BSIAB2 doesn't really sound all that good?

Started by grindell, July 10, 2009, 07:12:33 PM

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grindell

Just built the BSIAB2, and I find that it doesn't really sound all that good.  I've got it baised at 4.5 volt, and I played around with that a little, but still couldn't find a tone I liked.  I don't think there's anything "wrong" with the layout or build, I just don't think it sounds all that good.

The Dr. Boogey sounds like a way better circuit, much more like dual rec than that BSIAB sounds like a cranked Marshal.

Am I missing something?

And, does anyone remember a circuit called the jcm800 emulator?  Is it similar to the BSIAB2?

aron

It could be components, it could be a build mistake, it could be a bad match for your amp, it could be a bad match for your equipment. That's why we DIY so we can match it better to our needs. Sometimes you just like another type of circuit. Nothing wrong with that.

grindell

Hah.  You should have said it was my bad playing!   :icon_biggrin:

Yeah, it just wasn't what I expected....  I might build another one and compare them.  I didn't really sub any values, and I used gausmarkov's pcb....  Maybe I did put a wrong value in somewhere....

mth5044

IIRC, I read somewhere that they are meant to be played into clean jangly fender kind of amps... that could be a problem for you?

grindell

I'm playing it in to the clean channel of a Fender Prosonic, if that helps....

aron

Wow, you have a Prosonic? No need for dirt pedal there!

liquids

Compared to a Marshall, or what you were expecting, how does it sound to you?
Breadboard it!

grindell

Yeah, the Prosonic actually has a ton of gain.  Like, insane amounts for a Fender.  The clean is like a Fender clean, the distortion is like a Boogie meets a Marshall.  I've got one of the custom shop Prosonics.  It was the 2X10 combo, but I had a friend build me a 2X12 cab in purple tolex and then the amp itself is now a stand alone head with purple tolex and white pinstriping.  It's a great amp.  I don't get why they quit making them. 

Anyway, I guess the BSIAB sounds, and this is purely subjective, kind of blatty and fizzy.  Not as smooth as I would have thought it would be....  Also, there seems to be an annoying amount of boost on the treble, almost like there's a peak somewhere in the treble, even with the tone control set pretty neutral.


Talon5051

There are a lot of mods that have been posted in this forum that may change your mind about the BSIAB2.  Simple ones from using all 2N5457s to changing the tone configuration.  I think one of the great things about this pedal is that there is a lot of fairly simple mods to really dial in your tone.  This is the pedal that got me hooked on diy and I am still tweaking it.

bluesdevil

Yeah, I kinda had the same opinion when I built mine some years back. Definitely a bit piercing with a Fender amp, I found. You can increase a couple of cap values and transistor changes to get  a slightly beefier sound..... gotta find the post where I got the mods. After doing the cap/tranny changes, it helped a little bit. The best setting for the tone control was about halfway. Actually, this thing sounds killer recording direct to the computer via the ROG Condor speaker simulator, not so much through any of my amps.
"I like the box caps because when I'm done populating the board it looks like a little city....and I'm the Mayor!" - armdnrdy

aron

This is what mine sounds like. It's through the Logic Fender Amp simulator. I had it lying around so here it is. My Ibanez mini 335->Logic.

http://diystompboxes.com/pedals/sounds/bsiab7_10_09.mp3

Paul Marossy

[begin plug for BSIAB I]

I haven't built the BSIAB 2, but I did build the original BSIAB back in early 2003, and I am still using it. I think it sounds great!

[end plug for BSIAB I]

soggybag

I like the BSIAB II. Everyone is going to have their own taste. Many people like this. What sounds "good" is, in the ears of the beholder, so to speak.

liquids

yeah, not sure about blatty, but bright.  Older fender amps are more likely to have muddy bass, and Ed designed this around that sound, so it's tight.  I like it a lot looser even with my older fender amp...

If you've got it bread boarded, easiest way to explain some basic easy 'revoicing' of the sound:

Change the FETs to...well, anything but J201s. 2N5457s are common, and I like MPF102s or 2N5458s for the first stage for maximum touch sensitivity.  There's still plenty of gain, even with fairly 'low gain' FETs...J201s are kind of harsh sounding, in my opinion. All 2N5457s is a good, common, easy place to start...

Even if you leave the FETs alone, Change R10 to 3.3k, and C2, C4, C12 to .1uF, and change C8 to 1uF.  This means it stays marshall-like to me, but it makes the gain range more useful and the bass more neutral.

There's plenty more you can do, especially with the tone controls, but that's the core mods I do and a few others have liked. 
Breadboard it!

grindell

Thanks for the tips, everybody.  I think I'll build it again with the mods and A/B them....

darron

i built one and thought it was bloody awesome. then i gave it to a friend. built another one a couple of months later and it was pretty average... ):

not sure if it was the luck of the jfets that i used or the change to neodymium pickups...

i think just bias it by ear at the loudest point to for that circuit.
Blood, Sweat & Flux. Pedals made with lasers and real wires!

Ed G.

Quote from: grindell on July 10, 2009, 08:02:44 PM
Anyway, I guess the BSIAB sounds, and this is purely subjective, kind of blatty and fizzy.  Not as smooth as I would have thought it would be....  Also, there seems to be an annoying amount of boost on the treble, almost like there's a peak somewhere in the treble, even with the tone control set pretty neutral.



Something definitely sounds wrong here. Tone is subjective, what some people like, others don't, but "blatty and fizzy" is not normal. Sounds like a misbiased fet. Sometimes swapping out the "top" and "bottom" fets makes things sound a lot better, as we know, fets are variable devices, and some fall outside the parameters of what sounds good in this circuit. I'd measure the drain voltages on Q1 and Q3. They should be also around 4.5 volts.