My phase 90 clone isn't working

[snow123]

Turn the Rate control to mid-way and measure the voltages on pins 5, 6 an 7 of IC3.
What are they?

OK...Replace the IC socket first and than measure the voltages.

i shouldve clarified that i was talking about the transistor sockets

[snow123]

Turn the Rate control to mid-way and measure the voltages on pins 5, 6 an 7 of IC3.
What are they?

OK...Replace the IC socket first and than measure the voltages.

p5 = 5.4
p6 = started at 1.1, then kept going up every time i check, last time i checked it was at about 3.2
p7 = 7.8

[Slowpoke101]

Turn the Rate control to mid-way and measure the voltages on pins 5, 6 an 7 of IC3.
What are they?

OK...Replace the IC socket first and than measure the voltages.

p5 = 5.4
p6 = started at 1.1, then kept going up every time i check, last time i checked it was at about 3.2
p7 = 7.8

Good !!!!!  . The LFO (Rate Oscillator) is now working  . You need to carefully adjust the trimpot for best sweep effect BUT if the JFETs are loose in the sockets you will have problems. Replace the sockets but be careful and not cause more problems.

[snow123]

Turn the Rate control to mid-way and measure the voltages on pins 5, 6 an 7 of IC3.
What are they?

OK...Replace the IC socket first and than measure the voltages.

p5 = 5.4
p6 = started at 1.1, then kept going up every time i check, last time i checked it was at about 3.2
p7 = 7.8

Good !!!!!  . The LFO (Rate Oscillator) is now working  . You need to carefully adjust the trimpot for best sweep effect BUT if the JFETs are loose in the sockets you will have problems. Replace the sockets but be careful and not cause more problems.

i swapped the jfet sockets and nothings changed

[Slowpoke101]

Measure the voltage on pin 6 of IC3. Is it changing very slowly?

The Rate pot has three terminals. Only two terminals are used, the centre terminal and the terminal to its right when looking down on the pot with the terminals towards you. How do you have it connected?

[snow123]

Measure the voltage on pin 6 of IC3. Is it changing very slowly?

The Rate pot has three terminals. Only two terminals are used, the centre terminal and the terminal to its right when looking down on the pot with the terminals towards you. How do you have it connected?

i have it exactly like that except the first leg is connected to the input jacks ground, 'cause when i didnt have it connected to ground i was very noisy.

[Slowpoke101]

Disconnect that connection to ground. It should not be there at all. Do not worry about noise at the moment.

Then measure the voltage on pin 6 of IC3.
Does it vary?

[snow123]

Disconnect that connection to ground. It should not be there at all. Do not worry about noise at the moment.

Then measure the voltage on pin 6 of IC3.
Does it vary?

nope

[Slowpoke101]

With the Rate control mid-way, what voltages do you read on its two terminals?

[snow123]

With the Rate control mid-way, what voltages do you read on its two terminals?

wait its working now

[snow123]

i didnt do anything except snip the wire connecting the pots 1st lug to ground

[Slowpoke101]

i didnt do anything except snip the wire connecting the pot to ground

Good!

Now set the Rate pot to max (fast) - the voltage on pin 6 of IC3 should vary very quickly now, strum your guitar's strings and adjust the trimpot for best phase effect.

[snow123]

With the Rate control mid-way, what voltages do you read on its two terminals?

wait its working now

wait no it isnt

[snow123]

im gonna replace q5 socket

[Slowpoke101]

im gonna replace q5 socket

Why?

Finding out why the Rate pot has no effect on pin 6 of IC3 would be more productive and to start finding that out involves measuring the voltages on the Rate pot's terminals.

[snow123]

im gonna replace q5 socket

Why?

Finding out why the Rate pot has no effect on pin 6 of IC3 would be more productive and to start finding that out involves measuring the voltages on the Rate pot's terminals.

'cause it was working, and then just wasnt working so i was assuming there was a loose connection there.

[Slowpoke101]

If there was a problem with Q5 there would be no audio output. Or it would be weak and distorted.

Now what are those voltages?

[snow123]

If there was a problem with Q5 there would be no audio output. Or it would be weak and distorted.

Now what are those voltages?

lug 2: .5
lug 3: 0

also, a part of a track near q1 got loose (luckily nothing was soldered to it), and that probably was shorting out to one of the other tracks.

[Slowpoke101]

Lug 2 connects to the 4K7 resistor at the lower right of the board. This resistor then connects up to a 150K resistor connected to pin 6 of IC3. There should be a varying voltage on this lug. Look for a bad connection or broken wire.

Lug 3 connects to pin 7 of IC3 which you found was at nearly 7.8V. Lug 3 should have much more than 0 volts on it. Look for a faulty wire or short to ground.

[snow123]

Lug 2 connects to the 4K7 resistor at the lower right of the board. This resistor then connects up to a 150K resistor connected to pin 6 of IC3. There should be a varying voltage on this lug. Look for a bad connection or broken wire.

Lug 3 connects to pin 7 of IC3 which you found was at nearly 7.8V. Lug 3 should have much more than 0 volts on it. Look for a faulty wire or short to ground.

i replaced the 150k near q5 and the pedal is working!! but the trimpot is really fussy