Audio quality... Line level (analogue) versus optical / digital?

[Duncan Shea-Simonds]

Was just wondering...

I am a bit old skool and my experience of Hi-Fi... and amps specifically, has always been with Line Level (analogue) outputs / inputs.

I see an increasing number of amps with digital inputs these days.

I get why this would be, with the types of sources now being connected to modern amps.... But my question is whether using a digital connection would offer an improvement in audio QUALITY over an analogue one. All other things being equal?

Take the B2. Would switching to an amp with a digital input (and using the digital output from the B2) offer an improvement in audio quality over a similar quality amp using the line-out (analogue) from the B2?

Just musing really...

Cheers


Duncan

[Davywhizz]

The short answer is yes. This is because many amps with digital inputs will have a better digital to analogue converter (DAC) than the one inside the B2 and more available power than the B2's internal amplifier. So it's a combination of better DAC plus better amplification. 

You would get more obvious results If you are using WAV or WAV converted to FLAC files: there are more limited returns if your B2 holds mp3s. 

I currently run the B2 optical signal into a separate, combined DAC/headphone amplifier, then analogue line-out from that to an amp, so there are various permutations. If you have an analogue amp that you like, your best option might be to try a separate DAC (with or without the bonus of a headphone amp).

[Daniel Taylor]

Davy's answer is a good one, so you need not read my follow-up.  ;o)

When switching from an analog connection to a digital connection, you cannot compare the two without also comparing the DAC upstream of the analog output with the DAC downstream from the digital input.  If the two DAC's were identical, then you could attempt to compare the two methods of connection.  But in that case, the differences would be vanishingly small.  So the main issue is the quality of the two DACs.  Also, in the case of the B2, there is the amplifier that is downstream from the DAC before the output.  So not a simple comparison.

[Duncan Shea-Simonds]

Thanks Davy....

That's interesting.

I do have an amp I'm quite fond of... though was thinking it might be time for a change and whether I should source one with a digital input.

I hadn't considered the external DAC option.

Any thoughts on the kind of money I'd need to spend on a DAC to get a meaningful improvement over the internal one in the B2?

Cheers

Duncan

[Duncan Shea-Simonds]

Thanks Daniel....

Sounds like the B2's DAC might be the weak link here?

I'm interested in the external DAC option.

Wonder if anyone has any recommendations?

Cheers

Duncan

[Davywhizz]

Hi Duncan

Firstly, you need a DAC with an optical input as that's the only digital output the B2 has.  Some only have USB inputs as they are designed for use with a computer or phone. It also depends if you want other features.  I really like a built-in headphone amp, because higher end phones usually take more driving than the headphone socket in most amps can accommodate. I have a DAC/preamp (Topping EX5) which also offers high resolution Bluetooth, because I wanted it for a simple guest room set-up, to work with headphones and streaming music from a phone. 

I would happily use my Topping EX5 as the DAC/preamp/headphone amp for my main hifi, though I currently have a different one for that. The Topping E30 is half the price of the EX5, but has no headphone amp or Bluetooth. I couldn't recommend it as I haven't had one, but the company has a good reputation for high quality at affordable prices. 

If you go for a device that is both a DAC and a preamp, you need to be careful to set an output level that works with your analogue amp's input. Some have a choice of fixed or variable line-out levels, the latter adjusted either by a volume control on the DAC itself or using its remote control. The optical output of the B2 isn't an issue, it's fixed and the B2 volume control has no effect. So it's a case of starting with a low variable DAC output until you find the optimum level, then using the volume on your amp after that. A fixed DAC line out ought to be pre-set at the right level.

The Audio Science Review website gives a lot of information and they review all sorts of devices, from Amazon Basics to top end:

https://www.audiosciencereview.com/forum/index.php

[Duncan Shea-Simonds]

Brilliant - Thanks Davy. Very helpful.

[Anthony Deighton]

I use the digital output of my B2 into the digital input of a Marantz amp and output through a pair of QAccoustic speakers with excellent results. I also connect an analogue output from the amp to a Chinese valve headphone amp (Bravo) which completely belies its low cost (currently £60ish on eBay) and sounds simply superb using sennheiser phones. Hope this is helpful

On Friday, 25 February 2022 at 11:44:37 UTC dunc...@gmail.com wrote:

[Davywhizz]

Another option, which we haven't touched on yet, is that for a time I ran my B2 optically into a Bluesound Node 2i music streamer, to get the benefit of its DAC. Then the combined, analogue output went to the hifi amp. For anyone who is thinking of adding high resolution streaming as an additional source alongside a B2 that might be cost-effective, rather than just getting a stand-alone DAC. 

When I first got my B2, I ran it optically direct to an amp with a DAC, then to the Node, as above, but eventually realised that my DAC/headphone amp did an even better job, so it became the hub for the whole system.

[Steve Russ]

I got my B2 primarily to eliminate my very large and cumbersome Sony 400 disc changer, which was out of capacity, slow to access and has a very dated catalog system for keeping track of my music.  This CD changer was connected to a high-end two-channel system that is very revealing and pretty much presents the source audio exactly as it was output. No tone or loudness controls, just two 250 wpc stereo amplifiers, driving a pair of very large speakers, vertically bi-amped into an active crossover and a preamp with XLR in/outs to lower the noise floor and preserve dynamic range. The goal with this system is "wire with gain" as they say in the audiophile magazines...

When I first wired up the B2 via the 3.5mm analog output to the line-level RCA inputs on this system preamp, I have to say I was a bit disappointed with how it sounded compared to my high-end single-disc CD player or even the Sony 400 disc changer.  The B2 sounded muddy and both the high and low frequencies seemed attenuated when compared to either CD player and the imaging and clarity were lacking as well. I read that the analog output from the B2 has to go through the chip amp and internal DAC which is not ideal for line-level inputs on my preamp and clearly not up to my expectations for audio quality.  Not surprising really. The B2 Amp is just to give the unit stand-alone capability, with enough power for small bookshelf speakers. 

Like many others have posted,  when I connected the B2 optically to my stand-alone DACBenchmark DAC1, the sonics dramatically improved and I find there is no difference between my CD players and the B2 when the optical digital signal is rendered by my DAC. Connected to my system optically, the B2 excels and there is no loss in audio quality like I experienced with the analog amplifier output. 

My point here is that even an inexpensive outboard DAC connected to the B2 optically (or the internal DAC on equipped receivers or amps) and plugged into the line level inputs of your amplifier or receiver will provide a noticeable improvement in sonics. 

[Thomas Mangano]

I second everything Steve just said.  I have found going from B2 optical output to a DAC acting as preamp to some sort of music source be it, headphones, Bluetooth, or amplifier really unlocks the potential of the B2.  Like you I was using a bank of 4 and 2 mult-cd players and besides the real lack of control of what was playing, slow access, wear on the cds, and all the shelving and space needed, to think that a small B2 unit, paired with a DAC about the size of the B2, replaces all that and actually sounds better with more control.  Reminds me of this true analogy. 49 years ago I was in the disk drive business.  We packaged 2 disks drives that had a storage capacity of 20 mg each, was about size of about a 4 ft high rack, and cost about $15k to the end user.  Today’s storage capacities are just mind bending to us “old-timers”! 

[Iain Gartshore]

Duncan, I bought this little FiiO DAC a couple of years ago for £22 on Amazon, and it works a treat;

FiiO Taishan D03K Digital and Analog Audio Decoder

There is now an Amazon bestseller at just £12.99, and many others are listed.

I recently bought the Cambridge Audio EVO 150 and can run my Brennan directly into this, and it sounds great.

Iain

[fred.w....@gmail.com]

Here is my two penneth😁

I have an old (good) quad system that I have linked optically (via a little DAC) to my B2. I am very happy with this BUT if I was starting over or replacing anything, I would ditch it and just use Sonos speakers (I have 3).

Fred.

[Duncan Shea-Simonds]

Thanks for all the great advice gents.....