MHDT Labs R-2R NOS Tube DACs

It's more accurate to say that you can roll different versions of the same DAC chip. I believe all current production MHDT Dacs have socketed chips, so whichever chip the DAC is designed around you can easily replace with a better or different version of. It would be neat to have a circuit that one could roll completely different DAC chips. Maybe some jumpers and DIP switches could accomplish this.

 

The Pagoda probably doesn't offer simple swaps since it's SMD (unless something has changed in the Pagoda design recently, which is entirely possible).

 

Updated my Atlantis -> Atlantis+ conversion gif to include the new Atlantis+.

Differences between the previous Atlantis+

• Both BNC and RCA now have the Murata transformer (was just on the RCA input)
• Red PIO caps instead of Silver, which significantly increases the visual color palette of the output capacitors
• Black chassis for major sonic improvements?!!?!?
• 1 less cap because it's based on the current Atlantis PCB which removed a cap... no idea why but it's gone.

http://www.basshead.club/wp-content/uploads/2016/02/atlantis_comparison.gif

WTF is the Atlantis+? It's an MHDT Labs Atlantis with a bunch of mods (in order of audible change).

• Tube is a NOS Russian 6N26P (really improves extension)
• Output capacitors are Russian K40Y9 1uF/200V (paper in oil)
• Main power caps are ELNA SILMIC 2200uF/35V instead of Nichicon Fine Gold 3300uF/35V
• All 100uf Nichicon MUSE caps replaced with Elna Silmic II 100uf/35V
• RCA/BNC digital input now use Murata DA101C transformer instead of cap input
• Digital input cap: 0.01uf WIMA FKC instead of SMD 0.01uf
• Audio grade fuse: 1A 250V slow blow
• Larger toroidal transformer (honestly, there is no audible benefit to this unless you have a balanced MHDT DAC... stock is already overkill):
  • 53VA
  • I/P:0-115V 0-115V 50/60Hz
  • O/P:15V-0-15V 0.7A
  • 8V-0-8V 2.0A

 

And hey, here's a naked nude of the FrankenOrchid (which just reminded me to put my last "audio grade" fuse in the thing):

 

After way too much A/B testing, I decided I like the Atlantis+ better than the stock Orchid. The Orchid has a more open soundstage even stock, but the modded Atlantis is more engaging and romantic.

I started modding an Orchid (pictured above apart from the fuse change and straightened-out caps). So far, that means:

• TDA1541A R1 upgraded to a late production TDA1541A Taiwan chip (1998)
• Tube changed from GE 5670 to 6N26P
• Output caps changed to paper-in-oil K40Y-9
• Fuse swapped to "audio grade" fuse that I had an extra of from the Atlantis+ (I still can't seem to hear fuse differences. Shrug)

I'm not sure if I've changed enough to call it the Orchid+, but I'm calling it that anyway because I'm the one who's typing. It also came stock with most of the cap upgrades that were applied to the Atlantis+ so they didn't need replacing.

The more expansive soundstage remains intact, which is the main thing I was worried about.

The Orchid+ is definitively better for Rock in my opinion, based on my limited experience, and to my particular taste (thanks, @schiit). I'd honestly likely prefer the Gungnir Multibit for Rock because it's the only genre I still prefer oversampling for, but I can't afford two nice DACs at home.

Classical and Jazz trade blows, but the more expansive symphonic music goes to the Orchid+. The Atlantis+ wins with intimate female vocals or calm acoustic guitar.

Overall, the Orchid+ is a bit more versatile than the Atlantis+ and is a small step up from the stock Orchid. It has the lovely euphony of the TDA1541A. Realized to its full potential? Hard to say. Maybe the Audial Model S is better, but I don't own one and can't directly compare them.

I also have a TDA1541A N2 chip on the way. It's supposed to be some sort of oddball late production chip that measures somewhere in the S1/S2/1998 range.

 

@JoeDoe now owns my new Atlantis+ and he's starting to understand the allure of the MHDT lineup. I decided to tweak the Orchid to see what I could get out of it with mods and couldn't afford to keep both. Happy he got his hands on it!

Still loving the Orchid. I just got a Saga in today and it really does subtly wonderful things for the Jotunheim. Air, soundstage, and timbre are all improved.

 

Correct you are sir! With the exception of the smallish soundstage, there's nothing I'm not enjoying about the Atlantis! Where the keeps coming to mind is timbre. It's just so… Right.

Going to mess around later today with different inputs and research up DDC's. Also, I've got a 6922 tube adapter for the Atlantis on route. Maybe swapping in some tubes from that family will space things out!

 

And... a week later you are selling it?

 

He goes through gear like water. Admittedly, so do I.

 

More of a financial issue than a sound quality one.

But in a lot of cases, this is true too!

 

I'm 3 months into MHDT Labs Orchid ownership and I'm still loving it. I believe this is the best MHDT has to offer, at least to my taste.

I've also finished up with upgrades/mods and don't have any current plans to mod it further.

• TDA1541A R1 upgraded to a late production TDA1541A Taiwan chip (1998)
• Tube changed from GE 5670 to 6N26P
• Output caps changed to Jantzen Audio Superior Z-Cap (2.2uF 800V) from MHDT-branded
• Power caps changed to Epcos Sikorel (35V 3800uF) from Rubycon
• RCA input transformer changed to Murata DA101C
• Fuse swapped to "audio grade" fuse (1A 250V slow blow)
• Toroidal changed to one from an older Pagoda because I had it and swapped it... didn't make a difference, so I just left it in. If I do any significant mods in the future, it will likely be to isolate the toroidal transformer from the rest of the unit (maybe change to a different transformer in the process. We'll see).

 

I've put the now burned-in Orchid back in the shop on the main rack and will compare it with the Border Patrol and the Pagoda in a while. I also got a couple of Jantzen Z-Silver caps to put in, and I think it has a 3-Mica GE, which could become any of several options hanging around the shop. I'm going to wait for some conversations with Jiun before doing anything more than changing the tubes and output caps. It's been an impressive unit so far,

Also picked up an Audio Mirror Tubadour DAC, which is AD1865 based. I didn't get a chance to compare them head-to-head, but brief comparisons of both to the Denafrips Ares has me thinking that the Tubadour, as ridiculously named as it is (though we've normalized "Denafrips" and look at those MHDT fonts), might have to be my home choice. Non-oversampling but no loss in bass control or presence, instrumental and vocal dimensionality that was immediately felt, and upon further listening did reveal itself to be more than a thickness or syrupy bleed, but a surer presence. I need to do more listening.

That was an aside, anyway. I'll try to gather some other ears and get an Orchid v. Pagoda session before and after switching the caps.

 

I am looking for used inexpensive DAC for my office and found this http://www.usaudiomart.com/details/649379076-mhdt-paradisea-nos-tube-dac/ for $24. After reading this thread I would like to a NOS DAC but do not know anything about this one. Has anyone heard Paradisea and can share the opinion?

 

I've had and extensively listened to the Orchid for 9 days now so thought I would share some notes I made.

My opinion from day 1 to now hasn't changed. I've fallen in love a little bit with this DAC. Keep in mind that it's my first NOS DAC, so that undoubtedly plays a role. Even so, I would think that MHDT have created an excellent DAC if you're after the sort of sound NOS DAC's offer. Someone like @Luckbad can chime in for how it compares to others.

I've done most of my listening using the stock tube, but have also used a GE 5 star 5670 Double Mica tube from the 60's. I actually prefer the stock tube. The 5 star is more refined but it's a bit too neutral for my tastes. I prefer the richer, warmer sound of the stock tube. I have a WE396A tube coming next week.

Vocals sound more lifelike- really shines on vocal centric music
Guitars, particularly acoustic, sound more lifelike. The representation of vocals and acoustic guitars are the best things about the Orchid
Smaller soundstage but more 3d instead of 2d - I prefer it because I can get lost in the music more easily
Much better sense of rhythm compared to OS
Notes hang in the air for a touch longer which gives realism to what I'm hearing
Highly resolving yet more integrated/coherent into the music
Sounds natural, no longer a digital sound
Fatigue free listening - I'm very sensitive to treble
Notes have more weight to them
Usually don't pay too much attention to drums - but I seem to be more drawn to them with the Orchid
Easier to make out what the singer is singing
Less separation and a narrower soundstage may be considered as"flaws". Flaws in quotation marks because I prefer it, as I find it leads to a more engaging and emotional listen
Probably not recommended for critical listening; most definitely recommended for sitting back and enjoying music

All in all, I'm certainly a NOS fan and will only be on the look out for NOS DACS in the future. It's somewhat strange that @Luckbad seems to be only person on the internet who seems to have shared his impressions of the Orchid, considering how good it is and how popular a couple of the less expensive MHDT DACs are.

Considering OS DACs seem to be much more prevalent, I wonder how many people would actually prefer a NOS DAC without knowing it. I'm kind of curious to hear the average age of people who prefer NOS DACs. I'm in my 20s and am very sensitive to treble.

 

@smithyy what other DACs have you owned?

Your points are pretty on point (pun always intended). NOS DACs always suffer in soundstage, but the Orchid is about the best/most together of any I've heard. The dimensionality is not lost and is actually much more coherent than the majority of DACs, oversampling included.

The edges are a little soft, but less so than most NOS implementations. With some tubes, it's softer than the Metrum Amethyst. With others, it's sharper.

If you ever decide tube rolling doesn't quite get you what you're after, you can fairly easily swap out the output capacitors. The DAC chip is socketed so you can also chip roll. I liked late production (1998) Taiwan chips and N2 (some weird Dutch chip). The S1 and S2 are supposed to be great but I'm too cheap to get them.

I still have my FrankenOrchid, though I mostly use the Sonic Frontiers SFD-1 MKII SE+ (essentially maxed out). It has better synergy with my Eddie Current Super 7+ (modded).

 

It all started with the ODAC but have also owned the Modi Multibit, Gungnir Multibit and 2Qute.

I don't think theres much chance of getting a 1998 Taiwanese chip, but the TDA1541A S1 and S2 do intrigue me.

 

The Orchid is better at headstage than the Amethyst with a good tube (especially with Jantzen Superior-Z output caps).

I do want to hear the Adagio or Pavane at home someday (only ever heard Pavane L1 in another setup).

The great OS DACs I've heard in familiar situations have been better with soundstage than NOS (including my current Sonic Frontiers DAC). Holo Spring L3 excels at headstage width but I thought it sounded weird with speakers and lacked some in the depth department.

Of the rather many NOS DACs I've owned or listened to at home for an extended duration they all sacrifice something in:

• Soundstage (often closed in)
• Extension (they tend to roll off the extremes)
• Dynamic response and/or transient speed
• Note sharpness (i.e. they're always slightly soft)

The good ones give you something for the sacrifice. Things like musicality, romantic or engaging presentation, lack of fatigue, great acoustic timbre, etc.

 

Love the Pagoda, compared to the Bifrost.