Any comments on DAC directly to Power amp with no

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.

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.

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.

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.

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.

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.

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).