5.1+ Processors with Best DACs/Preamps?


For the 5.3 system I want to build, my plan was to have JRiver feed Blu Ray disc audio to this MCH DAC via USB. https://www.oktoresearch.com/dac8pro.htm   https://www.stereophile.com/content/okto-research-dac8-pro-da-processor 

But like most DACs, the Okto’s balanced outputs only deliver ~ 4.1 volts, which KR found insufficient to drive his power amps (Benchmark AHB2, NAD C298) with DIRAC Live 3 enabled. Thus, all balanced outputs of this processor would need to supply a minimum of 10 volts/channel to offset DIRAC gain losses of almost 20db  https://www.sowter.co.uk/decibels.php , as KR mentioned in his review of the Topping Pre90. https://www.stereophile.com/content/topping-pre90-line-preamplifier

Unfortunately, there are no 8-channel preamps available, either from audiophile or pro audio brands. KR's fix was to buy three Topping preamps, which as shown in Fig. 3 its balanced outputs deliver very low distortion, and which virtually continues decreasing well beyond 10 volts.  

https://www.stereophile.com/content/topping-pre90-line-preamplifier-measurements 

But stacking three Pre90 preamps doesn't seem the most elegant solution, and KR mentioned that struggling with the Pre90's crappy remote is no fun.  

So unless I find a reputable builder to affordably custom design a MCH preamp, the only alternative would be a MCH processor with a DAC section at least as good, but ideally far better than the Okto, and with all balanced outputs delivering at least 10 or 12 volts/channel.

If yes, how likely could its own master volume/mute remote control allow reducing all balanced outputs to ~ 5 volts or less without any loss of resolution and perceptible dynamic range?  

If yes, which model (s) would also have a pair of high quality potentiometers for selectively setting levels of the front and rear/side speakers-like the ones John Curl used for designing the JC-2 preamp https://www.partsconnexion.com/tkd-potentiomters.html , which JA raved about going head to head against his Levinson 380S? https://www.stereophile.com/solidpreamps/308para/index.html See p. 10-11. https://parasound.com/pdfs/JC2Manual.pdf

Theta Digital are the only MCH processors I’m aware of which might have DAC sections at least equaling the Okto DAC 8 Pro, though I doubt its preamp performance would match that of the Parasound JC-2.

Please suggest brands/models.

Ideally, such processors would also be customizable, allowing omission of video and unbalanced connectivity, thereby minimizing final cost.

 

 

ajant

The Lyngdorf MP-40 or MP-60 are worth looking into, and they have excellent, proprietary room correction that harkens back to the days of TacT.  Here are links to their website and a feature comparison chart just fyi…

https://lyngdorf.steinwaylyngdorf.com/electronics/

https://lyngdorf.steinwaylyngdorf.com/downloads/processor-comparison/?wpdmdl=4992&refresh=64012012605d01677795346&ind=1610966470844&filename=1610966471wpdm_LA%20processors2020.pdf

Best of luck. 

I have the solution but it's not very elegant. Buy a Theta Casablanca 3, regular not the HD, and two Six Shooters. The Six Shooter was reviewed in the Absolute Sound issue 158. It will compare to analog preamps in the 5k-10k range. You can run 2 for 12 channels of analog volume control with 3 inputs, two balanced and one single ended. Jim White of Aesthetix Audio, a former Theta engineer, designed the volume controls from which it's based. When I owned them, I compared them to several analog preamps at the time. I believe you could find all three components for 2k. Really you are only using the CB3 to control the Six Shooters as it will only decode DD. You will not be disappointed with the sound quality. They will have the voltage output you need for Dirac. If you use good dacs, in the method you mentioned, no prepro will be able to match the sound quality. But again, it's anything but an elegant solution.

I have 4 Theta Gen 8s3 dacs that I use. The best multi-channel device I have found to feed them is the Audiopraise Vanitypro. I run Roon and Dirac live with this set-up. I wouldn't use any prepro on the market for music, they all fall short.

 

There's a Parasound P7 multi-channel balanced pre-amplifier on ebay.  I'm not sure that this is the level you are looking for, but it's a fully analog linear power supply 8 channel preamp.

Just make sure the Parasound P7 can output the voltage you need. Kal Rubinson had one so he may have an idea. I couldn’t find that information. Last thing on the Theta stuff, it is class A, fully balanced and 20 Vrms max output. It is just a lot of boxes.

The Lyngdorf M40 would likely be the best all around option. If it didn't have twice the number of channels I need it would likely be within my $6500. budget. The Parasound 7's balanced outputs max out at 8 volts; twice what most DACs are but with DIRAC I'd be afraid to go with less than 10 volts.