Any comments on DAC directly to Power amp with no
I connected my new Hypex NCore NC400 Bridged mono block class D power amplifiers to my Bricasti M1 DAC direct (no pre-amp) and my system sounds terrific. The combination of the Bricasti M1 DAC & the Hypex NCore bridged power amplifiers mono blocks sound more natural, clearer, have more bass, a lack of noise, excellent dynamics and details. Another layer of sound is presented WITHOUT THE pre-amplifier in the system. The Hypex NCore bridged mono block class D power amplifiers are highly recommended. I also tested the Hypex NCore mono blocks and feel the bridged version (4 NCore 400 amps, 2 on each side) is well worth the extra money based on the improved sound quality I am hearing. After conversations with Bricasti, Hypex & James (James Romeyn Music and Audio, LLC), we decided to remove the R141 (circuit) from my Hypex NCore NC400 bridged mono blocks, thus lowering gain by 14 dB, requiring 14 dB higher M1 volume setting for same playback level. Bricasti says the goal is to have the M1 CLOSE to 0db front panel attenuation. If you reduce the volume on the M1 DAC, you cause more bit reduction meaning you lose sound quality. When you connect the Bricasti M1 DAC to a power amplifier, you have to balance the M1 DAC to the power amplifier in order to achieve your M1 volume settings CLOSE to 0db. I am still experimenting with this but my volume listening range is in the -15 to -25db range depending on the source material. I purchased the Hypex NCore Class D amps from James Romeyn Music and Audio, LLC (James). He was very helpful answering my many questions. http://jamesromeyn.com/#/home-audio-gear/hypex-ncore-nc400-build-service-on-time-or-free-build/ This is my first class D power amplifier and, based on my results, sounds terrific. Of course, everyone has a different opinion on this subject. You never know “how it really sounds”, until you listen in your room and system. In summary, I am thrilled with how good my system sounds. I am hearing details, imaging and bass that I have not heard before. I highly recommend the Hypex NCore 400 bridged mono block power amplifiers. In addition, the elimination of the pre-amplifier, in my system, greatly improves the overall sound quality (for me). |
Correction: I changed my mind and cancelled my order for the Ncore NC400. Please keep reading. INSTEAD, I ordered two new Hypex NCore NC400 BTL (Bridged Tied Load) mono blocks, Hypex SMPS1200 (1200W) power supply (same as NC1200 power supply), Siliconray chassis "RE-2507-NC" same as Stereo chassis, top panel cooling vents, Neutrik gold contact XLR fully balanced input only, natural brushed aluminum faceplate (no logo), rear panel toggle switch near top (up = play, down = input mute/4W idle), 8.5 lbs/ea. I discussed this with James Romeyn Music and Audio, LLC and decided it was worth the extra money to get the bridged Ncore mono bridged block amplifiers. I m expecting the new Hypex mono blocks in about 2+ weeks. |
I have been researching and thinking about going from my Bricasti M1 DAC direct to my power amp with no pre-amp for a while. It seems everyone has a different opinion on this complex subject. As many people above have already suggested, you never know the “answer" until you listen for your self with your system and room. I borrowed the Hypex NCore NC400 Audio Power Amplifier Regular Mono Block and connected my Bricasti M1 DAC direct (no pre-amplifier) to the Hypex Ncore NC400 and listened. After several hours of listening, I have decided that, for me, going direct from the DAC to power amplifier sounds great to my ears. In addition, in my opinion, the Hypex NCore NC400 Audio Power Amplifier Regular Mono Block sounds better than my Luxman L-590ax integrated amplifier. I ordered the Hypex NCore NC400 Audio Power Amplifier Regular Mono Block from from James Romeyn Music and Audio, LLC. He was very helpful in answering my many questions about the Hypex NCore NC400 power amplifier ($1,900). See: http://jamesromeyn.com/#/home-audio-gear/hypex-ncore-nc400-build-service-on-time-or-free-build/ My new Ncore power amplifier should arrive in about two weeks and I will return the loaner to my friend. |
Jon2020, Georgelofi & all others, Thanks again for your comments. They were all very helpful. I have been listening to the Bricasti M1 DAC loaner unit for several days (now returned). It immediately sounded much better than my Ayre QB-9 DSD DAC. It is more open, sounds great and the sound stage is larger. The music is clearer while the Ayre sounds good but the music is not as musical to my ears. The Bricasti M1 DAC is connected to my Luxman Class A 590ax integrated amplifier. I listened using Wireworld balanced cables connected to the fully balanced integrated amplifier. I then "switched" to Audioquest RCA cables connected direct to the amplifier section only in the integrated amp (separate button on). When running direct, the amplifier is NOT balanced. I switched back and forth several times listing to the same music. Unused cables were disconnected from the DAC (as was recommended). I kow that everyone has a different opinion on this topic. For me, using the balanced cables from the M1 DAC to the Luxman integrated amp, sounded better than using RCA cables and the amplifier section only (no pre-amp). It might sound better if the power amplifier section was fully balanced (I do not know). The pre-amplifier section in the Luxman 590ax is very good and I think it makes a difference. Results might also be different with another amplifier and cables. After listening for several days, I ordered the Bricasti M1 DAC. It is an excellent addition to my audio system. Delivery is expected in about two weeks. Thanks again for all your help. |
Hgeifman, Do not be swayed by comments on either side of this debate. Trust your own ears and make your own decision as to what makes you happy. It's your money to spend and you spend it to make yourself happy. Many well-respected reviewers in the audio press have indicated their personal preference to go with or without a preamp with respect to the specific dac under review. It all boils down to system synergy. What works for others may not work for you and vice versa. J. |
The "perfect" preamp if there ever has been one, has always been said to sound like a piece of wire with gain, not adding or taking anything away from the sound of the source And this is what a direct source to amp connection will sound like if done right, adding nothing or taking nothing away from the sound of the source. If you need to colour the sound to your liking then by all means add a preamp that will do this, but good luck on finding the right colouration, as they all sound different, and it will get very expensive looking for it. The right way is to change the source, speakers or room treatments to achieve this, to get the sound of your liking, not by adding more colourations. Cheers George |
Hgeifman, Resolution aside, even if that is not lost, adding a good pre-amp, at least for me in my system :- 1. fleshes out instrument body 2. adds warmth to lean recordings 3. enlarges soundstage in all dimensions 4. adds weight and foundation to orchestral performance 5 improves tone and timbre of instruments 6. improves instrument placement, imaging and separation. I simply can't go back to not having a pre-amp. As usual, the proof is in the listening, so to echo what others have wisely said, try it both ways before making a decision. Happy listening. Cheers! J. |
08-23-15: Cerrot Only if the Berkeley is below 75% of full output, it's called "Bit Stripping" Your Berkeley Dac from the specs I saw gives out a massive 6v XLR or 3v SE. And your Sanders Magntec Amp only needs 2v for full output. If you have to your Berkeley volume below 75% you get the volume down to where you want, this proves you have more than enough system gain without the need of extra gain that active preamp give. And your Berkeley dac output stage would even have better drive than most preamps have. So to get a valid idea you somehow need to reduce your system gain so the volume of the Berkely is used at 75% or over. From what I saw on the Berkeley site you maybe able to change the analogue's amps gain setting from 3v to 2v somewhere (maybe inside) "Unbalanced analogue output level setting: 3.25Vrms maximum, 2Vrms or lower recommended" This then should allow you to use it's digital domain volume control at or above 75% of full output which maybe change your opinions about loosing resolution and "warmth". Cheers George |
I asked my Luxman dealer about the 590ax being "fully balanced" and his response is below: "Your Luxman amplifier is a fully balanced design when operated as an integrated amp. The connection between the pre-amplifier and amplifier is internal to the unit (it does not make use of the pre-out/main-in connections on the back panel in normal operation). When the 'separate' button is pressed you gain the ability to use either the preamplifier or amplifier sections individually although this does make a compromise of using the single-ended connections (this will obviously not be balanced). As it will be a fairly rare instance in which you will use the pre-out or main-in functionality it was a reasonable design choice to make compromises in the implementation of this feature (were it done to reference level quality with balanced in and out there would be a substantial amount of additional expense and these larger connectors would take up valuable real-estate on the back panel of the unit, all for a feature that is quite rarely utilized)". The above answers my question about my Luxman 590ax being balanced. A loaner Bricasti M1 DAC is expected next Wednesday. The question is how will my Ayre QB-9 DSD DAC compare to the Bricasti M1 DAC. I will take the advice above and listen using only one interconnect cable connected at a time (XLR balanced for integrated amplifier and RCA unbalanced for M1 DAC volume controls). This is probably the safest approach. |
08-20-15: Zd542 So, basically what you're saying, is that a manufacturer may raise the gain on a single ended components xlr outputs to make it appear balanced if someone were to look at the spec sheet? My ex-girlfriend from Russia wasn't even that unethical. Zd542 No, no conspiracy, they may have to give them gain of the XLR input or output opamp/s, because many of them (the opamps) are not unity gain stable, this then will give more output voltage from a source or higher input sensitivity on a poweramp. This then is different to what the single ended outputs or inputs specs are on sources or poweramps, compared to the XLR connections. And yes many sources and poweramps are single ended before and after that pseudo XLR opamp. Cheers George |
08-20-15: HgeifmanPresumably selecting "separate" mode disconnects the preamp section of the integrated from the power amp section, and I would guess (and hope) that deselecting "separate" disconnects the "main in" jacks from the power amp section. However even if all of that is the case, if both inputs are connected to the Bricasti simultaneously it is possible that some low level leakage of the signals coming in on the input that is not selected could find its way to the power amp section, with audible consequences. Therefore if you want to have both connections in place at the same time what I would suggest is that you first connect each of them individually, and verify that with the other one selected (but not connected) that you don't hear anything, or at least that you hear very little. If you do hear something when main in is selected but not connected, changing the input selection to something other than the balanced input that is being used may help. Of course, only change connections while the amp is turned off. Also, you may want to make use of the level adjust set screws on the rear of the Bricasti, which control the level of its balanced outputs only, to equalize the volume levels in the comparison. Finally, I'll mention that fortunately the Bricasti drives its unbalanced and balanced outputs from separate and independent driver stages, according to its manual. With a lot of other designs, in which that is not the case, the results of your comparison might be muddled or altered if both outputs were connected at once. Good luck. Regards, -- Al |
"I've seen it all too many times. A typical example of this is my cd player which has both single ended and balanced outputs, the extra opamp they used for the balanced had gain compared to the single ended output, which bypasses the balanced opamp, therefore one less opamp in the signal path from the single ended output." So, basically what you're saying, is that a manufacturer may raise the gain on a single ended components xlr outputs to make it appear balanced if someone were to look at the spec sheet? I never even considered something like that. My ex-girlfriend from Russia wasn't even that unethical. |
All: I want to thank everyone above for your comments and suggestions. They were helpful and appreciated. Philip from On Higher Note (Luxman Distributor) said "To truly separate the preamp stage from the L-590ax, you need to run an RCA cable into MAIN IN and then hit the SEPARATE switch. If you run balanced cables, you will also be using the preamp stage of the L-590ax”. He had no comments if the 590ax is, or is not, a fully balanced amplifier. If we have to use the RCA main in jacks on the 590ax, it seems we are not taking advantage of the two balanced units (DAC and amp). I was told that, if RCA plugs separate the pre-amp section from the power amp, my Luxman 590ax is really not "fully balanced". I do not know or understand. The 590ax sounds great so maybe it probably is not important. Any comments on this? My loaner Bricasti M1 DAC with volume control is due next week. My plan is: 1) Plug the Bricasti M1 DAC using balanced XLR cables into the balanced inputs on the 590ax. This means the 590ax is operating an integrated amplifier including its pre-amplifier. The Bricasti M1 will only operate as a DAC. 2) Plug the Bricasti M1 DAC using RCA cables into the RCA main in jacks on the 590ax and press the separate button on the front panel. I will turn the input selector to another setting but I do not know what setting yet (any suggestions?). This might not be important since the separate switch is on. The volume control will be done using the Bricasti M1 DAC and not the volume control on the 590ax. The above cable wiring and operation will enable me to easily switch between integrated amplifier operation and the Bricasti M1 DAC used as a pre-amplifier (and its volume control). It is going to be an interesting experiment. I received many different opinions for running the DAC directly vs. through the preamp section of the Luxman. Obviously, it is a very gray area and I need to try it both ways in my system. Thanks again. |
Good points George! I can't see the Opamp solution being ideal for sound quality. A genuine differential balanced circuit would seem a better choice if someone is seeking true balance components. Still not a sure guarantee it will necessarily sound better than a well implemented single end circuit. Charles, |
08-19-15: Zd542 That can also be misleading, as if they used an opamp for the balanced input or output of source or poweramp it's very possible that it's not a unity gain stable opamp, so they had to give it some gain to make it stable, which would give different specs as you say. I've seen it all too many times. A typical example of this is my cd player which has both single ended and balanced outputs, the extra opamp they used for the balanced had gain compared to the single ended output, which bypasses the balanced opamp, therefore one less opamp in the signal path from the single ended output. Same went for a very well known famous high end poweramp $$$$K which I was repairing, the input went though an opamp first for the balanced which had gain because it also was not unity gain stable, and the single ended input was after the opamp. I laugh to myself when owners say the balanced sound better than the single ended on this amp, I don't have the heart to tell them because they were told by someone to use it that way for better sound. So the safe bet for the best sound is always use the single ended inputs, unless you run 10mts of interconnect then balance connection will only have an advantage in noise/hum not sound quality. Cheers George |
08-18-15: HgeifmanAlthough the L-590AX is described in various places as being fully balanced, I'm not sure that is the case. First, it seems unusual for a balanced amp to provide most of its line-level connections via RCA's, as can be seen in this rear panel photo, including the pre-out and main in connections as you mentioned. Also, the lightning bolt symbols near the speaker terminals, which are presumably intended to alert the user to the possible presence of high voltage, are adjacent to each of the red terminals but none of the black terminals. (A balanced amp would provide voltages on the black terminals that are essentially identical to those on the red terminals, aside from a polarity inversion). Also, in many cases a balanced amp will have a statement on the rear panel cautioning against grounding the negative (black) terminals, which is not present in this case. Check and see if the manual has such a statement; if not, it would cast further doubt on the amp being balanced. So in the event my suspicion is correct, as George suggested above supplying the amp with a single-ended signal may actually be preferable to supplying it with a balanced signal, since it would eliminate a balanced to unbalanced conversion from the signal path. Also, if you have a multimeter available you could make some simple measurements to verify whether or not the amp is fully balanced. Post back if you'd like further info on how to do that. In any event, good luck as you proceed. Regards, -- Al |
I have had beautiful results either way, with or without a preamp. However, lately the DACs are becoming SO good that putting a preamp in the chain is putting something in the road that doesn't need to be there. I am a strong advocate of shorter signal path typically being superior. This has almost always been the case, especially in terms of cleanness, detail and microdynamics. The issue is whether one can get the desired macrodynamics, soundstage and tonality. If those can be obtained via a DAC to amp setup, the results are breathtaking! The problem is, most DACs can't do it well enough. :( |
Thanks George, I'm interested in Hgeifman's listening impressions as I suspect that both methods can sound quite good but certainly different. I happen to agree with you in regards to balanced compared to single end RCA. The simpler RCA usually sounds better to me despite the touted advantages of going balanced. Certainly fair to say YMMV. On the other hand I do hear advantages with balanced AC power compared to non balanced AC. Charles, |
As far as XLR (balanced) or SE (single ended) goes. Unless you plan to run 10's of meters of interconnect from the dac to the amp, single ended connection should sound better, as usually there are less electronics in the signal path. Unfortunately many amps these days just have an added balanced opamp at the front end for XLR connection after which they go back to single ended, going single ended bypasses this opamp. And the final connection to the speakers in almost most amps is single ended, just + signal, and - which is at ground potential. Cheers George |
Georgelofi, Thanks for your comments and do not worry about the stirring up the debate. My Ayre QB-9 DSD DAC does not have a volume control so I cannot use it. I am getting a Bricasti M1 DAC loaner that does have a volume control. As suggested above, I will test the M1 with a pre-amplifier and also run it direct into my integrated ampliifer. RCA plugs are required to separate the pre-amp from the Luxman 590ax amplifier. Unfortuniately, I CANNOT use my balanced cables from the DAC to my Luxman 590ax integrated amplifier and need to borrow RCA cables. I am concerned about having a fully balanced DAC running into a fully balanced amplifier and NOT take advantage of the two balanced units. My test should help me decide how to proceed. |
08-18-15: Hgeifman Don't want to stir up a debate, but whoever told you this about your Ayre QB-9 DSD DAC is way way off the mark!! As I have said it will deliver from it's 2v SE or 4v XLR at a very low 71ohm source impedance, this is better drive than most preamps can deliver, especially tube ones. And a volume control done in the digital domain of a dac is superior if it's used at 75% or higher of it's range, that why I suggested you use the 2v se output, as most amp will clip (reach full output) at 2v input. Cheers George |
Charles1dad and others, Thank you very much for your comments and excellent advice. Based on my research, I am not going to run my DAC direct into my integrated amplifier. I have been told that most DAC’s do not supply as much drive as a properly designed preamplifier. I seriously doubt that the DACs volume control will match or exceed the quality in my existing Luxman L-590AX. In addition, I also checked the Luxman 590ax manual and discovered that RCA plugs are required to separate the pre-amp from the Luxman 590ax amplifier (plus the switch on the front panel). This means I CANNOT use my balanced cables from the DAC to the integrated amplifier. It makes no sense for me to have a fully balanced DAC running into a fully balanced amplifier and NOT take advantage of the two balanced units. Thanks again for all your advice. |
In My Humble Opinion, Having a tube pre amp using specific tubes for voltage gain can be verry rewarding indeed. These pre amps clearly demonstrate the strengths and weaknesses (if any) for using this tube. My faviorite is the 6SN7, the early GTs being the best, fortunately there are many fine exexamples still in circulation or available despite their age. The other advantage of the pre amp is a tad les esoteric,and more familiar to the average guy, you can hook up several sources these pres. I am still old fashioned and have a phono stage a CD player with it's DAC and yes even a tube tuner is plugged in more on this later. This makes switching sources easy. In truth I must admit I really like the sound with the right tubes the tone is rich warm and lush, the sound is full bodies with superb retrieval of detail. Simply put it's beautiful no more need be said except that it takes time to find the right tubes for your gear and musical choices, there is rarely instant gratification. Be patient and diligent, rewards await you! P.S.I wish I could just give you the the recipe but there are too many variables, but I will give you a start. Make sure you use a tube power amp. The old adage that a tube somewhere in the system tubifies the system sorry not true not even the very strong belief that a tube re amp makes it a tube system, no it doesn't. In fact a solid state pre with a tube power or out element gives you more of the tube magic. Don't believe me I don't care but I am telling you the truth. It took me about 8 years of f-ing aroung with tube pre and a tube out put on my CD player. When I finally broke down and said IK WTF. I was stunned. It was Holy S**T wowzer totally floored but they are good amps despite being Chinese. So I went all tube into very detailed somewhat hard edged Focal Electras. They came to life like never before the sound from then until my divorce was fantastic. If I can get the gear back I will set it as it was. I can't know if that sound is for every body but every visitor commented on how well the speakers had burned in not realizing it was the amps (Opera Audio Consonance Cyber 800 Mono Blocks using 4 X 6CA7 EH fat body making 78 wpc). That was responsible for the enormous change in my system. From now on if I can afford it I will use tube power amps. The imaging is jusut unparalleled. As long as I am ranting about widely held incorrect beliefs I will add the "Tubes make slow syrupy rolled off treble". sound. I think that might have been true 65 to 75 years ago, but modern tube equipment if anything sparkles in the treble frequencies. Modern tube amps and all of the associated gear isintended to yield bright crisp dlean bright signals. Lets try a simple test. Take a Current Shuguang 12AX7 and compare it to a 1950s Blackburn Mullard. I am sure you get my drift. Say Yes to simple 6SN7 Pre amps to those (me) who like them ! |
Hgeifman, You have received good replies, this topic has been covered multiple times on this site. By now thousands of opinions are available to read and will be no different from what you'll get this time around. There's no single answer that will be applicable to everyone as too many variables exist. It depends greatly on the quality of the particular preamp and what type of sound you are seeking. You'll get many supporters on either side of this. Truthfully you just have to compare both approaches directly in your system, listen and decide. This debate won't be resolved with universal consensus. Good luck to you. Charles, |
Hgeifman hi, Your Ayre QB-9 DSD DAC (if it has volume/level control) from it's single ended outputs at 71ohms and 2v will be a perfect impedance match going direct into the single ended 42kohm "main in" on your of your Luxman L-590ax. This will give you the most transparent sound possible compared to anything else. If you use the XLR outputs then you have 4v from the Ayre and this may be too much gain. Cheers George |
In addition to the factors mentioned above by Czarivey, it often comes down to the quality of the active preamp you're considering. It is therefore recommended that you try it both ways in a given system to determine which way you prefer, as well as whether the additional cost of the preamp is justified. |
Your amp is reported to be a very nice sounding Class A design. However the 42K ohm input impedance is IMO on the fence for going DAC-direct. Not bad, but higher would be better. If you look at the threads about passive vs. active preamps you will get a sense for the different sonic characteristics associated with the two approaches. As pointed out above, there are many variables not the least of which is the quality of the preamp. Other factors include the volume control implementation coming from the DAC or whether an auto former or transformer volume control is used, among many other considerations. One DAC that is supposed to have a very well-implemented volume control is the Empirical Audio Overdrive SE, and I am sure there are others. At the end of the day, you will have to use your ears to make this type of choice. |
I have tried this dac straight in several times and always gone back to my pre. Plus I have 3 sound sources. Got to use a pre for that. I have a Shindo Auriges pre and it totally transformed the sound of my system for the good. You are going to try it so do what sounds the best. Asking the question here is really a waste of time because you will get many different answers Alan |
