How do I choose a Standalone DAC?

[Discharge]

My current system:

Pro-ject Debut Carbon Evo
Wiim Ultra
Quad 99 CDP-2 CD Player
Musmys C2860+
Mumys E406
PROZOR Amplifier Speaker Switcher Selector
KEF 105/3
KEF 105 Series 1

I primarily want to get a DAC so I can move to XLR so I can find out if the lower noise floor will have any tangible effect as there is an audible hiss currently that might be ground loop, I also like to listen to music very loud and ive read that something like a Schiit Bifrost 2/24 can help reduce some of the harshness but do I even need to consider that if I have a Wiim Ultra with Room Fit?

There are a lot of DACs out on the market that do what i'm looking for by turning the system into a fully balanced setup but i'm struggling to work out what to buy.

I dont know very much about the subject matter so is there a way of narrowing the field down (my budget is $600 max)?

 

[voodooless]

Try to figure out the source of the hiss first before doing anything: try to short the inputs of the pre and/or amp, see if that makes it more quiet. If not, the WiiM is not your problem.

You can also try running the amp directly from the WiiM, see if that makes a difference.

 

[LTig]

My current system:

Pro-ject Debut Carbon Evo
Wiim Ultra
Musmys C2860+
Mumys E406
PROZOR Amplifier Speaker Switcher Selector
KEF 105/3
KEF 105 Series 1

I primarily want to get a DAC so I can move to XLR so I can find out if the lower noise floor will have any tangible effect as there is an audible hiss currently that might be ground loop,

You should know that balanced inputs have no advantage regarding noise compared to unbalanced inputs. They only suppress noise coming from external sources into the connection cable, not noise coming from the source.

I also like to listen to music very loud and ive read that something like a Schiit Bifrost 2/24 can help reduce some of the harshness but do I even need to consider that if I have a Wiim Ultra with Room Fit?

No. First do what @voodooless recommended above.

 

[Discharge]

Try to figure out the source of the hiss first before doing anything: try to short the inputs of the pre and/or amp, see if that makes it more quiet. If not, the WiiM is not your problem.

You can also try running the amp directly from the WiiM, see if that makes a difference.

I was running the Wiim directly to the E406 and I still get a hiss, dont get me wrong its not massive but it is "there", also when I was using the Wiim to a pair of Fosi Mono V3 while I was waiting for the E406.

Would Wi-Fi routers (TP-Link Deco XE75 AXE5400 using 3x units) and power strips cause it as all my rack/cables go past my router and I use a couple of strips?

 

[DWPress]

A new router won't help either. If you're getting hiss using the Fosi and Musmys with the WiiM do you get hiss with another source? If not, then it's potentially the WiiM, if you still get hiss with a different source going into the Fosi or Musmsy then it might just be the sensitivity of the KEFs. Is this something that just developed or had you noticed before?

 

[LTig]

I was running the Wiim directly to the E406 and I still get a hiss, dont get me wrong its not massive but it is "there", also when I was using the Wiim to a pair of Fosi Mono V3 while I was waiting for the E406.

Do you get hiss when the input of the E406 is not connected at all? If yes, does the hiss go down if you short cut the input?

Would Wi-Fi routers (TP-Link Deco XE75 AXE5400 using 3x units) and power strips cause it as all my rack/cables go past my router and I use a couple of strips?

Don't think so.

 

[Redacted]

Hiss is not usually a ground loop.
Hiss may come from the noise of internal electronics, and cannot be entirely eliminated unless you can cool to absolute zero, which is a pain. It can be reduced by good design and components. The source of hiss can be dirty connectors or dry joints, both cables and their connectors and those on the components too - hiss can be picked up if something acts as an antenna or where there is a big impedance mismatch.

As said, you need to isolate where hiss is coming from - you should not really hear it with modern gear; I can go full volume on my all-in-one streamer amp (Hypex) and put my ear in front of the treble speaker and hear nothing - point is that something may well be wrong with a component or a wire. Or one item of your kit is just not very good.

WiFi (or Ethernet) is not the issue as said. Unless the component hosting the WiFi module is faulty or poorly designed.

I haven't read the full details avove, but if you are using a turntable then that will be a source of hiss no matter what you do. Nature of the beast....

 

[Discharge]

Everything goes through the Wiim at the moment so i'll try nothing connected to the E406 and with my CD player alone, I forgot to add that to my system list - Quad 99 CDP-2 CD Player

 

[GGroch]

It sounds like you have (correctly) set aside trying to solve the hiss issue with a balanced DAC.

To add, while your Musmys E-406 (Accuphase clone) amp has balanced inputs, it is not internally a balanced amp. Not a fault, that's how the Accuphase was designed.

As a result, the internal S/N ratio (hiss level) is significantly worse using the balanced inputs compared to the single ended (in one Accuphase spec, 88dB balanced vs 104dB SE). This difference in increased hiss using balanced could well be noticeable. That said, your speakers are not super efficient so the hiss should not be audible from a normal distance in most use cases.

If you are troubleshooting, I would try removing the cheap Prozor switch from the chain. Its not likely the culprit but it is a wildcard.

 

[Discharge]

Okay tried a few things:

Turned off preamp: No change
Removed switch: No change
Removed the Wiim: No change
Tried the CD player on its own: No change
Turning volume up: No change in hiss

So that points to the power amps own residual noise, correct?

I was talking to a friend and he think it's normal on my 105/3 as the sensitivity is 93db:

Ear against the tweeter (5–10 cm): A faint white-noise hiss is completely normal with many class AB power amps (this is whats happening)
1 metre away: not normal
Listening position (2–3 m): something is wrong

I have a cheap DB meter and its showing 0 even when its pressed against the tweeter, so it sound like what hes saying is correct?

 

[Mart68]

So that points to the power amps own residual noise, correct?

Does seem most likely.

I was talking to a friend and he think it's normal on my 105/3 as the sensitivity is 93db:

No. I use speakers with a higher sensitivity than that, no hiss with volume at max and ear against tweeter.

 

[Discharge]

Does seem most likely.

No. I use speakers with a higher sensitivity than that, no hiss with volume at max and ear against tweeter.

What amp/speakers are you using?

 

[Mart68]

What amp/speakers are you using?

Sony TAE1000ESD > Krell KSA50S > Troels Gravesen Faital 3WC-15.

 

[Discharge]

Sony TAE1000ESD > Krell KSA50S > Troels Gravesen Faital 3WC-15.

That Krell seems to have a much lower circuit gain and of course much better component quality, correct me if i'm wrong but an amp constantly amplifies its own internal noise so a higher circuit gain would exacerbate the noise floor of a lower quality amp?

Also he stated "many" not "all"

 

[Mart68]

That Krell seems to have a much lower circuit gain and of course much better component quality, correct me if i'm wrong but an amp constantly amplifies its own internal noise?

You'd have to ask one of the experts that! All I can tell you is no hiss; sensitivity of the speaker system is around 94/95 dB 1 watt at 1 metre.

 

[amper42]

Musmys E406 is likely source of hiss. These Chinese-manufactured clones are known to create a minor but noticeable baseline hiss when paired with revealing gear. Try a Hypex or Purifi amp and see if you notice a difference.

 

[Discharge]

Musmys E406 is likely source of hiss. These Chinese-manufactured clones are known to create a minor but noticeable baseline hiss when paired with revealing gear. Try a Hypex or Purifi amp and see if you notice a difference.

Although I really like it, I dont think i'll keep the E406 forever. I will probably go for Audiophonics AP300-M450ET monoblocks if I can find them in good condition second hand.

 

[Discharge]

Okay I think the E406 might actually be innocent, I just got a Gustard R26 more as an experiment to see how much difference there would be between the Wiim and a mid-tier R2R dac (actual audible increase in fidelity).

However because i'm using XLR and the E406 is very sensitive, the volume pot on the pre became pretty much useless and rather than go back to RCA I wanted to try the -30DB pad on the R26.

This solved the volume problem but then introduced more hiss, so I thought that the R26 was to blame... but as a process of elimination I went through everything again.

Except this time I actually disconnected the pre (rather than just turning it off) from the e406 and even though it was on, it was dead silent, the faintest of hiss but only with my ear in the tweeter (im very sensitive to high pitch noise).

I thought it might be a ground loop on the sub (mordant performance 9), so I disconnected that but it made no difference.

So it looks like it's actually the C2860+?

 

[Discharge]

Lets see if this does the trick:

 

[Discharge]

One thing I’ve noticed in actual use is that the E406 feels extremely sensitive in my system. With the R26 feeding the C-2860+, I can barely use much of the preamp’s volume range unless I engage the R26’s -30 dB attenuator.

Looking at the published specs, that may be more about overall gain structure than the E406 alone.

The R26 can output around 5 Vrms balanced. The C-2860+ is specified at roughly 250 mV input sensitivity for 2 V output, which implies around 18 dB of preamp gain, and the E406 is claimed to have another 28 dB of gain.

That gives roughly 46 dB of analogue gain after a source that can already output 5 Vrms.

If the E406 really has 28 dB gain, 180 W into 8 ohm would require about 1.5 Vrms at its input. With ~18 dB of gain from the preamp, the C-2860+ only needs around 0.19 Vrms at its input to drive the power amp to rated output.

So a 5 vrms DAC is massively more than is actually required. The preamp volume control therefore has to throw away nearly 30 dB before you even get down to the level corresponding to full amplifier output, never mind normal listening levels.

Interestingly, the R26’s -30 dB attenuation almost perfectly fixes that mismatch. With it engaged, 5 Vrms becomes about 0.16 Vrms, which puts the whole system into a much more sensible gain range and makes the C-2860+ volume control far more usable.

There is still an unresolved issue with the E406 specs themselves: MUSMYS claims both 28 dB gain and 0.87 V sensitivity for rated output, but those figures don’t agree mathematically. At 180 W/8 ohm, 28 dB gain implies roughly 1.5 V sensitivity, whereas 0.87 V would imply about 32.8 dB gain.

So the E406 may still turn out to have higher gain than advertised, but my experience with the volume control doesn’t prove that by itself. The system already has far too much gain simply from combining a 5 Vrms DAC, an active preamp with significant gain, and a conventional power amp.

So it seems the C2860+ is innocent after all and not faulty...

The Ladder Bach 2 has solved the volume issue and sounds fantastic.