DIY sansamp BDDI clone

bigbadbob76 · #1 12-10-2010, 07:59 AM

Hi guys.
Having just built this
http://plexilandia.googlepages.com/tech12bassdriver.rar
I put it on the scope to see how the frequency response and distortion looks. seems ok but it really cuts the mids around 800Hz. output is also low so i added more gain in the output buffer.
has anyone else built it? if so how did you get on and did you like the sound? how does it compare to a real sansamp? does the sansamp also cut the mids?
all comments welcome.
Bob.

cybersnyder · #2 12-10-2010, 08:21 AM

Beware of .rar or .zip files.

bigbadbob76 · #3 12-10-2010, 08:34 AM

Ok i'll find a better link.
it's the triangular ear bass21 traced by diz. if you've built one you know what i mean, if you havn't, that probably looks like gobbldygook. lol.

edit-better link. http://www.freestompboxes.org/download/file.php?id=3084

Darkglass · #4 12-10-2010, 08:40 AM

Hey, I was the beta tester for that project back in the day. It works fine!

The Midscoop is part of the BDDI. How low is your output? If it sounds right, but you just want more juice out of it, I think increasing gain on the inverter buffer before the baxandall is the best, I think in the Sansamp is boosting x2.2 (10k as input resistor, and 22k in the negative feedback) You should be able to increase the 22k to 33k, 47k or even higher for a lot more Output level.

Best Regards

Doug.

bigbadbob76 · #5 12-10-2010, 08:52 AM

Hi Doug. I've seen some of your posts on this project, good pics too, was that a 1590BB box you put it in? must have been a tight squeeze.
the levels i'm getting are instrument level and i'm looking for line level for recording.
Yeah, i thought of boosting before the tone stage, but didnt want to boost the xlr output, just the unbalanced. so i cut the track that closes the feedback loop of the o/p buffer and slipped a 270k smd in there.
I thought of adding a mid boost stage as someone else has done but if the scooped mids are part of the sound i'll leave it be.
Thanks for your interest.
Bob.

bigbadbob76 · #6 12-10-2010, 12:46 PM

had a good play around with it tonight, sounds great through the PA, nice round tone and very controllable overdrive. now i just need to box it up.

GrooveWarrior · #7 12-10-2010, 01:15 PM

How much does something like this cost? Mind you, I've never built anything, so I would probably be asking someone to handle that for me.

bigbadbob76 · #8 12-12-2010, 03:09 AM

it's hard to put a cost on it, i've got loads of bits lying around so it's cheap for me. to build it from scratch for someone would probably cost as much as you'd pay for the behringer one.

Darkglass · #9 12-12-2010, 10:45 PM

yes, it was a 1590BB! I used an Alpha DPDT switch to save some space, but it was pretty tight!

If you still want to try boosting using the inverter, is pretty easy to re-adjust the output level for the DI. Just change the Resistor divider that goes from the output buffer to the DI section. Or better yet, change the resistors for a 100k pot, and you got a DI Level control!

For mids I used a single Baxandall as well, worked like a charm, but you have to make a small pcb, and mod the current one. IMO it was worth the trouble...

Regards

Doug.

karter2000 · #10 12-12-2010, 11:36 PM

Quote:

Originally Posted by Darkglass

For mids I used a single Baxandall as well, worked like a charm, but you have to make a small pcb, and mod the current one. IMO it was worth the trouble...

Regards

Doug.

Excuse my ignorance, but how does a single Baxandall work?

Thanks!

bigbadbob76 · #11 12-13-2010, 02:43 AM

Thanks Doug.
After a good band practice session yesterday i'm pretty pleased with the project. the guitarist cut his highs and lows which sounded good with my mid scoop. i may well do the mids mod though. more control is always a good thing. i was thinking of pulling R25 and tapping in there to a seperate pcb. the balanced output level control sounds good. my gain resistor is not really in the right place, it reduces the balanced output level. i've got plenty room in my box so i was thinking of grafting in a simple tuner as well. that would give me a single pedal for all my needs. tube sound, overdrive, active tone control, line and xlr outs, and tuner all in one easy to carry box. (hmmm.... compression too.... maybe...give me an hour to think about that.)
Thanks again.
Karter2000- fig 9 of this might help (or confuse) http://gilmore2.chem.northwestern.ed...=equal_prj.htm

bigbadbob76 · #12 12-13-2010, 04:43 AM

OH yeah, forgot to mention i added a 5k resistor between blend wiper and level pot. this cures a silent spot when blend and level are at extremes. did you find a better cure Doug?

tigert10 · #13 02-05-2011, 04:30 PM

Hey guys,
Looking to build this project but I would really like to make it phantom powered. What additional circuit is needed to power this with phantom power? Any suggestions/articles/layouts would be helpful! Thanks in advance!!!