News:

Forum may be experiencing issues.

Main Menu

Kingslayer IC - issues

Started by PhiloB, February 20, 2014, 05:45:05 AM

Previous topic - Next topic

PhiloB

I have built a Kingslayer from an etched board.  It works but the signal is super hot/distorted. I audio probed the in on the IC and it sounds clean and the right volume.  The out on the IC is crazy hot.  I have a TLC274CN in there.  Got it from Tayda.  Just looked at SmallBear and there tlc274 had different letters following the numbers 274...believe it was acd.  Is it possible that I ordered the wrong tlc274?  Should I be looking at something else?

jimilee

Sounds like a solder bridge just right off.  Have you checked the data sheets yet?
Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

madbean

Don't worry about the suffix N on the chip. Like Jimi said: hot IC means either a solder bridge or it is in backwards.

PhiloB

It's an etched board.  I'll check for solder bridges.

gtr2

1776 EFFECTS STORE     
Contract PCB designer

PhiloB

I'm off today.  I'll post layer

PhiloB

Ic1 (TLC274)
1. .52V
2. .48V
3. 1.5mV
4. 9.33V
5. 1.5mV
6. 143.7 mV
7. .52V
8. .51V
9. .51V
10. .63V
11. .52V
12. 81.4 mV
13. 147.1 mV
14. .52V

IC2 (Tl1044)
1. 9.33V
2. 9.33V
3. 1.7mV
4. 2.1mV
5. .51V
6. 8.8V
7. 8.8V
8. 9.33V

I've looked but ashamed to say I can't find info on what pins should have what voltage.  I do one of these readings should be close to 18V and there is nothing close:(

midwayfair

The kingslayer is split rail (+9v/-9v), not 18V.

All the audio pins should have 0v, and the V- pin (pin 11) should be -9V. Since you don't have anything approaching -9V, and pin 5 of your charge pump isn't creating the negative voltage, that's your first issue to fix.

PhiloB

So maybe I'm looking for a solder bridge in the part of the circuit near pin 5 of the charge pump?

PhiloB

Thanks BTW.  Jon, is the voltage info on the datasheets and I am just being dense?

PhiloB

Here is a picture of the solder side.  Looked over it carefully and removed/re flowed a couple spots.  Am I missing something?  Voltages are still the same.

davent

Looks to be a solder bridge to ground, third joint in- top left corner, dirt pot connection.

dave
"If you always do what you always did- you always get what you always got." - Unknown

If my photos are missing again... they're hosted by photobucket... and as of 06/2017 being held hostage... to be continued?

PhiloB

Thanks Dave.  I'll see if that fixes things later this evening.  Good eye.  As my momma says 'if it was a snake it'd have bit my head off'

PhiloB

Ok.  Have a clean solder joint around the dirt pot connection.  I put a guitar signal through it again just for fun.  Where I once had too loud and distorted, I now have no output.  The signal is making it to the IC at Pin 10.  No signal coming out of the IC.  Rechecked all my voltages around the IC's again after re flowing some suspect joints but the are all the same as above

jimilee

Keep at it. Did you look at the layout to make sure everything that is still bridges is supposed to be bridged?
Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.