Just to clarify: The Hi-Z buttons on both the UA-101 and the UA-25EX are on for this comparison.

The fact that you are hearing mouse polling could just be your particular computer, or possibly the USB power is not being isolated sufficiently.

Unfortunately I sent my Quad-Capture back so I cannot try this.

JazzSinger


I cannot record my MIM Fender Jazz nor my single-coil Epiphone Casino without some background buzzing on the track. Slow blues numbers are proving to be a particular problem.

My old Edirol UA-101 and Cakewalk UA-25EX work fine with both instruments, so it's not due to the different gain ranges.

Those segments do NOT indicate gain. They indicate input signal level. Those two segments you are seeing is the buzzing, so yours does it too. We are clearly seeing a general problem.

LOL, no I realised I'd put gain rather than input level.  You are of course correct.

Yes I'm confirming identical behaviour but I haven't found anything yet that doesn't record well with either Hi-Z engaged or out.

btw my Mobo is fine but like I say if you amplified any mobo enough you'd be able to hear something of the inner workings.

If I'm right at the very least the input sensitivity range is too wide, if you are right there's going to be a big product recall or firmware/driver update coming up for Roland.

I've brought it up with Roland UK so we'll see if they can shed some light.

But I honestly don't have anything to plug-into it that I can't get a good recording out of Hi-Z enabled or not.

I second that Jonbouy!

Roland UK tech support are investigating for me currently.

Meanwhile there are some related thoughts here.

http://forum.cakewalk.com/tm.aspx?m=2404147

Update: My technical support guy here at Roland UK has been very helpful so far, and he has now referred this to his colleagues in Japan.  So we are awaiting a response from them which may take a little while.

He stated his test unit did not produce 'anything out of the ordinary' in terms of noise.

That equates to two segments registered on the led gauge with output set at max, and mix knob set at 12 o'clock and sensitivity full up with Hi-Z engaged and the ground lift switch setting set to produce the least noise.

He was also interested to know whether I was using a laptop or tower.  So that may be worth mentioning if you are contributing to this thread.

Mines a tower as you can probably gather from my specs.

No tower.

6 different makes and ages of laptops, Acer 8951G the newest. Repeatable with battery power alone or with mains connected. Input shorted with a shorted jack plug. Sens at 3 o'clock (my Fender jazz gain requirement).

Here is a quick rundown of my hardware setup.

I have a tower PC.

I have one surge protector plugged into a nearby wall outlet.

Everything is plugged into that: PC, Display, Monitors, External USB HD Power supply, Desk lamp.

Scenario 1: Quad Capture with Hi-Z Off = No hum/buzz whatsoever. No segment lights on at full gain.

Scenario 2: Quad Capture with Hi-Z On = Steady hum/buzzing, Two segment lights on at full gain. Note: Ground lift setting makes no difference.

In contrast, I have a Steinberg CI1 USB interface and using the same usb cable on the same usb port, both Hi-Z and Mic/Line mode sound like Scenario 1.

And here is the explanation from Roland and it is rather a simple one.

The reason for the increased noise compared to the UA101/25EX etc. is the impedance level.
      UA-101 and 25EX = 470kΩ
      Quad = 680kΩ

Which is basically what I was trying to say in post #9.

I try and use Low Impedance and Balanced inputs anyway to get the best recording possible and if I was trying to record a guitar that wasn't giving good results direct into the unit with Hi-Z enabled or not I'd more likely be recording it by micing the cab or from a line-out from the amp anyway.

Given the amount of units out there and the lack of any concern on the web (this so far being the only discussion about it I can find) for the Octa or Quad being particularly problematic in this specific area I'd say it is pretty close to if not a complete non-issue.

As I said it hasn't caused me any problems in practical use and I can't see it ever doing so.

Hey Jonbouy, Thanks for the update.
 
Can I gather that to mean the 60 cycle hum/buzz when in Hi-Z mode is from the internals of the Quad Capture because of the impedance and not from some kind of external source that I'd need to hunt down? I wish I understood this stuff better but I assume that's what the folks at Roland are getting at.. If so that's fine, As long as it rules out other issues.

Anyway.. Back to work. :)