Bassamp's DI output to mixer?

[pedge22]

Mga masters.. Ok lang ba na i-connect ang Bass Amp through its DI output to mixer's XLR input kahit naka switched-ON ang phantom power? Hindi ba makakasira ng bass amp yung 48V phantom power? 

[KitC]

If the DI is an active type, it can be use phantom power. Passive DI boxes should not be damaged by phantom power and neither should that power be sent to the bass.

[pedge22]

Thanks for reply Sir Kit. 
Im not using a separate DI box. Built-in po sa bass amp (Ashdown Mag 300H Evo2). Nagkaron po kc ng unwanted sound yung bass amp ko, sound like turning a scratchy potentiometer. Hanggang ngayon maingay parin kahit walang bass na nakaplug. 2 times ko lang nagamit sa gig, I just plugged it in a phantom powered mixer tapos ganon na sya. 

[KitC]

Exactly how did you plug the bass amp to the mixer? I'm assuming an XLR cable was used from the Ashdown's DI out to the mixer's mic in. If that output is buffered, it should have no problems with phantom power. Unfortunately, an internet search revealed nothing about the Ashdown DI spec.

[sikyo]

Exactly how did you plug the bass amp to the mixer? I'm assuming an XLR cable was used from the Ashdown's DI out to the mixer's mic in. If that output is buffered, it should have no problems with phantom power. Unfortunately, an internet search revealed nothing about the Ashdown DI spec.

@sir KitC

will it be good practice to use the built-in DI of some guitar (not bass) amps (e.g., Laney) directly connected to the XLR input of a mixer with 48v phantom power? will the effects of the amp register, or would the output be dry? i see amps being miked instead of the setup i just described and suspect that there's a difference in sound quality between the two, though i'm not sure. we want better volume control in our church with a simpler setup sana. my apologies to the thread-starter, medyo OT  thanks po




making sound matter 
"Wisdom is supreme; therefore get wisdom. Though it cost all you have, get understanding." - Proverbs 4:7 (NIV)

[KitC]

AFAIK, the DI out is usually tapped to the preamp output and the FX loop is part of the preamp circuit, so yes, any fx plugged into the loop should come out of the DI output (BAMF! help me here).

What will NOT come out is the sound of the amplifier circuitry and speaker combination, which is what you hear when you mic a cabinet. So when you are pushing that cab into overdrive, you won't be able to capture that from the DI output. OTOH, if you have the guitar passing through a distortion or overdrive pedal, then THAT will be heard through the DI out. (did I get that right, Jobet?)

[skyjammer]

Thanks for reply Sir Kit. 
Im not using a separate DI box. Built-in po sa bass amp (Ashdown Mag 300H Evo2). Nagkaron po kc ng unwanted sound yung bass amp ko, sound like turning a scratchy potentiometer. Hanggang ngayon maingay parin kahit walang bass na nakaplug. 2 times ko lang nagamit sa gig, I just plugged it in a phantom powered mixer tapos ganon na sya. 

i observed the same thing on one Marshall bass amp's built in DI. I remember mikep explained something about it I just forgot. So now I just use the amp's pre-amp out. works better on the mixer's stereo input (PLs though I just use the left channel which makes it mono).

[pedge22]

Exactly how did you plug the bass amp to the mixer? I'm assuming an XLR cable was used from the Ashdown's DI out to the mixer's mic in. If that output is buffered, it should have no problems with phantom power. Unfortunately, an internet search revealed nothing about the Ashdown DI spec.

Yes sir from bass amp's DI out to Mixer's XLR mic input.
Pag naka bypass ang equalizer nawawala yung ingay, so pre amp section ang nagkadiperensya. Anyways under warranty pa naman, tawag nalang ako sa TMS. Thanks ulet.  

[pedge22]

i observed the same thing on one Marshall bass amp's built in DI. I remember mikep explained something about it I just forgot. So now I just use the amp's pre-amp out. works better on the mixer's stereo input (PLs though I just use the left channel which makes it mono).

In my case, even the amp is unplugged to the mixer the irritating sound is still there. So i guess the pre amp is already damaged.

[KitC]

Try plugging to a different outlet.

[pedge22]

Try plugging to a different outlet.

Ginawa ko na yun sir ginamitan ko pa ng AVR tapos dinala ko pa sa ibang lugar baka kasi outlets namin sa bahay ang  nagbibigay ng static sound pero ganun parin. Thanks for the suggestions Sir   

[KitC]

Ginawa ko na yun sir ginamitan ko pa ng AVR

Don't use an AVR! Most AVRs now use switching mode rectification which is very noisy electrically. Aside from that, AVRs are notorious for incorrect power output aside from power sag during high load. Either go direct or use an old moving coil (servo) AVR.

Also check the power lines that the amp is getting power from. Electric motors from the ref are also very noisy aside from being power hogs, and even fluorescent lamps can induce noise into the power line via magnetic induction.

[sikyo]

AFAIK, the DI out is usually tapped to the preamp output and the FX loop is part of the preamp circuit, so yes, any fx plugged into the loop should come out of the DI output (BAMF! help me here).

What will NOT come out is the sound of the amplifier circuitry and speaker combination, which is what you hear when you mic a cabinet. So when you are pushing that cab into overdrive, you won't be able to capture that from the DI output. OTOH, if you have the guitar passing through a distortion or overdrive pedal, then THAT will be heard through the DI out. (did I get that right, Jobet?)

i tried housing the post-amp speaker-level signal using a Samson S-direct DI, as per the DI's manual using speaker wires as instructed, but the sound was less than satisfying, sounded thin to me. could it be speaker voicing? chain is Soundcraft EFX 12 to Crown power amp to Beta 3 U15 with AWG 12 speaker cables na po. BTW, the amp is a Zoom Fire 30 only, for lead. am trying to do without miking and gating the amp sana for simplicity and budget constraints kung pwede po. thanks again, mga sirs




making sound matter
“Wisdom is supreme; therefore get wisdom. Though it cost all you have, get understanding.” – Prov. 4:7 (NIV)

[KitC]

i tried housing the post-amp speaker-level signal using a Samson S-direct DI, as per the DI's manual using speaker wires as instructed,

Was phantom power on? Did the DI have a new battery?

[sikyo]

Was phantom power on? Did the DI have a new battery?

yes, sir Kit, 48v phantom power was on. as per the Samson S-direct DI's manual, the DI will automatically detect and use phantom power even if a 9v battery is installed so i've never bothered to put a 9v battery in it. that has always worked for keys and acoustic guitar with good results and also worked for the Zoom Fire 30 except it sounded better 'unhoused' than when it is patched to the PA. the reason we're housing the guitar ampli is for volume control relative to the house mix (malakas mag-volume yung guitarist, natatabunan po ang vocals)

[KitC]

as per the Samson S-direct DI's manual, the DI will automatically detect and use phantom power even if a 9v battery is installed so i've never bothered to put a 9v battery in it.

I'm reading the manual right now and there's a phantom/battery switch right beside the balanced output. I know the manual says that it switches automatically, but why not be sure?

I completely understand your pain when it comes to guitarists being louder.

[sikyo]

I'm reading the manual right now and there's a phantom/battery switch right beside the balanced output. I know the manual says that it switches automatically, but why not be sure?

I completely understand your pain when it comes to guitarists being louder.

i'm sure i engaged the speaker level switch on the DI with the post-guitar amp signal going to the input and the output link going to the guitar amp's transducer (the XLR out going to the board). volume levels were good, it's the quality that was a little off on our ears. no battery on the DI, the switch is unengaged (for phantom power setting), the ground lift switch is unengaged (no bearing there, sir, di po ba?) anyway, try ko na lang po uli mag-experiment, maybe i'm missing something somewhere... thanks po uli




making sound matter
“Wisdom is supreme; therefore get wisdom. Though it cost all you have, get understanding.” – Prov. 4:7 (NIV)

[densmodina]

Back to the original topic, I think the phantom power should have no effect on the bass amp.  Just as a phantom power does not affect a dynamic microphone, not unless the cable used from the mixer to the bass amp is shorted.