The last couple days I have been working on my first real build, a Sabertooth.
My soldering skills are still pretty rough, and a couple spots don't look pretty. But there is nowhere locally where I can get desoldering braid at the moment. Hopefully I can in a couple days.
Also, I have an analog multimeter, not digital. And I'm not sure exactly how to use it all the time.
Whenever the circuit is bypassed, my clean signal comes through fine. When turned on, the LED lights up. No sound comes through though. This indicates a problem on the board, right?
I checked the 9v in, ground, and they are getting signal. After that, I'm not sure how to test for problems. When I put my thumb on the switch, sometimes there is some sort of static/white noise.
Being a newbie at this stuff, I can use all the help I can get.
Pics to be posted soon.
Your situation sounds like the classic "upside down enclosure" error. When you're debugging a new build and you have the enclosure open and upside down it's really easy to accidentally plug in backwards (guitar into pedal output, pedal input to amp). This gives you signal in bypass, LED but no signal in On state.
If that's not it, try posting the voltages on the legs of your transistors.
Quote from: mgwhit on August 04, 2011, 07:22:08 PM
Your situation sounds like the classic "upside down enclosure" error. When you're debugging a new build and you have the enclosure open and upside down it's really easy to accidentally plug in backwards (guitar into pedal output, pedal input to amp). This gives you signal in bypass, LED but no signal in On state.
If that's not it, try posting the voltages on the legs of your transistors.
some clear photos might help as well. there's not much to that build so it shouldn't be difficult to track the problem down.
These are the best pictures I can get with my iPhone. It doesn't like these small boards apparently.
And I realize I need to brush up on my soldering skills.
(http://img811.imageshack.us/img811/9204/img1129p.jpg) (http://imageshack.us/photo/my-images/811/img1129p.jpg/)
(http://img818.imageshack.us/img818/2250/img1130yb.jpg) (http://imageshack.us/photo/my-images/818/img1130yb.jpg/)
How well are your transistors seated in those sockets? If one isn't making good contact, that could result in no sound.
I would reflow your solder joints, some of them look suspect.
Josh
I'll try reflowing some of them.
Just curious, is there any "home remedy" for absorbing solder? As I said, my town doesn't have any and it will be a while before I can get some.
Thanks for the help, guys.
You can use a wire. Remove the insulation and use it as desolder braid.
It's hard to tell from those photos, but my guess iss that you have a solder bridge due to the excessive amount of solder. some of those leads should be trimmed flush as well. there is quite a bit of wire poking through on a few of those joints.
In the picture with the solder side, I see a very suspect joint. Its the joint right above Bite Lug 1, I believe its the collector of Q2. It looks like a solder bridge with the base pin of Q2.
Hi Gents,
I have a problem with sabertooth too...
I've soldered everything and the issue is that when bypassed i can hear the bass, when on 1N4001 is gettin extremely hot and all I can hear is constant "buzzing"
Any Ideas?
(I'm a complete noob so don't be angry if the answer is obvious)
It sounds to me like you've wired your power incorrectly. The 1N4001 is there for power protection, and it will get hot if power is trying to the wrong way through it.
Could you post some pictures for us?
Jacob
Pictures available below:
http://photobucket.com/gladzillassabertooth
Please also find my wiring schematics... finally it all cames to the same design.
(http://i134.photobucket.com/albums/q81/Gladki/sabertooth/mywiring.png)
Sorry man, those pictures aren't helping me see what I was hoping to see.
I need to see how you've wired your jacks, and where each lug of each jack is going to.
Have you taken a look at the "How to get tech help" thread yet? You should read through that to see some tips on how to find the right kind of info to help us help you
Jacob
Looks to me like you have your DC power jack wired up incorrectly. The big lug should be ground. I recommend testing each lug with a DMM to get a better feel for that kind of switched jack.
@ mgwhit
The simpliest solution appears to be the best. Everything works properly after switching DC Jack wiring.
:)
Thank you.
----
Still i wonder why - wiring schematics indicate that DC jack's TIP should be wired to +9V and in my DC jack TIP is connected with bigger lug. Please correct me if I'm wrong.
----
I will switch my pictures for "more useful" version in case of future questions and as an example of "how no to ..." ;)