Audio connection

[Tugdual]

I just found that my audio card accepts TRS inputs. Looks like the REV2 is unbalanced. Of course it works with a 6db attenuation and I could use a DI but I was wondering what was the best practice. How do you guys connect your REV2 output?

[OakBloodThree]

Does your audio interface actually have a differential balanced input?  Many have "impedance balanced" inputs where the ring terminal is just connected to a resistance matching the input resistance on the tip terminal.  It will attenuate 6 dB as you said, but a balanced source through a balanced cable will "see" a balanced input so the cable is less likely to pick up induced noise.

The line inputs on my interface are selectable (+4 dBu/-10 dBv), and I've found that the Rev2's unbalanced output is hot enough that some patches will clip on the -10 dBv setting, so I use +4.  Losing 6dB due to the unbalanced output is probably not going to be an issue.

Unless you need the balanced connection for noise immunity (e.g. if you have a long cable between the Rev2 and your interface), I wouldn't worry too much about it.  If you really want to use a balanced cable, maybe add some good signal transformers (or DI units if you must) as close as possible to the Rev2 end of the line?

[Tugdual]

Does your audio interface actually have a differential balanced input?  Many have "impedance balanced" inputs where the ring terminal is just connected to a resistance matching the input resistance on the tip terminal.  It will attenuate 6 dB as you said, but a balanced source through a balanced cable will "see" a balanced input so the cable is less likely to pick up induced noise.

The line inputs on my interface are selectable (+4 dBu/-10 dBv), and I've found that the Rev2's unbalanced output is hot enough that some patches will clip on the -10 dBv setting, so I use +4.  Losing 6dB due to the unbalanced output is probably not going to be an issue.

Unless you need the balanced connection for noise immunity (e.g. if you have a long cable between the Rev2 and your interface), I wouldn't worry too much about it.  If you really want to use a balanced cable, maybe add some good signal transformers (or DI units if you must) as close as possible to the Rev2 end of the line?

Yes I'm pretty sure it is balanced because the PC is radiating a lot of noise (it sounds like CPU activity, not a constant hum) which is totally cancelled when I use balanced inputs. For a long time I thought the noise came from the USB connection and I couldn't tackle the problem. When I found that inputs were balanced and used a stereo cable the result was miraculous.

The led me to wonder what other people do for good practice. I also wonder why balanced output on Synth is not a standard or at least a switchable option.

[OakBloodThree]

I'm not sure what you mean by "I'm pretty sure it is balanced".  I thought you said in the first message that it [the input on your audio interface] is balanced.

Either a differential-balanced input or an impedance-balanced input will help with noise when used with a balanced source and cable.  Impedance-balanced will attenuate 6dB.

Anyway, I would guess that a balanced output is not included on the synth because it would add components, complexity and cost, and may not make enough of a difference to be worthwhile for most people.

As for "best practices":

• When recording, turn the master volume of the synth all the way up to increase S/N ratio.
• Good quality cables.
• Cables no longer than necessary.
• Signal cables routed as far as possible from radiated noise sources.  Where they must cross power cords, do it at a perpendicular.
• If you can't make it work with unbalanced cables, use a passive DI as close as possible to the synth (i.e. connected to the synth with very short cables) and balanced cables from DI to your interface.

[Tugdual]

I'm not sure what you mean by "I'm pretty sure it is balanced".  I thought you said in the first message that it [the input on your audio interface] is balanced.

Either a differential-balanced input or an impedance-balanced input will help with noise when used with a balanced source and cable.  Impedance-balanced will attenuate 6dB.

Anyway, I would guess that a balanced output is not included on the synth because it would add components, complexity and cost, and may not make enough of a difference to be worthwhile for most people.

As for "best practices":

• When recording, turn the master volume of the synth all the way up to increase S/N ratio.
• Good quality cables.
• Cables no longer than necessary.
• Signal cables routed as far as possible from radiated noise sources.  Where they must cross power cords, do it at a perpendicular.
• If you can't make it work with unbalanced cables, use a passive DI as close as possible to the synth (i.e. connected to the synth with very short cables) and balanced cables from DI to your interface.

I'm actually certain that most inputs and outputs are balanced as mentioned on the doc p16:
https://static.roland.com/assets/media/pdf/VS-100_r_e2.pdf

I have a subsequent and a rev 2. The first is very noisy and radiating a lot and the TRS cable was a life saver. The REV2 is actually much more clean but also quiet even with the volume to the max. For now I'll use the unbalanced RCA inputs it will do the job.

Thanks fo the tips OakBloodThree