Balanced to unbalanced converter

[speakertom]

At today's meeting interested was expressed in the DIY balanced to unbalanced converter I made. Unfortunately the two issues audioXpress magazine that outline this project are each greater than the 1 MB limit of this vehicle so I cannot post them.  However, I am including the schematic. Balanced unbalanced converter 2.bmp (385.06 KB)  Also, here are two links to the datasheets for the active devices used with background info on balanced circuits.  www.thatcorp.com/datashts/THAT_1200-Series_Datasheet.pdf    www.thatcorp.com/datashts/THAT_1606-1646_Datasheet.pdf   Both devices are still available.

Tom

[mark]

Thanks for posting, I hadn't heard of these devices before!

Looks like Mouser carries them for less than $5 each.

Looking at their spec sheets, it looks like the single-to-balanced drivers have a minimum gain of 5 or so, presumably for stability sake. For the version you constructed, what is the overall gain as you go from either single to balanced or visa versa? I suppose logically you'd expect an overall gain of unity, but some other gain could be ok as long as you knew about it!

Thanks again!

Mark

[speakertom]

I broke the two articles down to more bite sized pieces so I can load them.  There were two issues.  The first one has files 1a - 1c.  the second one has files 2a - 2d.  There is a limit of three files so the two issues will go across three mails.

Tom


Balanced_unbalanced 1a.pdf (539.82 KB)

Balanced_unbalanced 1b.pdf (755.35 KB)

Balanced_unbalanced 1c.pdf (204.25 KB)

[speakertom]

Mar 25, 2018 10:02:40 GMT -5 speakertom said:

I broke the two articles down to more bite sized pieces so I can load them.  There were two issues.  The first one has files 1a - 1c.  the second one has files 2a - 2d.  There is a limit of three files so the two issues will go across three mails.

Tom


Here are the next two files from issue two.

Tom

Balanced_unbalanced 2a.pdf (523.22 KB)

Balanced_unbalanced 2b.pdf (338.24 KB)

[speakertom]

Mar 25, 2018 10:05:41 GMT -5 speakertom said:

Mar 25, 2018 10:02:40 GMT -5 speakertom said:

I broke the two articles down to more bite sized pieces so I can load them.  There were two issues.  The first one has files 1a - 1c.  the second one has files 2a - 2d.  There is a limit of three files so the two issues will go across three mails.

Tom


Here are the next two files from issue two.

Tom

Here are the last two files from issue two.

Tom


Balanced_unbalanced 2c.pdf (563.05 KB)

Balanced_unbalanced 2d.pdf (498.57 KB)

[speakertom]

Mar 25, 2018 8:32:58 GMT -5 mark said:

Thanks for posting, I hadn't heard of these devices before!

Looks like Mouser carries them for less than $5 each.

Looking at their spec sheets, it looks like the single-to-balanced drivers have a minimum gain of 5 or so, presumably for stability sake. For the version you constructed, what is the overall gain as you go from either single to balanced or visa versa? I suppose logically you'd expect an overall gain of unity, but some other gain could be ok as long as you knew about it!

Thanks again!

Mark

Hi Mark:

For the 1206 balanced line receiver the gain is -6 dB which brings the balanced drive level down to the equivalent unbalanced level.  The reverse is true for the 1646 balanced line driver which needs to boost the gain of the unbalanced input by 6 dB to get the equivalent balanced level.

Tom