Bias Amp w/External Cabinet: Amplifier "Hiss"
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I'm wondering if anyone is experiencing a pronounced his from the original Bias grid 600 watt amp? This happens when plugged into an external cab without any guitar being plugged in and doesn't appear to be "amp" driven. It's just a pronounced hiss when the amp is turned on.
I was told to do a factory reset but that doesn't seem to have any effect on i.
Anyone else experiencing this?
- rob c
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... hiss like this? https://youtu.be/H3NKdA8UiwA
That's the Bias rack of our bassist. -
@rob-cheplicki
I have the head and don't have any issues.Can you answer these questions for me -
Is there a guitar cable plugged in without a guitar attached to it?
If you switch to a clean amp model is there a hiss?
If you lower your volume knob is there a hiss?
If you turn the "utility" Noise Gate knob up is there a hiss? -
@danbieranowski The hiss appears even when no cable is connected. It is independent from the chosen amp, the master volume and from the noise-gate. Unfortunately there is a unforced temporary loss of volume too so it might be a hardware problem with the output stage. We will contact the support for further investigations and RMA.
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Unfortunately there is a unforced temporary loss of volume too so it might be a hardware problem with the output stage. We will contact the support for further investigations and RMA.
Does anyone have an idea how to investigate the theoretical offered output/volume of the BIAS Head/Rack?
We recognise a completely different output-volume on a 212/8 Ohm guitar cab to a 410/8 Ohm bass cab. Though, it could be a matter of the add of compression on the 212, too :/
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Sounded like normal power amp signal noise from amplification.
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@sascha-ballweg Are you referring to the "master volume" of the amp model, or the actual "output" knob on the amp?
What if you turn the output volume down or up, does the hiss increase/decrease?
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@danbieranowski the actual "output" knob on the amp. If we turn up the output volume the hiss keeps unchanged.
But over all it is not recognizable in a rehearsal environment and the Yamaha DXR12 activ-monitor of our singer does a similar hiss in standby. So it might be okay, but it is a bit anoying when playing at home at a low volume. -
@sascha-ballweg That's very interesting. The only thing I can think of is either just standard amp noise, or possibly "dirty power"... the circuit it is plugged into is introducing noise.
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@danbieranowski we had tried different circuits in different locations so it should be standard amp noise (similar to our Yamaha DXR12). But thank you anyway!
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Sorry for the delayed response, I never received notice that my question had been answered.
It is a pronounced and for me, unacceptably loud hiss.
From danbieranowski:
Can you answer these questions for me -
Is there a guitar cable plugged in without a guitar attached to it?- No
If you switch to a clean amp model is there a hiss?
- Yes. Switching to any amp from the amp makes absolutely no difference.
If you lower your volume knob is there a hiss?
- Yes
If you turn the "utility" Noise Gate knob up is there a hiss?
- Yes No amount of knob turning for the gate, volumes, switches, etc effects the hiss one way or the other.
I have a Mesa 1x12 Thiele and Bogner 2x12 guitar cabs as well as a 2x10 Avatar bass cab and it makes no difference what type of cab I plug it into.
I did get a response from Bias Tech Support to do a hard reset of the amp and no change whatsoever. It's extremely frustrating.
Rob
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And Sascha yes, it is exactly like your amp is demonstrating - except mine is the head version not the rack.
Rob
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@rob-cheplicki have you tried using the noise gate feature?(custom-knob on the device) I'd suggest you to set it to around 7~8'oclock position to dissipate the hiss.
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@felix The noise gate feature works well for the models, its the hiss that is produced when the amp is turned on that I find problematic. It has nothing to do with the models.
I've had a Boss Katana 50 amp modeler and when you turn that on it's completely silent, so this is obviously a power amp issue.
- rob
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@rob-cheplicki It's odd because it seems unit-specific. My head does not produce any hiss like that. I'm curious if there is a unit issue, or a dirty power issue.
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@danbieranowski Was there a fix for the hiss? I'm having the same hiss noise. I've used many other processors and never had anything but dead silence unless I was using high gain amp models. Tried the reset and and im using a furman rack mout power conditioner so its not noise from power.
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@danyaglowski I had the hiss issue and after some back and forth via the support desk it was deemed my Bias head needed a replacement part. Mine's currently still in for repair so I'm not sure what exactly the issue is but if you email/ contact PG support they'll be able to see whether you need a replacement/ repair to be conducted. They were really good with helping me so I wouldn't worry too much
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Hi all, I got my BIAS Rack a couple of days ago and I am facing the same issues as described previously. Does anyone got a solution for this?
I am wondering, why Positive Grid is releasing products with this high noise during operation and there is no standardized solution offered by PG? -
Hello everyone,
I am also facing same issue with my bias amp 600W. I have come to the conclusion that this might be typical amp noise and maybe with a really good noise gate pedal this can be resolved.
I am thinking of buying ISP Decimator II G string pedal but before I do I wanted to ask if anyone had already tried that out. I would appreciate the information :)
Last, here is something I tried and that made me realise that the noise gate of the amp not only works but works big time even though it doesn't eliminate the noise of the amp.So try the following:
1)Connect the head/rack through USB and open the app
2)With Noise Gate on the app turned on, put all knobs besides the Output knob at 10, Tube stages 5 with full distortion, Power Amp to the Max and Custom to the Max as well and with the clean channel selected. Remember, OUTPUT knob is in zero/off position and N.G. on the app is ON.
3)Turn on the output knob at any level. You hear the same little noise.
4)Now, turn DOWN the OUTPUT knob and turn OFF the NOISE GATE on the app.
5)SLOWLY! turn on the output knob. You will see that you won't be able to turn it more than level 2 because the amount of noise that will be coming out will be immerse.
With the above being said I am curious in hearing the opinion from people who don't hear any noise at all and from people who have the same issue. Maybe all of us have the same noise and some are being simply bothered whereas others might don't even care :)
And I am also curious in hearing how the Decimator II works if anyone tried that already!Thank you all for in advance . Keep healthy and safe during these crazy corona days we are going through.
Cheers!!
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I have the same "Hiss" noise coming from the loudspeakers of my 4x12" Marshall cab. I have the Positive Grid Bias Rack Amp unit. I just came up from my home studio, I have been trying to fix the noise problem for 4 hours straight, but with no luck, I might add.
My conclusion was that there is something wrong with the speaker out on my Bias Rack Amplifier. I have the latest firmware, I installed all the software earlier today. I have reset the Bias Rack Amp twice to factory reset, first from the software on my Macbook laptop and one time to factory hard reset from the rack itself using the "Hold" - "f1" + "f2" then wireless push button.
Nothing seem to work. The noise floor sound just like if you have a high gain amp with the gain set on full, or with a stomp box overdrive or distortion pedal set to full and not using any form of noise gate. The noise from the Bias Rack is constant and not changing to anything I do with the knobs on the unit or with anything I do in the software. It's a constant noise floor hiss.
I tried to disconnect the loudspeaker to test it with the headphones. Everything is fine on the headphones. There i no noise at all.
I then reconnected the speaker cab, the noise hiss was back. I then tried to use a high gain amp, in the Bias amp2 software, and slowly turn up every volume control on the Bias rack. I had disconnected the noise gate function on the Bias Rack first. I had to turn every volume almost to full on everything just to get the noise from the highly overdriven amp to overpower the constant noise/hiss from the noise floor of the Bias Rack Amplifier.
This last example should give you some understanding of the severity of this problem. For me to be using an amp with this much noise in my studio, is out of the question. It is unacceptable. I can see no solution for this problem other than to return the unit to get it fixed at the factory. It will probably take months until I can get to use it. This is not good, I had so high hopes for this after I bought the "Spark amp" from Positive Grid. It seem that I am not alone with this exact problem. I can not understand how this amount of noise slip by the quality controls at the factory that make these.
Roald Julin, Norway