JRC

Yes they're used extensively in the Behringer gear. I recall a few high-end audio kits from the electronics hobbyist magazines (RIAA & headphone pre-amps etec) using the 4558's when they were first released and so assumed they were quality parts.

The question I have is how Behringer manages to design their gear to have so much hi-frequency hiss?

I have one of these:

and at more than 75% rotation of either the input or master channel volume controls the hiss is very obtrusive.

Ok the Behringers are cheap so I guess you get what you pay for...

--
Cheers, 
Chris.

Call your favorite stock broker. Note: JRC:US Ticker Change JRC:US has changed to a new ticker symbol

I see that ad says: "EURORACK PRO RX1602 Professional Multi-Purpose

16-Input Ultra-Low Noise Line Mixer". If there is _ANY_ audible hiss, it CANNOT possibly be "Ultra-Low Noise".

One would be paying for lies and false advertising.

That reminds me of the time I did an emergency repair on a Behringer mixer for a local studio a long time ago. The mic input IC - a 4558 - on one channel was dead but I didn't have any low-noise opamp in stock, so I replaced the dead one with a TL072, warning the operators that they'll probably see a higher hiss level. A week later, I was surprised to hear that the channel was noticeably quieter than before.

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** They don't.

I doubt you have any idea nor the means to evaluate audio band noise.

** Meaningless bollocks.

..... Phil

I don't notice that the couple pieces of Behringer gear I own add any more hiss to sources than any other piece of equipment. Plug in quiet sources and you get a quiet output, plug in noisy sources and you get a noisy output, as one would expect.

Is he "testing" the noise performance with a source connected, or not And what is the source? If he's just cranking the gain on a channel without a low impedance mic or line source connected to the preamp then the current noise from the input stage won't be shorted out, the source impedance jumps up to the differential impedance of the input resistors and you get hiss.

Like um duh that's true of every mixer there is.