Build Your Own Clone Message Board

Since I was burried under feet of snow and most of my students cancelled, I figured it would be a great time to assemble my Phase Royal kit. It seemed to be a relatively easy one and all my others have fired up on the first shot. This wasn't the case this time however. I've since read all the threads to see if anyone was having the same issues I was butmine seem unique. I've de-soldered and re-soldered the pots and reflowed everything several times And get the same problem. Here it is;
Bypass works great. With the blend knob clockwise I get a nice clean signal. Counter clockwise I get almost no signal. At first I thought there was none but when I cranked my amp and turned the speed knob I could hear a modulation change. This disappears when I turn down the depth or the trim pot so those seem to be doing something. The feedback and switch don't seem to do anything at least that my ears can pick up. There is nothing that I would call phasing. Sounds more like tremolo. It's also super subtle and disappears when I turn the blend past 8 oclock. At 5 o'clock the clean is unbearably loud. So since I haven't been working much I haven't paid my cable bill so I'm doing this from my phone and can't send pics(I dont think) but I've gone over everything a ton. I even re-seated the switch to make sure there was no short and I took the socket off the back of the board and trimmed the leads underneath and re-soldered all of that. I feel like there must be a bum component somewhere but I don't know how to test them or where to start. Please help! I've easily spent six hours more on this since I "finished" it.

It sounds like the dry path is working fine but the wet signal path is interrupted by something. Did you happen to measure your resistors before installing them, or did you go off the color code? There is a photo on page 6 of the instructions. Hold your build up to the computer screen and do over each resistor one by one to see if you can spot one installed in the wrong location.

Do you have a signal tester? How about a DMM; can you take voltage readings?

I do have a DMM but didn't check the resistors as I went. Just used the color code. I'll definitely go through and check each one. I'm not sure how to go about checking voltage however. I'm a bit of a newbie

Here's a tutorial on reading voltage: http://www.ladyada.net/learn/multimeter/voltage.html

Record the voltages on all of the ICs. Here is the IC pinout:

I checked all the resistors and they seem to be in the correct spots. I tested them all and mostly got what I expected however r's 6,9,12,15,19 and22 gave values in the range of 180- 190 ohm range. I suspect this is due to the transistors. Also r's 23 and25 gave 18.2k and r's 24 and 26 gave 12.8k but I suspect this is due to the mix pot. R30 gave .7M and I couldn't get anything consistent out of r31 since it was hard to get to.
I took voltage readings as well using pin 4 as ground.
IC1: pin1 3.7 pin2 3.7 pin3 3.7 pin5 9.1 pin6 3.7 pin7 3.7 pin8 3.7
IC2: 3.5. 3.5 3.4-4.4 8.6 1.1mV 1mV .7mV
IC3. 3.7. 3.7 3.7 8.6 3.7 3.7 3.7
IC4: 3.7. 3.7 3.7 8.7 3.7 3.7 3.7
IC5: 3.7. 3.7 3.7 8.7 3.7 3.7 3.7
So it looks like I'm getting the +9v on pin5 but it says on the schematic that pin8 gets power so is something backwards? Everythings in correctly as far as I can see. IC2 shows some weirdness but I'm not sure where those pins go. Anyway I'm still lost

Whoops I'm dumb. Just looked at your pinout diagram and I just numbered 5-8 backwards so 8 is the 9v. Still confused though

Voltages look dead-on perfect. Except it looks like the voltage on IC2 pin 3 is oscillating, which is correct, but the voltages on IC1 pins 5-7 should be oscillating too. Is it?

I don't think you mentioned the trim pot. Did you dial it in? What happens?

If the voltages are oscillating like they should and you've dialed in the trimmer, it's time for pics.

I re-tested pins 5-7 on Ic1 and did not see any oscillation evenwhen I messed with the pots and trim. Previously I did dial in the trim pot which is to say I could hear the most modulation but as I said before I had to have the blend totally to the effect side to hear any modulation at all.

OK - turn the depth all the way up and measure the voltage at the middle pin of the depth pot. The voltage should oscillate and should speed up and slow down with the speed pot.

So I re-re-tested pins 5,6&7 on Ic1 this time with the circuit on(I shouldn't do this stuff with no coffee in me) and I DO see oscillation now. I also see oscillation on the center pin of Depth which changes as I move Speed. The depth speed and trim seem to work. It's the feedback and 4-6 switch that don't seem to do anything and the blend just passes the clean signal. At fully counter clockwise I get maybe 5% of the volume I get at fully clockwise

We know the ICs are working correctly and the Fets are likely fine too since the IC voltages are good. You've got signal blockage or a wrong/bad component somewhere between the input buffer and the mix pot. The best way to find it is using a signal tester. BYOC sells a kit, or DIT STOMP has a disgram of how to build one out of an old guitar cable or a 1/4" jack and a few other components.

The simplified wet signal path you need to diagnose is as follows: R4 > R5 > R7 > R8 > R10 > R11 > R13 > R14 > toggle switch > R23/MIX POT/R24. You can also try the shotgun approach and just resolder or replace all of those components. Also, posting pics usually helps.

You can also test your toggle switch to make sure it's working and is not shorted. Do you know how to do that?

I got my signal tester to work. On r4+5 I got the full clean signal. I also got a clean signal from r8. On r7 that subtle modulation kicked in and the volume was cut way down. It was the same on r10, 11, 13, and 14 as well as the pins of the toggle. The signal seemed to go from r23 to r24 as I turned the mix pot. I got the same very slight effect from the leftmost pin of the mix when set fully to the effect side and nothing from the right pin. Then when I turned the mix to clean I got that on the right pin which seems correct. Anyway the massive volume drop seems to happen around r7+8. Also I'm not sure how to tell if the switch is doing what it's supposed to. I got signal off the pins but it sounds the same whatever I did. I also checked the freq pot and got signal from the left and center pins. Does any of this narrow it down? I really appreciate your help and patience.

All right - all of that is really good info. Just to verify, trace the signal through IC3

You were able to ID the signal degradation to the area around R7 and R8, which is both the 2nd phase stage and the point where the feedback loop is injected from the resonance knob.

Since the problem appears to be in the 2nd stage, from here on out keep the pedal in 4-stage mode to isolate things further. Don't want to worry about the last 2 stages in 6-stage mode having a affect on anything.

1st lift/desolder one end of R16. This will kill the feedback loop (just making it a script circuit) and take that out of the equation. Any improvement?

Now test each IC output (pins 1 and 7). On my build, IC3 pins 1 and 7 and IC4 pins 1 and & are all about the same volume as IC1 pins 1 and 2.

I lifted r16 and that did not seem to change anything. I then tested all the Icpins. Ic1 pins 1&2 had the loud clean sound. I got no signal from Ic2. On Ic3, pin1 had a weak effected signal. Pin2 was a bit louder and less effected and pin3 slightly more loud and less effected(seemed to be). Pins 5,6&7 were louder still and seemingly clean though less loud than Ic1. Ic4 seemed go just have the weak effected signal all around and Ic5 seemed to have a slightly louder effected signal.

Try replacing IC3 with IC5.

Ok so now the signal is much louder on all the Ics except 2 which. I tweaked the trim pot and got a pretty good phase sound. Doesn't seem as lush as my phase90 though. The switch doesn't seem to do anything and I still have r16 off so the freq pot isn't in. What happened? Is it fixed? I feel like I should be getting more phase.

The IC you took out of IC3 is probably bad. Go get a new one or email BYOC to have them mail you a replacement. Once you have good IC's in both IC3 and IC5, you should get very lush phasing from the 6-stage position. And you can reinstall R16 to see if that intensifies the phasing.

Ok great! I'll do that. Thanks so much!