Roland Keyboard to PA connection Advice please

[Lizardpoint]

Good day team,
I have a gig coming up with a piano player and singer. The piano may have balanced outputs on xlr but I’m not sure at the moment.
Should I connect TRS outputs to d/I box then into multicore to FOH mixer or if it does have xlr outputs can I go direct into the multicore with a pad on the FOH mixer?
Your thoughts advice and next weeks winning lottery numbers would be most welcome.
Cheers
Dave

[Drew Stephenson]

If you can find out the model of the piano then you can check the specs and see what the output level is?

[Hugh Robjohns]

The piano may have balanced outputs on xlr but I’m not sure at the moment.

It's possible, but there aren't many keyboards/ stage pianos with balanced line outputs on XLRs.

Should I connect TRS outputs to d/I box then into multicore to FOH mixer or if it does have xlr outputs can I go direct into the multicore with a pad on the FOH mixer?

Again, few keyboards have balanced outputs — most are unbalanced on TS sockets, and virtually all DI boxes have unbalanced inputs.

Personally, I always advocate connecting stage instruments via DI boxes because of the mutual protection they provide. Assuming a DI box with a transformer, the galvanic isolation protects keyboard and FOH mixer from any electrical fault in the other. Perhaps more practically relevant, DI boxes also protect the keyboard from phantom power.

I use Radial Pro-D2 passive DI boxes for my own keyboards.

If you are intellectually averse to the idea of attenuating a keyboard output to mic level and reamplifying, you could use line isolation transformers instead of a DI box. The ART Cleanbox2 or DTI models are good examples which I use a lot. They provide the same galvanic isolation and phantom power blocking functions, but you get the same signal level out as you put in – there's no attenuation to mic level as in a DI box.

[The Elf]

It's for moments like this that I had a couple of custom isolator boxes built for me by Orchid Electronics. Into one side goes my line/keyboard level FOH, out of the other come both line level and mic level outputs - it's up to the PA guy which he chooses. In your situation all I would take would be my isolator and a selection of TRS-to-XLR and XLR-to-XLR cables. As long as I can connect to my isolator box the rest is up to the FOH guys.

There *are* quite a few keyboards that have balanced and XLR outputs (Kurzweil and some of the more costly Rolands, for example), so you do need to be prepared for that.

[bonefixer]

Yamaha CP88 also has balanced XLR outs. I go direct into the desk. Must say, I hadn’t thought about the ‘protecting the gear’ feature of DI boxes - I thought it was all about impedance matching and getting balanced lines from unbalanced inputs. I might have to get some more.

[Hugh Robjohns]

Must say, I hadn’t thought about the ‘protecting the gear’ feature of DI boxes...

I suspect you're not alone! But it is a serious benefit that can genuinely save gear (and even people) should something goes accidentally or horribly wrong... and it sometimes does.

The complication is that not all DI boxes have isolation transformers, so check if galvanic isolation is important (or mission critical). However, even DI boxes without transformers will protect against phantom power.

I thought it was all about impedance matching...

Not impedance matching; impedance conversion!

DI boxes typically present a very high input impedance — much higher than the source instrument's output impedance. That keeps guitars happy.

The output impedance is a low 150 Ohms or so, similar to a microphone, and roughly ten times smaller than the input impedance of the mic preamp.

The low output/high input impedance paradigm is all about voltage matching not impedance matching.

[Wonks]

DI boxes typically present a very high input impedance — much higher than the source instrument's output impedance. That keeps guitars happy.

Active DIs normally, passive DIs less so (at least for passive guitars and basses). Though passive DIs can work well on passive bass to achieve the classic Motown sounds due to the extra treble roll-off the lower input impedance gives.

[Lizardpoint]

Morning Team,
I have now confirmed the piano is a Roland RD700SX and does have balanced outs on xlr and also jack outputs.
Does this change anything ?
Is via d/I box from Jack o/p still the best way to go?
Gig is tomorrow night. Cheers chaps/chapesses.

[Wonks]

Unfortunately the manual doesn't say whether the XLRs are at line or mic level. They are probably line level, but without plugging them into a mixer (try the line level first), you won't know for sure.

Have you got a small mixer you can test the outputs into directly, say using headphones for monitoring, before deciding whether to use XLR to 1/4" TRS leads into line inputs, XLR to XLR leads into mic inputs or jack outputs into a DI box and XLRs from that into mic inputs.

Why do manufacturers leave out such basic important info from their manuals?

[sonics]

I have now confirmed the piano is a Roland RD700SX and does have balanced outs on xlr and also jack outputs.

I've mixed lots of those. The output can get very hot if cranked and played hard, so definitely much more than mic level.

[Lizardpoint]

Well I went with The DI box option in the end.
The gig went splendidly.
Thanks to everyone who gave advice.
Cheers
Dave

[Folderol]

Good to hear that, and thanks for getting back to us.