Twitch9o5

Hey folks,

I own two digital pianos, a Korg sp170 and a Roland FP50, I use them at home and at gigs, however. I was using the Korg, amplified through a Bose L1 compact, the Korg full volume and the L1 half volume...but when I got the Roland and plugged it into the L1 the volume was no where near as loud as the Korg...any suggestions????

Many thanks in advance.

D

Freebase Dali

Put the Korg on half volume and the L1 on full volume, and the Roland on full volume?

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GuitarBizarre

What connections are you using? If you're connected from a Line Out on the Korg but a Headphone output on the Roland, then that could explain it.

The reason is, Line Out is intended for studio equipment - it's peak output is fixed and set to 2V. No matter how you play or how loudly, the Line Out works by changing the voltage on a scale of 0 to 2V. If you play quietly, it simply outputs less voltage, but its absolute max is always 2V. This also has the advantage of getting the maximum resolution in the sound whenever it is used, and also powers long cable runs without losing definition over distance.

A headphone output on the other hand is very different - Firstly, its output scale is variable - the volume knob sets a limit on how loud the loudest sound can be. Secondly, a few hundred millivolts is usually more than enough for any headphones, and should be capable of powering headphones to ear damaging levels.

As a result, the designers know that feeding 2V out of a headphone jack is dangerous - a slip of the hand on the volume control could blow headphones, damage hearing, or both, with ease. For this reason, a headphone jack typically won't have the sheer brunt power output that a Line-Out has. On top of that, if you make a volume control that goes from 0 to 2V max output, then for most people only a small portion of its range will be usable, since it will simply be too loud for much of its sweep.


This is all complicated by equipment that ONLY HAS a headphone jack - On these items (Televisions for example commonly do this), a designer may want the port to pull double duty, and so they may design a port that is designed for headphones, but at max volume actually outputs 2V so that it can power studio equipment or amplifiers etc.

The upshot of all of this is that you should try to use a line out at all times, unless you're using headphones. That will always ensure the loudest, cleanest, highest quality signal between your keyboard and your amplifier. Use headphone jacks only if no line out is available, and be careful not to drive your amp too hard if you're using a weak headphone jack - remember, if the keyboard is half as loud, then to get the same volume the amp is working twice as hard to make up for it! Don't push it!

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MajorDud

I believe the FP50 does has 1/4" line out connections. What is not known is the output impedance of the keyboard and how it matches the input impedance of the L1. If the Korg has a lower impedance, it may be able to drive the L1 input better than the FP-50. This information does not appear readily available in manuals and you may need to consult tech support from Bose and Roland.