me that while many Caddocks have the characteristic "tizzy" signature common to metal films, these particular Caddocks do not.
Enough about the MP-1, this thread is about conversion of the Tri-Planar for balanced operation. Back to our regularly scheduled programming ...
Cheers,
Thom @ Galibier
Well, I just received delivery of my Atma-Sphere MP-1, and made the balanced conversion on my Tri-Planar tonearm yesterday.
I documented the process with photos and procedural hints in this web page in the Tri-Planar section of my website:
http://www.galibierdesign.com/prd_triplanar_xlr_build.html
The photographic quality is only o.k., but it gets the point across.
Note, that since the ground is common to both channels, you need solder pin-1 to the braided shield connection in only one channel.
I opted to solder the pin-1 connections in both channels and risk a ground loop. My reasoning was, that I could recover gracefully by lifting the connection to one of the shield connections inside the black junction box.
Inside the junction box, you'll find three wires soldered together: (a) the black ground wire used for single ended operation (b) and two yellow wires - with one going to the shield of each channel.
Strictly speaking, you don't have to open up the black junction box to do this job. You can clip off the black ground wire flush with the outside of the box and be done with it (or, alternatively leave it hanging free).
I tidied up the installation and made it more reversible by pulling the black ground wire back into the junction box, coiling it up, and tucking it into the box.
As an aside, your MP-1 will sound a bit soft (Ralph calls it "dead") for the first 20 hours, so don't let this alarm you.
I was a bit surprised that any metal film resistor (Caddock upgrade) along with Teflon capacitor (V-cap upgrade) could start out life sounding soft.
Ralph tells me that while many Caddocks have the characteristic "tizzy" signature common to metal films, these particular Caddocks do not.
Enough about the MP-1, this thread is about conversion of the Tri-Planar for balanced operation. Back to our regularly scheduled programming ...
Cheers,
Thom @ Galibier