Has anyone got a good high performance circuit for converting standard line level unbalanced signal into a balanced signal. Or maybe a PCB layout for a circuit.
Thanks
steevo
Thanks
steevo
One of the CCS variants of the BOSOZ or the UGS found in the pass forum would be good if you have the room or are looking for a preamp that will drive a balanced out. The CCS ends up giving the BOSOZ better tracking between the two output signals. There is an X-CCS-Cascode-BOSOZ variant.
http://www.diyaudio.com/forums/analog-line-level/150265-drv134-pcb.html or something of your own if you need to add SE to balanced into another component. The DRV134 uses Pass super-symmetry.
http://www.diyaudio.com/forums/analog-line-level/150265-drv134-pcb.html or something of your own if you need to add SE to balanced into another component. The DRV134 uses Pass super-symmetry.
That would be my recommendation as well.
Here's an example:
JT-11P-1 as "Phase Splitter" With Symmetrical Outputs
See the schematic on the right. Also note that the primary and secondary have been flipped around, i.e. the secondary is used as the primary and vice versa.
The same can be done with a CineMag CMLI-15/15B which costs less than the Jensen 11P-1.
se
Probably need level conversion too.
Standard line level for unbalanced is about -10dB. Balanced line level is +4dB. So you should need a gain of 14dB.
I did this using a 5532 op amp (balanced supplies). Make one op amp your gain stage and feed the inverting input of the second op amp (configured for unity gain). Take the outputs of both op amps for your output.
There are commercially available products that do this called the Matchbox that radio and TV stations use.
Standard line level for unbalanced is about -10dB. Balanced line level is +4dB. So you should need a gain of 14dB.
I did this using a 5532 op amp (balanced supplies). Make one op amp your gain stage and feed the inverting input of the second op amp (configured for unity gain). Take the outputs of both op amps for your output.
There are commercially available products that do this called the Matchbox that radio and TV stations use.
Hi Steve,
the Cinemag CMLI15/15b is used as a balanced to unbal at the receive end.
Are you confirming that by swapping it around it works as a transmitter from unbal to balanced?
the Cinemag CMLI15/15b is used as a balanced to unbal at the receive end.
Are you confirming that by swapping it around it works as a transmitter from unbal to balanced?
If by "transmitter" you mean an output transformer, then no, I wouldn't recommend using the 15/15B as an output transformer.
But as an input transformer, converting an unbalanced input to balanced, then yes, swapping the primary and secondary achieves just that.
Technically you could get away without doing that. Just that the primary is symmetrical and therefore balanced. However because of the winding techniques used, the secondary has a slight capacitive imbalance. It's probably not enough to really lose any sleep over though. SY has used them this way with good results.
se
I use and can recommend the PCBs offered; simple, use to use and work well.
Balanced Transmitter and Receiver II
Frank
Balanced Transmitter and Receiver II
Frank
Hey! First off I'm new to the forum. I've been getting into DIY stuff a lot lately and it just seemed that almost every time I looked something up at least a few of my top results were from this forum. Anyways, I need help. I've started constructing my own guitar amps for fun. I've started mostly with converting older organs, radios etc. for the sake of inexpensiveness and simplicity for I am still learning. The problem I've run into this problem multiple times now is this: My instrument signal is too weak for the majority of the units I'm working with. The few projects I have successfully completed or converted either already had a 1/4 inch input or I completely replaced most of the power-amp and preamp sections with older guitar practice amps. I need something that's passive, simple, cheap and compact. I will be using this design repeatedly so those 4 are a must. Would any of these aforementioned schematics do the trick or if not does anybody know of a schematic that would convert my instrument line to a line level signal? Thank you in advance for any help you may have =)
I suppose I didn't describe exactly how "newb" I am. Which part of this link am I supposed to be looking at? If it's any of those larger contraptions it certainly won't do.
sorry to bring up the old thread but does the transformer method create an opposite phase signal? how so?
You could look at it that way. It all depends on how you define the " + " and " - " (or "Hi" and "Lo"; etc) on the transformer windings. It's not uncommon to see a DPDT switch on the balanced side of the transformer, wired to allow for reversing the sense of the signal.
Dale
When I worked in TV...
and stereo TV first came out (around 1984 or so in the USA) we occasionally got a program with out-of-phase channels. This might not be noticeable if the viewer was listening in stereo but a mono listener would get nothing.
We built an XLR phase reverser that we would patch in to one channel of the playback machine to bring everything back in phase.
This was a temporary fix till we added the dpdt switch into one of the outputs.
and stereo TV first came out (around 1984 or so in the USA) we occasionally got a program with out-of-phase channels. This might not be noticeable if the viewer was listening in stereo but a mono listener would get nothing.
We built an XLR phase reverser that we would patch in to one channel of the playback machine to bring everything back in phase.
This was a temporary fix till we added the dpdt switch into one of the outputs.
The signals at opposite ends of the secondary winding are opposite in phase. Originally you have a signal referenced to ground. By removing the ground reference you now have out of phase signals, positive and negative.
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