Nobsound Voltage and Current meter

[pollock0424]

Has anyone tried this Voltage and Current meter?

Voltage / Current Meter for Amplifier / Speaker RMS Power Detector VU Tester | eBay

CT3 voltage and current tester: with 1 group of banana jack input and output, connected between amplifier and speaker to test the output voltage, current and power(P=UI), to detect that the actual output power of the amplifier is up to standard and the output of left and right channel is...

www.ebay.com

 

[solderdude]

Not very likely, nor recommendable.
As this is an all passive device and measures current it must have a series resistance drastically reducing the DF so you can only use it with test signals and not keep it in the signal path just to see needles swinging.
Also the range in which it can measure is not that interesting... max.3 A which is hitting the max at 12V in 4ohm = 36W.

 

[ppataki]

Not very likely, nor recommendable.
As this is an all passive device and measures current it must have a series resistance drastically reducing the DF so you can only use it with test signals and not keep it in the signal path just to see needles swinging.
Also the range in which it can measure is not that interesting... max.3 A which is hitting the max at 12V in 4ohm = 36W.

Can you recommend an alternative maybe? (not to see the needle swinging but to actually measure)
Thank you

 

[solderdude]

You would need a current clamp to measure current without impacting the circuit (speaker + amplifier) and that clamp needs an associated amplifier, also you would need a peak detection and possibly combine current and voltage and create a display if you want actual information.
This will be quite expensive.

This device is just 'swinging' needles for low powered devices.
You can buy it if needles that swing is all you want. It won't give you peak readings which is what music is really all about. As it is not known how much averaging there is (the needles seem to swing slowly in the video) it won't give you any real info.
Only with some steady state signals it might give some sensible readings.

 

[XTRProf]

Btw, what's your purpose of needing the meters? I always believe in keeping things as simple as possible (KISS) for the best sound. Anything we add to the audio chain will DEFINITELY give you more noise and distortion. Whether big or small is still noise and distortion, right? As we know, LED meters in the Hifi equipments do noise pollute. Best is able to switch them off.

 

[solderdude]

As we know, LED meters in the Hifi equipments do noise pollute.

How do we know ?

 

[staticV3]

As we know, LED meters in the Hifi equipments do noise pollute. Best is able to switch them off.

Hypex actually use LEDs in their HPR12 Voltage regulator to build supremely low noise and distortion Amplifiers: https://www.diyclassd.com/products/diy-components/accessories/hpr12

It's safe to say that LEDs polluting audio is an audiophile myth.

 

[fpitas]

It's safe to say that LEDs polluting audio is an audiophile myth.

Where do these old chestnuts start?

 

[pollock0424]

I don't mind loosing a bit of SINAD for visual indulgence and I like to listen with my eyes open in a dimly lit environment. I think that audio experience and auditory cues can be reinforced with some subtle visual cues. Anyhooo....


I tried this and it is a total waste of time and money and stay from it. It was introducing audible humming/buzzing.

Douk Audio VU56 PRO MIC & Analog Sound Level Meter, LED Music Spectrum Visualizer, Audio Splitter with Remote Control https://a.co/d/7jVOmYd

 

[fpitas]

I don't mind loosing a bit of SINAD for visual indulgence and I like to listen with my eyes open in a dimly lit environment. I think that audio experience and auditory cues can be reinforced with some subtle visual cues. Anyhooo....


I tried this and it is a total waste of time and money and stay from it. It was introducing audible humming/buzzing.

Douk Audio VU56 PRO MIC & Analog Sound Level Meter, LED Music Spectrum Visualizer, Audio Splitter with Remote Control https://a.co/d/7jVOmYd

I have no doubt a marginal design will introduce noise. Blaming the LEDs is like blaming the dog, though.

 

[fpitas]

LED's generate shot noise and thermal noise. It's not an outlandish claim to make.
In the old days some audio equipment with colorful LED bar indicators had a defeat switch to turn them off. This was not just for the visual irritation they might cause.
There are more than a few books written on this topic.

I design LEDs into low noise circuitry all the time. It's not that hard.

 

[fpitas]

No, it's not hard. So, you should well know things with PN junctions can certainly generate noise.

And, in devices like I think we're referring to here, had multiple LED's with most of them in a transitioning state all the time. (A colorful light show, to be sure.)
Somebody who's been around awhile might have memories of equipment like that. It could be XTRProf is one of those folks.

Yes, they make Johnson noise and shot noise. None of that is the buzzing and humming the audiophiles complain about. I have to suspect cheap noisy switchers to supply the LEDs.

 

[XTRProf]

Somebody who's been around awhile might have memories of equipment like that. It could be XTRProf is one of those folks.

Sorry for the late reply as I was not here. Yes, you are right. I am from that era and routinely switching off equipment LEDs, not because of the display distraction, during those days. Why should those equipment designers put a LED display switch to off it if they had not found sometime. Like I had written, no matter how big or small, it's still distortion and noise and the lesser the merrier at least for audio purpose.