Author Topic: Cembalet / Pianet Vibrato Clicking  (Read 467 times)

Offline theseacowexists

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Cembalet / Pianet Vibrato Clicking
« on: February 07, 2018, 02:22:16 PM »
My new Cembalet N is finally in playable condition!  The only major problem now is the vibrato.  When it's switched on, there's almost no intensity to it - instead there is a light clicking sound (which is more noticeable with the tone switch on 'high'), and the overall volume of the instrument drops just a bit.  The tremolo lightbulb works and the entire board has been recapped with the appropriate caps.  The rate trim pot changes the rate of the clicking, but the intensity trim pot seems to have no effect on the clicking.  This Cembalet seems to have the older version preamp with the germanium transistors.  Has anyone else ever experienced this?  So far I haven't found anything on the boards about a clicking vibrato.

Offline OZDOC

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Re: Cembalet / Pianet Vibrato Clicking
« Reply #1 on: February 07, 2018, 05:24:08 PM »
This is a long shot - but I've found that these are sensitive to the proximity of the bulb to the sensor.
Is the bulb too close/too far away.
And the sensor should not be exposed to other light when you are reviewing the effect - in other words you need to shade the board from room light falling onto the sensor if the cover is off.
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Offline theseacowexists

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Re: Cembalet / Pianet Vibrato Clicking
« Reply #2 on: February 07, 2018, 06:44:34 PM »
That's what I originally thought.  I've tried experimenting with moving the sensor further and closer to the light and it seems to make no difference.  Neither does having the harp cover on or off.

I have been using the 100mV output to my amp, but on a whim a few minutes ago, I switched to the 300mV output.  Now there's no clicking when the vibrato is on, but the slight volume drop is still there.  On the plus side, all three tone switch positions sound much better through the 300mV output.  When I was going through the 100mV, only the "up" position was usable without tweaking the amp (the "middle" was dull and bassy and the "down" was thin and tinny). 

Offline OZDOC

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Re: Cembalet / Pianet Vibrato Clicking
« Reply #3 on: February 07, 2018, 06:57:57 PM »
The 100mV output is intended for the accessory CP amplifier that hangs under the Pianet N.
The take-off point is before the final transistor in the circuit so I'm guessing the CP amp is looking for a different impedance than the normal output.
When you use this as your output what you plug in is interacting with the preamp circuit in an unexpected way.
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