Question about XLR2RCA with transformers


#1

Trying to get the 6dB+ from the XLR port. But have some question about the circuit.
I’m using this layout right now:
WX20180529-115104

But someone told me, the next one is better for the ground isolation.
Really? Quite confused.
WX20180529-115148

Any better way my transformers will work?


#2

And another question: How can I measure the outport level of the DSjr correctly?
I tried with a 1000Hz pure sine tone. The RCA output at 1.2+Vrms max, but the XLR only get 1.9~2.0Vrms max between the HOT & COLD.
Is my cheap multimeter up to the job?


#3

Check out the application notes at Jensen Transformers:

http://www.jensen-transformers.com/application-notes/
requires you to login so here’s one from the WayBack Machine:
https://web.archive.org/web/20120531140924/http://www.jensen-transformers.com/apps_wp.html
Especially AN003, but they all are good.


#4

Thanks Ted. I red the Jensen Notes long ago as you posted in another topic. My setup is the “better” type in AN003. So far so good.

But how can I measure the outport level of the DSjr correctly? Is my 1000Hz way right?


#5

It depends on your multimeter if 1k works or not. You could use 60Hz since many are built for that on their AC setting. As you surmised if you don’t get pretty close to twice the level with balanced compared to single ended something is wrong.


#6

Thx Ted.
Just found that the Jriver UPnP will only got 1.8Vrms(-2.5dB).
Don’t know why, but the Roon & USB input works good at 2.4-2.5Vrms.