Spin Semiconductor

Hi,

I've just made my first audio effect using FV-1. When I plug it to power, the clip LED is on all the time. There is great hiss from the output and when I touch input with finger, I can hear more hiss (what i think is a good symptom). The problem is, that there is no sound coming out, except of hiss.

Here is the schematic of my application, it's almost the same as in datasheet.
http://images47.fotosik.pl/69/e6afcfd409fdfa75.jpg


I would be very grateful for any idea what could be wrong,
Michael

Quick look at schematic mostly looks ok but you are missing the 15pf cap from X2 to gnd (see schematic in FV-1 datasheet) Some crystals require the additional capacitance to properly start.

Hi Frank,
Thank You for a quick answer. Unfortunately this is no fault of the capacitance because after reading forum it was first thing I tried. Maybe You have some other ideas?
Clip LED should be on only when input signal is to big or are there any other circumstances?

Correct, clip should only come on when signal approaches max levels, input too high or internal processing with too much gain.

OK, so lets start with the basics, select program 0, internal (T0 = gnd), set the pots to mid setting and do you get anything out? Try each internal program and see if any work or if there appears to me a difference in them.

How fast does your 3.3V rail come up to power? If too slow could mean the chip is not properly resetting.

Is the chip socketed or soldered?

Hi,

I'm sorry for long time without answer.

I still got this problem. First thing. The 3,3 V don't appear. It's only around 1,65V when I turn the board on.

There is no difference when I'm changing the programs. It's always annoying hiss.

I'll be grateful for any kind of help.
Michael

If you are only getting 1.65V when you turn on the board, there is a power problem somewhere. Check your power supply, any voltage dividers you have in the design, shorts, component values, etc.