"Steve, have you considered/tried adding a volume control to the Final Drive?"
I have. I can get an autoformer for the steps in attenuation. The problem is that it does not solve the problem for ALL DACs. Many do not have low output impedance, so they lack drive. What I would rather do is a preamp with a combination of active gain and transformer coupling, so I get low output impedance, galvanic isolation and true balanced output. Next project (I have so many on my plate...)
Steve N.
Empirical Audio |
The Overdrive SE DAC has earned several best of shows and just got a positive review from Audiostream:
http://www.audiostream.com/content/empirical-audio-overdrive-se-usb-dacpre
This has the big advantage of eliminating the preamp as well as providing a way to insert other analog sources using the Final Drives.
You don't need to resort to tubes to get the analog sound, even with 44.1 tracks. This is due to the clean power, digital filtering, point-to-point wiring and simple analog section. Sounds like a NOS DAC only more detailed. Accepts up to 24/192 with both coax and USB inputs.
Steve N.
Empirical Audio |
Charles - my last reference DAC was a tubeDAC, the Spoiler. Do a search and you will find it was excellent.
The problem was that the bass was never as tight as I can get with SS, even using Siemens CCA grey-plates. It is very musical, but leaves some parts of the music lacking. I still have yet to hear a tubeDAC that does everything right, top to bottom. I think the ultimate tube just does not exist. The new Chinese Psvane tubes are impressive however. I have monoblocks with these in them.
Steve N.
Empirical Audio |
"Everything was set properly (confirmed with Steve) but even with the volume control knob activated and on its most counter-clockwise position (supposed to be zero output) I was still getting a decent amount of volume through the speakers"
The Overdrive volume technology does not go to zero volume. This is normal. It has internal jumpers that can reduce this more, but if a normal listening level is at 9-12:00 on the dial, this is perfect. Muting can always be used if you want it quiet. It is better to have better control of listening volume IMO. A knob that goes from quiet to really loud in just a few degrees of rotation is not good IMO.
Some amps will sound better with a preamp than the FD. Its not really the difference between the Overdrive volume and the preamp that you are hearing. Its the fact that the preamp has a lower output impedance and the amps like this more. Its possible to wire the FD's to lower the volume by 6dB and lower the impedance of the Overdrive by a factor of 4. This would probably help here.
I would also like to hear what the effect of putting the Final Drives between the DAC and preamp. It is usually placed at the DAC, but can also be at the destination. The transformer is grounded to the destination.
Thanks,
Steve N.
Empirical Audio |
"Steve, as we both know, S/PDIF is a very jittery interface when it comes to a Master Clock recovery."
Alex - That used to be the case, but with the latest receiver chips, good transformers, good circuit design/layout and a good 75 ohm cable, it is just as transparent as a good USB interface. I am using right now my prototype Off-Ramp 6 XMOS interface driving my DAC with S/PDIF coax and its the best digital I have ever heard. Beats everything I have done previously. It matches my I2S for performance too.
Steve N.
Empirical Audio |
Matt - I actually offered my USB interface module to a couple of big manufacturers. It was not cheap, but not overly expensive either. They were too cheap to even try one. They are pinching pennies trying to eek out as much profit as possible. Those marketing guys don't come cheap and neither do the ads.
Steve N.
Empirical Audio |
Long break-ins are usually a result of a LOT of plastic dielectrics in the design; capacitors, cabling and circuit boards. IME, its better to use non-plastic dielectrics like ceramic, paper-in-oil and cotton. These require virtually no break-in and actually sound better than the plastics, even when the plastics are fully broken-in.
This is why I really like Jensencapacitors.com air-core inductors, ceramic caps and the Duelund caps. Great for speaker crossovers, actually the best on the planet.
Steve N.
Empirical Audio |
Mattnshilp - You will not need an external USB converter with the Overdrive SE:
http://www.audiostream.com/content/empirical-audio-overdrive-se-usb-dacpre
No resampling. Beats all comers for accuracy and analog sound.
Steve N.
Empirical Audio |
The best tubeDAC available IMO is probably the Killer DAC from Australia. Put Siemens CCA grey-plate tubes in it and drive it with an Off-Ramp 5, fully optioned.
As for best SS DAC, the Overdrive SE was compared to several high-end DACs in this review last month:
http://www.audiostream.com/content/empirical-audio-overdrive-se-usb-dacpre
Nothing beat it.
Steve N.
Empirical Audio |
Mattnshilp - I would be game in sending you an Off-Ramp5 and Dynamo power supply to use with the Lampi to compare with the Overdrive DAC alone. Its about $2.5K worth of stuff, so I would need another refundable deposit, but at least the Lampi would have a running chance. This is what Grannyring is proposing.
"just when I though it could not possibly sound any better"
-my wife
Steve N.
Empirical Audio |
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Shaw - I have not heard the new Directstream, but I have heard the Vivaldi in two different rooms at RMAF. The Overdrive beats it IMO. The Analog DAC was compared in the latest Overdrive review. The Overdrive beat it according to the reviewer. I have heard the Wavelength, Berkeley, Ayre, Chord Qute, and Bryston. Overdrive beats all of these. My roommate used the Lampi7 in his room in Chicago Axpona. He says the Overdrive beats it too. I have not heard the top of line Resonessence or the Bricasti yet.
I have both tube and SS monoblocks. The difference with tubes is mainly bass and depth. A bit more smooth on vocals maybe. My SS is extremely good though.
Each Overdrive version that I use at shows is different than the one previously used. It undergoes upgrades periodically. This is one big advantage of my products. I continuously try to improve them and offer these upgrades to my customers whenever possible. Each show sound Is improvedmovermthe last. This show is no exception.
Steve N.
Empirical Audio |
Matt - I will send you a set of Final Drives and a Short-Block to use with the Overdrive. You can try with and without, bit I think you will find these to be essential.
Thanks,
Steve N.
Empirical Audio |
Actually I was able to save you some money and do 3-day. I thought I had missed the UPS driver, but he appeared really late. It should be there on Friday.
Steve N. |
Matt - one thing you should know is that even broken-in components usually need a couple of days break-in after shipping them. I call this the trade-show effect. As hard as we try to break everything in, it still needs a bit on the first day of a trade-show. I believe this is probably due to temperature changes and static charge build-up in the dielectrics.
Steve N.
Empirical Audio |
TBG - my room partner and I used my Overdrive in one system and the BMC in another system in or RMAF room last year. BMC is good at that price point, but not in the same league.
Steve N.
Empirical Audio |
Wisnon wrote "DallasJustice had the Empirical Dac with all the trimmings and abandoned it for a TotalDac with Legato 16/44 transport and I think moved on to TotalDac Server and USB converter."
That is true, but realize that this was the original Overdrive and not the Overdrive SE. Big difference.
BTW, the TotalDAC USB cable is evidently the one to beat.
Steve N.
Empirical Audio |
"What you really needed to do was change out the rectifier."
This is good advise, but I'll give you even better advise:
Power all of your digital gear from a Plasmatron 3 from VHAudio.com:
http://www.vhaudio.com/plasmatron.html
All of the show exhibitors that have used one on loan buy one. I did and I love it.
Steve N.
Empirical Audio |
"Aeris is powered by two separate low noise, passive power factor corrected, switch mode power supplies (SMPS) – one for analog and one for digital."
Actually, the Overdrive SE uses three SMPS, one for digital and two for analog. Each has a Hynes-type linear regulator on the output. All of these are housed in a separate chassis. Very similar to Aeris I think, except for one important distinction; the Hynes regulators. The power and ground return techniques are very similar too.
Another key difference in the Overdrive SE is that any trace in the analog section that would be over about 3/4" long is replaced with an externally routed pure silver cotton insulated twisted-pair cable. FR4 glass-epoxy is the enemy of good analog signals. Dielectric absorption is the issue.
Steve N.
Empirical Audio |
Granny - I learned this lesson from modding Mark Levinson gear, which is very dark sounding. I jumpered most of the long traces with silver wire and it opened up and became airy. No darkness. I don't mod anymore, but I learned a lot from 10 years of it.
Steve N.
Empirical Audio |
Just to give you an idea, the latest Overdrive upgrade, my ground-plane mod is $200. This one takes the USB module performance to a new level, passing up the external Off-Ramp 5 with Dynamo power supply.
The last upgrade was the digital D/A Hynes reg, which was $400. Improved power to the digital section of the D/A chip, which improved dynamics and imaging.
Its like getting a new DAC with each of these upgrades. The customers love it.
Steve N.
Empirical Audio |
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Time to try direct to amps with all of the DACs. How about this weekend?
Have you tried the Final Drive yet with the preamp?
BTW, here is what I would recommend for room treatments:
1) to eliminate HF sidewall reflections, put Sonex panels, 3'X5' on the spots where you see the tweeters when putting a small mirror on the wall and looking from the listening position. If these do not pass the WAF, then look to absorbing panels from GIK acoustics with graphics on them. I have some of these as well with a nice Fender guitar printed on it:
http://www.gikacoustics.com/product/gik-artpanel-acoustic-panels/
2) get two ASC 1/4 round tubetraps, as tall as your tweeters:
http://www.acousticsciences.com/products/tube-traps
Place these just behind your speakers (2" behind) with the inside curved surface faced inward. Start with the flat surface parallel and in line with the speaker inner facing side. Then "tune" by rotating the left one counter-clockwise and the right one clockwise. At some point you will get razor-sharp focus, but too much rotation will compromise the width of the soundstage. Rotate them back until you have just the right mix of width beyond the speakers edges and sharp focus of the vocalist in the center. If you have a reflective surface like a TV screen, these will eliminate the effect of it by scattering the back-wave from the speakers. This is a very effective treatment for both imaging and bass that I have used at shows and at home for years.
Steve N.
Empirical Audio |
"Steve (Empirical Audio), is it safe to say your Final Drive is virtually a Music First or Bent TAP-X without a volume control?"
Essentially yes, except for the transformer quality. I have an all-silver Music First and the FD beats it hands-down. The FD is in two chassis on purpose, so the fields do not interact. I use better switches than the MF. The MF also has some strange wiring in it, different for left and right channels on grounding...
Steve N.
Empirical Audio |
" I know Steve Nugent made the comment that Rowland has a darker tinge to it"
Actually, I was talking about Mark Levinson. I have had Rowland, ML and Pass Labs preamps in the house. None of them lit my fire. Like most components, I needed to mod them and even then, not spectacular. These were older models though. Some of these guys have learned some lessons I think.
Steve N.
Empirical Audio |
Guido - the Final Drive is only for analog outputs, not AES/EBU or S/PDIF inputs.
Steve N.
Empirical Audio |
Brightness is of course subjective, however there are some key things in a DAC design that can cause this perception:
1) out of balance dynamic response
This occurs when the power subsystem cannot respond exactly the same speed to a low-frequency transient as a high-frequency transient. Low frequency transients require power reserves. High-frequency transients require fast regulation and low ESR decoupling caps. Even though the DAC measures perfect for frequency response, the dynamic response can be and usually is out of kilter. It requires both excellent voltage regulators as well as optimum mixes and locations of decoupling caps to achieve the correct balance.
2) Compression
Compression is when the active stages, whether discrete, op-amps or tubes cannot react linearly under all circumstances. Circumstances such as high energy bass, high-level signals or fast transients can sometimes push active stages too far and they cannot react linearly. They may behave differently when amplifying low-level signals versus high-level signals. Local heating in integrated circuits or current sharing in the on-die power distribution can cause this. Power supply and decoupling can also play a role. Reflections of significant power back to the output driver can cause it to go non-linear (see #3).
3) insufficient output drive or reflections
The output drive must have low-impedance. It must behave the same when driving difficult loads and easy loads. However, like a high-Q cable, a low output impedance and fast slew-rate has its downside: It must be critically damped for HF reflections. Many DACs do not have any termination and this can cause harshness at the leading edges due to HF reflections. Even though reflections are an RF or digital phenomena, these can occur on the output cable. The question is whether these affect the behavior of the output driver or not. It is best to put a treatment there to address this IME.
Steve N.
Empirical Audio |
It would be interesting to know the effect of the FD between DAC and preamp and preamp and amp. One of these might be a substantial improvement, particularly if your preamp has no transformer either on the input or output.
Steve N.
Empirical Audio |
"Finally, I will try the ODSE to Criterion to Veritas as I have been, but add in the Short Block (which, from what I understand, basically divides the small dc USB power from the line which helps to improve sound."
The SB should always be used with the Overdrive. It filters out the common-mode noise from the computer and ground-loops, improving SQ. The side effect of this filtering is that the 5V power in the USB cable is compromised. Rather than selling something that compromises USB power, I just cut the power wire and limit the use of the SB to products that do not use the power in the USB cable like the Overdrive. Because a high inductance is inserted in the ground wire between computer and DAC, it is important to plug the DAC and the computer into the same AC outlet. Using some power conditioners that add even more inductance in the earth ground can be problematic. They usually don't help with digital power anyway. A solution like the Plasmatron from VHaudio.com makes more sense and improves SQ significantly for digital.
Steve N.
Empirical Audio |
Audiolabyrinth - Yes, I have a Plasmatron 3. Everyone that listens to this in their system has bought one. Chris loaned us one at RMAF and we had to use it for the entire show. It's really cool looking too. Some tubes for this have plasma fire in the tops.
Steve N.
Empirical Audio |
Matt - the 18" cables were my own cable line, when I used to sell cables. They are bare-wire pure silver suspended in space. I don't have anyone to build them for me now, and besides the silver wire is getting very hard to source. Not to mention that every Tom, Dick and Harry thinks he is a cable designer.....
I would not expect the FD to make much difference if you have either transformer in the preamp output or the amp input already. It's primarily for no transformer situations, although it allows you to insert other analog sources like HT and vinyl preamp into a system with DAC direct to amps. That is really the reason that I created it, along with the SQ benefits when running balanced.
The fact that the soundstage is larger and deeper when using it Pre to Amps, even though there is already a transformer at the pre output indicates that somehow the transformer balanced output from the pre is not really that balanced. This is a similar effect that I get with no transformers in the Overdrive DAC or amps.
Steve N.
Empirical Audio |
I just though of something that might make it a bit more unfocused. Because you already have transformers in the pre outputs, adding the second transformer in series floats the wiring between the transformers and the transformer cores on the FDs are not grounded. This can cause it to pick-up hum and RF, just like a ground-loop. Its essentially an antenna.
If you were to ground pin 1 on the FD input connectors to earth ground, it might eliminate this defocusing.
Connecting a transformer to another transformer is really not optimum. Only one is needed between components.
Steve N.
Empirical Audio |
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Matt - the FD really helps if you don't have transformer on the output. If you have it, you don't really need the FD.
IF the transformers in the pre were same ones used in the FD, now this would make a BIG difference. It would also add at least $4K to the cost, with dealer markup.
If you had a pre without transformers, this would be the one to get the benefits of the FD.
Steve N.
Empirical Audio |
If the DS transformer is an I/V converter, then the Final Drive may still be beneficial. Depends on the impedance of the transformer and whether it is galvanically isolated or not.
Steve N.
Empirical Audio |
I do not build onesey-twosey on products that cost $200. It would be a waste of my time.
If you order an Overdrive, Off-Ramp or Synchro-Mesh, these orders go into the queue and get built in that order. I don't wait for more orders. Standard wait time on an Overdrive is 2-3 weeks, 1 week on an Off-Ramp and 2-3 days on a Synchro-Mesh
Steve N.
Empirical Audio |
Synchro-Mesh and Of-Ramp have 30-day money back, less shipping. You just waited too long.
Steve N.
Empirical Audio |
I cannot speak for other DACs, but due to extensive use of Hynes regulator technology, I found that putting an expensive power cord on the Overdrive SE only helped a tiny bit. I still use one, just because I have it. I really don't believe its necessary though.
Maybe Matt tried more than one cable on it?
Steve N.
Empirical Audio |
I actually have a more affordable DAC in my plans, that supports DSD (and native) for the masses that must have this. Its probably a year off. Too many other things on my plate right now.
Steve N.
Empirical Audio |
Jafox - literally every linear supply on the market as well as many SMPS are just too slow reacting to be interesting for digital. The regulators just dont compare to the Hynes technology. Most aupplies dont have very good input noise rejection either. Another area where Hynes tech shines.
The supply upgrades for my Off-Ramp and Synchro-Mesh are Hynes tech linears also.
Steve N.
Empirical Audio |
Jafox - it is better to use two separate supplies, one for the Mini and one for the Of-Ramp. Its just like the analogy of stereo amp versus monoblocks or preamp and amp versus integrated. Separate power is ALWAYS better.
Besides, I have optimized the Hynes design for use with my Off-Ramp and Synchro-Mesh. Its a different supply.
The Mini supply I highly recommend from Hynesdesign.com.
Steve N.
Empirical Audio |
DSD cannot be added to the ODSE, but the new DAC will have it.
Steve N.
Empirical Audio |
TBG - Ive had the BMC DAC in my rooms at trade shows, as well as the Overdrive SE. My partners in the room that sell BMC will tell you which DAC is better, a LOT better. The price difference is there for a reason. There is a lot more technology in the Overdrive. Contact Vapor Audio (vaporsound.com) They make some of the best speakers on the planet, particularly for the money BTW.
Steve N.
Empirical Audio |
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"In other words the Roland may crush the ODSE on SPDIF were as the ODSE sounds better due to it's USB implementation.."
I seriously doubt it. My S/PDIF is one of the best out there. If you drive it with my Off-Ramp 5, it is very close to the internal USB interface. I uses exactly the same path through the USB module. The internal USB interface is a bit better, but you expect that.
Steve N.
Empirical Audio
|
Regarding acoustic treatments: I consider the absorbing side panels the #1 priority. Put a mirror on the side walls if you have them and when you see the tweeters from the listening position this is where you put them. I recommend the absorbing panels with graphics from GIK acoustics:
http://www.gikacoustics.com/product/gik-artpanel-acoustic-panels/
As for bass and imaging, I recommend the 1/4 round tube-traps in a height that matches your speakers. These not only tame bass, but by acting as inner scattering devices, they improve imaging significantly by scattering the inner back-wave from the speakers. You position them inside and just behind the speakers with the round surface facing inwards.
http://www.acousticsciences.com/products/quarter-round-tube-trap
Steve N.
Empirical Audio |
Alex is of course in competition with me and throwing disparagements where possible. He knows I'm reading this too.
The theory behind my D/A conversion is to approximate a NOS DAC, with no digital filtering at all because this sounds best, period. You can select the digital filter on my DAC and I recommend the profile for 192 to be used for all sample-rates. This simply sounds best.
As for the house-sound or character of Analog Devices D/A chips, I have found them to be more natural and lifelike than most other chips, including Sabre, AKM and many other favorites by DAC designers these days. I have built prototype boards using many of these to evaluate them, as well as modding many DACs from other manufacturers in the past. Some of the TI/BB chips are also excellent. If I had to pick a new chip for a new DAC, it would be Analog Devices or TI/BB.
Steve N.
Empirical Audio |
Audiolabyrinth - the problem with trying to evaluate D/A chips by listening to different DAC implementations is the following:
Some D/A chips, like Op-Amps, require a bit more babying in the power delivery in order to deliver the goods. If the same lame treatment for power delivery is done for all D/A chips, then the ones with better on-die power delivery and better packaging/power-pin assignments will always win. On the other hand, if one optimizes the power delivery, the results may be very different. The better D/A chip may have poor on-die power structure, but actualy sound more natural. So you see, the answer is not black-and-white.
Steve N.
Empirical Audio |
Guido - The Overdrive can select between 3 digital filters and preemphasis. There is no upsampling. This allows one to feed a really low jitter digital signal and get the full benefits.
I have heard the effects of non-apodizing filters and other custom filters. I didn't care for any of them. The only good filter is a single-order analog filter IMO. The same trend is happning is speaker crossovers, low-order and minimized filters.
If you look at the impulse response of my Overdrive, the pre and post ringing is minimal. Pretty ideal. The plots are downloaded from the webpage.
Steve N.
Empirical Audio |
Mccondon - the source is all about the jitter level. If the interfaces are poorly designed, then even the best source may be compromised. Comparing USB input to S/PDIF is apples-to-oranges too.
Besides jitter, common-mode noise can come into the equation, if you are using AES/EBU or USB as your transport cable.
These are systems, so everything matters. I don't call it synergy. Its more a matter of both the transmitting and receiving interface being designed well and the cable being designed well.
Steve N.
Empirical Audio |
"His claim that with 192 option selected there is no oversampling is not exactly correct, at least to my knowledge."
I never made such a claim. Show me the post.
My Overdrive does no upsampling and the filters are selectable so that you can select the 192 filter when playing 44.1 tracks, resulting in minimal damage and approximating NOS DAC behavior.
Steve N.
Empirical Audio |
The problem with attenuator volume controls is that they add resistance to the signal path, which adds thermal noise. In the case of passive attenuators, these change the impedance of the signal path, which can cause low-pass filtering and/or loss of dynamics.
The Overdrive DAC has less than 50 ohms in the signal path. The volume technology on it is superior to any other technology available. I can say this with confidence because it adds nothing and changes nothing in the signal path. It only adjusts the D/A reference voltage, which scales the height of the stair-steps created by the D/A conversion. This is the perfect way to adjust volume. No loss in resolution, no added distortion or noise. The behavior actually reduces THD as the volume is decreased. All other volume technologies increase THD as the volume is decreased.
Steve N.
Empirical Audio |
Guido - its very simple. The D/A chip I use allows selection of three digital filters, one tuned for 44.1, one tuned for 96 and one tuned for 192. You can manually select these. The de-emphasis is standard on most DAC's but like the other filters, its automatically selected. On the Overdrive, you can manually select this filter as well. I have found it to be useful on a few older tracks, such as some Led Zeppelin and some Jimi Hendricks. If it sounds harsh and bright, sometimes it is because it has pre-emphasis.
Steve N.
Empirical Audio |
Matt - the volume control is just the nature of the beast. It never goes completely to zero due to the technology used. There are internal jumpers that will get you closer though. I like it set the way it is because I don't want the volume to go up 12dB with only 10 degrees of knob rotation. I don't think its really an issue for you because you are using your preamp anyway.
Steve N. |
