Author Topic: Glasshole bypass LFO tick  (Read 164 times)

jpier2012

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Glasshole bypass LFO tick
« on: February 26, 2021, 03:11:38 PM »
Hello! I recently built the Glasshole and am getting LFO tick, both with the effect on and in bypass.

Does anyone have experience with this? I'm hoping I can just add another cap to the LFO circuit to take care of any transient spikes.

Thanks!

James
« Last Edit: February 26, 2021, 03:16:57 PM by jpier2012 »

danfrank

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Re: Glasshole bypass LFO tick
« Reply #1 on: February 28, 2021, 09:35:57 PM »
I had this also and I fixed mine by moving the 2 jumper wires on the PCB closer to the case and away from the 470nf cap that is close by. That cap does not like those wires close to it.

geetarm@n1

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Re: Glasshole bypass LFO tick
« Reply #2 on: April 07, 2021, 02:23:34 PM »
Hello.

I've got the same problem with mine, but the LFO ticking is only present on the 6 and 8 stage settings, is not something that is made more or less present with higher/lower Depth and Feedback settings, it's not made more or less present with a buffered effect before or after it and also is not bleeding thorough in bypass.  Not affected in any way by moving the short flying leads.  No more or less present whether it is in the enclosure or out of it.   It's simply a very consistent tick that is of a tolerable volume - at least in slow settings (not any less present, just fewer of the ticks trying to tick me off) - but loud enough that it is pretty much unusable at higher rates of speed.   It's not louder than the guitar when picking/strumming, but letting a chord die out is going to reveal the problem within seconds (as soon as the guitar level starts to drop).

But it's quiet as a mouse in 2 and 4 stage mode, and fortunately, the higher speed settings are more useful to me with fewer phase stages anyway, so if I can't get this resolved I'm still going to be extremely happy with this build. 

What I've done so far:

a) Checked voltages - everything is in line with the published voltages.   Grounds at jack are good.  Grounds from board are good (or I'd not be phasing, presumably).

b) I've tried moving the two jumpers by C18 as suggested.  Mine were originally both very short an on top of the board.  I've tried very short ones under the board (without success), then tried longer (2") loop under the board, giving me something that can be moved around.   Moving them around makes no difference.

c)  I've now disconnected the leads connecting the jack's tip to the board and board to switch and replaced them with shielded straight runs from jack to switch (shielding connected at the jack sleeve lug).   Moving them around makes no difference. 

Overall, the build seems super stable to me - I guess I'm used to building gain devices where you get all kinds of noise/radio/squelchy stuff with the back plate off, while poking around inside and moving wires (and where I can fix things like this by doing so - I've never resorted to using shielded wire in a build).   This thing is completely silent and stable in or out of the box and moving wires or putting my hands on the board don't seem to affect it adversely at all.  Other than the tick, it's as clean/clear as anything I've made.

Being that I'm not at all at the level to understand this circuit, I've now exhausted my knowledge on how to fix it.  So with brain failing me, I've resorted to using my eyes and I see that:

1) my 470nf cap C18 itself is larger than ideal (both of them, actually).  It's a 100v cap and has one leg bent inward/under it to reach the hole and the cap is therefore extended further out toward the light shield than it would be if I'd used a smaller cap, but since moving those jumpers and tipping this cap forward/backward don't show any indication of a change for better or worse, I expect my issue is not here.  I'll order a smaller caps anyway and see what happens.

2) I did use the four non-essential/visual-only LEDs for the "stage" indicators, each a different color (all diffused) and I notice that the blue LED used for the 6 stage setting doesn't ramp on/off as smoothly as the rest - it comes on and drops off a little more abruptly and is brighter than the rest.  Given that this LED is not on when the ticking is present on the 8 stage mode leads me to believe this is a non-issue.

Regarding components:   I used all 1/4 watt resistors standing on end where required.  One small ceramic and maybe 15% of the resistors are carbon film.  Most of the 6n8 caps were greenies purchased from Jameco on a whim and I've not tested them.  Everything else was the normal "good stuff" from Smallbear or the specific items from Mouser listed on the BOM.

Any suggestions would be most appreciated.


So enough of the complaining/troubleshooting for a minute.   Let me give a big thanks to Brian and bangerang101 for making this project available.  I foolishly sold my own Mutron Phasor II many (many) years ago and this is by far the closest I've come to replacing it and closer than expected.  I've been building pedals for years but haven't really advanced my electronics too far.  As such, I can still believe in magic when it comes to gear and the Phasor II is a magical thing to me and I expected this build to result in a working phaser that was cool and worth building (as all phasers are), but without any expectation that it would hold a candle to my recollection of how it felt playing the real deal at loud levels with the sound filling the room.   Well, it definitely does (hold said candle).  The quality of sound of this build is fantastic.  I had a chance to A/B it against my brother's Phasor II while tuning mine and found it to be very similar.  Not quite as loud and a bit less roomy/spacious sounding as the original - didn't seem to inhale the guitar as much (not quite as much headroom maybe?) - so the feel is different, but the sounds the Glasshole produces are somewhat more clear/refined sounding overall and the richness and smoothness of the sweep plus the (controllable) vowel-y content are beautiful and exactly what I'd hoped it to be.   I can now kick myself a little less vehemently for selling my original.

madbean

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Re: Glasshole bypass LFO tick
« Reply #3 on: April 07, 2021, 06:02:05 PM »
I'll get mine out tomorrow and take another listed to see if I can hear any ticking.

It's not unusual to get some "pulsing" in analog modulation pedals. This is unavoidable since amplitude changes will carry the noise floor of the circuit to the output. However, there should not be any kind of hard transient (like a click) with that and certainly not in bypass. There are some steps to take but let me listen to mine again to see if I can identify a problem.

geetarm@n1

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Re: Glasshole bypass LFO tick
« Reply #4 on: April 15, 2021, 02:30:10 PM »
I just reread my original post and I mentioned that it was a "continual" ticking and should clarify.    That is only the case at higher speeds.  When at slow speeds I hear two tick/thumps - one at the peak of the sweep (peak of the indicator LED brightness) and once at the bottom of the sweep (well after the indicator LED has turned off).


I've also spent some more time today listening to it with the amp up loud but without a guitar in hand - just listening.   The tick/thump is absolutely not present at all on the 2 and 4 stage settings.

The volume of the tick/thump is a little less than what I get when switching between the different stages with the rotary with the effect active (neither are sounds that worry my in terms of speaker health - unlike the pop from engaging either of the Phase 45s I've built, but that's another discussion altogether). 

The overall hiss (and its low end content) and the click/pop when engaging the effect are all very negligible.   In other words, it is hard to believe that I've miswired something, used an incorrect part value or that I have a bad solder joint as everything really seems to be working as expected other than the tick at the top and bottom of the cycle of stages 6 and 8.

If there is any reason to think that the ICs are to blame I can swap them around but I'd prefer not to pry them out of the socket arbitrarily.