PedalPCB Blender - not much from tone knob or boost switch

T

Toy Sun

New member
Pedal sounds great, and pretty close to my 1973 Fender Blender (I'll post an a/b video once I get it all sorted). Tone knob and especially boost switch don't do much, especially in comparison to the 1973. Despite what has been posted on this forum, the 1973 tone knob works with both "tone boost" on and off, and the "tone boost" really changes the sound.

Thoughts?

Thanks
John
 
I didn't personally trace the Fender Blender, but I have traced the Shields Blender and I see something that might be relevant...

Want to try an experiment? Looking at the left footswitch on the Blender wiring diagram, swap the yellow and green wires at the PCB.
1751140579319.png
 
Are you trying to blow up the Internet?

It's obvious the Green and Yellow Wires on the left should be swapped at the switch.
 
Six-of-one, a half-dozen of the other.

My sister's old dance partner used to say "Six of one, a dozen of the other"...
We tried to correct him, explain to him that the saying involved a half-dozen, to which he exclaimed:

"BUT! That's the SAME THING!"

Yes, Dwayne, that's the point.
 
Feral Feline said:
Yes, Dwayne, that's the point.
Click to expand...

A guy I used to work for used to say "Six of one half does the other".

I had never heard the actual phrase so I heard this for years before realizing what he actually thought he was saying.

I just accepted it as one of those weird things old people say. :ROFLMAO:
 
Robert said:
Want to try an experiment? Looking at the left footswitch on the Blender wiring diagram, swap the yellow and green wires at the PCB.
Click to expand...
Click to expand...
BINGO! That did the trick. Thank you very much!

While we're at it do you know how I might be able to get more clean signal from the Blend pot? right now the clean signal is lower when engaged then the clean signal when the pedal is off and it'd be nice to start from a similar place and blend in the fuzz.

I don't know if this is the "volume drop" that people are talking about with the reissue or not but I don't see a a corresponding resistor between what they're talking about and the pedalpcb one.

Thanks again!
 
Well this is interesting...

It looks like almost all of the Fender Blender schematics floating around online have misinterpreted the switch wiring and mixed up the common lug. I've compared to every gut shot I could find, this original Fender schematic, and the Shields Blender trace.

Almost every schematic shows the common lug of the switch connecting to lug 3 of the level pot. I can't find a single photo of an original unit where this is the case. Instead, what I'm seeing is that the common lug of the switch is connected to the wiper of the tone pot.

Unless I'm mistaken, we may have been building this wrong for many years.

hfndee2iyqsm8rthokrd.webp


INCORRECT​
CORRECTED​
Incorrect.png Corrected.png
 
Feral Feline said:
CORRECT WIRING

SWITCH IT UP!
Click to expand...

Yep, I do believe that's correct. I can't find an example where it isn't but I want to make absolutely sure before updating the doc.

I've never bothered tracing the "classics" because I just assumed they were all correct at this point, but between this and the recent discovery that one of the Bluesbreaker schematics might be incorrect.... I don't know.... :unsure:
 
Yeah...Everything is suspect.

Look at how much the good ol' Muff varied within just one year of production (pick any year! 😸 ), using whatever was on hand.

Nothing's set in stone; and when a new person is on the assembly-line putting electrolytics in the wrong way round for a few days/weeks before the mistake is caught... then years later somebody traces the anomaly instead of a true production unit...


Menheer Van de Krol also came across a correction of an old DIY-staple — incorrect for years... the Philosopher's Tone.
From Aion's (re-)tracing journal:

But, there is one key difference: R19, the 6k8 resistor from the original trace, is 68k in the Micro. This resistor sets the gain ratio of the wet signal in the op-amp stage, and higher resistance means a higher signal level.
Click to expand...


Then there's the Blue Clipper skipper, which ROG thinkered twas incorrecto and came up with the New Clipper...

Blue Clipper New Clipper corrected schematic.png


SPEAKING OF ARMSTRONG's colour-coded series...

I've only ever seen ONE (1) Yellow Humper for sale, long after it had been sold. If you ever see one in the flesh, @Robert, please by hook or by crook TRACE IT!

Currently there are only vague guesstimations based on the Purple Peaker as to what the Yellow Humper is based on, for which there are a couple of vero layouts out there, but...






GETTING BACK ON TRACK...

I'm looking forward to @Toy Sun 's comparison video of his original Fender Blender with his PPCB Blender-build.
 
Feral Feline said:
Yeah...Everything is suspect.
Click to expand...
Great examples. One that immediately popped up in my mind is the Hornby Skewes Treble Booster— for years all of the schematics showed it, among other issues, as not having any input or output capacitors. There was debate over how it was acting as a treble boost without these caps present. Years later someone scores one on ebay, and it turns out the existing trace of it was just from pictures of a non-functioning half-cannibalized unit. Still much of the info you find for the HS treble booster claims that it has no input or output capacitors, and that this somehow contributes to the ‘unique’ sound.
 
Can anyone confirm that this is the common lug on these Carling switches?

I can't find a datasheet that spells it out plainly.... I'm sure I have a switch somewhere but it'll take some digging.

1751298600715.png
 
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