Phase 45 Debug (full info inside)

[Evad Nomenclature]

alright.

Another debug... my last 2 builds I'm having 0 luck =/
Here's the info.

Project : Tonepad PCB of the MXR Phase 45

Link:http://www.tonepad.com/getFile.asp?id=70

Problem: When plugged in, I am getting signal of the guitar very distorted underneath with a lot of oscillation.  The pots are controlling the oscillations... as I turn them the pitch and speed goes up and down.  Not really Phase 45'ish =D

Here are the voltage readings:

IC#1
Pin 1= Varying between 3.95 and 4.30
Pin 2= Varying between 4.09- 4.21
Pin 3= Varying between 3.73-3.84
Pin 4= 0
Pin 5= 7.63
Pin 6= 7.32
Pin 7= 7.34
Pin 8= 7.95

IC#2
Pin 1=7.30
Pin 2=7.29
Pin 3=7.60
Pin 4=0
Pin 5=5.16
Pin 6=7.27
Pin 7=7.31
Pin 8=7.99

Q1 and Q2 both read the same

Pin 1=7.59
Pin 2=7.60
Pin 3=7.76

That's it...
any ideas.
got a lot of debugging to do today between this and my Rat.. fun...

[Paul Marossy]

I'm not sure that I will be much help here, but I built mine per the layout at www.tonepad.com except for substituting the FETs with J201s, using a 200K trimpot instead of 250K, and using 0.047uF caps instead of the 0.05uF caps specified on the schematic. It works great! Even though it's not supposed to with those FETs. 

Which FETs are you using in yours?

[Govmnt_Lacky]

Once again, like I stated in your Rat debug post. Dont rule out a BAD Tonepad PCB. Gotten 2 so far and took a long time to find bad traces or missing traces on the PCB.

[Paul Marossy]

I don't think the tonepad layout is bad in this case, however. I built mine from that same layout and it worked fine.

[Evad Nomenclature]

I'm not sure that I will be much help here, but I built mine per the layout at www.tonepad.com except for substituting the FETs with J201s, using a 200K trimpot instead of 250K, and using 0.047uF caps instead of the 0.05uF caps specified on the schematic. It works great! Even though it's not supposed to with those FETs. 

Which FETs are you using in yours?

yeah, sorry I forgot to mention subs...
I subbed the .05 caps with .047's as well, and also put 201's in it (they have the same pinout also) I double checked that just to make sure... I had also read build reports where someone had mentioned using 201's and they actually liked it better than the 5457's.
The only other change that I made was an 18k resistor for the 20k (this was my only question if it may have been off, but I don't think that would cause an oscillation problem)
Been trying to find a couple of different resistor and cap values for certain recipes and usually have no luck, or they are way overpriced (maybe due to rarity or something)

Ummm that's it, I'm still double checking stuff. 

[Paul Marossy]

Hmm... well just check all the usual stuff. Maybe it's just something simple that you have overlooked.

[nordine]

yeah, sorry I forgot to mention subs...
I subbed the .05 caps with .047's as well, and also put 201's in it (they have the same pinout also) I double checked that just to make sure... I had also read build reports where someone had mentioned using 201's and they actually liked it better than the 5457's.
The only other change that I made was an 18k resistor for the 20k (this was my only question if it may have been off, but I don't think that would cause an oscillation problem)
Been trying to find a couple of different resistor and cap values for certain recipes and usually have no luck, or they are way overpriced (maybe due to rarity or something)

these subs wouldn't make your phase45 squeal as it does

time of questions:

-did you put the zener in place? checked correct polarity?
-how about some pics of the board? photos can be very revealing

touch the board on the soldering side, touch everything, press, bridge tracks with your fingers... if its not the zener thing, im sure your circuit is missing some Vref point, you should find it out with the pressing thing

[R.G.]

Another debug... my last 2 builds I'm having 0 luck =/

The whole point of the debug process is to convert working pedals from luck to an exercise in thinking.

Problem: When plugged in, I am getting signal of the guitar very distorted underneath with a lot of oscillation.  The pots are controlling the oscillations... as I turn them the pitch and speed goes up and down.  Not really Phase 45'ish =D
IC#1
Pin 1= Varying between 3.95 and 4.30
Pin 2= Varying between 4.09- 4.21
Pin 3= Varying between 3.73-3.84
Pin 4= 0
Pin 5= 7.63
Pin 6= 7.32
Pin 7= 7.34
Pin 8= 7.95

IC#2
Pin 1=7.30
Pin 2=7.29
Pin 3=7.60
Pin 4=0
Pin 5=5.16
Pin 6=7.27
Pin 7=7.31
Pin 8=7.99

Q1 and Q2 both read the same

Pin 1=7.59
Pin 2=7.60
Pin 3=7.76

That's it...
any ideas.
got a lot of debugging to do today between this and my Rat.. fun...

Actually, debugging is fun. It's certainly better than doing crosswords. 

Hmmm... let's think for a moment. It looks like all the signal pins of IC2, half of those in IC1, and both transistors are floating right up next to your power supply voltage, or just a fraction of a volt below it. Since the opamps and transistors won't work right with all their pin voltages the same, that kind of means that some part of the problem is that the pins are not pulled down towards ground properly. Just at a guess (tonepad is not responding right now for me to see that particular schematic) something is wrong with your bias voltage supply, leaving it up around the full power supply voltage, not somewhere down between power and ground.

The step you take when you say "hey, these voltages look odd; now what could cause them to look that way?" is a huge one. It's the one that lets you start really understanding circuits.

[Evad Nomenclature]

The funny thing is...
I tried to build 2 circuits at the end of last week... the Proco Rat and the phase 45...

I think I'm also realizing that the problems I am having with one, I am having with the other...

Still no luck.  Gonna keep scouting...

[solderman]

alright.

Another debug... my last 2 builds I'm having 0 luck =/
Here's the info.

Project : Tonepad PCB of the MXR Phase 45

Link:http://www.tonepad.com/getFile.asp?id=70

Problem: When plugged in, I am getting signal of the guitar very distorted underneath with a lot of oscillation.  The pots are controlling the oscillations... as I turn them the pitch and speed goes up and down.  Not really Phase 45'ish =D

Here are the voltage readings:

IC#1
Pin 1= Varying between 3.95 and 4.30
Pin 2= Varying between 4.09- 4.21
Pin 3= Varying between 3.73-3.84
Pin 4= 0
Pin 5= 7.63
Pin 6= 7.32
Pin 7= 7.34
Pin 8= 7.95

IC#2
Pin 1=7.30
Pin 2=7.29
Pin 3=7.60
Pin 4=0
Pin 5=5.16
Pin 6=7.27
Pin 7=7.31
Pin 8=7.99

Q1 and Q2 both read the same

Pin 1=7.59
Pin 2=7.60
Pin 3=7.76

That's it...
any ideas.
got a lot of debugging to do today between this and my Rat.. fun...

Looking at the readings and the schematics the IC 1 pin 3 and 2 Pin 5 wold act the same way. Yours don't. I wold expect IC 1&2 Pin 8 to read close to 9V. How do you power the circuitry. Are you sure you're power sources is OK 9 clean filtered volts?? This (bad power supply/battery ) might be the problem for both you're builds.

I have made a shrunken layout of this one to fit in a 1950A box and it works grate so post again if you cant get it to work and Ill post the readings from mine.

//Solderman 

 

[MikeH]

Are you using a battery?  If so it's pretty dead; try a fresh one and repost voltages.

[Evad Nomenclature]

Tried 2 of them...
The first was one that I had out for a bit, it registered at 8.32.
The second was fresh.  So I've ruled that out...
The only thing I can blame it on right now is my soldering
And unfortunately, I'm gonna have to let the project sit for this week because I have tons of work and school.
Oh well.  maybe a fresh look in a few days will be the best remedy.
Thanks guys

[Paul Marossy]

Many times when I have had problems like this, I set it aside and came back to it later. The problem usually slapped me in the face when I picked it up to look at it again. 

[MikeH]

Many times when I have had problems like this, I set it aside and came back to it later. The problem usually slapped me in the face when I picked it up to look at it again. 

Yeah, I did that with my sans amp project... then I did it again, and again... and again... I've been looking at that thing with fresh eyes for almost a year now.

[Paul Marossy]

Many times when I have had problems like this, I set it aside and came back to it later. The problem usually slapped me in the face when I picked it up to look at it again. 

Yeah, I did that with my sans amp project... then I did it again, and again... and again... I've been looking at that thing with fresh eyes for almost a year now.

Yeah, I have had one exception: my Boss Slow Gear clone. I never have been able to get that blasted thing to work! 

[nordine]

and, of course, its never a bad decision re-doing the damn thing from zero

saves lots of nasty feelings inside

[solderman]

Many times when I have had problems like this, I set it aside and came back to it later. The problem usually slapped me in the face when I picked it up to look at it again. 

Yeah, I did that with my sans amp project... then I did it again, and again... and again... I've been looking at that thing with fresh eyes for almost a year now.

Yeah, I have had one exception: my Boss Slow Gear clone. I never have been able to get that blasted thing to work! 

Oh, I am relieved to hear that I am not the only one with Boss Slow Gear problems. I did not have the FET on the BOM so I tyred every FET I had, about 10 different ones,  combined with  zener diodes from 4.0 to 9.1V. It almost works but in a very narrow setting and not that long swell I have heard form sound samples. I eventually ordered the correct FET. It helped a bit but not at all to my satisfaction. So now I have an effect that does works but not to the full extent. That is frustrating since I don't know how I shall trouble shoot it cause it does work. I have quadrupole checked every component value and solderjoints. So this is the first build, from about 50, I have to toss in my towel on.

\\Solderman     

[Paul Marossy]

Oh, I am relieved to hear that I am not the only one with Boss Slow Gear problems. I did not have the FET on the BOM so I tyred every FET I had, about 10 different ones,  combined with  zener diodes from 4.0 to 9.1V. It almost works but in a very narrow setting and not that long swell I have heard form sound samples. I eventually ordered the correct FET. It helped a bit but not at all to my satisfaction. So now I have an effect that does works but not to the full extent. That is frustrating since I don't know how I shall trouble shoot it cause it does work. I have quadrupole checked every component value and solderjoints. So this is the first build, from about 50, I have to toss in my towel on.

\\Solderman     

Hmm... well, at least I don't feel so alone now. You got further along than I did - I never got anything at all out of it. Very frustrating.