H9: Does headroom depend on power supply voltage?

[murmichel]

There are several reports on this board of the H9 clipping when used in an effects loop. I’m experiencing this too.

I’m wondering if the headroom depends on the voltage supplied to the H9. I’m running it on 9V, but apparently it works on 12V, too.

Is the input voltage always regulated to the same value or could a higher voltage increase headroom?

[gkellum]

murmichel wrote:

Is the input voltage always regulated to the same value or could a higher voltage increase headroom?

The input voltage is always stepped down to 5 volts.  So, using a higher voltage won't increase headroom unfortunately.

[nickrose]

The analog supply rails are independently regulated (they have to be as otherwise sound quality would be too dependent on the input voltage quality). This means that higher power voltages will not increase headroom.

Note that using non-Eventide power supplies may damage the unit, and such damage will not be covered by warranty. In particular, unregulated supplies above 9V must be avoided.

 

[PeterJohn]

Hi…..This is a good question and to answer it correctly requires an understanding of gain structure, which is a relatively simple thing that nonetheless gets overlooked/badly misunderstood by a lot of people.The amount of signal (headroom) that a device can handle is determined by the voltage rails that power the device. A typical op-amp chip can be powered by between +/- 15 volts, which gives a peak to peak voltage swing of 30 volts*. A device powered by a single 9 V battery has a peak to peak swing of ( volts (in practice slightly less), or the same as running 4.5V rails.

[Author]

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