Help with new dynacomp build

[jmdfd415]

Im still pretty new to this so I am hoping someone here can help me.  I just finished a dynacomp build on vero from toneys layout http://aronnelson.com/gallery/album28/Dynacomp.  I followed it completely and didnt change a single value of anything.  I have checked over my wiring and I have checked the orientation of my trannys and ic.  It works when it is on bypass and when I turn it on I get sound but its a distorted kinda sound that breaks up and is most noticeable on the bass strings.  Both the pots work somewhat.  Whenever I turn down the sustain I get no sound and the volume pot works fine.  Could someone please help me?? I dont know what else to check!

[R.G.]

Here's what to do: Go the "Debugging thread: What to do when it doesn't work". Read and follow.

[Jay Doyle]

SOunds like you need to check the bias trim. But first follow R.G.'s advice.

[jmdfd415]

Ok I looked over that page and I had basically everything except for voltages and here they are.  I hope I did this right.
Q1:
C: 9.45
B: 5.21
E: 5.02

Q2:
C: 5.14
B: 5.71
E: 5.05

Q3:
C: 9.07
B: 0
E: 0

Q4:
C: 9.05
B: 0
E: 0

Q5:
C: 9.48
B: 9.02
E: 8.49

IC PINS
1: 0
2: 4.5
3: 4.5
4: 0
5: 0
6: 9.47
7: 5.71
8: 0.67

Hope this helps!  Thanks for the help so far guys!

[jmdfd415]

sorry had the ic pins wrong here the right order:
1: 0
2: 4.5
3: 4.5
4: 0
5: 0.67
6: 5.7
7: 9.47
8: 0

[R.G.]

Your bias voltage is 'way too high. The base of Q1 is sitting up at 5.2V, it should be about 2.9V-3.1V. Look for a problem with the 56K/27K resistors that make Vb.

[jmdfd415]

Im not real sure what I am looking for .  Could you be more specific on what I do?  I am still pretty new to all of this.  Thanks for all your help!

[Processaurus]

Hi, as far as looking for the trouble in that part of your circuit, I'd double check the resistor values RG mentioned (using the resistor color code) and make sure you are using the correct values , that those resistors are soldered correctly on either end (especially the one that goes to ground), and also for an unintentional short between that point in the circuit and another, that could pull the bias voltage up to the 5.2v you're getting now.

[jmdfd415]

Thanks I will see what I can find.

[jmdfd415]

Ok looks like I have a new problem now.  After looking over the board I decided to take a razor and scrape between the tracks to make sure there wasnt any solder connecting two tracks.  After I did this I put the battery back in and went to check voltages on q1 and c,b, and e were at at around 1.5 and I felt the board get really hot.  Any new suggestions on what to do.

[R.G.]

voltages on q1 and c,b, and e were at at around 1.5 and I felt the board get really hot.

You have now caused a short. Get out a magnifier and look for it, or use your ohmmeter to test for shorts between places that are close but should not touch. There's no way to tell where, other than to look around where you scraped.