more highs in my BSIAB 2?

[Cabezahead]

Are there any parts you can change to brighten up the tone on this thing?  It just sounds to me like the tone control doesn't go a trebly as it should... and goes too bassy.

I searched for other posts about this - but nobody really answered dudes question - at least - with a definite 'yay.'

thanks

-CH

[Ed G.]

Are there any parts you can change to brighten up the tone on this thing?  It just sounds to me like the tone control doesn't go a trebly as it should... and goes too bassy.

I searched for other posts about this - but nobody really answered dudes question - at least - with a definite 'yay.'

thanks

-CH

You can lift one or both of the lpf's at the end.

[Cabezahead]

my next question, in that case, is 'what's an LPF?'

Low pass filter?

-CH

[Cabezahead]

I think you're talking about the two 10ks and the cap to the ground...

I already lowered those to 100ohm resistors after audio-probing it and realizing that that was the point where it gets mudded up. Haven't lifted the cap yet - i'll  try messing around with that area tonight.

I think my mudiness is coming from the fact that I really fudged a lot of the capacitor numbers for the closest thing I had - and now i'm trying to compensate for that in other places.

Otherwise - i'm REALLY digging the circuit.  I can hear the potential in my setup already.  I'll letcha know how my experiments go.  :-)

Thanks a bunch.

-CH

[Cabezahead]

Toyed with what i think is the 'lpf.'  And messed with c1 and c3b.

Perfect.

Now the tone knob takes me from bright bright to transparent to dark dark.

Really digging this pedal (i've got in a RACO box... suits it perfectly, i think.) through my SS Polytone.

Tomorrow - i'll slam it up against my Ampeg V4.  

Thanks a bunch!

-CH

[Fret Wire]

Low pass filter?

Yup, and it sounds like you've found it.

[mojotron]

I've played with this idea a bit too - not because I thougt the BSIAB2 needed more high end.

The low pass filter (lpf) is made up of two first order lpf to create a 2nd order lpf (approx. reduces 12db/octave)..

What I found was that I got a good bit more treble if I lifted c14 - but I liked the original sound better.

You can put a 20k pot in series with c14 and get some control over the amount of treble you want to add. I imagine a dual-ganged pot would be pretty cool - where each of the pots was in series with c13 and c14 respectively. But, like I said, Ed did a great job on the tone shaping on this circuit and I ussually go back to the original design after my experiments.

One other thought, if you want more treble, is to reduce C1 to 150pF.. but you may start picking up more radio stations..

I originally built this circuit using components that I thought were close enough to the specified values, I was much happier with the BSIAB2 when I corrected all of the values that were not exact... I would start there before I changed anything else.

[Ed G.]

Tomorrow - i'll slam it up against my Ampeg V4.  

Thanks a bunch!

-CH

Let me know how that goes. I'm a fender guy, but I LOVE ampegs.

[Cabezahead]

Let me know how that goes. I'm a fender guy, but I LOVE ampegs.

Sounds incredible. It's like a having two different amps.  It immediately took a spot on my board.

I'll try to post up some clips sometime this week.

Thanks a bunch for the design... all the rave reviews and it still beat my expectations.

-CH

[robotboy]

You probably already did this, but don't forget you can tweak the bias with the trimpot. I found that to make a huge difference on my BSIAB II.

[Cabezahead]

You probably already did this, but don't forget you can tweak the bias with the trimpot. I found that to make a huge difference on my BSIAB II.

Indeed - that bias pot can take you from not working, to sounding like shit, to sounding incredible, to sounding like shit, to not working over it's full throw.

I biased it by ear though...  I guess I should measure what that drain actually is...

-CH

[Cabezahead]

You probably already did this, but don't forget you can tweak the bias with the trimpot. I found that to make a huge difference on my BSIAB II.

Indeed - that bias pot can take you from not working, to sounding like shit, to sounding incredible, to sounding like shit, to not working over it's full throw.

I biased it by ear though...  I guess I should measure what that drain actually is...

-CH

[d95err]

My BSIAB II was also a bit dark too and little low on output level.

I used a 100k resistor in paralell to the whole tone stack. I.e. from the negative side of C9 to the volume pot. This made the whole thing a lot brighter, though turning the tone know now only makes fairly subtle changes. It also increased the output level some.

It will take some more expermientation to find the right value for this resistor, and I might keep one of the LPF at the end rather than going all the way to the volume pot.

I'll do some more error checking as well to see if there is some other reason why the output is a bit low. It's sligthly over unity level on max, but significantly lower than my Tubescreamer.

[Parko]

sorry to dig up an old topic, but in regards to the overall output level, i found that using polar electrolytic caps in C3a and C9 gave me a higher output than using non polar. I'm no engineer so i can't tell you why, but it did the trick for me.
Now all i have to fix is the tone pot range (i'm always setting it to max as it's too dark anywhere else), and then i'll be set  

[Ed G.]

I'll do some more error checking as well to see if there is some other reason why the output is a bit low. It's sligthly over unity level on max, but significantly lower than my Tubescreamer.

Something's wrong, maybe a funky fet or something, but the output on the BSIAB is healthy, definitely over unity, not even a problem.

[Cabezahead]

Mine gets way over unity... I only used one j201 - couldn't tell you which spot.

Although - I have a lot of weird cap values in there and barely any filter anymore.

Also - just as an update to my build, as long as it's up here...  My brown sound box has been working wonders for my smooth sustain these days.  I still use a tubescreamer for my low gain grit, and tap on the brown sound when I want to really sing and hold day long notes.  It's pretty damn transparent, too - it's a real smooth progression from clean, to TS to BSIAB...

Edit = hopefully someone will record some of my band's shows and i'll have some nice clips of the brown sound working with my whole rig.

-CH

[JT]

Toyed with what i think is the 'lpf.' And messed with c1 and c3b.

Perfect.

Now the tone knob takes me from bright bright to transparent to dark dark.

Hey CH ,
          I just finished a BSIAB II and i find it too dark ....can you tell me what values you ended up with on c1 and c3b  to get your results? did you tweak anything else?
Thanks in advance!
JT

[Bucksears]

>>Hey CH ,
I just finished a BSIAB II and i find it too dark ....can you tell me what values you ended up with on c1 and c3b to get your results? did you tweak anything else?
Thanks in advance!
JT

Me too!! I just finished with the BSIAB and wanted to know what values you tweaked yours too as well.

Thanks,
- Buck

[Cabezahead]

Ahhh... Just saw this - sorry guys.

I really have no idea the values I used...  And my pedalboard is currently locked away in a studio - so I can't pop it open and check it.

I don't even really know if I raised or lowered anything...

I do remember that I pretty much took out the entire LPF at the end...  Raise that last cap from the ground and see if that does it for ya.

Sorrry I can't help much - I really just don't remember.

:-(

-CH