Bad Power Supply (Europe)

[underwood]

Hello,

I have a Time Factor and a Mod Factor for about two years and a Space for a few month now. Using all three together I got some problems with noise and the Space changes parameters, when it had run it for about 30mins when I use presets like Blackhole that need loots of cpu/dsp power.

After changing the space power supply with the mod factor supply the noise was reduced a little, haven't made a longer test of the Space yet and it seems to run more stable.

The Space has a smalller power supply and because I read, that lots of people had problems with the supplys I have done some meassuremts.

The Eventide support wrote here in the forum that the pedals need 500mA@9V or can run with 12V to and need 400mA. 12V is the maximum voltage, should not be exceeded, as the support wrote. (Look at the results without load!!!!)

I use a 20 Ohm load for tests, that is less than the load from the factor pedals.

The supply Model A40912G (Made in China)  that I got with the Time and Mod Factor has 9V and 1,2A printed on. I messured 13,02V with no load and 10,45V with 20 Ohm load. That is a voltage drop of 2,57V. This is not a regulated power supply. The hum voltage is 1,8V.

The Space comes with the Model MKD41-0900500GS Made in Taiwan that has 9V and 500mA printed on. I messured 14,87V (!!!) without load and 9,24V with load. That is a drop of 5,62V. The hum voltage is 2,1V. This supply is eaven worst than that of the Mod and Time Factor and has no regulation or stabilisation nor filtering at all.

For comparison I tested a switching power supply from a network-switch with 12V@1A that I got for 2,95€ from a remaining stock. Made in china to. It has a voltage of 12,18V without load and goes down to 11,60V with the 20 Ohm load. This is a drop of only 0,58V. I can't meassure any hum voltage but there may be some high frequency switching noise but I can't see it on my oszilloscope so it's out of the audio range.

Why has a 500,-€ effect pedal a power supply that is eaven worst than a power supply that is delivered with a 29,-€ network-switch???

I've build a DC-Filter with overvoltage, overcurrent and polarity protection that has some LC-Filters and some capacitors for a more stable voltage in it. I use the filter with the 2,95€ switching power supply on my eventide pedals now. I hope these are better than the one I got with the pedals.

I post some pictures of the messurement and the dc filter soon.

greets

underwood

[nickrose]

Eventide Stompboxes have internal power regulation and have loose specifications from their external power supplies. Essentially, they need between 9V and 12V under load, with some ripple tolerance beyond that. More than of 15V under load may cause damage. Your 20 ohm resistor will give a current draw of  0.5A, which is more that the maximum draw of these pedals, so, unless their filter capacitors are broken and passing too much ripple, I would say that they are probably OK.

That said, we have had some batch problems with power supplies, so if you find a noticeable difference between them, you should contact support@eventide.com

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