[mikoss]

Nvm figured it out. I'm dumb and the two line out's confused me.

First impressions with the HD-650's:
Damn, is this thing ever fast, crisp, clean, yet still very luscious sounding. Female vocals are killer!

Looking forward to hearing more.

 

[David Pritchard]

The ZD is a special amp with the Sennheisers. In fact I enjoy the 600, 650, and 800 with my ZD # 17. The ZD really improves with a Synergistic Research aftermarket fuse. I think a better choice than muli tube rolling at the 6SL7 position. They are one of the few fuse sellers that offer a 30day return policy.
 
Like most OTL amps, the ZD really responds to power cord selection and please consider using an audio grade A/C duplex over the standard home A/C inlet.
 
I like the Synergistic Research outlet at $99.00 and the Furotech GTX-R outlet ( but it is $239.00). The SR plug gives a sense of more music coming to the headphone (perfect for the 800), and the Furotech-bigger soundstage and more detail (perfect for the 650)!

 

[fire2368]

  The ZD is a special amp with the Sennheisers. In fact I enjoy the 600, 650, and 800 with my ZD # 17. The ZD really improves with a Synergistic Research aftermarket fuse. I think a better choice than muli tube rolling at the 6SL7 position. They are one of the few fuse sellers that offer a 30day return policy.
 
Like most OTL amps, the ZD really responds to power cord selection and please consider using an audio grade A/C duplex over the standard home A/C inlet.
 
I like the Synergistic Research outlet at $99.00 and the Furotech GTX-R outlet ( but it is $239.00). The SR plug gives a sense of more music coming to the headphone (perfect for the 800), and the Furotech-bigger soundstage and more detail (perfect for the 650)!

What's the exact fuse/part number/model number and how do you install it? Interested to try to out to get more out of the amp. 

 

[David Pritchard]

You want a small slow blow 4.0 amp fuse. The fuse that comes with the amp is 3.25 but I discussed this with Craig Uthus (ZD designer) and he gave me the green light to use a next size bigger fuse. Synergistic Research makes two fuses. The original and the more expensive RED. US dollars are $59.00 and $89.00.
 
Either fuse will be an improvement over the 25 cent stock fuse.
 
There is a fuse holder right where the power cord plugs in. You can easily pop it out with a flat head screw driver
 
It is a fun and satisfying improvement.
 
Enjoy your amp.
 
Enjoy your music.
 
 
David Pritchard

 

[mikoss]

Very few pieces of gear have ever brought tears to my eyes, but the Zana Deux has reduced me to this state. It's a purely emotional connection with the artist I've never achieved before.
 
I've listened to music with my HD-650's pretty much religiously for the last 4 years or so, and they have never sounded the way they do with this amp. I've acquired tubes like a mad man, I've swapped different combinations, I've bought certain rare pairs for over $500, just to glimpse into the euphonics that are now entirely prevalent with this amp.
 
I always loved the sound of my WA2 OTL with the 650's, but was always aware of an overly warm/gooey blanket of smoothness that seemed to mask some of the details. It bothered me enough to roll a bunch of different tube combos, but I was always astounded with the presentation, nonetheless. What the ZD has done to that blanket is removed it entirely, while still retaining a silky smoothness, with the addition of euphonics, and excellent detail retrieval.
 
My personal chase for the perfect amp for my 650's is over.

 

[AppleheadMay]

That's Quote:

  Very few pieces of gear have ever brought tears to my eyes, but the Zana Deux has reduced me to this state. It's a purely emotional connection with the artist I've never achieved before.
 
I've listened to music with my HD-650's pretty much religiously for the last 4 years or so, and they have never sounded the way they do with this amp. I've acquired tubes like a mad man, I've swapped different combinations, I've bought certain rare pairs for over $500, just to glimpse into the euphonics that are now entirely prevalent with this amp.
 
I always loved the sound of my WA2 OTL with the 650's, but was always aware of an overly warm/gooey blanket of smoothness that seemed to mask some of the details. It bothered me enough to roll a bunch of different tube combos, but I was always astounded with the presentation, nonetheless. What the ZD has done to that blanket is removed it entirely, while still retaining a silky smoothness, with the addition of euphonics, and excellent detail retrieval.
 
My personal chase for the perfect amp for my 650's is over.

 
Concur. And not only for the HD650. I found it great with any can I had in my profile. Heavely with all the Sennheisers and Lawtons I had over the years and AT Woodies and non-woodies as well. Craig uses two cans for testing all his amps: ATH-AD2000 and Grado RS1.
 
That’s why I wonder about the difference in sound signature there is between a Zana and BA. Would love to hear some impressions from others.

 

[BournePerfect]

  After years of painfully waiting I finally heard the Zana at last Saturday's Head-fi Meet in Staten Island. I was very impressed w/ how it made my HD800s sound. The only non-stock tube in it was the Sofia Princess in the front. I might have to contemplate getting one before my end game Wa5....

 
YMMV of course, but, I thought the ZDSE thoroughly trounced the WA5 (total ~5k with tube upgrades) in every single area with the HD800. Be sure to hear them both first, if possible.

 

[AppleheadMay]

   
YMMV of course, but, I thought the ZDSE thoroughly trounced the WA5 (total ~5k with tube upgrades) in every single area with the HD800. Be sure to hear them both first, if possible.

 
Anyone tried the Sophia 6SL7 yet? I have a couple of them but haven't got to trying them yet.

 

[BournePerfect]

Iirc that was the one I settled on for my HD800s. Never tried any Mullards, but they seemed highly regarded with the HD800 from what I recall.

 

[atomicbob]

My take. I have three favorite recreational systems (as opposed to production systems, of which I have different picks):
 
1. Yggdrasil / Auralic Vega  -> Zana Deux SE -> HD650 / HD800 / TH900
Amazing system, period. I've heard plenty of systems and this is my first pick, even over the BA and 2A3 mk IV, both of which I have heard. Ok, I'm an OTL person. YMWV.
 
2. MSD192 -> Project Sunrise III -> HD650 / AH-D5000
Stunning performance for a sub $1500 system when the PS-III SMPS is replaced with a linear supply such as HP U8001A, and either an e80cc, 12BH7  or PSVane 12AU7 is used.
 
3. MSD192 -> BH Crack -> HD600 / HD650 / HD800
With an e80cc or PS Vane 12AU7 and a TungSol 6AS7g this is a very fun system of which never ceases to amaze me at how much enjoyment this system produces.
 
I can settle into any of these three and enjoy an evening's listening session without fatigue or getting bored. Obviously as you go up the chain the level of detail, 3-D realism, etc. improves.
 
I have many other DACs and Amps, most of which are here for analysis / audition and will probably be sold when that project is finished.

 

[Liu Junyuan]

My take. I have three favorite recreational systems (as opposed to production systems, of which I have different picks):

1. Yggdrasil / Auralic Vega  -> Zana Deux SE -> HD650 / HD800 / TH900
Amazing system, period. I've heard plenty of systems and this is my first pick, even over the BA and 2A3 mk IV, both of which I have heard. Ok, I'm an OTL person. YMWV.

2. MSD192 -> Project Sunrise III -> HD650 / AH-D5000
Stunning performance for a sub $1500 system when the PS-III SMPS is replaced with a linear supply such as HP U8001A, and either an e80cc, 12BH7  or PSVane 12AU7 is used.

3. MSD192 -> BH Crack -> HD600 / HD650 / HD800
With an e80cc or PS Vane 12AU7 and a TungSol 6AS7g this is a very fun system of which never ceases to amaze me at how much enjoyment this system produces.

I can settle into any of these three and enjoy an evening's listening session without fatigue or getting bored. Obviously as you go up the chain the level of detail, 3-D realism, etc. improves.

I have many other DACs and Amps, most of which are here for analysis / audition and will probably be sold when that project is finished.

Very nice. I find it refreshing to see a post praising the Project Sunrise above the Crack with the HD650.

Have you heard the DNA Stratus? How would you compare it to your 1?

 

[fire2368]

  You want a small slow blow 4.0 amp fuse. The fuse that comes with the amp is 3.25 but I discussed this with Craig Uthus (ZD designer) and he gave me the green light to use a next size bigger fuse. Synergistic Research makes two fuses. The original and the more expensive RED. US dollars are $59.00 and $89.00.
 
Either fuse will be an improvement over the 25 cent stock fuse.
 
There is a fuse holder right where the power cord plugs in. You can easily pop it out with a flat head screw driver
 
It is a fun and satisfying improvement.
 
Enjoy your amp.
 
Enjoy your music.
 
 
David Pritchard

 
Is there a difference between a 250V 4A slow blow and otherwise? The fuse I got is a 250V. My ZD is a 120V.

 

[mikoss]

Is there a difference between a 250V 4A slow blow and otherwise? The fuse I got is a 250V. My ZD is a 120V.

250V is just fine. You can use a higher voltage fuse without any trouble. Just ensure the old one was a slow blow 4A as well. It probably was... Also ensure it's the same size fuse, physically.

With fuses, the voltage rating basically dictates that the fuse will properly "blow" and interrupt the current in a fault. I've seen 30V fuses used in a 120V circuit, and what happens is the arc is sustained for longer (sometimes with a lot of noise).

 

[jamato8]

I use the ceramic sand filled. They cost more, about 15 dollars for 5 but sound better than standard and I think, as good as the super expensive stuff. I have used them for years. They are a good investment. 

 

[meraias]

   
Anyone tried the Sophia 6SL7 yet? I have a couple of them but haven't got to trying them yet.

Yes, I tried it, very nice all rounder I say, pretty much good in everything, good bass and sound stage, does sounds like a Mullard ECC35 short glass tall brown shield. The real one is still much better tho, deeper sound stage, and better lower frequency definition. Yet for the price which is 1/2 of the original, you cant complain for the performance.
Aside, I have 2 versions of Mullard ECC35 tall glass short brown, ADZAM and valvo. (ADZAM is taller), They both excel in bass, especially the ADZAM, The Valvo version is quite equally as good but have better definition. The short glass tall brown shield sounds more balanced, and is the most detailed of the 3 with deepest sound stage, but not the best bass.  I use these for mostly HD800.
Brimar's 6sl7 (I own a khul-tube version black base) are the most transparent of all I have, may sound a little lean and sterile, but does sounds the most ethereal of all, very detailed and gets clogging out of the way.
One tube that I highly recommend ZD owners is the tungsol black glass brown base 6SU7GT. This is a magical tube, detail is not its strongest suit, in fact it may sound slightly veiled in some music but the mids to the upper bass is the most alluring of all my collection. I enjoy it a lot using it with my W3000 and AD2000, with the right music, it works wonders, and I am being serious that it conveys emotion and smoothness that draws me into quite a few music even the best of Mullards cant do.