Noise gate between amp and speakers?

[Clint 55]

Re: Noise gate between amp and speakers?

Is there some reason you can't do both?

[Hank-]

Re: Noise gate between amp and speakers?

Like I said, the source of the noise is my ac power bank that I just got. It's a charge able battery pack with a regular ac outlet so I can run anything I want off of, including amps. The problem is that it doesn't have a real earth ground, only a chassis ground. So powered by the power bank, all of my amps are excessively noisy except for the 1/2 watt nano. The nano plugged into the power bank isn't any noisier than my twin plugged into the wall though, so no big deal. I ended up with a way better portable rig than a pos battery powered amp. Nano into 10" Mesa closed back. I still think it would be a cool innovation since plenty of amps are noisy.

So what this battery pack ya got with ya would fall under UPS(uninterrupted power supply). Well there are various kinds of these, you will get hum with a basic one.What you really need to get rid of the obnoxious hum is a Pure Sine Wave UPS. Even if you had a noise gate designed to be used between a amp & speaker unit, it would not mask the hum when you played, it would be at a very audible level, unless the power supply is clean.

[Chistopher]

Re: Noise gate between amp and speakers?

Is there some reason you can't do both?

If you removed all of your sources of noise, why would you need to mask it at the end?

[zizyphus]

Re: Noise gate between amp and speakers?

If you removed all of your sources of noise, why would you need to mask it at the end?

I agree - try putting it in the loop. This may make having two of them redundant.

That’s where I’ve had the most success when I’ve used gates (admittedly, that’s in part because I often use amp distortion rather than pedals)

[Clint 55]

Re: Noise gate between amp and speakers?

If you removed all of your sources of noise, why would you need to mask it at the end?

Ok monkey boy. Read my posts. For the 3rd time... THE BATTERY PACK IS THE SOURCE OF THE NOISE. All my **** is dead quiet. Including my single coils. The only things in any of my rigs that are noisy is my twin which buzzes on its own. Could be cool to fix that. And also any of my amps plugged into the battery pack except for the lowest powered of them, the 1/2 wat nano. It's no big dead tho because I don't need to use a giant amp for a mobile rig. If I want to use a giant amp I can just find some place to plug it in.

So what this battery pack ya got with ya would fall under UPS(uninterrupted power supply). Well there are various kinds of these, you will get hum with a basic one.What you really need to get rid of the obnoxious hum is a Pure Sine Wave UPS. Even if you had a noise gate designed to be used between a amp & speaker unit, it would not mask the hum when you played, it would be at a very audible level, unless the power supply is clean.

It's a pure sine wave power bank. I'm pretty sure it buzzes because there's no ground going into the earth. It has to rely on a chassis ground.

[zizyphus]

Re: Noise gate between amp and speakers?

Ok monkey boy. Read my posts. For the 3rd time... THE BATTERY PACK IS THE SOURCE OF THE NOISE. All my **** is dead quiet. Including my single coils. The only things in any of my rigs that are noisy is my twin which buzzes on its own. Could be cool to fix that. And also any of my amps plugged into the battery pack except for the lowest powered of them, the 1/2 wat nano. It's no big dead tho because I don't need to use a giant amp for a mobile rig. If I want to use a giant amp I can just find some place to plug it in.

Ya, my bad I also didn't read all the later posts where you went on to say the battery pack was the source.

I wish I had a solution. I took there push-push 10db gain boost out of my les paul for this exact reason, and stopped using some of the switchable onboard preamps I used to play with.

Is there a smart person out there who can help?

[Clint 55]

Re: Noise gate between amp and speakers?

Thx, it's no big deal. The nano plugged into the battery pack buzzes less than my twin plugged into the wall. I just brought it up because I thought it was an interesting topic. If you had the noise in ur signal chain minimized so it at least wouldn't be taking over ur sound while playing and then be able to gate it after the amp, thereby silencing absolutely everything while ur not playing...

[Hank-]

Re: Noise gate between amp and speakers?

Ok monkey boy. Read my posts. For the 3rd time... THE BATTERY PACK IS THE SOURCE OF THE NOISE. All my **** is dead quiet. Including my single coils. The only things in any of my rigs that are noisy is my twin which buzzes on its own. Could be cool to fix that. And also any of my amps plugged into the battery pack except for the lowest powered of them, the 1/2 wat nano. It's no big dead tho because I don't need to use a giant amp for a mobile rig. If I want to use a giant amp I can just find some place to plug it in.



It's a pure sine wave power bank. I'm pretty sure it buzzes because there's no ground going into the earth. It has to rely on a chassis ground.

For a quick test you could take a 3 pin plug & wire up the third ground pin only, connect that to the mains outlet, the other end you could loop around any of the screws of the amp chassis & tighten it up, it will ground the amp even while using the power bank, I'm not sure how much or if any hum it will take out though. If the power bank is indeed generating a clean AC converted output, then it should work the same or better than connected to mains supply.

Got a link to this power bank you have with you?

[Larioso]

Re: Noise gate between amp and speakers?

If it is as you suspected - lacking ground - you can just find a source for earth/ground like radiator in a room or similar.
Even the full grid 115VAC or 230VAC(europe) rely on actually sticking a pole into the ground. You are not send a ground cable back to a power plant, I mean.

The problem as already described by many - is that if tube amp, the very end from amp is a transformer winding expecting a certain load. If 8 ohm you have one winding in output transformer for that - if 16 ohm you have another winding. And tubes are really sensitive not getting a proper load. Tubes feed the primary winding of transformer and speaker on secondary winding is the load.

Common to both power amps, solid state or tube - is that the load need to take the power as the speaker does.
So question arise - which electronics would be transparent as speaker load and yet work taking away hiss or hum at a certain level alternating current like sound.

If you have 50W r.m.s into 8 ohm that is 20V AC and 6.25 A current coming that way over to speaker. This must be unmodified not to alter sound. So you would need some fast switching device, like a tyristor or something connecting a circuit like a filter at high rate that can withstand 50W and/or ensure that load 8 ohm is maintained.

This is easy to do at signal level, just drop signal to ground when below a threshold, but with output circuit rather advanced to maintain all properties that a speaker is.

I remember from my youth getting to a concert - like Deep Purple or Zeppelin - and anticipation for concert to start. You just heard the noise from power amps on Marshall stacks waiting to burst into sound later.

If that is what you get - see it as adding to the listening experience, maybe.

Having had really bad power grid 230 VAC here a many years I looked for solution to stabilize this, since some tube preamp pedals just shut down when a carpenter at this farm started a drilling machine or something simple as that. Really bad. You immediately got below 170V or so.

I found a double converter that made dead current from mains, and an inverter creating a nice 230 VAC 50 Hz again from that - really nice. But what I also found that is that specs on these are very different - some have restrictions on what kind of load they can take. Some clearly stated no electric motors etc. Usuall electronics were normally fine, since they usually have a transformer that do low voltages for inside units. Tube amps is a bit of different as I see it - since you often in real life take mains and just rectify as is as anod voltage for tubes since so high. 300-400V or so. No stabilizer or anything usually, straight from mains pretty much.

I watched a rig tour for Brian May and he used a frequency converter in the price range of $2000 that gave him exactly 234 VAC 50 Hz for his Vox AC30 amps, if he had 4 on stage, two regular use, and two spare ones if anything breaks down. So he got them sounding exactly the same wherever he went in the world on tour.

The one I found was $250 and worked fine for my 20W amps at least. No noise or anything. So the inverter part creating AC from DC battery would be the same issue - making AC from DC. Total 1000 VA(or W if to simplify). Entire studio worked fine on that. Amps, computers, synths etc.

So I think it's about how simple circuit you went for. I have seen plenty for 12V in cars making mains level AC etc to run a laptop or similar electronics and cost $50 or so and we can imagine how good they are.

If you just rectify mains out to anod voltage for tube amp - this noise would come through as is over to audio. Normally filtered for the purpose it's designed for. Any flutter on input AC is making it's way to audio.

But as I understand you found a different inverter package that works better.