UPDATE 12/09/18: Orchid DAC burn-in, gonna try a different tube and see what changes. Break-in required for sure. Sound keeps changing.

UPDATE 12/14/18: MHDT Orchid DAC (tube change #1)

Purchased and installed a very low use 1949-1950 year Western Electric WE396A/2C51 square getter tube. The WE tube was listed as a category #1 one tube by MHDT Labs for their DACs so I thought I'd give it a try. I really do like the stock GE tube provided with the doc, particularly after it gets broken in.

WE396A, too early to tell:
I'm guessing its not broken in because it looked perfectly brand new, not used much, if at all. It has sounded "okay" the first few hours but not as nice as the now-broken-in stock GE tube provided by MHDT with the DAC. I can tell already the WE tube is a tad more rolled off on the highs (as others reported it would be) and the MIDRANGE presence definitely stands out more so right from the get-go. The weight of the bass is difficult to tell.

Need to let the WE run for a few weeks at least and see if it's worth the hype or not in the MHDT DAC.

Need to let the WE run for a few weeks at least and see if it's worth the hype or not in the MHDT DAC.

I don't think it is hype. It's just system dependent. Let us know how it goes.

Tube Break-In is a rollercoaster.
 

On day-3 with the change to the Western Electric WE396A tube, I'm learning to leave the MHDT Orchid powered on continuously right now whether I'm using it or not this first week. I did cycle it on/off the first few days but I took another listen after it had been left on and the sounded opened up a (in a different way) today.

A little more top-end detail surfaced but I'm nothing this tube produces a tad more pronounced midrange sound as if it pulls background midrange more forward - if that makes sense. If I play tracks where I'm normally use to hearing guitars in the background like 10 rows away from the stage, it now sounds like your are in the first 4 rows of the stage closer to player.

I'll let it break in for sure, and the switch back to the stock GE tube that comes with the DAC to then determine which i like better. Both tubes produce different sound which is fun to be able to yield a different sound from each, whatever you prefer. Clearly, more time needed to see if it changes further.

I ran the Orchid for a few hours today. The presentation is different than the Abbas. I will post more after it settles in.

the 1st day was veiled over quite a bit on mine. It seemed after the 4th day it started to show promise and became more musical with the stock tube.

I have made a conscious effort not to critically listen to either Dac while they settle in.

The Abbas has a enveloping mid-hall sound stage. Speakers seem to disappear. The Orchid is more like rows 5-10. Similar to the Havana. It sounds a little rough. Probably due to the new tube. I got a couple of nice used Raytheon windmill getter 5670's. I will give them and a burned in GE 5 star a go.

Digital debris/glare/artifacts are absent from both units. :thumbsup:

Update#3: Roller Coaster Ride on break-in under first 30 days.

Day 1:
laid back, veiled over, some detail. Nice sound but break-in needed.

Day 2-3:
softening, opening up. Too much midrange now. Weird.

Day 4:
opening up more, less midrange, more detail coming back.

Day 5-7: balancing out more evenly today across highs, mid, lows. Sound stage has really opened up but not in a harsh way.

After leaving the MHDT powered on the past few days solid seems to help break-in progress move along faster for sure. It's starting to come in more so now. More open, smoothening.

CORRECT: no digital glare. Listening to something now with someone hitting a wood block, and it's producing a unique and natural sound in a good way.

.

Floridaboy,

[EDIT] As I'm finding out with more break-in time on the MHDT Labs Orchid DAC, and starting to try the different tubes:

The characteristics of more or less "midrange" appears to be tube specific in the MHDT Orchid DAC.

Factory GE Tube provided is fairly neutral and and retains detail, not overly smoothed over - sounds nice. Not bad at all for a factory supplied tube.

WE396A/2C51 tube is a tad warmer, more pronounced midrange and mid bass, highs rolled off a tad; but it allows you to listen to just about anything with no digital glare or "artifacts" as you noted previously. As discussed offline this could be a great tube for someone running a brighter sounding solid state amplifier with the MHDT DAC. Sounds good with my tube preamplifier and tube amplifier combo but I'd really like to see how it sounds with a nice SS amp, could be a great combo!

GE 5-Star is a great balance of detail and smoothness so far. It offers a larger sound stage than the WE tube with more detail in trade for extra plushness with the WE. Kinda liking the GE 5-Star too so far.

Others with other DACs -

Anyone else here liking a particular DAC (with or without) tubes?