Double Bass A short question about the EDB 1

[franzose]

There is one thing I don't get with this preamp, about the phantom power function.

The purpose of the 2 channels is to mix 2 different sources, for example a piezzo with a microfone.

Microfones generaly need to get powered, while piezzos are often passive.

On the EDB 1, when you engage the phantom power function, it will feed both channels (18 V for the microfone side and 12 V limited to 10 mA for the other channel).

But the users manual says, that when mixing 2 sources, if one doesn't need to get powered you have to cut the phantom power off.

So as far as I understand, you can't combine an active mic with a passive piezzo and power the mic through the EDB1, which would be surprising considering the fact that this combination is pretty common, and would take one of the great advantage of this preamp away.

Or is there something I didn't understand (the users manual is in english and I'm french/german) ?

Thanks for your advices.

 

[bassist14]

hallo franzose

couldn´t you find an answer here in the headway thread? :
http://www.talkbass.com/forum/showthread.php?t=574997

you could also ask the german distributor :
http://www.talkbass.com/forum/showthread.php?t=574997

 

[Ric Vice]

Microphones generally need to get powered, while piezzos are often passive.

On the EDB 1, when you engage the phantom power function, it will feed both channels (18 V for the microphone side and 12 V limited to 10 mA for the other channel). Thanks for your advice.

My interpretation of the manual says Headway only supplies phantom power to Channel One if a Stereo plug with three connections is inserted into the 1/4 Jack which would mean you had your mic and pickup both connected to the Stereo Jack on the Channel one input. At least that's my reading of the manual. Contact John at Headway for clarification.

Ric

 

[franzose]

@ bassist14 : I couldn't find any info in the related thread, which is more about the sound of the EDB 1

@ Ric : the users manual says passive piezzo should be connected to ch.1, which has a high impendance knob to make there signal more usable.
(Invalid Link Removed : p12 and 14)

If I want to add a mic, I'll have to connect it to the ch.2 XLR.

Now, to feed the mic connected to ch. 2 XLR, I have to engage phantom power. This will result in feeding both channels (1 & 2), which is a problem because the passive piezzo connected to ch. 1 does not need to get powered.

Or do I need to connect the piezzo to the ch.2 jack while the mic is connected to the ch. 2 XLR ? But then I can't use the 2 gain knobs of each channel to mix both sounds , and I'm not sure the piezzo signal will be usable considering the fact that the ch. 2 jack has no high impedance knob.

I'm confused, and I'd like to be sure I can use a passive piezzo and an active mic feed through the EDB 1, before I buy it.

 

[flatback]

@ bassist14 : I couldn't find any info in the related thread, which is more about the sound of the EDB 1

@ Ric : the users manual says passive piezzo should be connected to ch.1, which has a high impendance knob to make there signal more usable.
(Invalid Link Removed : p12 and 14)

If I want to add a mic, I'll have to connect it to the ch.2 XLR.

Now, to feed the mic connected to ch. 2 XLR, I have to engage phantom power. This will result in feeding both channels (1 & 2), which is a problem because the passive piezzo connected to ch. 1 does not need to get powered.

Or do I need to connect the piezzo to the ch.2 jack while the mic is connected to the ch. 2 XLR ? But then I can't use the 2 gain knobs of each channel to mix both sounds , and I'm not sure the piezzo signal will be usable considering the fact that the ch. 2 jack has no high impedance knob.

I'm confused, and I'd like to be sure I can use a passive piezzo and an active mic feed through the EDB 1, before I buy it.

what you are asking is in fact the main functio of the box. Of course it does what you are asking and that is how I use it daily : Passive pickup i line 1 ad mic with phatom in line 2.

 

[Ric Vice]

@ Ric : the users manual says passive piezzo should be connected to ch.1, which has a high impendance knob to make there signal more usable.

You are correct, this is the way I do it and it works just fine

If I want to add a mic, I'll have to connect it to the ch.2 XLR.

Once again you are correct, this is the way I do it and it works just fine

Now, to feed the mic connected to ch. 2 XLR, I have to engage phantom power. This will result in feeding both channels (1 & 2), which is a problem because the passive piezzo connected to ch. 1 does not need to get powered.

My understanding is that as long as your pickup uses a standard 1/4" mono phone plug there is no current going to the peizo. This would only be an issue if your pickup had a 1/4" Stereo phone plug.

Or do I need to connect the piezzo to the ch.2 jack while the mic is connected to the ch. 2 XLR ? But then I can't use the 2 gain knobs of each channel to mix both sounds , and I'm not sure the piezzo signal will be usable considering the fact that the ch. 2 jack has no high impedance knob.

My understanding is that you cannot plug two devices into channel 2.

I'm confused, and I'd like to be sure I can use a passive piezzo and an active mic feed through the EDB 1, before I buy it.

YOU SHOULD email HEADWAY THEY ARE VERY GOOD AT RESPONDING TO QUESTIONS. Invalid Link Removed

 

[franzose]

Ric, thanks a lot for your explanations. I didn't get the difference between mono and stereo jack. If I use a mono jack for the ch.1 there is no power transmetted to the pick up, because the power is only transmitted to the ring of a stereo jack when using one.

Order placed !