# Tone Bender MK I - Vintage Edition



## andare (Nov 6, 2022)

Hello everybody. I'm very happy to present my most rewarding build to date: a Tone Bender MK I.
I built it on turret board with 1W carbon film resistors (but there's a 1k8 1/4W metal film resistor in there too) and big axial capacitors.

The coolest thing about it, however, is the vintage style wedge enclosure, courtesy of our friend and fellow Cracovian @temol
I had the pleasure of meeting him this week and over a coffee we talked shop. He brought a few enclosures to show me and I picked this one in a sparkly metallic gold. Very light construction, beautifully executed and quite solid. The top has a smooth finish, the bottom has a textured matte surface.





I added a toggle switch to turn the battery off when the input cable is connected:





Gut shots:





Together we planned how to assemble it. The board is mounted on top of the pot dust caps with double-sided foam tape. The carbon zinc battery is held in place with velcro.
You can see how Temol left the enclosure raw in strategic locations so it can be grounded. A very nice touch.





Turret board is not easy to work with and quite heavy so it's not ideal for pedals but look at how groovy it looks!


*Nerdy stuff*

*Circuit tweaks*

I spent a lot of time with this circuit on a breadboard. The Protoboard Micro definitely got a workout. I read every thread I could find about Tone Benders on several forums, noted down what gain and leakage worked and which voltages were measured in original units and great sounding clones.

Here's some tweaks that worked:

Lowering the 470k resistor reduced the gated tones with Attack turned down. 330k was very nice but ultimately I kept the stock value because I enjoy having those starved tones at the beginning of the Attack sweep.
I bumped up the 15k resistor to 120k to lower Q3c below -8.5V. A major departure from the stock value but hey, it works!
A50k for the Attack pot. B50k had almost no sound at 0 and a sudden increase in gain at 9 o’clock. The log pot has sound at 0 and a more gradual gating range at the beginning of the sweep (see demo below).
Tweaks that didn’t work:

Swapping transistors with different hFE and Iceo didn’t fix the sound with Q3c above -8.5V. The battery in the pedal is new and it reads 9.3V so the actual voltages are now higher but the pedal sounds great. In fact the decay is much better now than on the breadboard with standard components and a slightly used battery.
Increasing the value of the Attack pot makes it less useful IMO. I tried values up to 500k but there was too much gain too early and no variation after that.
Lowering the 2.2M resistor to 1M made it a tad louder but it ruined the decay of the notes. 2.2M reaches unity at 2 o'clock. Increasing the Attack makes it louder.
*Transistor info*

I only have 90 or so Germanium transistors so I tested and numbered all of them and I keep them in a binder each with their own individual card.

*Q1*

#002
AC125
hFE 86
Iceo 202uA
*Q2*

#029
ASY34S
hFE 117
Iceo 43uA
*Q3*

#031
ASY34S
hFE 490
Iceo 133uA
*Voltages - Attack at 0*

Q1e -1.25V
Q1b -1.3V
Q1c -9.14V


Q2e 0
Q2b -0.05V
Q2c -9.11V


Q3e 0
Q3b 0
Q3c -8.60V
*Voltages - Attack at 10*

Q1e -1.26V
Q1b -1.3V
Q1c -9V


Q2e 0
Q2b -0.19V
Q2c -4.61V


Q3e 0
Q3b -0.01V
Q3c -8.34V

*Sound samples*

Here's the range on the Attack knob (The riff is Evil by Cactus - originally played with an Ampeg Scrambler octave fuzz). The first usable tone is at 10 o'clock but it's cool to have those weak sounds in there. The higher the Attack the louder and brighter it gets and the more attack the notes have. Truth in advertising. Fender Strat on the bridge pickup with 10-42 D'Addario flatwounds (plain G).


__
		https://soundcloud.com/ceppaloni%2Ftb-mk-1-attack-range

Here's a riff I came up with today. Level and Attack at 2 o'clock. The intro is my Strat rolled back to 7, the main riff is at 10.


__
		https://soundcloud.com/ceppaloni%2Ftb-mk1-riff


*Conclusions*

This was such a wild ride. I only started breadboarding earlier this year (thanks to @BuddytheReow 's tutorials) and I can't believe how much I've learned.
Special thanks to @temol for the tips and for making this fantastic enclosure. How cool is it that we both live in the same city?


----------



## steviejr92 (Nov 6, 2022)

😍


----------



## JamieJ (Nov 6, 2022)

Great job @andare !!! Sounds (and looks) great.


----------



## Harry Klippton (Nov 6, 2022)

Goddamn that came out great. I have wanted to build a mki like that in a wedge enclosure for a bit too. Even better that it's a @temol creation


----------



## Mentaltossflycoon (Nov 6, 2022)

Beauty


----------



## Fingolfen (Nov 6, 2022)

That is a sweet looking and sounding build! I'm a dead sucker for anything vintage...


----------



## RetiredUnit1 (Nov 6, 2022)

I have a tone bender that I traded for bailing a friend out of jail in the 70's.  Cost me 30 or 40 bucks (hard to remember), lol...


----------



## temol (Nov 7, 2022)

Super cool! How about a decal or a faceplate?


----------



## JamieJ (Nov 7, 2022)

temol said:


> Super cool! How about a decal or a faceplate?


@andare - I have a PDF with the correct font somewhere. Let me have a look for it.


----------



## andare (Nov 7, 2022)

temol said:


> Super cool! How about a decal or a faceplate?


I'd love a decal!


----------



## Fuzzonaut (Nov 7, 2022)

Amazing build - and build report. The enclosure is super sweet.



andare said:


> I only have 90 or so Germanium transistors (...)


Only 90? How can you sleep at night?


----------



## temol (Nov 7, 2022)

Fuzzonaut said:


> Only 90? How can you sleep at night?


What is the minimum amount beyond which it's difficult to sleep at night? And what happens when you have more than 500? No more daytime naps?


----------



## temol (Nov 7, 2022)

Something like this...?


----------



## andare (Nov 7, 2022)

temol said:


> Something like this...?
> View attachment 35456


You misspelled Bone Blender 

I would use a different font. As soon as I have time I'll put together a mockup, thanks


----------



## Route14 (Nov 7, 2022)

Absolutely stunning!


----------



## temol (Nov 7, 2022)

There's only one other font you can use...


----------



## Bret608 (Nov 7, 2022)

This is an absolute beauty! I appreciate all the information you shared as well.


----------



## Feral Feline (Nov 7, 2022)

Wow!

🤯



😻


The attention to detail on the box is only rivalled by the attention to detail of the build, which is rivalled again by the attention to detail in the build report. 

"Only" 90 Ge transistors? Pffft, I had 9 — just recently broke into the low double digits. 😸

Thanks for such an inspiring post, you and Temol make a great team.


What a beautiful build, through and through.


----------



## andare (Nov 7, 2022)

Thanks everyone for the kind words.
Couldn't have done it without this forum and its wealth of knowledge and inspiration.


----------



## THeHammer82 (Dec 8, 2022)

Fantastic build and that enclosure looks awesome!


----------



## Coda (Dec 28, 2022)

I want it.


----------



## aefpv (Dec 28, 2022)

Something about a good tone bender makes me tingle!  I love that circuit and sound. Great playing too!


----------

