Massdrop Cavalli Tube Hybrid Amp

Appreciate the correction; I misread the 0.5% static/2% dynamic voltage output as linear. Post edited.

 

Two red WIMA caps should be on signal path?

 

yes - these are the coupling caps and the only caps directly in the signal path.

..dB

 

dBel84, Thank you!!!

 

I've had mine on and burning in for about a day now, listening with ZMF Atticus and Classic. I will eventually get around to listening with the HD800 but for now the synergy with the Atticus is so superb I just want to soak that up. I don't want to write too much since it's still new, but at first listen I was surprised at the clarity and space this thing is capable of. The unit is a lot more attractive than I was expecting, too. It'll look great next to the Classics in my office. I might get one other tube to roll in, something warm and round and tubey. I bet a good LPS would do this thing really right.

 

I've had mine for almost 2 weeks running and running it using Sylvania 6922 tube with power being fed by Acopian LPS Thanks to @atomicbob and @rtaylor76 for helping out with the Acopian.
Synergy with both Massdrop HD 6XX and Hifiman HE400i( acquired brand new on eBay for very cheap, just to play with) is very very pleasing.

 

I was just looking at the MCTH thread on HeadCase...it seems the output is inverted on these. I didn't see that on bob's measurements.

Don't mean to scare you audio nervosa types on absolute polarity, but I thought I should mention.

 

My measurements don't typically include absolute polarity and given so many media players or some digital devices in the path allow for polarity reversal it shouldn't be a big deal to fix if it bothers someone.

 

There is also no telling if this can be reversed with the XLR balanced output (because it it not really balanced output).

So really the only way to fix it is with reverse input cables or using DSP beforehand. But like Bob said, it should not big deal or should not change much, just wanted to make sure that info is out there.

Also, Kevin Gilmore was kind of dogging the design, but he does that.

 

Do you know of any adapters at the 1'4" or rca inputs? Probably more important, will I hear a difference?

 

I knew audio nervosa would set in.

It's highly debatable if it makes a difference. I don't want to open that can of worms. You have to decide youself.

You can't do it at the 1/4" adapter because L and R share a common ground. You can do it at the driver level. Although, like I said earlier, easiest way is with polarity inversion RCA cables. Although some players have polarity flip plug-ins/DSP.

 

Kevin Gilmore disparaging an amp's design is nearly as certain as death itself. He's a certified blowhard and has a vested interest in all amps that he doesn't make being bad.

 

Gah, I have just become aware of another one of those words that has a completely different meaning depending on which side of the Atlantic you're more familiar with. "Dogging" means a completely different and very NSFW thing in the UK.

 

I'd rather have it set once and forget with a MCTH only cable. Swapping the signal and shield connection at the amp input is the way, eh? Or does the shield suck as a a signal wire?

 

Swapping signal and shield on unbalanced connections is asking for trouble. Use JRiver MC and setup a polarity invert in the DSP chain. JRiver MC is available on all platforms and is still $50 US for single platform license. Much cheaper than ruining equipment.

 

If I only just used Jriver. I watch movies, Hake a Roku app on the tv , have a streamer using LMS, and have other headphone amps and powered speakers.
Limiting the correction to just the MCTH is preferable and if there is no good way to do it, then doing nothing would probably be best,

 

It'd also be worth a second, actually-neutral source, could confirm that there is indeed a polarity issue on the MCTH. Using the ADI-2 DAC to change the polarity on both channels, I'm pretty darn sure it sounds worse. The soundstage seems to collapse in on itself. Yes, I'm testing with the 1/4" output that he claims inverts phase.

In his own words:

He traced and came up with an approximate schematic himself, which is what he used to conclude that there is a problem. Put no trust in this buffoon.

And song #2 comes on... can't actually tell which sounds better. Shrug. Maybe Tom Petty had inverted phase in the recording? F if I know.

In any case, f that dude. He has no respect for other members of the audio industry and has a following of zealots who parrot his malicious intent across the Internet.

 

Absolute polarity is one of those audio nervosa things that can mess with your mind. I hadn't tried flipping the absolute polarity when listening to the MCTH yet. The posts this evening got me to try the MCTH with different absolute polarity.

One of my audio listening tests is Daft Punk's RAM. I own it in both CD and 24/88.2 from Qobuz. One of the things I notice with the high-res version is that there is more of a pillow or envelope around the sound, and that pillow can at times pulse with the beat of the music. That pillow thing happens with the high-res, but not so much with the CD-res. A main factor in that pillowing seems to be absolute phase, but there is also more going on.

I tried the MCTH and flipped the phase using JRiver and listened to RAM in high-res. And that pillowing was there. Turned off the absolute polarity flipping in JRiver and the pillowing was less, and in some cases during several songs was almost sucked out. I think the MCTH likely is inverting the phase based on subjective listening. Either that or I'm drunk. I've had 4 high gravity IPAs this evening while enjoying several hours of music listening.

I'll also add here that my Liquid Fire is an audio pillow envelope making machine. Play Random Access Memories in high-res on the Liquid Fire and wow! So much pillowing compared to the CD version. The MCTH (now that I've tried flipping the absolute polarity during playback) and Liquid Carbon give hints to that sort of pillowing and envelope. But the Liquid Fire is what delivers that experience.

I'm listening to the MCTH using a Modi Multibit fed by its internal USB. My Fire and Glass are fed by an OG Gungnir Multibit with an Eitr.

 

One thing you could do is prove to yourself whether you hear difference with change in polarity. foobar2000 won't cost you anything and has ability to change polarity in the DSP chain. Take a few select tracks you know well and listen with both polarities. If you don't hear a difference, problem solved. Remove fb2k and continue enjoying with that experiment behind you and knowledge gained.

If you do hear a difference, then ask yourself if you want to take on reversing polarity with the MCTH. Personally I would opt for terminating headphones with 4-pole XLR connector and using a Neutrik NC4MX to NC4FX and Canare L-4E6S and reverse polarity at the NC4FX. This only works if there are four individual wires from the headphone transducers, such as HD6x0, HD800, Focal Clear, etc. Headphones with only three wires, Left Right and Shield Common, won't be able to work with this method.

 

I'll have to try this at home as I have JRiver and my DSJr dac has phase reversal (I assume digital reversal but maybe using internal hardware).