JSR03 - information

[Keljian]

all the parts are in the right way around also

[peranders]

If it's possible, can you take one or more close up pictures so I can see the parts you have used? (Max 1 MB please.

You should have the output voltage at pin 7. Have you really checked the schematic and also understood it? You have two ways of feeding the opamp. R12 should not be used, only R11.
Check the picture very carefully:
http://home5.swipnet.se/~w-50674/hifi_pics/hifi_100pr/jsr03r0_topview.jpg

Is the opamp turned right? The notch should be a the left. The small ring at "IC3" is pin 1.

[Keljian]

If it's possible, can you take one or more close up pictures so I can see the parts you have used? (Max 1 MB please.

that's the best I can do with my digital camera (I tried about 20x to get it that close)

pin 1 on the opamp is near the little circle near IC4

the tombstoned resistor is a 56k (RN60D)

[peranders]

R10? Should be a wire = 0 ohms. Check my picture. I have a wire jumper, that beige thing.

[Keljian]

R10? Should be a wire = 0 ohms. Check my picture. I have a wire jumper, that beige thing.

R10 is jumpered on the other side of the board

[Keljian]

I'm thinking I may have fried the 557 transistors, by firing up the board completely populated, I'm going to change them out for BC560Cs and see how I go

[peranders]

Don't change the transistors until you have measured that are broken, I'll doubt that. Do you have 0.6-0.7 volts between the base and the emitter?

Do you have connection between the feedback R8, R9 and the inverting input of the opamp? R10 = 0 Ohms

[Keljian]

Don't change the transistors until you have measured that are broken, I'll doubt that. Do you have 0.6-0.7 volts between the base and the emitter?

yes

Do you have connection between the feedback R8, R9 and the inverting input of the opamp? R10 = 0 Ohms

yes.. all of the above is correct.

[peranders]

If you have 0.7 volts that's good.

Do you have the same voltage at pin 2 as over R9? Meening do you really have a wire in R10? On the solderside?

[Keljian]

If you have 0.7 volts that's good.

Do you have the same voltage at pin 2 as over R9? Meening do you really have a wire in R10? On the solderside?

yes, I can post a picture if you like, but I assure you I've bridged it on the solder side.

I checked it with my multimeter, 0 resistance over R10.

[peranders]

AD797 may not like too much differential voltage. I don't recommend it as you may have noticed, still you can fix this by applying two diodes across the inputs.

Would you please measure:

Pin 2, 3, 4, 6, 7

Vout

Vin

Voltage across T4

[Keljian]

AD797 may not like too much differntial voltage. I don't recommend it as you may have noticed, still you can fix this by applying to diodes across the inputs.

Would you please measure:

Pin 2, 3, 4, 6, 7

Vout

Vin

Voltage across T4

2-6 = 6.45v

2-7 = .302v

3-5 = 1.1v

3-6 = 7.16

4-7 = 1.3v

Vin = 33.23v

Vout = 8.27

T4 = 2.57, and .574

[peranders]

Could you please measure the opamp voltage with ground as reference.

Are you sure you have solder all IC pins with success?

Aha, 431, startup problems, I may know what your problem is. The problem may be the feedback of the LM431. I'll come back soon with a solution. The resistor values must be chosen with taste. The problem is when the 431 is inactive, then the ref voltage must be LESS than the feedback from the output. If not you will get a stable hang-up condition.

[Keljian]

Could you please measure the opamp voltage with ground as reference.

Are you sure you have solder all IC pins with success?

Aha, 431, startup problems, I may know what your problem is. The problem may be the feedback of the LM431. I'll come back soon with a solution. The resistor values must be chosen with taste. The problem is when the 431 is inactive, then the ref voltage must be LESS than the feedback from the output. If not you will get a stable hang-up condition.

well, I'm using an LM329 not a 431.

[peranders]

Ok, in that to rule out latch-up, set the gain to 2 or around. Then you would get 13.5-14.0 volts. If you get those voltages you may have a problem with the opamp and the common mode limits. If so, try to solder in two diodes across the inputs.

Will you measure the opamp voltages with respect to ground.