[duncan1]

Not to happy about this -sound weshost PS.
        It says -suitable for high -end PS-its not.This is as "simple" as you can get in electronics.
        The input fuse is a surge limiting fuse there fore a s/c in the full-wave rectifier yes the fuse will blow but where is the protection for the AMP !!
         the secondary circuit is "straight through"  there is nothing stopping total damage  to the amp from a fault  condition less than the value of the fuse.
         A real -Hi-end PS would at least have quality voltage regulators which a capable of acting quicker than a fuse and shutting down in the event of a fault condition.
                Therebye saving outright destruction of the amp.
                  If you dont have the technical knowledge to fit regulators then please at least fit OUTPUT fuses.
 

 

[DutchGFX]

Hey so its all constructed, but the sound is quiet, and very distorted. Both channels. How do you suggest i troubleshoot?

 

[duncan1]

To answer you correctly I would need to drag through a whole lot of checks. It could be any where.
                        It would be quicker if you could post a link to the circuit diagram  or maybe one of the other posters here already has the circuit diagram and can answer quicker having worked on one.
                          In the normal mode of testing for a fault  condition in a kit you start at the PS -are the voltages correct? -are the smoothing caps the "right way round"?-on something built as a kit you can see there are many possible fault situations.
                          But logically thats where I would start.

 

[DutchGFX]

To answer you correctly I would need to drag through a whole lot of checks. It could be any where.
                        It would be quicker if you could post a link to the circuit diagram  or maybe one of the other posters here already has the circuit diagram and can answer quicker having worked on one.
                          In the normal mode of testing for a fault  condition in a kit you start at the PS -are the voltages correct? -are the smoothing caps the "right way round"?-on something built as a kit you can see there are many possible fault situations.
                          But logically thats where I would start.

Caps are the right way. I'll test voltages between DC out and GnD if that's what you mean, I think it should be 15 volts so well see.

http://www.twistedpearaudio.com/images/power/lcbps_schematic.jpg that's the PSU schematic

http://www.twistedpearaudio.com/docs/linestages/ventus_ez_schematic.pdf that's the amp schematic

 

[duncan1]

 Thank goodness!- Your power supply is exactly as I suggested in last post-That previous PS circuit is dangerous for your amps heath.!
                          Is the pos/neg of the PS balanced at I take it +/- 15V or whatever the setting voltage [equal pos/neg voltages.] As I see it is adjustable for balance.Remember to check for correct voltage not only at the PS -BUT also at IC1 +IC2 voltage pins
                            Are the ICs soldered in or are they pushed into an IC socket .If soldered in check EVERY soldered connection too EACH pin for S/C between EACH pin
                             Cant fault the quality of the ICs.
                              Get back if still faulty

 

[DutchGFX]

Eh are soldered but I was unable to screw them each to the heatsink however.

 

[DutchGFX]

So I used my multimeter and established that FB has been shorted to GnD somehow. I checked my solders, none are touching at all. Both boards this is the issue, how should I go about trying to fix?

 

[Avro_Arrow]

Some clear, detailed pictures would be a great help

 

[duncan1]

I agree with AVRO- but if not then check the resistance to ground of the input ics= IC-1 in both cases  Thats at each IC input -at the PINS .While not likely the ICs could be damaged by leakage from a cheap soldering iron  -but thats an outside shot.
                           Next step is check EVERY pin on each IC that should return to EARTH-not negative-but earth. Then  check every component that requires an EARTH return to see if it is terminated to the earth -dont just look at it-Measure it with the MM.-ALL earth returns should be COMMON to each other AND attached to the EARTH on the PS.                        
 

 

[duncan1]

Just  realised something else the feed-back capacitor on both -IC-1s is taken from the OUTPUT to INPUT. While shorting the INPUT to earth should be okay -It depends on the IC whether a S/C at the OUTPUT would cause damage to the ICs.
                         This depends ENTIRELY on the internal design of the ICs. Not likely in modern ICs but I have come across some ICs that arent protected.

 

[DutchGFX]

So I should check all GND's on the PS? Here are pics: The jumpers were when I used MM to test connections, although, It didn't change the sound, so I think they were already connected, nice job Radioshack MM lol
 

 

 

 

 

 

 

 

 

 

 

 

 

 

[duncan1]

Thanks for the photos. The actual parts are of good quality.
       I do notice it is a double sided PCB with copper tracking on each side .
        In that case check -BOTH sides of each soldered connection especially the higher wattage resistors. 1-leg of your MM on one side of the soldered connection and the other leg of the MM on the reverse side of the PCB on the other soldered connection. in case of a high resistance soldered joint.
       Yes it will take a while.
 

 

[Avro_Arrow]

After seeing the photos, I have to ask:
You do know you are supposed to use the connector block to connect the wires to the power supply/amp...
You don't need to solder them on directly.
 
Why are there extra jumper wires soldered to the bottom of one of the amp boards?
Did the op amp and buffer come already mounted on the board? There is too much
solder on the bottom side of the board. There are places where the blobs may be shorting
to the pad next to them. Some solder wick or a solder sucker can clean those right up.

 

[DutchGFX]

After seeing the photos, I have to ask:
You do know you are supposed to use the connector block to connect the wires to the power supply/amp...
You don't need to solder them on directly.

Why are there extra jumper wires soldered to the bottom of one of the amp boards?
Did the op amp and buffer come already mounted on the board? There is too much
solder on the bottom side of the board. There are places where the blobs may be shorting
to the pad next to them. Some solder wick or a solder sucker can clean those right up.

How should the Ps connect then? I don't see any terminal? And the jumpers are removed.

The opamp and buffer came per mounted. I have a desoldering pump so I'll try to clean it up. I am checking for bad joints ATM

 

[joeyjojo]

Quote:

 

 
This is pretty ghastly. Far far too much solder and possibly some cold joints. The principle of soldering is to heat the board and the lead simultaneously and apply solder to the interface AWAY from the iron, so that solder flows into the gap, bonding the part board together.
 
Also are those black bits burns???