Anyone know of a project for this

[flanagan0718]

Hello fellow forum members,
     Had a friend of mine ask if it was possible to do a clone of sorts for the Tech 21 Sans Amp Bass DI. Anyone know where or even if there is a similar pcb or possible 2 in one combo for this? I'm not to familiar with the product so I figured I'd ask the pro's here. Thanks in advance.

[Frag Magnet]

I'm actually working on one myself but the current board doesn't work and I need to do some troubleshooting.  If nobody else chimes in, I'll let you know when I get it going and let you have the Eagle files.

[Haberdasher]

google triangular ear bass21.  if you can't find it pm me your email and i'll send it over.

i etched this for someone a couple of years ago.  never heard back from them about how it turned out though...

[mremic01]

Here's an slightly improved version of the original layout: https://dl.dropboxusercontent.com/u/3565959/Bass%20Driver%20Relayout.pdf

Here's the original by 12afael: https://sites.google.com/site/plexilandia/

If you use these docs, double check the switch and XLR wiring. I remember there was an error.

I've built this and it works and sound good, but it's a bit different from my v2 BDDI. The pots don't have the same response, even though the v2 BDDI should all have B100k's (http://i162.photobucket.com/albums/t275/aguy133/Tech21SansAmpBDDIguts002.jpg), and I didn't get quite as much volume on tap as the real thing.  The older version only has the Phantom & Ground Connect switch. The v2 added Line and Instrument Level switches for both outputs. The fact that the project is always referred to as the Triangular Ear Bass21 makes me think the original tracing was from the Behringer BDI21 and not the SansAmp, but I couldn't find much on where the original schematic came from.

I have a BDI21, and the board is visible, but the SansAmp requires a lot of desoldering to get to the component side of its own board, so I've sat down to compare the circuits. From what I've read on freestomboxes, the SansAmp uses something other than TL072/TL074 for one or two of the IC's, but freestompboxes is down right now. I think the IC's in question have the part number sanded off, but someone figured out what they were. When the site come back up, I'll dig up what I can and post it here.

The fsb guys have also been working on the Tech21 Character series, so it'll be cool to see if they can come up with a VT Bass schem.

[flanagan0718]

Thanks for the links and info. I did see this when poking the googles. I'll see what he thinks. Thanks again


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[flanagan0718]

Ok after looking at the schematics and build docs, It seems pretty straight froward. I do have a couple of other questions. I read a bit on a couple other forums and it seems like people are pretty sure they didn't use the TL 074/072 for the op amps. Any idea what would be a decent substitute? I know the 64/62 is less noise but there are others with the same pin out but more gain. would this be better for bass? Any one got a busted one they want to gut? Thanks.

-Mike-

[mremic01]

The OD section of the circuit reportedly uses TLC2272 or TLC2262. The other IC's are TL072/TL074.

[flanagan0718]

The OD section of the circuit reportedly uses TLC2272 or TLC2262. The other IC's are TL072/TL074.

Great thanks! I'll see if I can locate these. I guess my best option is to socket and try some different ones. I have plenty of the 72/74 combo, I'll look into the others. Thanks again.

[kothoma]

I know the 64/62 is less noise

Wrong. The TL06x draw less current but are more noisy than the TL07x.

[flanagan0718]

I know the 64/62 is less noise

Wrong. The TL06x draw less current but are more noisy than the TL07x.

Thanks for making that more clear, or, less...fuzzy! haha sorry couldn't resist.