• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Preamp direct to FOH, do I need a DI?

DonaldR

DonaldR

Mar 26, 2012
2,220
2,209
#1
I'm using a Peavey Alphabass tube preamp direct to FOH (ampless). Since it only has unbalanced output, should I use a passive DI to go XLR? Right now I use a 5meter 1/4" cable into line input on Mackie analogue board and I'm not hearing any noise.
Di balanced XLR or stay with 1/4" unbalanced cable?
 
#4
DonaldR said:
I'm using a Peavey Alphabass tube preamp direct to FOH (ampless). Since it only has unbalanced output, should I use a passive DI to go XLR? Right now I use a 5meter 1/4" cable into line input on Mackie analogue board and I'm not hearing any noise.
Di balanced XLR or stay with 1/4" unbalanced cable?
Click to expand...

Depends on your future needs.

Obviously the 1/4" instrument cable is working for you now...sounds like the PA is mixed from the stage so the cable is suitably short to minimize signal degradation. You may still be loosing a little bit of high end but nothing catastrophic.

If you anticipate needing longer runs of cable you should get a DI. XLR mic cables are more resistant to noise and can be run for much longer distances without signal degradation.
 
#5
Wasnex said:
XLR mic cables are more resistant to noise and can be run for much longer distances without signal degradation.
Click to expand...
It's not the cable, it is the balanced signal. A lot of guitar/bass players invest quite a bit into solid, high quality instrument cables.
If the FOH guy were to use cables of that quality, the box that is filled with fifty pounds' worth of XLR cables would cost a fortune.

But I agree on the point that as long as the buffered signal runs through a cable that short, nothing will happen. You need the DI signal if you run the cable from the bassrig to the stagebox, from there via multicore to the mixer that sits 30m away from the stage.
 
#7
el murdoque said:
It's not the cable, it is the balanced signal. A lot of guitar/bass players invest quite a bit into solid, high quality instrument cables.
If the FOH guy were to use cables of that quality, the box that is filled with fifty pounds' worth of XLR cables would cost a fortune.

But I agree on the point that as long as the buffered signal runs through a cable that short, nothing will happen. You need the DI signal if you run the cable from the bassrig to the stagebox, from there via multicore to the mixer that sits 30m away from the stage.
Click to expand...

I totally agree on the benefits of balanced versus unbalanced.

My understanding is instrument cable typically has higher capacitance than microphone cable which results in cumulative high frequency roll off when distances are great. I know this to be true with instruments such as guitar or bass. I can't say with certainty the signal degradation is significant when using instrument cable with a buffered circuit. Perhaps you can explain.

Guitar Cable Length and Signal Loss through Capacitance
 
Last edited:
#9
Stumbo said:
IME, an active bass helps push the signal when you use longer instrument cables.
Click to expand...

I agree.

I play an active Yamaha TRB6P. I have experimented with 1', 7', 15' instrument cables and noticed cumulative HF losses with increased length. Signal path for the experiment was bass, instrument cable, line matching transformer, mic cable, mixer. The 1' and 7' cables where generic quality. The 15' cable was supposed to be high quality (Monster cable or similar).

I have noted similar results comparing 7', 15', and 20' instrument cables plugged directly into an amp. IMHO the difference is subtle but perceivable for these lengths.
 
#11
DonaldR said:
I agree that unbalanced cables from bass to amp might have an impact. But was wondering between preamp and amp (or mixer in this case) since the signal is way stronger.
Click to expand...

I think we all agree that for great distances you are better off with a DI. Improved noise resistance alone is sufficient reason.
 

Latest posts

Top Bottom
Back