Hypex Ncore

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A pot as the feedback network around in inverting op amp circuit is the cleanest analogue volume control you can make. One I made with a 9mm car audio pot sounds completely transparent and with a decent op amp distortion is unmeasurable at all useful gain settings. For high input impedance, add an input buffer. For balanced input, make that an instrumentation amp. Actually the input circuit is more difficult to get right (as in "inaudible and unmeasurable") than the volume control section.

God ! :confused::( Now I am afraid to buy your amps ! I can hear what kind of resistor I use both from the inverting input as well as the feedback resistor !
 
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Another question on this topic, if I may :
When the pot resistance approches zero, the gain does the same (which is the desired effect to mute the output). Doesn't one run into stability problems for the op amp ?

No, the opamp's inverting input ties to the output, so the result is an extremely stable circuit. The most dangerous opamp environment is one or both inputs open. Edit: this assumes voltage inputs, not a BJT opamp.
 
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Bruno, when you're done with that preamp article and you find yourself with too much free time :)p), I believe that an "I/V stage for 9018 based DACs" article would be very welcome.
I'm sure Jan will be happy to publish it and many of us will be more than happy to build it. Just saying, no rush, we can all wait say... a couple of months. :D
 
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they even created a logo that was almost identical to Nipper.

I was so discussed at PF I called RCA Victor over their stupid logo and reported it to their TM lawyer...

Careful there boyo. That was Bruno, a very wonderful dog who lived with my friend Ian.

It was supposed to be a local rag for the group of guys that hung out and played with audio here in town. A little homage to RCA was fun. It kinda got hijacked by a more ambitious editor.

I was the first technical editor of PF. I am no longer (and haven't been for a long time) affiliated with the organization.

By the way, you are *supposed* to discuss about this stuff, that's the point. (preferably with a pint in hand)



Alan
 
My order status is pending. Hope I'll get from this batch.
I payed by bank transfer and I never got a confirmation that Hypex had received the payment. That something that would have been nice to receive.

If you see that order status is ' pending' then we have received the payment by bank, Paypal or credit card.

Indeed production is working hard to get the modules ready for shipping....
 
pinout on the NC400.

There are four color wires.
Red
Black
Yellow
Silver

Well, the actual pins on the J9 connector are more important than the colors, but on the cables I have the colors are:

Pin 1 - INH - Red
Pin 2 - INC - Clear
Pin 3 - nAMPON - Black
Pin 4 - Ground - Yellow

As for pinout on the XLR is it:
Pin 2 Red
Chassis Black
Yellow?
Silver?
INH and INC (Red and Clear) go to the signals pins on the XLR - pins 2 and 3. Yellow is ground, and goes to pin 1/chassis. The black one, nAMPON, is for turning the amp on by connecting it to ground - so no need to bring it to the XLR at all.
 
Well, the actual pins on the J9 connector are more important than the colors, but on the cables I have the colors are:

Pin 1 - INH - Red
Pin 2 - INC - Clear
Pin 3 - nAMPON - Black
Pin 4 - Ground - Yellow

INH and INC (Red and Clear) go to the signals pins on the XLR - pins 2 and 3. Yellow is ground, and goes to pin 1/chassis. The black one, nAMPON, is for turning the amp on by connecting it to ground - so no need to bring it to the XLR at all.

Thanks. So the black wire goes to chassis ground then?
 
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