Ruby Help ????

[arawn]

Built A Ruby With the bassman mod and I have no output.
Voltages
Battery 8.87v
Transistor (Mpf102)
Gate 0.00v
Source 334mv
Drain 8.87v

IC lm386n1
Pin1 0.0
P2 0.0
P3 0.0
P4 0.0
P5 22.3mv
P6 74.9mv
P7 36.3mv
P8 32.6mv 
Scheme

Perf layout


I was trying to do th K.I.S.S method for this perf build hence no switch and no led but i do have both The Volume and Gain Pots.
The Bassman Mod
Bassman
Replace the .047uF cap from the FET source pin to the volume pot with a 0.1uF. Place a 220pF cap from lug 3 to lug 2 on the volume pot. Remove the Gain pot and place 2k2 fixed resistor between pins 1 and 8. In this configuration, Ruby sounds very much like an old Fender Bassman to our ears. With the Volume control at half rotation and below, you'll notice smooth and sparkly cleans with good depth. With the Volume pot set high, you'll hear nice overdrive that is great for blues playing. The transition from dirty to clean can be controlled with your picking or strumming. This aspect can add an extra dimension to your playing.

Unfortunately I have no output at all, any help or thoughts would be appreciated

[brett]

You have no power going in.  One of the pins (pin 7 ??) should be at battery voltage.

[ambulancevoice]

pin 6 needs to get 9v+
make sure its connected, and check the pinout of your transistor just in cause
also, check for that everything is orientated correctly, like, the 386 is the right way, and the electrolytic caps are the right way around, check your dc jack (if your using a metal enclosure with a non plastic dc jack, you need to isolate the dc jack)
check for cold solder, jumpers etc

[arawn]

Okay fixed the voltage to ic and now get voltages more in line with what I expected to see
Voltages
Battery 8.66v
Transistor (Mpf102)
Gate 0.00v
Source 1.509v
Drain 8.75v

IC lm386n1
Pin1 1.33v
P2 9.0mv
P3 0.0
P4 0.0
P5 4.63v
P6 8.20v
P7 4.18v
P8 1.306v
Still no sound and my pots have no appreciable effect on the voltages

[gutsofgold]

If I read that correctly, you did all the mods except you kept the gain control ... so you didn't jumper pins 1 and 8 with a resistor?
If you kept the gain pot and you still put the 2.2k resistor between pins 1 and 8 I dont think you'd be getting enough gain through thus no output.

I don't know how comfortable you are with perf boards but I just built the Ruby as my first perf build and I had about a dozen lightbulb moments where I noticed a simple wiring mistake. Check your trans orientation too!

I'm also getting the same exact readings as you are.

[arawn]

nope omitted the 2.2k in favor of the gain control

[ambulancevoice]

nope omitted the 2.2k in favor of the gain control

checked for cold solder?

correct polarity? etc

[brett]

Hi
is the JFET on?
Use an audio-probe to find out? (touch it to the source)
cheers

[arawn]

ok everything is working now with the exception of the volume pot and I'll deal with that later just glad to get sound !!!!

[diablospyder]

I had a similar problem with my Ruby; I got sound when one of the pots was in a "sweet spot" (forgot which pot it was), but neither pot was varying anything. The weird thing was that it had worked fine (with the minor problem of picking up radio stations) before I boxed it up. Turns out a wire shifted when I boxed it up, which connected pins 7 and 8 on the 386. I'd recommend giving that area a quick once-over with a magnifying glass just to make sure you didn't make the same mistake that I did.

[arawn]

Nope swapped both pots out one was a bummer from Radio Crap and the other i replaced with a much higher value (100k) works great and sounds awesome but I personally don't like it with 12 volts stick to 9. You get way more gainey sounds out of it that way