- This topic has 6 replies, 3 voices, and was last updated 3 years, 9 months ago by
.
-
Posts
-
Finished a Vibe with 2/4-stage mod. Don’t have the energy tonight for further troubleshooting. Tossing this up here because I’m likely overlooking something. Barring that, it will get disassembled, everything reflowed, and some wires rerouted.
Bypass works, turning the board on is a very slighter booster, nothing else. Slight pop when I flip the 2/4 switch.
Top-mid resistor on the switch goes to bottom pad of R17, top-right lug to top of R17. Bottom-mid lug to bottom pad of R10, bottom-right resistor to top pad.Center post of DC jack to gnd pad at bottom, G2 and in ground to sleeve of in jack.
LED does not turn on, but an LED held to the pads does light up. I likely flipped or burnt it when I cut the leads short and soldered wires on. Pot, switch, and trimmer appear to have no effect, but I do get a buzz when touching resistor/wire joint at the switch.
Aside from a short or a missed connection somewhere, I suspect a bad IC only because I had a bad one I got from here (so a trusted source) but fear my storage (legs pushed into craft foam, and then stored in my plastic box of sockets) may have had a detrimental effect.
Not ruling out a burn transistor either, but I haven’t torched one yet.
I also feel the need to point out a couple errors in the build doc.
D1 is reversed either on the silkscreen or in the populated image. The populated image has a resistor in R16, which is stated as omitted. R31 is shown as a 47R, but is 10R on the list.This is the result of two image typos on the populated image. I will correct.
D1 is correct with the stripe facing down following the board silkscreen as you have built it.
R16 was accidentally populated on the populated image. I will remove it though it would not cause your build not to work. You can just clip it out.
R31 should be 47R per the schematic but 10R will work. This is for power and not in the audio path.
The only thing that would be an issue is if you put D1 in upside down by not choosing the board silkscreen orientation, but your board image above is correct.
Did you try adjusting the trimmer by ear till you hear phasing? Make sure your Rate Knob is turned up to make it easier to dial in.
If anyone else sees anything by all means pop in.
Yeah, tried the trimmer first, after seeing that mentioned about phasers a few times. Doesn’t seem to do anything.
Going to reflow everything first, once I have a day that isn’t ten hours straight on my feet.Just an additional note on the trimmer – it is VERY sensitive and the “sweet spot” is a very narrow range of the trimmer’s sweep. Move it VERY slowly to see if it will dial in.
Haven’t managed to go as in-depth as I want yet, but no luck yet. Trying to rule out certain things before I start disassembling further.
Is there a certain voltage I should be looking for on certain legs of the JFETs, or voltages relative to other points?
- You must be logged in to reply to this topic.