BSIAB II is done!

[Ed G.]

Finished it last night and had to sub the 2N5457's(but there on the way, thanks Peter). First I tried MPF102's....weak, unimpressive. Then I tried all J201's.....harsh, big hum, once again unimpressive. Finally I tried 2N5485's much better, lots of harmonics. The tone control would add or subtract treble but not really add bass.

I still can't find my original :x  I think I had added a cap on a switch for a treble boost when the volume wasn't at max. Can't remember how I did it.

Looking forward to seeing the difference in the 5457's

I'm not familiar with 2N5485's, so I don't know what difference it will make. The tone control does maintain the bass when turned up, unlike other BMP tone controls, it just worked out that way on the breadboard.

I remember on your original bsiab, I suggested sticking a cap on the volume control, I think you stuck a .001 or such, I thought it was a pretty high value, but it seemed to work for you.

[Bill Bergman]

Cool Thanks Ed!
Now I understand the tone control.
Wow, great memory on the cap thing.....which lugs do I connect the cap to on the volume pot.

[Bill Bergman]

Screw the cap thing I was talking about....... :shock: I just stumble across something that makes this pedal SCREAM

I was messing around with the a cap on the volume pot then the tone pot and had marginal result ......then by mistake I jumped a wire between the output on the stompswitch and the middle lug on the tone pot...bamm...big  volume jump, way extended tone range, more gain and or even cleaner brightness,glassyness and presents on the gain low setting.
Wow, either I have something wired wrong originally  or I've found a killer mod. Sombody try this and let me know.....just run a wire from the middle lug of the tone pot to the output.

[Eric H]

Screw the cap thing I was talking about....... :shock: I just stumble across something that makes this pedal SCREAM

I was messing around with the a cap on the volume pot then the tone pot and had marginal result ......then by mistake I jumped a wire between the output on the stompswitch and the middle lug on the tone pot...bamm...big  volume jump, way extended tone range, more gain and or even cleaner brightness,glassyness and presents on the gain low setting.
Wow, either I have something wired wrong originally  or I've found a killer mod. Sombody try this and let me know.....just run a wire from the middle lug of the tone pot to the output.

Makes sense,Bill --you just bypassed the two-pole passive low-pass filter on the end of the circuit --which cuts highs, and gain.

-Eric

[Bill Bergman]

Oh.... just goes to show ya I don't know what the heck I'm doing :oops:
still I guess it make a good rhythm lead switch.

[RDV]

Or you can add another gain stage after the tone control like on a BMP to make up for the filter.

RDV

[Ed G.]

Screw the cap thing I was talking about....... :shock: I just stumble across something that makes this pedal SCREAM

I was messing around with the a cap on the volume pot then the tone pot and had marginal result ......then by mistake I jumped a wire between the output on the stompswitch and the middle lug on the tone pot...bamm...big  volume jump, way extended tone range, more gain and or even cleaner brightness,glassyness and presents on the gain low setting.
Wow, either I have something wired wrong originally  or I've found a killer mod. Sombody try this and let me know.....just run a wire from the middle lug of the tone pot to the output.

Makes sense,Bill --you just bypassed the two-pole passive low-pass filter on the end of the circuit --which cuts highs, and gain.

-Eric

Yep, you could even make that switchable, like a bright switch to compensate for darker amps. I run my stuff into a fender super reverb, a rather bright amp, so the LPF works for me.

[Bill Bergman]

Ed, I'm getting even more(not more better just more different) cool tones on my strat also as opposed to my parker(active pickup). Also with this mod/filter bypass, with the volume at max you get different  and even better characteristics but the boost is way to high as opposed to bypass mode. I'm thinking maybe a master volume and a 2 position cap filter switch would give an incredible amount of flexibility. I know more  knobs takes away from the pedals simplicity, but with only the 3 existing knobs and the one simple mods I'm getting almost all the tones of my sansamp clone. With the other mods I mentioned above it would even better.

Ed, try the simple jumper and let me know what you think...try all the  different setting on the 3 pots before you decide it's too bright.

[Ed G.]

I tried it on the breadboard several times and it's still too bright for me, but I play strat into fender amp -- that's a bright combination.
But hey, if it works for you, that's all that matters.
BTW, I got the idea for the LPF from the ROG designs. I had breadboarded the prof. tweed and still had it on the breadboard. I think it works great as far as shaving off the harsh high fizzy parts, while leaving the 'good  stuff' in. There was a thread about this a while ago and Mark Hammer really went into detail about the desirability of multi-pole LPFs

[Bill Bergman]

Thanks Ed!

[Ed G.]

BTW, have you tried it yet with the 2N5457's? How do you like the sound with the 2N5485s? I don't know how much gain those have, but the MPF102 definitely doesn't do it in that circuit, too little gain.

[Bill Bergman]

Waiting on the 2N5457's....I'll let you know when i try'um

[Eric H]

BTW, I got the idea for the LPF from the ROG designs. I had breadboarded the prof. tweed and still had it on the breadboard. I think it works great as far as shaving off the harsh high fizzy parts, while leaving the 'good  stuff' in. There was a thread about this a while ago and Mark Hammer really went into detail about the desirability of multi-pole LPFs

I completely agree --those filters can do a great job of shaving the fizz a little bit --without killing the high-end earlier in the circuit.  Good stuff.

-Eric

[Bill Bergman]

I hate fizzys :wink:

[Eric H]

I hate fizzys :wink:

--Caution: old geezer content--

You mean the ones you threw in a glass of water? Fruit-flavored Alka-Seltzer?
:?  :shock:

[Bill Bergman]

I remember those (certified geezer), it was more like bubbly coolaid.

[Bill Bergman]

Well I crapped out my BSIAB..... I took a simple to operate pedal added a few knobs,an extra switch and pot, threw in a couple caps(got to clean that up when i figure out which ones to use) and made a pedal that difficult to operate.  http://www.freewebs.com/elroy2/  pic#2

[Ed G.]

Looks killer!
As soon as my parts come in from small bear I'll be able to move beyond the breadboard. Imagine that! One day I too will have my own BSIAB II!
So I understand the filter bypass function, but what's the extra control and footswitch do?

[Bill Bergman]

The foot switch activates the filter bypass, the rotary switch introduces 2 different filter caps back into the circuit and the pot controls the added gain due to the filter bypass. That creates a lot variations. I think the original volume and treble may be effected but mabe I just wired it a little wrong or maybe be the 5485's are lacking the gain. The level seems too low with the volume at 50% when in the original mode.

[Lonestarjohnny]

Cool Lookin Pedal Bill, any sound clips of it ?
JD