Aion Refractor Help: Tone Pot adds & cuts gain path treble, only cuts clean path

[tlite]

Hi All,

Built an Aion Refractor:
https://aionfx.com/project/refractor-professional-overdrive/

Here's a link to the build document https://aionfx.com/app/files/docs/refractor_documentation.pdf, with the schematic on pg. 7.

And it sounds pretty good- only issue is that the tone pot is adding and cutting treble as it should in the gain path, but only seems to cut treble with the clean path, which means the pedal as a clean boost is pretty dark.

So, I'm only able to darken my signal if I use this as a clean boost (I have to turn the tone pot up to full to preserve the original clean signal's treble), but the gain path works like (I assume) it should.  That said, I've never played one of these before, and the only Klon-type pedal I've played (and own) is the Caline Pegasus, which does boost and cut treble across both saturated and clean paths so I'm guessing there's something to fix on this Refractor build.

I tried searching and found lots of stuff on this circuit, but I'm stumped on this one.

I am comfortable using an audio probe, reading voltages, checking continuity, etc. 

I have checked continuity all through the tone control section and through (I think) all of the clean audio signal path.  I haven't yet gone and reflowed everything as for the most part the pedal seems to work, but I can if I need to.

Thanks so much for any ideas!

-Ted 

[willienillie]

Your "JRC 4558Ds" are counterfeit.  Obviously they are working dual opamps of some kind, since you are getting signal through your pedal, but maybe they don't have a good tone for this circuit.  Use some real TL072s for the original sound.  Get them from a reputable vendor.

And as always, check C16 for proper orientation.

[antonis]

Let's welcome for a start..

[tlite]

Your "JRC 4558Ds" are counterfeit.  Obviously they are working dual opamps of some kind, since you are getting signal through your pedal, but maybe they don't have a good tone for this circuit.  Use some real TL072s for the original sound.  Get them from a reputable vendor.

And as always, check C16 for proper orientation.

Whoops and good catch- I put in the 4558D's to see if any improvement over the TL072's I originally had in there.  I did try this with TL072's - they came from Tayda I think.  C16 is oriented properly, though I nearly got that wrong on install so totally fair point to check!

FWIW- how can I tell if an IC is counterfeit?  That's amazing that you spotted that! 

[tlite]

Let's welcome for a start..

Thanks!  Happy to have found my way here! -Ted

[tlite]

Your "JRC 4558Ds" are counterfeit.  Obviously they are working dual opamps of some kind, since you are getting signal through your pedal, but maybe they don't have a good tone for this circuit.  Use some real TL072s for the original sound.

Here are the TL072's I had in the pedal originally...

[tlite]

SOLVED.  Of course, I finally go nuts and ask for help from the powers of the DIYStompboxes forum, and figure it out after stepping away from it for a bit.

The problem?

R9 should be 1K.  I had installed a 100R by mistake.  Ugh.  I'm such a rookie.

Thanks for the help all- I'll be back with more stupidity sometime I'm sure!

[bluebunny]

Thanks for the help all- I'll be back with more stupidity sometime I'm sure!

You certainly will!  We all do.  Hotel California and all that...   

[duck_arse]

also welcome. it matters not at all, but both your blue-banded diodes are backwards to how you think they are. they would seem to be of the russian style marking, where they band the Anode instead. you can see the little disc inside the glass, that [disk] end most nearly always is Kathode.

[tlite]

also welcome. it matters not at all, but both your blue-banded diodes are backwards to how you think they are. they would seem to be of the russian style marking, where they band the Anode instead. you can see the little disc inside the glass, that [disk] end most nearly always is Kathode.

THANK YOU!  Those are indeed Russian D9E's (supposedly).  I had no idea they were backwards. Darn those devious Russian diode manufacturers...

[willienillie]

FWIW- how can I tell if an IC is counterfeit?

In this case, the markings are different from a real JRC.  It can be difficult with other brands that weren't so consistent.  And eventually the counterfeiters will probably get better at making the markings look correct.