marshall crunch - Zvex BOR or BSIAB II?

[burningwater]

Id like to get a marshall type pedal. I tried the MI crunch box but it was a bit too compressed for me, nice VH tones but I want something more ampy sounding (dynamic and open)

Has anyone owned both the BSIAB and BOR and could you compare them? Also is the circuit in those fairly similar?

[jonathan perez]

everyone has owned a BSIAB2! and everyone has heard the box of rock...

two different monsters. if you dont want van halen tones, steer clear of the BSIAB.

if you want "ac/dc" tones, box of rock is yours.

VH not ampy sounding enough, huh? hmm..how about buying a tube amp? 

[burningwater]

HA! I have owned many, more than you Im sure
I didnt mean to imply the crunch box sounded just like Eddies plexi, just did a nice version of it for a pedal. Too compressed for me though, I like a more open sound from a pedal and Im not going for the VH tone. From what I hear the BOR is more open and dynamic than the crunch box but it can get a bit flubby in the bass. You say the BSIAB2 is different but dont say how. So if its not VH, and not AC/DC, how would you describe it? More useful info please and less smarmy BS. Thanks -j

[jonathan perez]

smarmy bs? calm down, gunpowder.

you misread, the bsiab has VH tone written all over it.

what amp are you using? guitar? pickups? these things are bigger factors than the pedal itself, as of this moment.

[remmelt]

I hear the Thor is supposed to be like a Marshall stack. I made one but it's in the To Debug pile, right next to my BSIAB2....

[slacker]

If you want a more open sound from the Crunchbox pull the clipping LEDs and replace the opamp with a rail to rail one like a TLC2272.

[MartyMart]

BSIAB II - VH tone to die for, not a ton of low end but a superb circuit and quite responsive, I've used it on lots of
recordings, including most of the distorted tracks from "The Decoders" album, hear some mp3's here : www.thedecoders.com

BOR - Fuller tone to it and not quite as much "dirt" as the BSIAB II fully cranked - they share the same tone control
/ output and final R/C combo BTW !!!!

THOR - A quite "true to original" Marshall clone and all round the better "daily use" contender for me personally, gain range seems
about accurate to the amp and it responds real well when "hit hard" with a TS-9 or Rangemaster for example.

All three are superb and have their place, it's more a case of which tone/gain range you're after ?

Marty.

[markm]

It's my understanding these two circuits share some common design.
Perhaps the different voicings are differences in Gain plus filtering?

[wampcat1]

It's my understanding these two circuits share some common design.
Perhaps the different voicings are differences in Gain plus filtering?

Well since the BOR is basically a couple of sho boosts in series with the bsiab tonestack at the end it will indeed sound similar to the bsiab in tonality.
However, if you really want 'amplike', I'd go with the ROG Marshall amp emulations - they are much more open and responsive.

bw

[burningwater]

Thanks for all the info guys. My buddy just told me about a fetto which he says has much more gain and is tighter than BOR, yet more dynamic and responsive than crunch box. Sounds like that may be a good way to go. Perhaps Ill buy one and build one.

Sounds like the Thor might be a better build for me than the BSIAB.

Interesting idea about modding the crunch box, too bad I sold it already, can you give me a quick explanation of how a rail to rail opamp differes from the standard 4558 dual opamp? Thanks

[Alex C]

Is the "Crunch Box" mentioned in this thread the MI Audio Crunch Box?

And is this the same circuit that was called "CrunchIt" in this thread? 

Just wanted to clarify whether "crunch box" is being used generically to mean "dirt box" or "gain pedal."

-Alex

[slacker]

yes and yes

[Alex C]

Thank you, sir. 

-Alex

[slacker]

No trouble. The Crunch IT is well worth building it might not be quite as good as a BSIAB2 but it definitely makes my Twin sound a lot more "British".

Interesting idea about modding the crunch box, too bad I sold it already, can you give me a quick explanation of how a rail to rail opamp differes from the standard 4558 dual opamp? Thanks

The main difference is that normal opamps clip when the signal gets within about 1.5 volts of the power rails so with a 9 volt supply you only get about 6 volts of headroom before they clip. Rail to rail opamps can swing all the way to the power rails so you get more headroom and less clipping, this helps make them sound more dynamic. I also think they clip in a softer way as well but I'm not sure. All I really know is that my Crunch box clone sounds a lot better with a TLC2272 in it than other opamps.

[burningwater]

Very interesting Slacker, Ill have to give that a whirl. Thanks!-j

[MartyMart]

Here's the Thor demo that I made for ROG : http://www.runoffgroove.com/thorsgroove.mp3

Rhythm parts @ gain 75% and lead at 100% with some delay, quite "amp like" I'd say !

MM.

[Ed G.]

That Thor clip sounded great, really tight, fat and crunchy!

If you want less compression from the bsiab, use all 2n5457s in the circuit. Change C5 for a 560pf polystyrene. That'll open it up a bit. Change C8 to 1uf film for more bass.

[snoof]

pertaining to the rail-rail opamp question, is the r to r spec for an opamp listed in the datasheets??  Just curious...

[slacker]

Not sure, I think rail to rail opamps will state this on the datasheets. The TL07XX datasheets I've got show the maximum peak output voltage compared to the supply voltage so you can see how close to the rails they can get.

[markm]

It's my understanding these two circuits share some common design.
Perhaps the different voicings are differences in Gain plus filtering?

Well since the BOR is basically a couple of sho boosts in series with the bsiab tonestack at the end it will indeed sound similar to the bsiab in tonality.

Really?