• 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.

Poweramp sensitivity

Hypocrite

Hypocrite

Jun 3, 2009
1,240
1,882
Aalborg , Denmark
www.facebook.com
#1
Looking for advice on how to get more juice out of my rig.
I'm currently playing an active bass into a DG B7KU - > 500W poweramp - > 800W 8x10 at 4Ohms, stereo. I find myself having to dime the volume on both pedal and amp just to hear myself between our drummer and guitarist, something easily achieved when going through the power section of my 300W 4x10.
We play techdeath in a fairly small room, but we watch our levels and aren't too loud, considering. I have always-on distortion for some extra definition and clank, and I don't have my mids scooped or lows boosted enough to shake the walls.

So, what gives? Is it as simple as changing the input sensitivity from 1.4V to 0.7V or 26dB, or is there some other aspect I'm missing?

Cheers

Edit: I'm feeding the amp an unbalanced signal, surely that can't account for the low volume, can it?
 
#2
Hypocrite said:
Is it as simple as changing the input sensitivity from 1.4V to 0.7V
Click to expand...
It certainly could be. If that is an easy option, just try it.

Hypocrite said:
Edit: I'm feeding the amp an unbalanced signal, surely that can't account for the low volume, can it?
Click to expand...
It may not be helping the matter. The amp is expecting a balanced signal and providing an unbalanced signal means your input level is even that much lower. That being said, many, many devices with "balanced" outputs have impedance balanced outputs which helps with the noise characteristics of a balanced connection. But, they don't actually have audio signals with opposite polarity on the two lines. Which means that when the two lines are summed at the input of a device, the audio signal is still the same level as if you ran an unbalanced line between the two.

In other words...
Truly balanced output to balanced input:
a - (-a) = a + a = 2a

Impedance balanced output to balanced input:
a - (0) = a

- John
 
Last edited:
  • Like
Reactions: agedhorse and BasturdBlaster
#4
JKos said:
It certainly could be. If that is an easy option, just try it.
Click to expand...
Thanks, that is the easier thing for me to test next time.
JKos said:
It certainly doesn't help. The amp is expecting a balanced signal and providing an unbalanced signal means your input level is even that much lower.
- John
Click to expand...
I thought that might be the issue, but again, I get much lower volumes than running the same signal into a lesser rig. In any case I can try with an XLR cable, see if that makes a huge difference.
 
#13
I agree with @agedhorse, that you need to know the output level and max output level of the pedal to set your amp input sensitivity correctly. I will also add that unless you are using the Direct Out for something else, with your setup I would use it to feed the power amp.
 
#15
PraiseBassing said:
I agree with @agedhorse, that you need to know the output level and max output level of the pedal to set your amp input sensitivity correctly. I will also add that unless you are using the Direct Out for something else, with your setup I would use it to feed the power amp.
Click to expand...
I don't think the direct out has sufficient level to drive a power amp.
 
  • Like
Reactions: Matthew_84 and BasturdBlaster
#16
You have checked to make sure that you don't have the input pad on right?
And you have a fresh battery in your bass right?
And, have you tried using other cords both to the pedal and to the amp?

Lots of simple thing that can trip you up.

Also, if you haven't cleaned your amp in more than a year, you need to get a can of DeOxit5 (red-label can) and clean all the 1/4" plugs both input and output that your amp has (unplug your amp first of course). Real easy for a jack, especially an unused jack, to get some corrosion on it and if the signal path of the amp goes across that jack, you can get volume drop, static, pops, etc. Just spray some cleaner on a 1/4" plug and move it in and out of each jack about 10-15 times. Do that on an annual basis to keep your amp in good shape.
 
#17
Tiny, tiny amount of DeOxit. Don't spray it into the amp.

Just had an amp in the shop yesterday that was ruined by a way to liberal application of such cleaner (don't know what it was), amp was so slimy and nasty inside, all the pots ruined, spray got into the high voltage parts of the switchmode power supply... cost of repair exceeded the value of the amp. Would have been a $75 repair otherwise.
 
#19
Hypocrite said:
I'm currently playing an active bass into a DG B7KU - > 500W poweramp - > 800W 8x10 at 4Ohms, stereo.

Edit: I'm feeding the amp an unbalanced signal, surely that can't account for the low volume, can it?
Click to expand...

Change the battery in your active bass if it is not fresh.

810 at 4 ohms stereo ? Just wondering how stereo? This is a Gallien-Krueger 810 RBX isn’t it?

Setting the input sensitivity on your power amp to 0.7v means that is the RMS voltage that is required to drive the amplifier to full power. It can help if your preamp signal is low.

I would try the balanced out on the pre into the power amp.

It is important that the power supply of the pedal is a full 9VDC well regulated, otherwise the pre can hum.
 
  • Like
Reactions: Squittolo and Bob Lee (QSC)
#20
agedhorse said:
Tiny, tiny amount of DeOxit. Don't spray it into the amp.

Just had an amp in the shop yesterday that was ruined by a way to liberal application of such cleaner (don't know what it was), amp was so slimy and nasty inside, all the pots ruined, spray got into the high voltage parts of the switchmode power supply... cost of repair exceeded the value of the amp. Would have been a $75 repair otherwise.
Click to expand...

They probably didn't use a paper towel to block off the area, and sprayed it like ether into a carb.
Also decided to clean everything they could see, bc I've had a couple people tell me that's their line of thinking cleaning instruments & amps.
 

Latest posts

Top Bottom
Back