Massdrop Cavalli Tube Hybrid Amp

Also received the MCTH late last week along with the Focal Clear loaner. Have been listening almost non-stop. Like @crazychile. I'm finding it hard avoid listening to entire albums. Complete system setup here. You might say I am re-energized to recreational listening with this setup.

 

Somebody sell me that CTH, you really don't need it.

 

Got mine yesterday. It's reaaally good. Stayed up listening way past bedtime.

 

Can anyone recommend a LPS that would be suitable for the MCTH? I currently have one that has dual 12V / 3A outputs, but the MCTH needs 28V / 1.25A if we're basing it upon the supplied wall wart?

 

Acopian makes some of the best LPS, L28MC200 found here:
https://www.acopian.com/store/single-l-goldbox-infinity-t.aspx
A bit DIY, requires wiring AC and DC sides. Don't forget the fuse.

 

@atomicbob What about your noise nuke? Would you consider it to be worthwhile for the MCTH?

 

Did anyone else notice theirs sounding kind of odd right out of the box, or did it sound fine?

First hour of playing with mine it didn't sound good- kind of a 'metallic' sheen to it, and painful treble. Left it running overnight and the next day it sounds good.

Two layers of light dimming film certainly improved the aesthetics as mine is mounted at eye level. That little pinhole-sized LED is bright.

 

Thanks, it's reassuring to read that I'm not simply imagining things.

 

Thanks, Bob! Do you plan to take the LPS route yourself with the MCTH?

 

What are the specs of the switching supply?

 

No. Not all SMPS are stable with a reactive load. Unfortunately the MCTH SMPS is one of those unstable with reactive load. SMPS works fine into MCTH.

After I put some time in listening to stock MCTH and have a chance to measure performance, I may drag out the Keysight U8001A and have a listen / look at the differences with an LPS.

 

SMPS is marked 28Vdc 1.25A.
Measured power consumption by MCTH:
28.05Vdc
0.34A during initial startup (LED red)
0.36A during run time (LED white)
However I did not measure inrush current, which might be substantially higher.

 

I thought mine sounded fine out of the box, but I only listened for about 1 hr then let it play unattended for the rest of the day. It may have been a little better the next day when I really started to spend time with it.

About 15+ years ago I had an amp that used EL34 tubes. The EH tubes I tried sounded horrible for the first 10 hours or so. Then I ended up liking them better than any of the other commonly found EL34s that I tried. So I think your comment about Russian tube burn in is correct. Maybe I just got lucky with the one I got with the MCTH.

 

Just a note about the MCTH power supplies

Alex has developed his psu skills quite remarkably since the early days. The 28V at the front end is used in a number of was to produce a true split rail supply for the output buffer, the 6.3V DC supply for the tube heaters and a high voltage supply that self adjusts to 100V B+ for the tube. This is one of the reasons that it sounds as good as it does with the 6922/6DJ8/ECC88 tubes. Each of these individual supplies is in some way regulated with additional noise suppression. Obviously a very noisy smps on the front end will not be good but given the additional internal filtering and design, the changes with a linear supply would be expected to be small.

..dB

 

here's what Tube Depot says about tube burn in.

 

Due to life circumstances and a busy work schedule my CTH has been sitting in it's box since the mailman dropped it off over a week ago. I finally got around to plugging it in tonight with the intention of listening a few minutes to some favorite tracks and here I still sit nearly 2 hours later.... This thing is good, folks!

Replacing a Vali 2 for me, which has been a great amp, but the CTH already seems to be giving a more spacious, more energetic, more engaging sound. So far my listening tonight has been with my ZMF Eikon's and I am definitely impressed by what I am hearing.

 

How would you compare it to the Crimson that you have?

 

I hope that is the problem in my case, as I hear little static storms every few minutes that die out after 10-20 seconds... and they are not volume dependent, as they don't diminish in character when I turn the music volume all the way down. It is not white background noise as some have described, but more defined static bursts that fizzle out. I read on Massdrop of one other person having this problem with their CTH, but anyone here experiencing this?

I have a Torpedo III hybrid tube headphone amp that never exhibited this behavior during tube burn-in. I have only gone about two thirds through the recommended 100 hour burn-in period, so time will tell I guess.