Can a BDI21 be used as a preamp?

riker1384 · #1 05-30-2009, 01:07 AM

Behringer markets the BDI21 as a "preamp/stompbox". Does that mean it can drive a power amp? The Sansamp VT Bass pedal is supposed to be able to, but I don't know about the BDDI or the BDI21. Has anyone tried it?

warwick.hoy · #2 05-30-2009, 01:20 AM

Although it can be done...it wouldn't be ideal.

It's got something to do with output from the preamp not matching the input sensitivity of the poweramp.

I used to use a 3 channel programmable BDDI to push an Ampeg SVP-1500 poweramp and it worked but I had the level on the poweramp and the preamp maxed and still struggled to keep up (4x10 speaker cab @ 4ohms) in a band setting. I switched to a proper rackmount preaamp and was able to achieve much more volume and headroom.

I'm not even sure the VT bass is designed to push a poweramp. Don't quote me on that though.

riker1384 · #3 05-30-2009, 01:27 AM

The Character Series manual specifically says they can be used as a preamp to drive a power amp. I'm not sure if it works in bypass mode, though.

I ask this because I may be able to get a good deal on a used power amp. I recently bought both a BDI21 and a VT, so when I read the VT manual I thought with a power amp, I'd just be a used cab away from a full-sized bass rig. Of course, I might not want the "VT bass sound" all the time, so I was wondering about the BDI21. If it works the same as the BDDI, then you can use the onboard EQ even if the blend is set to completely bypass the tube emulation.

warwick.hoy · #4 05-30-2009, 01:47 AM

Scroll down this page (the link) till you see a paragraph marked "can this preamp drive a power amp?" in bold. It is tber bongomania's page (giving credit where credit is due). It's a lot to digest and a little frustrating since companies tend to not make such information available. I couldn't find the specs that I'm looking for to answer your question definitively. You might want to contact the manufacturer directly to get find what you are looking for.

TL5 · #5 05-30-2009, 10:09 AM

Quote:

Originally Posted by riker1384

Behringer markets the BDI21 as a "preamp/stompbox". Does that mean it can drive a power amp? The Sansamp VT Bass pedal is supposed to be able to, but I don't know about the BDDI or the BDI21. Has anyone tried it?

Tried it? yes.
The VT Bass is capable of driving my power amps (both a newer Yamaha and an older Biamp) but the pedal had to be engaged with the volume all the way up on the pedal. It didn't work in bypass.
The BDI21, no. Not even close engaged or in bypass with my poweramps.

Suggestion: If you're wanting to use the BDI21 as a 'tone shaper' in front of a poweramp, you can utilize an inexpensive mic preamp to boost the level up. Some examples on the cheap would be Behringer's Mic100, or the ART Tube MP (which the Behringer is a clone of). I'm using a M-Audio preamp after my pedal board (VT Bass is my simulator) and I'm really pleased with the way it works. YMMV

riker1384 · #6 05-31-2009, 06:45 PM

Quote:

Originally Posted by TL5

Tried it? yes.
The VT Bass is capable of driving my power amps (both a newer Yamaha and an older Biamp) but the pedal had to be engaged with the volume all the way up on the pedal. It didn't work in bypass.
The BDI21, no. Not even close engaged or in bypass with my poweramps.

Suggestion: If you're wanting to use the BDI21 as a 'tone shaper' in front of a poweramp, you can utilize an inexpensive mic preamp to boost the level up. Some examples on the cheap would be Behringer's Mic100, or the ART Tube MP (which the Behringer is a clone of). I'm using a M-Audio preamp after my pedal board (VT Bass is my simulator) and I'm really pleased with the way it works. YMMV

If I was going to buy another item, I'd want a proper bass preamp with some EQ, and hopefully a headphone output so I wouldn't have to buy that in a separate box if I needed it. I don't see any cheap ones, though. For the price of the cheapest rackmounts I see, I could get an entire small combo amp that would probably have the same preamp features. I guess they just assume anyone looking for a separate preamp is willing to pay a lot.

Fishman has a little $140 box that appears to be conceived for upright bass. It has a compressor and a graphic EQ. If I was going to get a little handheld box like that, I'd prefer if it had a headphone jack. The cheap modeling units from Behringer, Zoom and Line6 have headphone outs, but I'm not sure I would want to have to run by bass through a DSP all the time.

[Edit: actually I realized I have an old "palmtop studio" that can be used as a headphone amp, albeit a noisy one, so I don't need that.]

JazzyLambert · #7 06-01-2009, 01:40 AM

I used a BDI as a pre on a Jands 1200W power amp from a P.A. It worked ok., but the sensitivities must have matched, I spose after reading bongomania's fascinating page.

Can't Groove @14

http://www.youtube.com/watch?v=kN9DTrLaqVU

warwick.hoy · #8 06-01-2009, 01:59 AM

For a "proper preamp" check for used stuff....I bought an old (I like to call it vintage) Yamaha PB-1 in a 2 space rack with a power conditioner for 200 bucks out the door. The PB-1 is typically cheaper on it's own. It is solid state, but none of that bothers me. An amp to me is a means to an end. If I can get it loud enough and clean enough...I'm good.

[/amp discussion in FX forum]