[Freo-1]

Been investigating NOS DAC’s of late, and I’ve been pleasantly surprised at their performance.
 
For example, recently picked up an Oritek Audio NOS DAC second hand just to see if the NOS sound had progressed over the years.  The more I listened to it, the more it sounds pretty musical to me.  Not having heard them for a long time, one would have thought that NOS DAC’s would have been lacking in smoothness and detail compared to the plethora of oversampling DACs available, but that may not be the case.  The Oritek sounds more like a master tape than most of the DAC’s I’ve heard at its price point. 
This DAC has piqued my interest with the NOS approach, so I’m going to try out a Wavelength Audio Cosine DAC with the NOS setup.  The topology uses a passive I/V stage, Mangaquest transformer coupling, and a 6GM8 output valve.  Should be interesting to see how it sounds.
 
So, who else has used NOS DAC’s, and what are the observations?  Interested in folks take on them  (likes, dislikes, strengths, shortfalls, etc).

[jtwrace]

Been investigating NOS DAC’s of late, and I’ve been pleasantly surprised at their performance.
 
For example, recently picked up an Oritek Audio NOS DAC second hand just to see if the NOS sound had progressed over the years.  The more I listened to it, the more it sounds pretty musical to me.  Not having heard them for a long time, one would have thought that NOS DAC’s would have been lacking in smoothness and detail compared to the plethora of oversampling DACs available, but that may not be the case.  The Oritek sounds more like a master tape than most of the DAC’s I’ve heard at its price point. 
This DAC has piqued my interest with the NOS approach, so I’m going to try out a Wavelength Audio Cosine DAC with the NOS setup.  The topology uses a passive I/V stage, Mangaquest transformer coupling, and a 6GM8 output valve.  Should be interesting to see how it sounds.
 
So, who else has used NOS DAC’s, and what are the observations?  Interested in folks take on them  (likes, dislikes, strengths, shortfalls, etc).

Where is the Wavelength Cosine that you mention?  I don't see it on his site. 

[Freo-1]

It's not part of his currrent line of products.  Here is link to it:
 
http://www.wavelengthaudio.com/Cosine-det.html

 
 
 

[Freo-1]

The cosine DAC arrived yesterday.  So far, very impressed!  For CD playback, it is as good (and perhaps) better overall than the tube Modwright Oppo, which is high praise indeed. 
The DAC does remind me a lot of a good analog source, such as a turntable or high end reel to reel (only without any noise issues to deal with).  There does indeed seem to be something going on with the NOS setup.   There is noticeable absence of harshness or fatigue with this DAC.  One could listen for hours happily with this unit.

More to follow...

[Quiet Earth]

Welcome aboard the non-oversampling bus Freo. Enjoy the ride man. 
 
I still remember the day I sold all of my Audio Alchemy boxes because I finally found a DAC that made me want to listen to entire CDs rather than surf through specific tracks of precious few discs. Thank goodness those days are over! I think I'm running out of room for all the CDs I've accumulated since then. What a major turn around for me! . And all of those 80's discs? Well they sound pretty good too.  Check 'em out when you have the time.

I think it's interesting that you posted your enthusiasm about NOS DACs here in the Lab. Not because there wasn't a better circle to talk about it, but because here is a device that sounds so very correct to many listeners, having that direct from the tape quality that you mentioned, yet measures so badly compared to its over and up sampling cousins. Pretty cool huh?

FWIW, I have a personal preference for transformers and tubes over op amps or discrete transistors for the gain stage after the I/V resistors. YMMV, and I'm sure that it does. 

Enjoy your new discovery!

[satfrat]

I love my MHDT Havana dac with my 44.1Mhz library. Seeing how I'll never be progressing to Hi-Rez, I see no reason to look past the Havana that I've slightly tweaked & with a stash of half dozen different cryoed tubes. I definitely see the attraction of a NOS dac with no op-amps or digital filters. 



Cheers,
Robin

[Freo-1]

Well, after spending some time with the Wavelength Cosine DAC, I can say with absolute certainty that it is without question one of the finest sounding DAC’s I ever heard. On CD playback, (IMHO) it actually outperforms the Modwright Oppo BDP 95 with the tube upgrade. It also sounds better than the Eastern Electric Mini Max plus.

The Cosine sounds very natural, and possesses sonic qualities one would normally associate with a first generation master tape (or listening in the studio itself). I’ll be keeping this for quite some time.

[SET Man]

Hey!

   I've been using NOS DAC since 2006. My first one was an inexpensive kit based on a single Philip TDA1543 chip direct output to the pre. It was battery operated and due to my stupidity I shorted it out 

   Anyway... Currently I'm using a kit with 4 TDA1543 chips in parallel direct output also....









    There is something special about NOS DAC that I like. I've heard a few DACs, 24/96 and etc, some in my own system. But always like the NOS sound best. Althought not as extended or extremely detailed like higher bit DAC. I do find the NOS DAC to sound more analog-like. Not to mention less mechanical and artificial sounding also than some higher bit DACs I've heard. The music seems to have a better continued flow to it. Sometime with certain CDs it almost make me feel like I'm listening to my turntable.

   Of course I'm speaking strictly on 16/44 CD playback here.

Take care,
Buddy 

     

[groovybassist]

I've also become a fan of NOS DACs, switching from the EE Minimax + to a Neko Audio D100Mk2 - much easier on the ear and much more natural sounding to me.  I find there's plenty of detail in the Neko - it's just not thrust out at you like some other DACs.  In addition to switching DACs, I switched playback software from Decibel to Audirvana Plus - this made a big difference and really brought the Neko to life.  There's so much more to this than the "bits is bits" mantra.

[FJK]

Love my DiyhifiSupply Satch DAC based on TDA1541.

[radarnyc]

What do folks think about these previously (2004) reviewed positively by 6moons?

http://www.scott-nixon.com/dac.htm

http://www.6moons.com/audioreviews/nixon/tubedac.html

[Freo-1]

Just picked up a MHDT Havana DAC (balanced version) for the audio only system.  After a couple days to break in, and rolling in a pair of NOS Tung-Sol 2C51's, I can report that this DAC sounds remarkable.  I was amazed at just how dead quiet the line stage is, and how the music sounds so natural coming from it.  For CD and DVD-Audio, once you hear this, it's hard to go back to any delta/sigma type DAC setup. 

The music just sounds more natural, not unlike a top tier turntable cartridge, only without any record surface noise or associated distortions/dynamic limitions.  Most highly recommended for an audition.

[wisnon]

I compared this to my old delta-sig Lampizator Dac (generation 3) and its no contest to me, the Lampi clearly wins. I will soon test a new NOS lampi (generation 4) and see how that stacks against both.

[Freo-1]

Well, as they say, its "horses for courses".  I think the system as whole plays into sonic impressions.  I found the sound from the Havana DAC to be quite different connected to a Pass Lass X 2.5 preamp compared to a Conrad Johnson clone.  The tube preamp fleshes out the sound in a manner that is more enjoyable compared to the solid state offering.  I have found most delta/sigma DACs to be overly bright/brittle sounding.  The only way I can listen to the Oppo Blu Ray BD 95 for SACD/Blu Ray in two channel CD is with the 6SN7 output.

[ton1313]

I have a Havanna DAC that I purchased a few months back, and I love it. It replaced a Cambridge Audio 840C that I was using as a DAC, being fed by a Squeezebox Touch. Nothing against the 840C, and I truly enjoyed it, however the Havanna has such and organic quality that I find very seductive and listenable.

I can't comment on the stock sound as the unit I purchased was used and modded by one of the previous owners with the following:
1) The replacement of the two input capacitors with Jensen copper foil paper in oil in aluminum case ones.
2) The replacement of the cap behind the input caps with a Jupiter HT.
3) The replacement of the two output coupling caps with Jupiter HTs.
4) The conversion of the RCA coaxial input connector to a BNC connector for true 75 ohm compatibility
5) The substitution of a Hi-Fi Tuning Fuse for the stock fuse.
6) The substitution of the stock tube with a Western Electric JW396A/2C51.

[wisnon]

Well, as they say, its "horses for courses".  I think the system as whole plays into sonic impressions.  I found the sound from the Havana DAC to be quite different connected to a Pass Lass X 2.5 preamp compared to a Conrad Johnson clone.  The tube preamp fleshes out the sound in a manner that is more enjoyable compared to the solid state offering.  I have found most delta/sigma DACs to be overly bright/brittle sounding.  The only way I can listen to the Oppo Blu Ray BD 95 for SACD/Blu Ray in two channel CD is with the 6SN7 output.

I hear you.

However, please note that the Gen 3 Lampi DS Dac is still a TUBE output stage dac with an SSRP differential summator circuit. It is very meaty and has great tonal accuracy. Super smooth and sweet midrange. The new owner (who had the Havana DAC) is over the moon and he runs a Mac tube pre AND stereo tubed power amp.

I dont mind the Havana DAC at all, its pretty nice, but is the clear loser in a head to head contest.

[Freo-1]

I hear you.

However, please note that the Gen 3 Lampi DS Dac is still a TUBE output stage dac with an SSRP differetial summator circuit. It is very meaty and has great tonal accuracy. Super smooth and sweet midrange. The new owner (who had the Havana DAC) is over the moon and he runs a Mac tube pre AND stereo tubed power amp.

I dont mind the Havana DAC at all, its pretty nicce, but is the clear loser in a head to head contest.

I think my objection is your referral to the term "loser" in a head to head comparison.  That may be true in your system, but in a different system, another may say the DAC you currently own would be a loser. 
I'm happy that the Lampi works better in your system, but I think one needs to be careful when stating that one DAC is better than another.  I think all one can state is that "in my system" DAC X sounds better than DAC Y.   That would certainly make sense in your situation.
 
Keep in mind that I have the balanced Havana, and that sounds different than the standard Havana, as it has twice the circuity.   The balanced circuity provides an improved sense of dynamics, a lower noise floor, etc.

[Folsom]

I love NOS DACs with a good power conditioner. Without I can understand the appeal of oversampling units as the detail tends to improve a lot but if you add power conditioning then they sound less subtle and more thin to my ears. The NOS  DAC's retain a full body with the most finesse for detail with power conditioning. Plus I think NOS DAC's are just easier on the ears in general.

[wisnon]

I think my objection is your referral to the term "loser" in a head to head comparison.  That may be true in your system, but in a different system, another may say the DAC you currently own would be a loser. 
I'm happy that the Lampi works better in your system, but I think one needs to be careful when stating that one DAC is better than another.  I think all one can state is that "in my system" DAC X sounds better than DAC Y.   That would certainly make sense in your situation.
 
Keep in mind that I have the balanced Havana, and that sounds different than the standard Havana, as it has twice the circuity.   The balanced circuity provides an improved sense of dynamics, a lower noise floor, etc.

Perhaps I did not make myself clear. I am borrowing the Havana Dac from my buddy who bought the Lampi off me. He runs a full Mac Tube system, preamp and power amp (the 275). I run a SS system with a NAD c375BEE integrated modified by a Swiss firm to improve the SE class A preamp and to have negative output impedance on the power stage. This mod makes the classic c375 BETTER than the stock M3 and thus the firm (Rowen) was forced to mod the M3 as well, due to dealer backlash.

In BOTH our system, we vastly preferred the Lampi to the Havana AND I REPEAT THE HAVANA IS A VERY GOOD DAC. I am currently in Lampi limbo and am using the Havana Dac for the past month, so I know it fairly well.

I can concede that in the context of the discussion that perhaps the term loser is harsh, but semantics aside, the preference was clear and unequivocal and my buddy and I clearly have very different setups, except for our speakers...we have different models of Heil AMT speakers.

I am not in the absolute camp about DAC chips or components. I find that excellent implementation can make any philosophical approach sound excellent. Obviously tubes will tend to be warmer and Ss will tend to have tighter bass,  and DS will be more analytical and resolving while Ladder Dacs can be more analog sounding, but all can approach the strong points of the other while still enjoying their natural advantage.

[wisnon]

I love NOS DACs with a good power conditioner. Without I can understand the appeal of oversampling units as the detail tends to improve a lot but if you add power conditioning then they sound less subtle and more thin to my ears. The NOS  DAC's retain a full body with the most finesse for detail with power conditioning. Plus I think NOS DAC's are just easier on the ears in general.

Actually, you positive comments mirror the pro reviews of the Lampi Dac generation 3 and earlier, all of which used a DS dads. Also, not all DS oversample! The DS Lampi had UPsampling built in, but there was NO oversampling in the chip or the circuit as far as I understand and I asked  for clarification several times.

Having said that, I agreed that R2R type Ladder DACS do have the natural advantages you describe and you do have to work harder with DS Dacs to approach those desirable features. However, some DS Dacs can handle pure DSD and from what I hear, that is something else! No ladder Nos Dac can do dsd from what I understand. By next year, I expect DSD capability to be in vogue and ubiquitous among DS DACs in 2014.