EQD boosters/ods/preamps: Speaker Cranker, Arrows and Black Eye.

[Plexi]

I've been building/messing around the Speaker Cranker, a great boost/od pedal.

Now I'm starting the Black Eye; another kind of beast, mosfet booster and... preamp?


What about the Arrows? Any Schematic?

It seems that Arrows and Black Eye adds a little mids/shimmering hump to the signal.

Experiences?

[nocentelli]

... the Black Eye; another kind of beast, mosfet booster and... preamp?

Pretty much the same as the Zvex super hard on booster

[davepedals]

Ahhh.... now I have a place for my 5k trims!  But dang it... no 10m resistors!

[Plexi]

... the Black Eye; another kind of beast, mosfet booster and... preamp?

Pretty much the same as the Zvex super hard on booster

That's it


I would say "the same" with output 100k volume pot and higher R3 res (Bias?=less volume?).

[duck_arse]

davep - you don't want to mix your 10m resistors with your 10M resistors, the results will disappoint. you can use 9M1 or 8M2 or 7M5 and it won't make much difference, really.

and plexi - that image needs a [img height=400] ..... edit, so it will actually fit my screen.

[Plexi]

Thanks Duck for the trick!

What about the diode (x2 in SHO) position?

[highwater]

D1 is polarity protection for the whole circuit (backwards battery, wrong wall-wart), and D2 protects the MOSFET from static and/or reverse-bias on the gate.

The SHO does it a bit differently, but the diode pair achieves the same results.

The diodes won't affect the sound in either case. (unless something goes wrong, in which case they'll stop that wrong thing from being even worse)

[Plexi]

Now I understand.
In other words; they don't mess with tone/gain

It's the first time that I saw a diode there, crossing Mosfet from gate to source.

[thermionix]

Two output jacks, but only one of them turns the pedal on.  Odd.  I guess there are appropriate markings on the box, like "use this output first" or something.

[snk]

Hello
I just built the EQD Black Eye for a friend (using this layout) and the sound I get from it is not good at all :
- It doesn't provide a lot of boost (just a tad above unity)
- It sounds quite harsh, with some nasty artifacts on transients


The little mods I made are the following :
- instead of a 5k trimmer, I have used a switch (with a jumper on one side and a 3.9k on the other side) so I can (in theory) get a cleaner sound or a dirtier sound. It seems to work as expected (I can get a louder and dirtier sound when the swith is on).
- I have also used a switch for the input capacitor (56nF or 150nF), so i can either cut some bass or use it with an extended bass range. It seems to work as expected (when used on a bassline, I can hear more or less bass frequencies depending on the switch position).
- I didn't had any more 100k pot, so i used a 50k pot for the volume.


I am going to double check the resistor values, and try with another BS170. But if anyone has an idea about which could be the issue, it would help me 
Thank you in advance!

[snk]

Sorry, I forgot to post the voltage ratings I got :
D = 6.77V
G = 0.52V
S = 0.10V

[Plexi]

Hello
I just built the EQD Black Eye for a friend (using this layout) and the sound I get from it is not good at all :
- It doesn't provide a lot of boost (just a tad above unity)
- It sounds quite harsh, with some nasty artifacts on transients


The little mods I made are the following :
- instead of a 5k trimmer, I have used a switch (with a jumper on one side and a 3.9k on the other side) so I can (in theory) get a cleaner sound or a dirtier sound. It seems to work as expected (I can get a louder and dirtier sound when the swith is on).
- I have also used a switch for the input capacitor (56nF or 150nF), so i can either cut some bass or use it with an extended bass range. It seems to work as expected (when used on a bassline, I can hear more or less bass frequencies depending on the switch position).
- I didn't had any more 100k pot, so i used a 50k pot for the volume.


I am going to double check the resistor values, and try with another BS170. But if anyone has an idea about which could be the issue, it would help me 
Thank you in advance!

For BS170, bias pot (5k) at S go from max to min (0hms), D voltage should go from 7.2V down to 4.0V.
4/4.5v should be bias mid center, if I'm not wrong.

About Vol pot, try 100k or bigger. I would not go for 100k or less, you're under impedance (again: if I'm not wrong )

[Ben N]

Pretty much the same as the Zvex super hard on booster

But alas, no