Conrad Johnson D/A-2b Digital Processor Review

Spinning CD’s in that DR1 connected to a D/A-2b? Talk about it here.
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Conrad Johnson D/A-2b Digital Processor Review

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Conrad Johnson D/A-2b Digital Processor Review

Intro:
I should start at the beginning as my quest to acquire the CJ D/A-2b processor was quit a long one. I had been looking/searching ebay and audiogon for a very long time for this component but it would rarely come up for sale. When it was for sale I thought the price was always a little excessive. After starting CJO I figured I post a wanted ad in the Classifieds and Wanted section of the website. I guess I was quite lucky as one very nice CJO member responded that they had a unit that they were willing to part with for a reasonable price. We completed the transaction and a pristine condition D/A-2b arrived at my doorstep in a few days. As Christmas was not to far off and I was quite busy with "life", I decided to hold off on the installation and open it up as a Christmas present. So this week I finally got to open my long awaited prize and put it to the test. I figure I give a brief review of the product as well as some pictures.

Appearance:
I have attached some pictures below, but there is not much to say about the unit's overall appearance. This is Classic Conrad Johnson. Simple and clean cut. The champagne colored thick metal faceplate signifies what you imagine in your mind when you hear "Conrad Johnson." My unit is in brand new condition, no scratches or blemishes that I can see. My unit also had the stock power cord replaced with a Tice power cord.

Sound:
Ok, so this is the big one. Frankly, I was not expecting a significant improvement in sound quality. After all, I felt that I was getting a pretty good sound from my Oppo CD player being fed directly into my CJ PV12 preamp. When I put on that first CD, boy was I surprised. It is difficult to describe the difference but it was quite obvious. The music simply became more.... well,... "musical." In the past year I have been slowly moving toward more and more vinyl because the sound seemed more pleasing to the ears. I think this may start a shift back to Compact Discs. The new sound is smooth like vinyl, yet without any of the artifacts or limitations of the format. I was originally worried that dynamics and detail would be diminished but this was not the case. The music is just as dynamic as ever and clarity is exceptional. The D/A-2b removes all the "digital harshness" inherent to the CD format. I did some test CD's, with my most critical pre/post comparison with Cyndi Lauper: The Body Acoustic (CD) which I had just listened to prior to putting the D/A-2b into the system. The low end was even more lively than before, mids quite accurate, but the greatest improvement was in the very high notes. Cyndi Lauper often sings with a very high pitched voice that if any higher would be a "screetch". This can sound somewhat harsh on some setups but with the new D/A-2b in place it was "accurate" but without any harshness whatsoever. I was simply amazed.

Conclusion:
I simply could not be happier with this unit. I had very low expectations as I simply thought that since CD's are digital there would be minimal difference with a new processor. Boy was I wrong. A very nice and pleasant surprise. If any of you have an opportunity to buy this unit I guarantee you will not be disappointed.

A big thank you for our member "rthomeint" as he was very generous in selling this wonderful unit.

Specs:
Sensitivity: 1.0 VRMS output at 0 dB (maximum output)
Distortion: less than .05% THD
Bandpass: 5 Hz to 20 KHz, +0, -5 dB
Hum and Noise: 92 dB relative to 1.0 V output
Phase: 0, 180 degrees of phase shift switch selectable
Inputs: One RCA coaxial, one BNC coaxial, one TOSlink optical. ST Glass optical input is optionally available.
Digital Output: one BNC coaxial
Dimensions: 14.375D x 19W x 3.315H inches
Weight: 19 tbs
Attachments
Stock image D/A-2b
Stock image D/A-2b
digital.jpg (31.06 KiB) Viewed 13778 times
D/A-2b packaged in original box
D/A-2b packaged in original box
fr_450.jpg (130.75 KiB) Viewed 13778 times
D/A-2b and PV12 in rack
D/A-2b and PV12 in rack
IMG_3901.JPG (115.22 KiB) Viewed 13778 times
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Re: Conrad Johnson D/A-2b Digital Processor Review

Post by rthomeint »

I glad you like it . The tubes were pretty new when I shipped it there was less than 300 hours on them. The ST optical input sounds better in my opinion than coax the problem is that format is nonexistent now. The best sound I got out of the unit was with an Ayre D1X transport outputting balance into the Genesis Digital lens with the digital lens outputting ST optical into the DA2b.I try a lot of different DACS over the years, but I always went back to the DA2b. The only thing I like better is my CJ HD3 usb dac.
Last edited by rthomeint on Tue Jan 01, 2013 1:54 am, edited 1 time in total.
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Re: Conrad Johnson D/A-2b Digital Processor Review

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rthomeint wrote:I glad you like it . The tubes were pretty new when I shipped it there was less than 300 hours on them. The ST optical input sounds better in my opinion than coax the problem is that format is nonexistent now. The best sound I got out of the unit was with an Ayre D1X transport outputting balance into the Genesis Digital lens with the digital lens outputting ST optical into the DA2b.I try a lot of different DACS over the years, but I always went back to the DA2b. The only thing I like better is my CJ HD3 usb sac.
Thanks, love it! I am currently using the toslink input on the D/A-2b which is coming from my Oppo player. I have heard of the Genesis Digital lens, it supposedly removes all jitter. Very nice. I wouldn't mind adding that into my system at one point and giving it a go! I'm sure the tubes have plenty of life in them although it would be fun to just experiment with different sets just to see what effect they have on the sound.

The CJ HD3 is one of their newer products, and I have heard very positive reviews. No doubt it served as a way for CJ to get back into the DAC market. It's usb connectivity offers a unique advantage over the D/A-2b and other previous models. Nonetheless, currently I am very happy! :)
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Re: Conrad Johnson D/A-2b Digital Processor Review

Post by rthomeint »

I suggest you try a coaxial cable. That my second choice after the ST cable. The tubes were CJ sourced,I think there are more of choices for 6GK5 tubes than there use to be. I don't think the DA2b sold well I never saw a review in any of the high end magazines at that time. I listen to the Premier 9 DAC at the time and this with the upgrades was about 90% of the Premier 9 at 60% of the price. I bugged CJ for years about upgrades to the DA2b but they never offered one. When I saw the HD3 at CES 2011 I told my dealer I wanted one as soon as it came out. I don't see myself giving it up anytime soon.
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Re: Conrad Johnson D/A-2b Digital Processor Review

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Is there a reason why you expect one digital input to be superior to another? Whether toslink or coaxial it should all be a pure bitstream of data from the transport (44 khz, 16bit for standard CD). Prior to you recommending trying the other inputs I did not consider trying different variations of inputs... but now you got me interested? :)

Once again, I hear very good things about the HD3. However, the HD3 is solely for music from a computer, correct? I don't believe it has any other inputs other than USB? Not that it would be a problem as computers are very inexpensive these days. I have a media PC connected to my setup as well so it may be something I may consider in the future (for now I am going to enjoy my D/A-2b).
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Re: Conrad Johnson D/A-2b Digital Processor Review

Post by Ray »

admin wrote:Is there a reason why you expect one digital input to be superior to another? Whether toslink or coaxial it should all be a pure bitstream of data from the transport (44 khz, 16bit for standard CD). Prior to you recommending trying the other inputs I did not consider trying different variations of inputs... but now you got me interested? :)

Once again, I hear very good things about the HD3. However, the HD3 is solely for music from a computer, correct? I don't believe it has any other inputs other than USB? Not that it would be a problem as computers are very inexpensive these days. I have a media PC connected to my setup as well so it may be something I may consider in the future (for now I am going to enjoy my D/A-2b).
back in the day, as I recall, Toslink was frowned upon by "audiophiles" as being inferior, with Coaxial being preferred.
...having said that, running an optical link between various devices was a solid way to help eliminate ground loops, but that's another story.

I always had felt that well designed Coax or Toslink should have identical performance, all else being equal.

In the end, again as I can recall from memory, both Toslink and Coaxial were deemed inferior due to possible clock jitter issues. Thus the inability of the receiving device (DAC) to "time base correct" the data stream. The receiving device had to lock to the inherently jittery embedded clock in the data stream. So in the end, it wasn't that there were bit/data errors, the problems were related to sample points being shifted w/respect to other sample points within the stream due to clock jitter. This sample point time shifting in the data was found to degrade the decoded audio...even though all the bits where there.

At this point in time, I'd suspect these issues are so far down in the weeds that they are meaningless.

but...enter Asynchronous USB, which presumably eliminates source device clock jitter by not relying on a clock signal from the source. I've been using Asynchronous USB now for quite some time and it works great, although I suspect it would take a mighty fine set of ears to detect a diff between well designed Coax/Tos/Async USB systems these days, and I surely don't have that mighty fine set.

I'm only scratching the surface, and I've probably forgotten other key points, hopefully others may fill in the gaps and/or correct my ramblings where necessary.
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Re: Conrad Johnson D/A-2b Digital Processor Review

Post by rthomeint »

admin wrote:Is there a reason why you expect one digital input to be superior to another? Whether toslink or coaxial it should all be a pure bitstream of data from the transport (44 khz, 16bit for standard CD). Prior to you recommending trying the other inputs I did not consider trying different variations of inputs... but now you got me interested? :)

I found the coax just overall sounded more focused. I also had a lot of transports over the years. I when I got the DA2b I had a $400.00 Parasound CD1 with the DAC disconnected.I have a Pioneer Elite DV09 DVD player the sounded bright via the coax output. The best sound I got was my Ayre D1x. All these transports sounded different. All were used with the Genesis Digital Lens in the system.

Try a coax cable and see you may hear a difference you may not. Use a decent video cable at 75 ohms.

Once again, I hear very good things about the HD3. However, the HD3 is solely for music from a computer, correct? I don't believe it has any other inputs other than USB? Not that it would be a problem as computers are very inexpensive these days. I have a media PC connected to my setup as well so it may be something I may consider in the future (for now I am going to enjoy my D/A-2b).
Yes it only works from a music server. All of my music is ripped to a hard drive I don't play CDs anymore. However I can play a cd from the drive in the Mac mini I use as a server.
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Re: Conrad Johnson D/A-2b Digital Processor Review

Post by miatadan »

rthomeint wrote:
admin wrote:Is there a reason why you expect one digital input to be superior to another? Whether toslink or coaxial it should all be a pure bitstream of data from the transport (44 khz, 16bit for standard CD). Prior to you recommending trying the other inputs I did not consider trying different variations of inputs... but now you got me interested? :)

I found the coax just overall sounded more focused. I also had a lot of transports over the years. I when I got the DA2b I had a $400.00 Parasound CD1 with the DAC disconnected.I have a Pioneer Elite DV09 DVD player the sounded bright via the coax output. The best sound I got was my Ayre D1x. All these transports sounded different. All were used with the Genesis Digital Lens in the system.

Try a coax cable and see you may hear a difference you may not. Use a decent video cable at 75 ohms.

Once again, I hear very good things about the HD3. However, the HD3 is solely for music from a computer, correct? I don't believe it has any other inputs other than USB? Not that it would be a problem as computers are very inexpensive these days. I have a media PC connected to my setup as well so it may be something I may consider in the future (for now I am going to enjoy my D/A-2b).
Yes it only works from a music server. All of my music is ripped to a hard drive I don't play CDs anymore. However I can play a cd from the drive in the Mac mini I use as a server.
Same here, all my music ripped ( using dbPowerAmp ) on to NAS drive ( Netgear Ultra 2 ) playing files using Naim Network player
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Re: Conrad Johnson D/A-2b Digital Processor Review

Post by camusmuse »

Another ripper here as well....figured I would weigh in because I too have been looking for one of theseDACs forever. Came close with the SS model, sounded amazing, even with a mid-fi system.

As for the Toslink vs. Coax. You are all right on point, the biggest thing to many purist is that the Toslink adds ANOTHER chink in the armor so to speak. Toslink get a signal from a coax source(I believe) and then it is converted to light, then run down the cable, and eventually turned back in to an electrical signal. Ideally the less gear the better but the benefits far outweigh the "differences". You can run a Toslink cable around your house a couple few times before it starts to degrade, if at all. Coax, like any electrical signal will degrade with distance.

Of course to me the biggest positive has already been mentioned, the Tos eliminates any sort of of electrical connection(short of the mains) between components. Thus eliminating any of the nastiness that can occur, ground loops, feedback, etc, etc. I have used Toslink for years, and only used coax when I have to...and only in as short of runs as possible.

I too use a USB to Toslink to a completely different part of house(50' glass run) in the listening room, on a hard wired network with cat5(another 50' or so). That 100' would probably never work just running a coax digi source. Right now I am using a terabyte usb drive to my old laptop(that Im on now and playing music to a Parasound AVC 1800 in this room room and a Sony EP9ES(100' away in cable length), both of which have OK dacs, but nothing like the SS CJ I *USED* to have.....sigh.....


Now I just gotta get a "Like New" CJ Tube DAC...lol. Sadly my SS DAC was in similar condition, I think the only time it was touched was when the original owner took it out of the box, and then put it back in for me...FLAWLESS!!!

So Mr. Ad Min, how much you want for that *outdated* Tube CJ DAC???? lol, sorry just have to ask....like I dont have enough going on as it is anyway...heh
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Re: Conrad Johnson D/A-2b Digital Processor Review

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camusmuse wrote:
So Mr. Ad Min, how much you want for that *outdated* Tube CJ DAC???? lol, sorry just have to ask....like I dont have enough going on as it is anyway...heh
No chance! :)

It took me over a year to find this unit, and I absolutely love it. It give that warm vinyl sound to my CD's, yet does not smear any detail. Just wonderful!
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Re: Conrad Johnson D/A-2b Digital Processor Review

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I too spend afew months on epay and it turned out to be a marvellous one.

I have used it for three months by now. My impression on it as compared to Marantz CDA-94 is that the CJ sounds smoother and more transparent at all spectra of sound. The Marantz is a bit of a all rounder to me until I acquired the CJ DAC.
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Re: Conrad Johnson D/A-2b Digital Processor Review

Post by Vagante »

A friend is giving me a DA 2b. It will replace a McIntosh MCC 205 which has issues. How would the Cambridge transport for $499 work with it?
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Re: Conrad Johnson D/A-2b Digital Processor Review

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Vagante wrote:A friend is giving me a DA 2b. It will replace a McIntosh MCC 205 which has issues. How would the Cambridge transport for $499 work with it?
As someone who also uses the DA2B I think you will be very impressed. My personal opinion is that the DAC is going to be much more influential on the sound than the transport. If I had to choose between a $1000 DAC and $100 transport vs $1000 transport and $100 DAC, I would go with the better DAC every time.

I currently use an Oppo player as my transport but in all honesty I could not tell the difference in the sound compared to using a cheap Aiwa CD player as my transport. However, when I pull the DA2B out of the system, there is a big difference.
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Re: Conrad Johnson D/A-2b Digital Processor Review

Post by Vagante »

Now that is what I really wanted to hear! Thanks very much. I have read until my eyes were blurry the argument of the importance between the transport and the DAC. Although I've never had a DAC it only makes sense in my mind that that is the more important piece of equipment in terms of interpreting the sound. This post was particularly important because you actually have the DAC that I will be receiving and you have played it on two different transports, one inexpensive, and one good one. Thanks
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Re: Conrad Johnson D/A-2b Digital Processor Review

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Question: Since the PV12A is phase inverted, have you utilized the phase shift on the D/A-2B to eliminate hooking up the speakers L=R to compensate for the phase? Also, what brand are the 6GK5 tubes you are using?

Thanks.
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Re: Conrad Johnson D/A-2b Digital Processor Review

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P51guy wrote: Sun May 28, 2017 7:38 pm Question: Since the PV12A is phase inverted, have you utilized the phase shift on the D/A-2B to eliminate hooking up the speakers L=R to compensate for the phase? Also, what brand are the 6GK5 tubes you are using?

Thanks.
I don't use the phase shift on the d/a-2b because I also have my turntable as another input on the PV12. If I phase invert at the last step (speaker wires) I can feed all sources into the PV12 and not have to worry about phase inverting each individual source.

As for the tubes,.. I actually can't remember off the top of my head as I am using the ones that were installed when I bought the unit. I'm sure I have it written down somewhere but for the love of god I can't remember where. I should really open her up and take a look.
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Re: Conrad Johnson D/A-2b Digital Processor Review

Post by P51guy »

I get the turntable logic, just wondered about the digital sources. Thanks!

I've read that the Mullard 6GK5's are sweet, so if I get the unit I've bid on, I'll likely spend the bucks to get those. BTW, it was your review that has prompted me to seek a D/A-2B!
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Re: Conrad Johnson D/A-2b Digital Processor Review

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Wonderful. You won't be disappointed. It is by far my favorite DAC that I have ever heard (but I may be somewhat biased). Let us know how you like the Mullard's as I probably will have to get some new tubes in the future.
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Re: Conrad Johnson D/A-2b Digital Processor Review

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Will do!
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Re: Conrad Johnson D/A-2b Digital Processor Review

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One last question: How warm does the D/A-2b get as compared to the PV12A? My reason for asking is that it will be going into a tight cabinet slot adjacent to an identical slot for the PV12A. I use a component fan for the PV12A and it works quite well in cooling the unit, but I see that the D/A-2b does not have near the vents that the PV12A has. The CJ owners manual goes to some lengths to caution about ventilation.
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