Double Bass active or passive input?

[bassplayer48]

Hi guys i have realist pup through an iamp 800 and NL-210 i was rehearsing last night and had it plugged into the passive input but i noticed it was clipping, so changed it too the active and it seemed fine, i was running the the input vol at about half.

Is it normal to use the active or passive input?

 

[bolo]

Just looking at the numbers / specs, I would think you would want to use the passive input w/ your Realist. Piezo pickups are sensitive to input impedance, and generally speaking like to "see" values from 1M ohm to 10M ohms. The passive input on the iAMP is 1M ohm (good), but the active input is 10K ohms (not so good).

It should have produced less volume with the active input and the knobs set the same, which in general people would probably not want.

But ... how it sounds to you is ultimately the most important measurement.

Could you try the passive input, with the Input Level knob set lower but the Main Output knob set higher? That would cut back on the signal hitting the preamp section, and presumably reduce the likelihood of clipping.

 

[bassplayer48]

Just looking at the numbers / specs, I would think you would want to use the passive input w/ your Realist. Piezo pickups are sensitive to input impedance, and generally speaking like to "see" values from 1M ohm to 10M ohms. The passive input on the iAMP is 1M ohm (good), but the active input is 10K ohms (not so good).

It should have produced less volume with the active input and the knobs set the same, which in general people would probably not want.

But ... how it sounds to you is ultimately the most important measurement.

Could you try the passive input, with the Input Level knob set lower but the Main Output knob set higher? That would cut back on the signal hitting the preamp section, and presumably reduce the likelihood of clipping.

Thanks thats great info i'll try running the input vol lower and see how it goes, there's miles of headroom so its not an overall volume issue, i just wasn't sure which input suited it best.

That setup gets a great sound too, i was using a GK BL600 with the ea cab and it just way too boomy, but with the iamp i just cut the low frequency 40hz and it sounds very transparent.

 

[bolo]

Yeah I think the passive input on the iAMP is definitely the way to go with piezo pickups or passive electric basses.

I have also found that you can play some with the relative positions of the preamp and power amp dials to get subtle differences in tone. For example, if you turn down the Input dial and turn up the Output dial and try to match volume, you may find that using less preamp and more power amp gives you a cleaner sound, sometimes a little "harder" sound. Turn the knobs the opposite way, and at the same relative volume, hitting the preamp harder introduces a little "wooliness" or thickness to the sound. That's a broad generalization. But it seems to hold up with my iAMP 200, Focus 2R, and my D-TAR Solstice. I hear this effect even when the overload light on the iAMP's preamp is not lighting up. Pushing the preamp section harder gives a thicker, more dense and powerful sound. OTOH, keeping the preamp dial down and letting the power amp do the bulk of the work seems to produce a cleaner, truer, more transparent sound for me w/ my upright. They both sound good, more a matter of personal preference, fitting in to the musical setting you're in, etc.

Anyway, you might also be interested in Invalid Link Removed. It tells you how to set the EQ knobs on your BL600 to get closer to a "flat" EQ.

 

[bassplayer48]

Yeah I think the passive input on the iAMP is definitely the way to go with piezo pickups or passive electric basses.

I have also found that you can play some with the relative positions of the preamp and power amp dials to get subtle differences in tone. For example, if you turn down the Input dial and turn up the Output dial and try to match volume, you may find that using less preamp and more power amp gives you a cleaner sound, sometimes a little "harder" sound. Turn the knobs the opposite way, and at the same relative volume, hitting the preamp harder introduces a little "wooliness" or thickness to the sound. That's a broad generalization. But it seems to hold up with my iAMP 200, Focus 2R, and my D-TAR Solstice. I hear this effect even when the overload light on the iAMP's preamp is not lighting up. Pushing the preamp section harder gives a thicker, more dense and powerful sound. OTOH, keeping the preamp dial down and letting the power amp do the bulk of the work seems to produce a cleaner, truer, more transparent sound for me w/ my upright. They both sound good, more a matter of personal preference, fitting in to the musical setting you're in, etc.

Anyway, you might also be interested in Invalid Link Removed. It tells you how to set the EQ knobs on your BL600 to get closer to a "flat" EQ.

Thanks again thats some great info, i'll definately give it a try, i have also read fdecks very imformative review on the BL600, however i think the realist, does not perhaps suit my bass, which is quite dark sounding, so the control you have with the iamp seems to balance it out nicely, although for the money the BL600 is a killer head.