The Waxwing Thread

[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.

 

[Brian Hall]

It appears that the record grading option gets confused when playing the Drif album by Heilung. During a section with a lot of various sound effects, chanting, yelling and drums only the Waxwing grading was going crazy, changing from C+ to D- and sometimes F from A+ during a more "normal" music section. This is a brand new record. First play. I did clean the record before putting it on the turntable.

Just to make sure, I turned off the "Magic" option and replayed that section to listen for scratches or other damage and I didn't hear anything bad.

Not a big deal. Just thought it was interesting that the algorithm could get confused like that.

 

[Snoopy]

It’s interesting to read a post from someone saying a C+ record suddenly sounds great with Magic. Just shows different tolerances with noise between people. I think my worst record is a C+ but most are somewhere around a A.

But even with magic on I notice „issues“ that bother me here and there. That might be noise between tracks or clicks and pops that are a very mild pop. That is with Headphones. With loudspeakers I usually have no problems with noise.

Mono and Super Mono is a great feature for bad stereo recordings or real mono recordings. I love those 2

Overall the waxwing is a great phono stage and I would definitely buy it again.

Also would love to try the waxwing as Line-in for a tube Phono stage.

 

[Brian Hall]

It’s interesting to read a post from someone saying a C+ record suddenly sounds great with Magic. Just shows different tolerances with noise between people. I think my worst record is a C+ but most are somewhere around a A.

But even with magic on I notice „issues“ that bother me here and there. That might be noise between tracks or clicks and pops that are a very mild pop. That is with Headphones. With loudspeakers I usually have no problems with noise.

Mono and Super Mono is a great feature for bad stereo recordings or real mono recordings. I love those 2

Overall the waxwing is a great phono stage and I would definitely buy it again.

Also would love to try the waxwing as Line-in for a tube Phono stage.View attachment 386643

If you were responding to my post, I wasn't saying the record was a C+ or worse. I was saying that the combination of sounds on Heilung's album confused the grading algorithm used by the Waxwing.

I do have some really old records I inherited from the 50s and 60s that have a lot of problems. One old Sinatra record that is rated F quality (scratches, lots of pops and crackles) sounds almost perfect with the Magic function so yes, that does work well.

 

[Thomas_A]

If you were responding to my post, I wasn't saying the record was a C+ or worse. I was saying that the combination of sounds on Heilung's album confused the grading algorithm used by the Waxwing.

I do have some really old records I inherited from the 50s and 60s that have a lot of problems. One old Sinatra record that is rated F quality (scratches, lots of pops and crackles) sounds almost perfect with the Magic function so yes, that does work well.

There are other records that can fool the algoritms. The ABC ” Lexicon of love”-album fools the RTClickrepair and it is audible. It finds the peaks of beats and reduces the dynamics.

 

[antcollinet]

There are other records that can fool the algoritms. The ABC ” Lexicon of love”-album fools the RTClickrepair and it is audible. It finds the peaks of beats and reduces the dynamics.

It appears that the record grading option gets confused when playing the Drif album by Heilung.

You should both message Shannon Parks with this information. He may be able to use those songs to improve the algorithms.

 

[Brian Hall]

You should both message Shannon Parks with this information. He may be able to use those songs to improve the algorithms.

I emailed them about it and named the album where I saw it happening.

 

[somebodyelse]

It appears that the record grading option gets confused when playing the Drif album by Heilung. During a section with a lot of various sound effects, chanting, yelling and drums only the Waxwing grading was going crazy, changing from C+ to D- and sometimes F from A+ during a more "normal" music section. This is a brand new record. First play. I did clean the record before putting it on the turntable.

Just to make sure, I turned off the "Magic" option and replayed that section to listen for scratches or other damage and I didn't hear anything bad.

Not a big deal. Just thought it was interesting that the algorithm could get confused like that.

I take it Magic isn't adding any audible artifacts in that section? Magic and Grade are meant to use the same detection algorithm.