XLR/Jack stick generator?

[altec9440]

Hello,

I look for a sine generator with calibrated output level for use in live/PA systems. Something simple like a stick that you plug on XLR or Jack in order to check level with enough accurancy.

any field feedback on a commercial product or a link to a diy design are welcome.

Thanks.

 

[simon7000]

https://www.parts-express.com/Gold-Line-GL1K-Microphone-Level-Input-Tester-390-860?quantity=1

Apparently not currently in production.

So try Shure A15TG

 

[1audio]

Look for the Minirator and minilizer https://www.nti-audio.com/en/products. They do pop up used and are probably ideal for your application. https://www.ebay.com/sch/i.html?_fr...nti+audio&_sacat=181939&_odkw=nti&_osacat=293

 

[turk 182]

i was always partial to the Whirlwind Qbox myself.
https://www.whirlwindusa.com/products/ac-power-testers-qbox

 

[altec9440]

thanks friends.

I'll take a simple one that I could borrow and a more complete one that I'll keep in my toolbox.

I'm surprised with all the brains on this forum, no one's ever made one !

 

[1audio]

They exist for testing TV coax but not really useful for your applications. I think you could make a simple oscillator and imbed it into an XLR connector. Maybe a second matching connector with a meter? A good manageable DIY project. . .?

 

[altec9440]

I think you could make a simple oscillator and imbed it into an XLR connector.

A Phase-shift oscillator can do the job but having a calibrated and constant output level seems harder to achieve. How to get a level standard providing 7.775mV

​

 

[turk 182]

it might help if we knew why three digit resolution at millivolt level was needed for a live audio application....most of the time your lucky if you get a useful soundcheck in terms of getting levels let alone the kind of precision your looking for.

 

[altec9440]

Okay, here's the story. I had level problems on microphone tracks of a mixer.
I first checked the input sensitivity setting on each channel. Then I swapped the cables and then the microphones, I ended up swapping the inputs. to find that the defect affected 3 tracks., The mixer was new.
That's why I'm looking for a generator whose output doesn't vary with battery wear.

 

[Potentiallyincorrect]

Not quite what you want, but…
Get some ear pods, tear out the speaker part. In its place put a resistive divider to get the output level you want and connect to an XLR Jack. Then use phone with a signal generator app.

 

[turk 182]

so you have three bad channels on a new mixer?

i would be hard pressed do discern anything but gross differences in level between mic inputs...and without greater details like whether or not the inputs where fed all the same mics and checked with similar sources.

no chance pads are engaged? or that eq setting's are different?

 

[altec9440]

I had the same assomption and checked pads . I even did a factory reset...
It's really a hardware defect. A repair is needed.

Shure A15TG seems interesting but I haven't found the specs yet on website.

 

[turk 182]

Specifications​

Output Frequency​

700 Hz +20%, when terminated with 150 Ω

Output Level​

-41.5 +4.5 dBV (8.4 mV typical) when terminated with 150 Ω

Total Harmonic Distortion​

5% typical for any output termination greater than or equal to 150 Ω

Output Impedance​

15 Ω

Battery Type​

1.5 V (such as A76 alkaline, 357 silver oxide or 675 zinc-air hearing aid battery)

Temperature Range​

Operating Temperature

-12°C to 50°C (10°F to 130°F)

-29°C to 74°C (-20°F to 165°F)

Housing​

Steel with gray enamel finish

Dimensions​

19 mm (.75in.)diameter; 141 mm (5 17/32 in.) long

hope that helps...i'm still partial to the Q box's 440 hz output.

what mixer are you having this trouble with?

 

[altec9440]

thanks

-41.5 +4.5 dBV (8.4 mV typical) when terminated with 150 Ω

Does the level vary depending on the impedance or is it adjustable?

i'm still partial to the Q box's 440 hz output.

Whirlwind products ?

what mixer are you having this trouble with?

Soundcraft Ui24r.

 

[turk 182]

yikes ok that's a problem.

yes Whirlwind.

adjustable as in pad??

 

[altec9440]

I found a schematic on an ad. Simple design topology with phase shift oscillator and transistor to lower output impedance. no stabilisation. it's not worth the price