The Waxwing Thread

[Bob from Florida]

In the Waxwing app, it has the Gain option on the second line. The clipping indicator (triangle) appears between the lock icon and the "Gain" text. When I tapped the triangle it popped up a box that said clipping was detected. Lowering the gain setting made the clipping indicator go away.

Well, I just learned another feature! If you look at the peak ADC levels, what do you see with your current cartridge / gain combination?

 

[Brian Hall]

Well, I just learned another feature! If you look at the peak ADC levels, what do you see with your current cartridge / gain combination?

 

[Brian Hall]

I increased the gain to 39db to make it show the clipping indicator. The clipping was not caused by a bad record. The grading for the record I had playing was A.

 

[Bob from Florida]

I increased the gain to 39db to make it show the clipping indicator. The clipping was not caused by a bad record. The grading for the record I had playing was A.

I keep my peaks around -10 db on the ADC input and have never seen the clipping indicator. I noticed the DAC output is 0 db on yours at the 39 db gain setting. I wonder if that is the source of the clip.

 

[AaronJ]

What about the Air +2 setting you have? Might this be clipping any high frequency content? Ortofon 2M Blue is a very hot cart specced for 5.5mV output which is pretty high for running 39db of gain so I’m not surprised if you’re getting some clipping on peaks.

I don’t have a waxwing yet but I’ve messed around in the app a bit. The little tooltip shows max DAC output is 2.1V and max ADC input is 1.05V. What could be causing your input to be only 7.5db down from 1.05V? That’s a transient of 425mV. And 425mV incidentally is 38db of gain for 5.5mV so makes me wonder where in the chain the gain is added. Seems like it may actually be occurring before ADC?

 

[Bob from Florida]

What about the Air +2 setting you have? Might this be clipping any high frequency content? Ortofon 2M Blue is a very hot cart specced for 5.5mV output which is pretty high for running 39db of gain so I’m not surprised if you’re getting some clipping on peaks.

I don’t have a waxwing yet but I’ve messed around in the app a bit. The little tooltip shows max DAC output is 2.1V and max ADC input is 1.05V. What could be causing your input to be only 7.5db down from 1.05V? That’s a transient of 425mV. And 425mV incidentally is 38db of gain for 5.5mV so makes me wonder where in the chain the gain is added. Seems like it may actually be occurring before ADC?

If you change gain - it will be reflected in average and peak levels reported at the ADC input. There may be additional gain in the digital domain - Shannon could answer that. It safe to assume all RIAA and equalizer adjustments are in digital space. All I do is pick a "loud" record and leave 10 db of headroom in peak input levels. I have not seen the clip triangle yet doing it this way. I am using optical out to a Schiit Modius - balanced output, so I get an extra 6 db of gain there. But that gain is not related to the Waxwing.

 

[AaronJ]

If you change gain - it will be reflected in average and peak levels reported at the ADC input. There may be additional gain in the digital domain - Shannon could answer that. It safe to assume all RIAA and equalizer adjustments are in digital space. All I do is pick a "loud" record and leave 10 db of headroom in peak input levels. I have not seen the clip triangle yet doing it this way. I am using optical out to a Schiit Modius - balanced output, so I get an extra 6 db of gain there. But that gain is not related to the Waxwing.

If you don't clip the ADC you shouldn't clip the DAC right? Looks like the DAC adds another 3db to get to 2.1V max output. Could messing with the EQ (Air +2) cause the clipping issues Brian is seeing on the DAC side?

 

[Bob from Florida]

If you don't clip the ADC you shouldn't clip the DAC right? Looks like the DAC adds another 3db to get to 2.1V max output. Could messing with the EQ (Air +2) cause the clipping issues Brian is seeing on the DAC side?

His screenshot showed 0 db output on the DAC. Digital ain't Analog, so once you hit 0 db it would seem you are "done". Nice to know "why", but if backing the gain off a bit solves the clipping problem - that's the solution.

 

[AaronJ]

His screenshot showed 0 db output on the DAC. Digital ain't Analog, so once you hit 0 db it would seem you are "done". Nice to know "why", but if backing the gain off a bit solves the clipping problem - that's the solution.

What would cause the DAC output to clip?

 

[Bob from Florida]

What would cause the DAC output to clip?

The peak input to the ADC is most likely culprit. Think of it this way. The input waveform exceeds the level that results in all bits being a "1". The max out is about 2 volts in this case. The width of the clip is dependent on time spent above max input. The ADC max level might be above the digital word - all bits on - that describes max DAC output. I do not have sufficient experience with ADC & DAC chips to be technically confident in the explanation. Leaving headroom to avoid this is easy - reduce gain and/or use a lower output cartridge.

 

[Brian Hall]

The Waxwing gain section has a calculator. I entered the 5.5 figure for the Ortofon blue. It said the gain should be set to 36db. I still get the clipping indicator on some records at that level. Changing the gain to 34db seems to be about right. Changing the "Air" and "Warmth" didn't seem to affect the clipping. Maybe my Ortofon blue is "hotter" than average.

I'm using the optical out of the Waxwing going into the Eversolo DMP-A6 so not using the DAC section of the Waxwing.

 

[Bob from Florida]

The Waxwing gain section has a calculator. I entered the 5.5 figure for the Ortofon blue. It said the gain should be set to 36db. I still get the clipping indicator on some records at that level. Changing the gain to 34db seems to be about right. Changing the "Air" and "Warmth" didn't seem to affect the clipping. Maybe my Ortofon blue is "hotter" than average.

I'm using the optical out of the Waxwing going into the Eversolo DMP-A6 so not using the DAC section of the Waxwing.

For reference - when I put the AT VM95SH on, I set the gain to 38 db. That cartridge is 3.5 mv.
The calculator suggests 40 db while I picked 38 db based on peak input level.

 

[mike70]

At vm95sh have 2: advantages compared with ortofon blue:
- "standard" output (ortofon is really hot)
- shibata stylus (no sibilance or micro distortion with much better tracking)

 

[Soniclife]

The Waxwing gain section has a calculator. I entered the 5.5 figure for the Ortofon blue. It said the gain should be set to 36db. I still get the clipping indicator on some records at that level.

FWIW I believe manufacturer cartridge output levels are as believable as speaker sensitivity levels. It's good the waxwing has a clipping log so you can fine tune, it seems a really great product.

 

[Soniclife]

FWIW I believe manufacturer cartridge output levels are as believable as speaker sensitivity levels. It's good the waxwing has a clipping log so you can fine tune, it seems a really great product.

As a follow up I just stumbled across the following measurements.

Ortofon 2M Bronze 2M Black

From Hi-Fi World - November 2007 issue M Factor Ortofon's brand new 2M Bronze and Black moving magnet cartridges sound

www.hi-fiworld.co.uk

Output of both is unusually high at around 8mV at 5cms/sec rms.

Different cart but way above the quoted output.

 

[Balle Clorin]

Well, I just learned another feature! If you look at the peak ADC levels, what do you see with your current cartridge / gain combination?

AT-OC9MLii MC Step-up 20dB & 41db peaks at -3db on Clapton Unplugged «Running on faith» . Puffin , but I believe the Waxwing design is the same internally. With this setting I do NOT get clipping, on any records. Sounds fantastic by the way…

 

[ABE43]

As a follow up I just stumbled across the following measurements.

Ortofon 2M Bronze 2M Black

From Hi-Fi World - November 2007 issue M Factor Ortofon's brand new 2M Bronze and Black moving magnet cartridges sound

www.hi-fiworld.co.uk

Different cart but way above the quoted output.

Thanks a lot for the link, this confirms my suspicions with the 2M Black cartridge I own. The VU meters on my preamp are pegged when reading the signal coming from my phono preamp, I've lowered the gain on my phono preamp to its lowest setting and there's still no difference. I've been hemming and hawing about buying the Waxwing mainly for it's ability to regulate gain in a better way than most other phono preamps I've seen and this link confirms it's not likely some error on my part.

 

[antcollinet]

I've lowered the gain on my phono preamp to its lowest setting and there's still no difference.

That doesn't sound right - what preamp do you currently have. The 7.9V measured output is only 4dB hot - a reduction in gain of 4dB or more should counter this.

 

[Bob from Florida]

That doesn't sound right - what preamp do you currently have. The 7.9V measured output is only 4dB hot - a reduction in gain of 4dB or more should counter this.

40 db gain - typical MM Phono preamps is a voltage gain of 100 - times 7.9 mv equals 790 mv. A preamp should have no problem with this input level under normal conditions. Abnormal would be sending that signal directly to a "phono" input on the preamp that has a phono stage for real instead of just another line stage. This can and does happen at times stemming from owner confusion.

 

[antcollinet]

40 db gain - typical MM Phono preamps is a voltage gain of 100 - times 7.9 mv equals 790 mv. A preamp should have no problem with this input level under normal conditions. Abnormal would be sending that signal directly to a "phono" input on the preamp that has a phono stage for real instead of just another line stage. This can and does happen at times stemming from owner confusion.

Good point. @ABE43, if you can let us know which phono pre, and which preamp you have, and how they are connected, we might be able to offer some ideas.