Spin Semiconductor

Hi everyone!
I just got my fv-1 eval board but i find there is too much "hiss" type of noise. It's not PSU related cause i supply it with dedicated PSU; it's not a 100Hz hum, it sounds like a "shhhhhhh".
I tryed putting a buffer pedal on the input, on the output, tryed to ground the input channels but it's always there.
If i kick a patch, noise doesn't get modulated, so it sounds like it's coming straight from FV-1.
I read all threads about noise in FV-1 but i didn't get any answer.
Any suggestion would be greatly appreciated!

Thank you

I have put the scope at the FV-1 output and it shows 10mVpp noise with or without grounded inputs.
Looking at the FFT it shows that the noise level is full band.

I tried to power it with 9V Battery, same thing.

I have to assume that the noise comes straight from the FV-1.
How can you use such a thing if it is so noisy???

It might be fun to play with it and make some experiments, but as musician i could never play a live gig with such a thing.

I don't know why you are getting such noise, depending on the way you have the board connected you may need input and output buffers and you should drive the inputs as hot as possible (3Vp-p). More info on how you have it connected may help.

The signal path is very easy:
guitar-->buffer-->fv-1 board-->buffer-->amp

I am driving the ADC input with guitar level which is too cold but i expected little less output noise.

This morning i will adjust the in/out gain to match the ADC full scale. If the noise comes from the A/DAC i should get some noise reduction

I gave a look at Holy Sustain schematic which runs FV-1 and i don't get why they didn't boost the guitar before hitting the ADC..
Btw i will let you know how my tweek goes!

Ok i did some test with in/out gain and the noise drops to acceptable levels.
With my strat if i hit hard on the low E i can get 2-3V peak which is two times the max input of the FV-1... Need for smart gain here

My goal, before i even start to write a single instruction on this device, is to retain all the input information. I don't wanna loose dynamics

Time to get into the predictive compression world!

dsPaul wrote:The signal path is very easy:
guitar-->buffer-->fv-1 board-->buffer-->amp

I am driving the ADC input with guitar level which is too cold but i expected little less output noise.

This morning i will adjust the in/out gain to match the ADC full scale. If the noise comes from the A/DAC i should get some noise reduction

I gave a look at Holy Sustain schematic which runs FV-1 and i don't get why they didn't boost the guitar before hitting the ADC..
Btw i will let you know how my tweek goes!

Never blindly trust a schematic on the web...