A quicky - preamp really required??

[timnkoo]

Hi all, just starting out on my journey to decent sound with a budget build extensively using this forum's resource of knowledge. Scouring the forum hasn't provided me with a direct answer relevant to my equipment, so new thread (other threads are close but not quite equivalent).

Plan was:
Pi source (Spotify Direct via Moodle or similar) > E30 DAC > MPA-S250NC (NC252MP based stereo XLR power amp) > Elac Debut Reference DBR-62

I had planned to use the E30 in preamp mode to control volume and makeup RCA to XLR cables to suit. I've purchased all but the DAC and speakers.

I've now changed my mind and instead would like the Schiit Modius DAC to maintain a fully balanced path (along with better resale when moving on), losing volume control on the DAC.

Plan now is:
Pi > Modius > NC252MP > Elac DBR62

My question- is losing the preamp and simply relying on source volume control via Spotify app a concern (regarding safety and/or sound quality)? Listening levels will typically be low to medium in a large (6 x 8m) lounge/dining area. Note I do find myself getting lost in the digital bit depth/SNR reduction chat.

Would you recommend an alternative? i.e. passive preamp like the Schiit SYS (RCA only though) or Nobsound XLR relay switched attenuator or ?? on the analogue out. Obviously goal is to limit number of boxes, price and wife friendly.

Also, please feel free to critique my device selection for any obvious deficiencies (impedance/quality mismatch etc).

Thanks in advance!

 

[gvl]

Not using a preamp with a fixed volume DAC is a recipe for blown speakers. As for the volume control itself, if it is done in 24 or 32 bit space there is little reason to be concerned with quality loss. Getting a balanced DAC and using a single-ended preamp is sort of pointless. Schiit Frea S would be nice, but it is not cheap. Maybe get a Topping A90?

 

[jae]

Having a real volume control is essential to me. I personally would not want to take the risk of not having one, all it would take would take is some software update, crash/bug/error, or slip of the mouse or phone to have your speakers blaring at max volume or possibly causing some damage. Having to rely or have access to a digital device to change something like volume should be an option, not a requirement in my opinion.

SMSL M200 might be a good option for balanced if you don't want to go to the D90 price range. But E30 seems to have a better multitone at -120 dB though, based on the measurements provided by Wolf. Probably not a real issue

 

[gvl]

The E30 can potentially blast on full volume too. Also there were reports of it making popping noise when switching sampling rates between songs that will be audible over a direct connection to the amp.

 

[solderdude]

To reach full power you need 1.75V. This is 1dB below 2V.
There seems no need to attenuate using a (passive) pre-amp.

What this means is that you can use it the way you want but with a few possible snags:

1: The amp will clip at 0dB from the DAC just slightly so that isn't a problem

2: When you have average levels far below 0dB (most well recorded music) you may be left wanting a bit more power sometimes.
In this case an active pre-amp will help as you get a bit more gain.

3: There is the possibility that volume control is set to max or some weird pops come out of the DAC and this could be very loud.
When using a passive pre-amp you can limit that max loudness but and/or can only attenuate and not go beyond that.

 

[timnkoo]

Not using a preamp with a fixed volume DAC is a recipe for blown speakers. As for the volume control itself, if it is done in 24 or 32 bit space there is little reason to be concerned with quality loss. Getting a balanced DAC and using a single-ended preamp is sort of pointless. Schiit Frea S would be nice, but it is not cheap. Maybe get a Topping A90?

Yeah I am concerned about protecting the speaker, even if it's just from power on/off pops etc. The Frea S is out of budget as is the (D?)90 unfortunately, hence the initial E30 plan.

 

[timnkoo]

Having a real volume control is essential to me. I personally would not want to take the risk of not having one, all it would take would take is some software update, crash/bug/error, or slip of the mouse or phone to have your speakers blaring at max volume or possibly causing some damage. Having to rely or have access to a digital device to change something like volume should be an option, not a requirement in my opinion.

SMSL M200 might be a good option for balanced if you don't want to go to the D90 price range. But E30 seems to have a better multitone at -120 dB though, based on the measurements provided by Wolf. Probably not a real issue

Thanks for the response. I did see the recent M200 reviewed quoted well. This does go close to fitting the bill but with unnecessary features (Bluetooth etc) that would rarely be used. Good to maintain balanced though...

 

[timnkoo]

To reach full power you need 1.75V. This is 1dB below 2V.
There seems no need to attenuate using a (passive) pre-amp.

What this means is that you can use it the way you want but with a few possible snags:

1: The amp will clip at 0dB from the DAC just slightly so that isn't a problem

2: When you have average levels far below 0dB (most well recorded music) you may be left wanting a bit more power sometimes.
In this case an active pre-amp will help as you get a bit more gain.

3: There is the possibility that volume control is set to max or some weird pops come out of the DAC and this could be very loud.
When using a passive pre-amp you can limit that max loudness but and/or can only attenuate and not go beyond that.

Thank you for a detailed reply. Just wondering whether you are referencing the E30/Modius with RCA output voltage of around 2V? I thought I read somewhere the balanced outputs from the Modius are ~4V?

 

[solderdude]

Indeed... it is 1.7V with balanced in and the Modius will be 4V so you have more headroom but also will header louder 'pops' or other things that may become very loud.
You can 'protect' your speakers by using a passive attenuator as you can use it to limit the max output power.
It would have to be a balanced one though.

 

[sejarzo]

I wanted a balanced DAC to drive a pair of Emotiva PA-1s and bought a lightly used SMSL SU-8 v2 for $150 (the going price for them on Head-Fi or other forums) It works great.

 

[JungleXray]

I wouldn’t feel safe relying on just the software volume control.

I would stay with your original plan. You don’t really have much of anything to gain by being fully balanced, and the E30 is so cheap its kind of a wash vs reselling the Schiit later... meaning you’ll break even either way.

 

[A Surfer]

Thanks for the response. I did see the recent M200 reviewed quoted well. This does go close to fitting the bill but with unnecessary features (Bluetooth etc) that would rarely be used. Good to maintain balanced though...

Shame. My M200, new to my system sounds perfect via Bluetooth. I listen to really well recorded music with plenty of micro detail and with the M200 connected via Bluetooth I can't believe how wonderful and perfect the musical reproduction sounds. Well, I can believe it as I have been using Bluetooth for years so really no surprise there.

I also installed the XMOS drivers and via JRiver bit perfect WASAPI I am unable to hear any difference at all as compared with USB, like not the remotest whisper of a difference. As a result I can now avoid firing up my computer, using a wireless keyboard and needing to turn on a television set. Now I simply use my phone which has a large selection of Flac files and stream directly to the M200 so orders of magnitude more convenient. When I need JRiver for say playlists (still better than trying to make playlists on a phone) I will have USB then.

Thinking Bluetooth is an unnecessary feature is frankly pretty shortsighted. Everybody I know who objects to Bluetooth does so out of the incorrect assumption that it can't sound as good as a USB or optical connection. Categorically false. Try doing some blind listening tests. If you can hear the difference between properly implemented Bluetooth and USB I suggest that you go to the hospital immediately as you may have become a bat.

 

[timnkoo]

Shame. My M200, new to my system sounds perfect via Bluetooth. I listen to really well recorded music with plenty of micro detail and with the M200 connected via Bluetooth I can't believe how wonderful and perfect the musical reproduction sounds. Well, I can believe it as I have been using Bluetooth for years so really no surprise there.

I also installed the XMOS drivers and via JRiver bit perfect WASAPI I am unable to hear any difference at all as compared with USB, like not the remotest whisper of a difference. As a result I can now avoid firing up my computer, using a wireless keyboard and needing to turn on a television set. Now I simply use my phone which has a large selection of Flac files and stream directly to the M200 so orders of magnitude more convenient. When I need JRiver for say playlists (still better than trying to make playlists on a phone) I will have USB then.

Thinking Bluetooth is an unnecessary feature is frankly pretty shortsighted. Everybody I know who objects to Bluetooth does so out of the incorrect assumption that it can't sound as good as a USB or optical connection. Categorically false. Try doing some blind listening tests. If you can hear the difference between properly implemented Bluetooth and USB I suggest that you go to the hospital immediately as you may have become a bat.

Great to hear you are enjoying your M200 and that you're using it's features, which makes sense given you purchased it. I don't doubt HD Bluetooth quality is good, but I don't have a use for it, so it's not short sighted at all. 99% of my use will come via my Pi source as a Spotify Connect node which will be controlled by any smartphone/tablet in the house. Waaay more convenient than Bluetooth for all users in the house, at the expense of very high quality source material (flac etc) of which I do not own any regardless. If Bluetooth is needed later on I'm sure that's available via Pi. Thank you for your input and I'm pleased you're enjoying your M200.

Edit- it's called Spotify Connect not Direct

 

[Gyroscopics]

I need another balanced DAC to use as preamp for a 2ch speaker system. I was about to buy the M200 seeing the value for $. But I'm afraid it has the same issues as my SMSL SU-8 v2 which is the reason why I don't use it as preamp. The SU-8 v2 issues are:
1) it makes loud popping noise when I switch between inputs (usb/opt/coax)
2) it makes popping noise (not as loud as #1) when it plays a new file type (MP3/ALAC to FLAC/DSD)
3) my Volumio R-Pi restarts (software-restart) whenever I switch from USB to opt/coax then back to USB, which tells me that the SU-8 stops it's usb-dac function when switched to another input.

On the contrary, I use a Topping D70 as pre-amp on my main stereo speaker system and I never encountered the issues listed above. I sometimes use my Topping D50 as preamp and never encountered such issue. I've read somewhere that these are common issues with SMSL DACs. BTW, I just use the SMSL SU-8 v2 as DAC in my headphone setup as my headphones (Elex, HD600, etc) are much cheaper than my speakers for the SU-8 to blow up.

Can anyone who use the M200 as DAC/pre-amp confirm if the issues above have been resolved on the SMSL M200? Otherwise I don't want to waste $279 on M200 and just go for D90.