Runoffgroove Ruby Help please.

[Frankgb]

Hi,

I hope someone can help.

Just finished a Ruby on perfboard but it doesn't work. I have got input signal to pin 2 of the 386, but no output at all.

Pin Volts are
1 = 1.6v
2 = 0v
3 = 0v
4 = 0v
5 = 4.5v
6 = 10.4v
7 = 5.3v
8 = 1.6v

thanks in advance

Frank Berend

[HeaD]

have you checked if caps are correctly polarized? and nfet pins?

[petemoore]

1 and 8 set gain, not sure what voltages to look for on them..
 Pins 2 and 3, the inputs are not biased, time to dig in with the close in light, schematic, and 'dig in with the DMM. With the inputs sitting at 0v, I'd look for open connection or connection to ground around the inputs....generally checking around the input area...resistor color codes and/or actual values.
 Hope this Helps !!!

[B Tremblay]

What are the FET pin voltages?

[Frankgb]

Thanks for help thus far.

fet volts are :

Drain = 9.5v
Source = 1.3v
Gate = 0v

As pre schematic pin 3 goes straight to ground.

Mr Tremblay, is the Fet buffer unity gain??? I can get  input signal via the pot to pin2 but as stated above no output.

cheers

Frank

[B Tremblay]

If you have signal at pin 2 of the amp, then there's probably a wiring issue around the output.  All your voltages look good, though.

[Frankgb]

Thank you for your help!!!!

Problem was open circuit speaker!!!!

Crikey, it's a loud sucker.

regards

Frank Berend