Loaner: MD x EC ZDT Jr.

That is JRiver Media Center.

 

ZDT Jr. #1 should be in @JoshMorr 's hands soon. Impressions posted. Guys don't forget that you are obligated to post something about the loaner you auditioned...

 

ZDTJr #2 on it’s way to @captkirk. Impressions to follow once I get some job stuff out of the way. Just a quick note. The #2 loaner only has the GE JAN 5654W’s in the front position. My impressions are definitely different than @ButtUglyJeff ’s. I’m thinking this amp is more tube dependent than others, such as the Valhalla 2.

 

@JoshMorr. @ButtUglyJeff seems to say in his review the #1 loaner only has stock tubes and the #2 unit has the GE JAN 5654W’s in the front, but not the stock tubes, we are comparing apples to oranges. Might I suggest taking @Gaspasser up on his offer of sending a pair of the GE’s to you so we have both units with the same front tubes? Marv’s comments on the stock front tubes seem to suggest they aren’t ideal. And the differences in the opinions on the #1 vs. #2 unit seem to bear this out. I’d be glad to send a pair, but I’m in NorCal and @Gaspasser is in D.C. so he can get them there faster.

 

If Gaspasser doesnt mind - Im all for it, would like to hear what you Best Coasters are hearing to compare.

 

We should find a pair of the stock front tubes for the #2 unit as well. Yes, the burned up, drowned out Coast would love to have you hear it with these tubes. BTW, love your lobsters !

Joking aside, hope you guys are thawing out. Looked really nasty.

 

I was wondering about this very possibility. There still may be the issue of personal preference but the two units appear to have consistent disparity in the impressions. I've only heard the unit with GE JAN 5654Ws and bought several pairs for my ZDT Jr. when it ships.

 

It’s the only variable that isn’t consistent between the two units. I also bought a couple of pairs of the GE’s for my unit.

 

I want to first say thanks for allowing contributors into the loaner tour. This is the first loaner I’ve been able to participate in, and I hope I join other loaners to expand my frame of reference.

Atomic Bob graciously hosted a mini-meet where he had measuring equipment, graphs, and the ZDT Jr setup with a HD650, RME ADI2-Pro, and his Immersion visualization system.

Bob did a lot of work measuring both the ZDT Jr. and ADI2 pro, and If you look at the posted measurements, there is a sweet spot with the ZDT Jr where feeding an approximately -20db signal showed a significant improvement in distortion. Bob’s graphs of the ADI2 also showed improvements in distortion when the output was lowered.

I think the synergy of the ADI2-Pro (NOS)/ZDT Jr/HD650/IVS is pretty incredible. All of the components are reasonable sized you can most likely fit this kick ass system on any desk. This particular unit had the GE tubes 5654 tubes.

I felt like this combination really exhibited the pleasant warmth of the amp. Detail was incredible, but not sharp. The background was very deep which I want to attribute to the IVS, but there was also contrasting warmth to the background which may have been the barest hint of hum.

When I took it home an aspect of the ZDT I liked was while it is comparatively forward and close in; It still had separation, and nuance even when music got busier.

The chain I have at home is the Soekris DAC1541 (NOS)->ZDT Jr->AZ PMx2. ZDT Jr was kept at 0db gain, and I did my best by ear to volume match with the Sonett 2 (I don’t think I was successful). I had the Soekris 1541 set to -30db to -37db between the two amps depending on whether I used the SE or balanced and the type of music I played.

I think the ZDT is capable of powering high efficiency planar headphones, but I don’t think it was the best match with the PMx2. The PMx2 is the most forward headphone I’ve owned, and the forwardness compounds with the ZDT Jr.

Overall, I enjoyed my extended time with the amp. I might get one if Massdrop does another run. People should grab the GE tubes since they are still at reasonable price for now.

I may edit later with more content. I am really late with the impressions so I posted what I had now.

 

While I don't disagree that better tubes might help. The amp is still the amp. $1500 silver cables don't make an HD650 an HD800 in resolution.

I just want the future owners of this little gem to band together to figure out best tube compliments, and save everyone time, money and drawer space...

edit - these might be considered pre-production units. Just a thought as "final tuning" might not be set in stone at this point...

 

Or maybe get #1 to @Hands to compare to his. Those two might differ the most. Whichever is easier...

 

Totally agree. We should do are best to see if we are looking at preference or two amps that might not be sounding the same. At this point “just tubes” may not be the issue. Vansen has a good idea.

 

I would like to measure loaner #1 with stock tubes, at the end of the tour, for comparison with loaner #2 with GE JAN 5654W tubes.

 

I'm sorry if it's already been discussed before, but for benefit of the first timers, is the GE JAN 5654W tube you're referring to the same as
http://www.thetubestore.com/Tubes/1000-to-5999-Types/JAN-GE-5654W
or
https://www.amazon.com/Riverstone-Audio-Fully-Tested-Amplifier-Electron/dp/B01BFJDTW0

From the pics these two look different. Apologies if these indeed are the same.

 

They're the same.

 

I second the motion. The scientific method is the only way to resolve this. Plus it might give good feedback to Massdrop to make sure there is good quality control when they start production. In other words I want mine to sound like loaner #2, not like #2! Thanks @atomicbob for volunteering once again.

 

A pair of GE JAN 5654W is in the mail today to @JoshMorr and should stay part of the east coast loaner package. I have no way of testing them, but if there are any problems, I have another pair.

 

ZDT Jr #2 received from @Ringingears.