#1
Alright, I decided that i needed to get a little better at soldering, so I got the stuff to make a few rubies.

I made my first one today, and I went by the diagrams available off of runoffgroove.com. I also added in a simple switch to break the positive lead off the 9v to conserve power.

Whenever I turn the battery on I get what sounds like an alarm buzzing. The buzzing doesn't get louder as i turn the volume up, just higher pitch. The gain control didn't do much of anything until I broke the ground off of it, now it acts like the volume control, but not as extreme.

I checked the diagrams over again, and I think I have everything wired up right. I touched the positive lead of the battery to every ground point in the circuit and the signal went quiet and the battery started heating up for whatever its worth. The speaker also has two positive and two negative leads. I tried them all and both do the same thing on each side.

This was a cheap radio/clock. No big deal if something is broken, but I'd like to figure out the problem. Any ideas on what the problem could be? I'll check the diagram again tomorrow.
Quote by SomeoneYouKnew
"If I said you had a beautiful body, would you hold it against me?"
#2
Troubleshooting is pretty much useless without the voltages on your build (IC and transistors) and photos (if you wish).

Your builds oscillating. Super hard to say why this is happening without more detailed info.
#3
All of these are off mouser. 9v circuit

Parts List -

2N5457
N-Channel Transistor

NJM#386D
Low Voltage

CCF60-2.21K-E3
1/2watt 2.21Kohms 1%

CF1/2CT52R100J
10 ohm 5%

CCF55-3.92K
1/4watt 3.92Kohms 1%

CCF55-1.5M
1/4watt 1.5Mohms 1%

5ZH104MACJI
50volt 100nF 20%

UKT1A220MDD
10volt 220uF 20%

2222-418-90017
47nF 250volts 2%

UKW1A101MDD
10volt 100uF 20%

Pots-

P160KN0QD15B1K
16mm 1Kohm

P160KN0QD15B10K
16mm 10Kohm

Any of that help? I'll work on getting a photo, though i can tell you right now its a messy set up.

original circuit can be found here -

http://www.runoffgroove.com/ruby.html
Quote by SomeoneYouKnew
"If I said you had a beautiful body, would you hold it against me?"
#5
Alright. I'll go grab my multimeter.
Quote by SomeoneYouKnew
"If I said you had a beautiful body, would you hold it against me?"
#6
I measured across the components, and I made a quick paint mock up of what i found. Sorry for the quality, but either the part is marked with a 1 v, or a .04 v. I did the battery, and it was giving a solid 8.8v The speaker got between .2 and .7 depending on what i put the potentiometers at.



Well. I guess the 2N5457 was getting .01v. But it all isnt what its supposed to be. I might just try rewiring everything with what that looks like.

Edit: Battery negative was connected to ground, forgot to mention that earlier.

Oh, and something strange was happening. When I had the volume set at zero and blew on the bread board it would go silent. If I turned up the volume it would work as a volume control, just for the buzzing. I tried to fiddle around with the connections but nothing worked except blowing on the circuit.
Quote by SomeoneYouKnew
"If I said you had a beautiful body, would you hold it against me?"
Last edited by C/ruel at Oct 19, 2008,
#7
The 1.5M resistor should be getting less volts after than before it.
Gear:
Schecter Hellraiser Deluxe
Boss DS-1
Crate GTD65

GAS List:
Mesa Boogie Dual Rectifier Roadster
Last edited by asfastasdark at Oct 19, 2008,
#8
Alright. Completly ignore everything about the multimeter I previously mentioned. Here are the results that might actually help someone.

D- 7.3v
S-7.28v
G- 8.0v

1- 1.23v
2- .01
3- 0
4- 0
5- 1.21v
6- 3.9v
7- 8.08v
8 - .5v

And what they should be-

2N5457 JFET:
Drain = 9.18V;
Source = 0.84V;
Gate = 0.00V

LM386 opamp:
1 = 1.34V;
2, 3 and 4 = 0.00V;
5 = 4.56V;
6 = 9.18V;
7 = 4.64V;
8 = 1.34V

So I'm getting too much voltage to my source, And I need to check for grounding with my Gate.

My 2nd pin is getting a small amount of voltage, I'm going to check for grounding there. maybe just a bad solder joint or something. My pins 5, 6, 7, and 8 are all screwed up. Unless There numbered wrong? Is 1 opposite of 5?

Regardless, I'm going to look for the other problems, and hope that they sort out the pins.

Any other suggestions?
Quote by SomeoneYouKnew
"If I said you had a beautiful body, would you hold it against me?"
Last edited by C/ruel at Oct 19, 2008,
#9
Quote by asfastasdark
The 1.5M resistor should be getting less volts after than before it.

That is just a pulldown...

It dosen matter what the voltage is there (small anyways). No idea why the TSer measured there.

I would check your grouding TS. I think your very close to a working build.