I agree it does not make much sense.

 

I don't think I've seen anyone using analog outputs from their DAC to DSP. Doesn't make any sense.

Folks are typically using DAC as a digital pass-through to the DSP. So you have a Phone/DAP - USB DAC (digital) - COAX / Optical cable (digital - DSP Digital input.

 

so what is the DAC doing in that setup? just a USB/bluetooth to optical/coax converter?

 

I use a 10 inch Samsung tablet playing FLAC files via USBAPP over USB into a SMSL PO100AK dac, which outputs a digital signal via wired SPDIF to the digital SPDIF input on my Minidsp. Since everything is kept within the digital realm, the DSP receives an extremely clean, full range signal which makes for an improvement over an analogue connection.

When I changed from analogue to digital via the SMSL there was an obvious and quite dramatic step up in sound quality, sound staging etc.

 

There is a school of thought out there that the DAC in some of the high end players is so good (ie better than Helix) that you actually get such a high quality analog signal going to the DSP that even after a 2nd ADC/DAC conversion in the DSP it sounds better than straight digital.

I am not in that school. Based on the context where I heard this idea(youtube) I have a theory that this was being used to justify connecting the OEM HU to the DSP using the digital port as that was the best solution given a MOST bus or no access to a clean analog signal. Since most DSP's only have one digital input (not sure why its so hard to have multiple switched digital ports) they then had nowhere to connect a digital player for ultimate SQ without HU limitations. So they made up that theory to support it since really at that high of a level can anyone really tell the difference ?
However the people who say that swear its noticeable and that most listeners agree the digital player (if its sufficiently high end) sounds better in analog than straight digitial.

as I said I'm not a subscriber to that theory but there it is

 

Probably the extra conversions ( DAC inside the source, ADC inside the dsp) are making the sound more pleasant to the listener , but the signal quality is not better.
I can’t see how a digital signal from one device like smsl/ topping can be distinguishable worse than a digital signal from a $1k dap.

 

I don't think running a signal through extra conversions improves it if you run it through a top tier DAC 1st. Each time the signal is degraded. However, there are people that like 2nd order distortion in their music and this could be a way to get just that. Some speakers and amps are that way as well. There's plenty of references on the psychology of sound on what humans perceive as "better" may be worse on paper. So, there's that.

 

I agree that adding additional D to A and A to D conversions doesn't make sense. I saw this recently on Matt Schaeffer's youtube video on a Lambo Urus install. He had 3 presets, 1 using the factory output with a Nav-TV with a digital output, 1 using BT directly to the DSP and the third was a DAP using analog out. He claimed that they used the analog out to utilize the DAC's and to process "anything on the player even if the DSP can't." He claimed that with digital out they can only process what the DSP can and it won't allow playing certain files. This is all at 7:50 in this video.

This didn't make sense to me, but maybe I'm misunderstanding.

 

Sounds to me like the DSP can't process all music formats like his DAP can. Perhaps he has multichannel recordings?

 

I have used the phone into the SMSL Pro, and now i have a HIBY DAP. I prefer the DAP. I have an iphone so its not as flexible as the DAP when it comes to fine tuning the music to my personal taste. I wish I could get a head unit with coaxial out but my car has EVERYTHING tied in to the head unit.

 

it is cheap to mod the HU to coax out

 

im not sure, never seen it done.

They do have some Chinese head units with optical/coaxial that fit along with CAN BUS adapters but ive seen some guys on my car forum have had issues.

Easy solution is DAP directly into DSP

 

im not sure, never seen it done.

They do have some Chinese head units with optical/coaxial that fit along with CAN BUS adapters but ive seen some guys on my car forum have had issues.

Easy solution is DAP directly into DSP

I am doing this. i use the coax digital to my DSP coax digital. my dsp does not have optical but my head unit does (it has both)
my head unit also runs the dsp software (android app) its a nice solution.
volume and balance are also sent through the digital. the head unit has an option to send an "volume / balance adjusted" signal or a pure signal

 

I have two head units modded this way,...it is a cheap mod that cost under 50USD

 

Please post some instructions and pictures

 

https://www.civicx.com/forum/threads/optical-line-out-from-oem-hu.70740/

I want to try this one day when I feel extra brave... and have the parts.

 

Once you go DAP you don’t go back! 🤣

 

I can see a couple of scenarios this may come into play but personally I wouldn’t.

1, where the digital connection toslink on particular hardware has 16/44.1 to 16/44.1 digital path and has volume management done digitally. It does give some quantitization errors and slight drop in dynamic range.

A good dac where volume control is either fixed on the digital side or done analog circuit could in theory sound better when the input device is runnnig a medium to low volume where on the Digital to Digital there is a certain amount of quantisation erroring going on.

But , in many adaptors ( most / a2b) in car audio the 16 bit audio gets reclocked using 24 or 32 bits before getting outputs to 96k-192k / 24 bit on toslink. I doubt anyone could pick any erroring .

2, Where the media source is hi res and the device output dac can do high res conversion but on its digital out limits the device to 16 bit / 44.1 and limits dynamic range to what 16 bit can do. I doubt I could pick it up,especially where it’s going to get processed by a downstream dsp. And the ADC would have to have an amazing dynamic range / low noise floor to be better.

As a side note modding car stereos and other input devices for spidif to toslink can either be done as per the earlier post or some will have I2S available on the circuit board ( like original old school cd players or raspberry pi’s )

A simple device like I2S to toslink board can be added to give a digital audio bitstream to an existing device if a SPIDF stage isn’t available.

 

I can see a couple of scenarios this may come into play but personally I wouldn’t.

1, where the digital connection toslink on particular hardware has 16/44.1 to 16/44.1 digital path and has volume management done digitally. It does give some quantitization errors and slight drop in dynamic range.

A good dac where volume control is either fixed on the digital side or done analog circuit could in theory sound better when the input device is runnnig a medium to low volume where on the Digital to Digital there is a certain amount of quantisation erroring going on.

But , in many adaptors ( most / a2b) in car audio the 16 bit audio gets reclocked using 24 or 32 bits before getting outputs to 96k-192k / 24 bit on toslink. I doubt anyone could pick any erroring .

2, Where the media source is hi res and the device output dac can do high res conversion but on its digital out limits the device to 16 bit / 44.1 and limits dynamic range to what 16 bit can do. I doubt I could pick it up,especially where it’s going to get processed by a downstream dsp. And the ADC would have to have an amazing dynamic range / low noise floor to be better.

As a side note modding car stereos and other input devices for spidif to toslink can either be done as per the earlier post or some will have I2S available on the circuit board ( like original old school cd players or raspberry pi’s )

A simple device like I2S to toslink board can be added to give a digital audio bitstream to an existing device if a SPIDF stage isn’t available.

Non of which apply to astell and kern sp3000 as far as I know 😏

 

Been using my FiiO m17 through analog for months now to play Tidal due to certain files not playing on digital. I don't think I could tell a difference between analog to digital on a blind test to be honest. Have done numerous back and forth comparisons having a Helix Director it is pretty easy to do.

I do like Tidal over Apple Music though for SQ. At low levels analog may sound slightly better as it seems to have more pronounced details. This observation has been magnified significantly now that I switched to SD GAN amps.

Bottom line FiiO direct to DSP is definitely better than my I-phone when running it digital through NavTv Zen interface.

 

s a side note modding car stereos and other input devices for spidif to toslink can either be done as per the earlier post or some will have I2S available on the circuit board ( like original old school cd players or raspberry pi’s )

If its so easy why don't the F'ing manufacturers do it would cost them $10 in their head units.

 

Exactly. If I didn't live down under with a country population of 5 million I’d do these mods as a retirement job a bit later on. Limited market here.

 

What head unit ?

 

Is this to me A fyt u7870 processor 9.5 inch 12gb ram 256 storage l.

 

When I'm in a "Listening/Jamming Mood" (opposed to casual or drive-time podcast listening via Factory Head Unit); I use a good DAC (RHA DACAMP L1) that has tactile Bass/Treble shelving controls as a realtime program EQ for song-to-song adjustments.

Realtime "at your fingeretips" bass/treble program EQ is a hassle from most DSP's either by flipping through tiny menus to adjust a few PEQ bands (and a TRUE L/R PROGRAM EQ - NOT a speaker/pass-band EQ, as that is NOT the place for tone controls!), or by recalling a mountain of DSP presets with minor tone tweaks - no thanks... My solution gives me basic tactile knobs for bass and treble shelfs - just as they should be. Great for fattening up thin 80's productions, or brightening overly dark and swampy productions.

Crank the bass shelf, and not only do the subs light up - but the 8" Midbass also blooms nicely while remaining totally aligned with the subs because the downstream and calibrated speaker processor (the DSP) is still set to the reference tune. Adjusting the DSP's EQ on the sub channel would not maintain this alignment (would actually mangle it) - and would also miss the natural midbass bloom from a L/R program bass shelf. Helps keep the "up front bass" anchored up front where it belongs. And the program treble shelf is just plain convenient since productions vary up there almost as much as in the low end. It's rare - but I'll even cut highs a dB or two on really shrill productions.

Fed from iPhone USB > DAC > Analog L/R into Alpine DSP.

DA/AD generation loss is negligible if not completely inaudible for descent converters. Chances are most music you listen to has already been converted back and forth a handful of times in production (individual elements during mixing, AND the entire mix/master through an analog chain). There is a thread around here about "What did you used to worry about, that you since learned doesn't matter" and recursive DA/AD conversions were mentioned a few times by seasoned members (including yours truly). If your install calls for a DA>AD conversion to make it more functional - who cares Functionality wins over the negligible degradation from descent converters. SINAD chasers can throw functionality out the window in chase of a full "pure" digital chain - chopping off their nose to spite their face in the process.

 

might work, return if it doesn't. Many years ago I tried a topping d10 with my phone at the time, didn't work and swapped to a fiio.

 

I did and it will be here Thursday. My head unit is one of those tesla styles which doesnt have optical out, but does have type A USB. My hope is to use android developer and enable audio out over USB, then to my Audison

 

It’s hard for me to buy that stuff without testing. I would want to see if there is any added noise or loss of signal during the conversion process. The SMSL is about as perfect of a converter as money can buy according to 3rd party testing.