System planning, pre-amp, DAC etc...

[tonapo]

I am considering my options for my main stereo set-up (this is the fun bit), I am basically wondering about adding a pre-amp to my setup whilst also thinking about room correction which could perhaps be done in the DAC/streamer etc.

I am currently using a NAD M23 power amp, with a RME ADI-2 DAC FS as a pre-amp/DAC (I have a Topping D90 DAC normally in my main set-up but I have swapped it with the RME for now). The DAC is fed by a Raspberry Pi4 streamer running Raspberry Pi OS and Roon Bridge (hardwired ethernet). I also connect a Cambridge Audio CXC CD transport into the DAC via spdiff toslink. My speakers are Kef reference 1. As I occasionally get power outages, the kit is all connected to a Cyberpower - CP900EPFCLCD Uninterruptable Power Supply. I have my roon core on an Intel NUC 12WSHi7 running ubuntu server.

I also have some room correction convolution filters loaded in Roon from Home Audio Fidelity, but obviously these are only applied to the Roon input and not for the CD input. I do still buy CDs but also rip them for use in Roon, but I do still like spinning discs too!

Anyway, I like the idea of a adding a pre-amp to my main set-up (as I am always slightly nervous, rightly or wrongly, that the speakers will be fed 100% power without a dedicated pre-amp), with a separate DAC which also has the possibility of running room correction filters.

In terms of the pre-amp, I have a few on my short list, the Topping Pre90 (I could pair it with my Topping D90 DAC), Schiit Freya S preamp, Hypex DIY preamp kit and the Benchmark LA4. I would want a good remote too.

In terms of the DAC, I have been looking at the Minidsp SHD (I can then move my RME back to my desktop), as this has Dirac included, so I could measure my room and do my own room correction, which could be applied to both the Roon and CD inputs.

Is this a sensible approach, e.g., passive pre-amp + DAC with room correct? Is there any other kit I should look at? I am in the UK, so would prefer to buy locally for warranty etc.

 

[MacCali]

I am considering my options for my main stereo set-up (this is the fun bit), I am basically wondering about a passive pre-amp whilst also thinking about room eq perhaps via DAC etc.

I am currently using a NAD M23 power amp, with a RME ADI-2 DAC FS as a pre-amp and DAC (this DAC is usually in my desktop setup, but I have swapped with my Topping D90 for now). The DAC is fed by Roon (hardwired ethernet) via a Raspberry Pi4 running Raspberry Pi OS and Roon Bridge. I also connect a Cambridge Audio CXC CD transport (feeding into the DAC via spdiff toslink). My speakers are Kef reference 1. As I occasionally get power outages, the kit is all connected to a Cyberpower - CP900EPFCLCD Uninterruptable Power Supply. I have my roon core on an Intel NUC 12WSHi7 running ubuntu server.

I also have some convolution filters loaded in Roon from Home Audio Fidelity, but obviously these are only applied to the Roon input and not for the CD input. I do still buy CDs but also rip them for use in Roon, but I do still like spinning discs too!

Anyway, I like the idea of a passive pre-amp (as I am always slightly nervous, rightly or wrongly, that the speakers will be fed 100% power without a dedicated pre-amp), with a separate DAC which also has the possibility of running room correction filters.

In terms of the pre-amp, I have a few on my short list, the Topping Pre90 (I could pair it with my Topping D90 DAC), Schiit Freya S preamp, Hypex DIY preamp kit and the Benchmark LA4. I would want a good remote too.

In terms of the DAC, I have been looking at the Minidsp SHD (I can then move my RME back to my desktop), as this has Dirac included, so I could measure and do my own room correction, which could be applied to both the Roon and CD input.

Is this a sensible approach, e.g., passive pre-amp + DAC with room correct? Is there any other kit I should look at? I am in the UK, so would prefer to buy locally for warranty etc.

Actually a user on here has the same dac and pre 90 with the M23. He says it sounds superb.

I think you may be confusing certain terms, but the pre 90 is an active pre. Honestly it’s good because it feeds so much voltage to the amp.

The rest someone else will have to answer.

I have a topping D70s pre90 and M23 and I’m very satisfied with the results

 

[delta76]

I'm obviously out of my depth here but why do you need preamp with playing digitally? can't you feed the data directly to the DAC?

 

[tonapo]

Thanks for the replies.

Honestly it’s good because it feeds so much voltage to the amp.

The RME seems to do the same, I currently have the M23 in low gain mode and its v.loud.

I have a topping D70s pre90 and M23 and I’m very satisfied with the results

Interesting, so if I went the pre 90 route, my chain would be - rpi4-D90-pre90-M23. Thats a cheaper option, and I could continue to have room correction convolution in Roon, although I would miss out being able to include the CD player.

I'm obviously out of my depth here but why do you need preamp with playing digitally? can't you feed the data directly to the DAC?

I think the DAC would be fed the data from the raspberry pi/cd inputs or other source before going to the pre-amp. This is so I can have piece of mind that the speakers won't ever be fed 100% volume from the amp as the pre-amp should ensure this does not happen. As I said above, I am not sure how rational this worry is!

 

[MacCali]

I'm obviously out of my depth here but why do you need preamp with playing digitally? can't you feed the data directly to the DAC?

Honestly playing digitally doesn’t even technically need it, however the situation at hand is a lot of times I see a pre amp used to add some flavor to the presentation. Also unless you’re high up in the audio equipment range the preamp section which I believe is incorporated into all dacs is not going to be as good as what’s in a single stand alone box.

My previous system actually did seem to get louder and in addition which maybe part of my imagination run cooler. I have not tried the M23 without the pre90.

@tonapo I also use a rpi4 but mine is with HAT and that’s what feeds my d70s running Volumio to use roon

 

[delta76]

Honestly playing digitally doesn’t even technically need it, however the situation at hand is a lot of times I see a pre amp used to add some flavor to the presentation. Also unless you’re high up in the audio equipment range the preamp section which I believe is incorporated into all dacs is not going to be as good as what’s in a single stand alone box.

My previous system actually did seem to get louder and in addition which maybe part of my imagination run cooler. I have not tried the M23 without the pre90.

@tonapo I also use a rpi4 but mine is with HAT and that’s what feeds my d70s running Volumio to use roon

Not sure I understand what you said. A preamp is used to boost the signal, so if you are using some analog source, like vinyl yes it is needed if not required. If you play with digital, any decent DAC should have sufficient output to feed into an amplifier. You don't need a preamp here.

And a preamp should not add any "flavor" to the source. That is essentially adding distortions.

 

[HoweSound]

I have recently updated my system, which is less elaborate than yours. I have a fanless pc, running Linux as a music server, also a Raspberry PI with Volumio less often. I have analogue inputs from a turntable and universal CD/DVD player to an integrated amp. I'm moving to separates with a Schiit Freya S and Hypex Nilai power amp. I am waiting for my Eversolo DMP A6 to arrive (due today). Hopefully it will replace my PC and Raspberry Pi as a music server dac and streamer. Were it not for my analogue sources and concerns about using the Eversolo as a preamp, I could dispense with the Freya S. The Freya S coupled to the Hypex, set on medium gain sounds superb. I expect an improvement when the Eversolo's dac is the source.

 

[tonapo]

I am waiting for my Eversolo DMP A6

Exciting!

The Freya S coupled to the Hypex, set on medium gain sounds superb

I can't seem to find one in UK, which is a shame, I might keep an eye on ebay.

 

[HoweSound]

Exciting!

I can't seem to find one in UK, which is a shame, I might keep an eye on ebay.

The only place I could find the Schiit was directly from the manufacturer's website. they're in the USA, but shipping to Canada went smoothly, although a little more expensive than I expected. You might check to see if they can ship to you if you think the Freya will meet your needs.

 

[Rednaxela]

Have you considered doing room correction with the RME?

 

[tonapo]

The only place I could find the Schiit was directly from the manufacturer's website. they're in the USA, but shipping to Canada went smoothly, although a little more expensive than I expected. You might check to see if they can ship to you if you think the Freya will meet your needs.

Thank you, I will check this. I do note they have a UK store but lots of kit out of stock, I will probably enquire there too.

Have you considered doing room correction with the RME?

Thank you, yes, I had. I did work with the Home Audio Fidelity owner, Thierry, earlier on in the year on this, with mixed results. I will see if I can find my notes, but there were certain limitations, from memory, across the five bands, and I was never happy with the results, hence thinking about the minidisp SHD, or sticking with loading room correction filters into Roon.

 

[OCA]

I am considering my options for my main stereo set-up (this is the fun bit), I am basically wondering about adding a pre-amp to my setup whilst also thinking about room correction which could perhaps be done in the DAC/streamer etc.

I am currently using a NAD M23 power amp, with a RME ADI-2 DAC FS as a pre-amp/DAC (I have a Topping D90 DAC normally in my main set-up but I have swapped it with the RME for now). The DAC is fed by a Raspberry Pi4 streamer running Raspberry Pi OS and Roon Bridge (hardwired ethernet). I also connect a Cambridge Audio CXC CD transport into the DAC via spdiff toslink. My speakers are Kef reference 1. As I occasionally get power outages, the kit is all connected to a Cyberpower - CP900EPFCLCD Uninterruptable Power Supply. I have my roon core on an Intel NUC 12WSHi7 running ubuntu server.

I also have some room correction convolution filters loaded in Roon from Home Audio Fidelity, but obviously these are only applied to the Roon input and not for the CD input. I do still buy CDs but also rip them for use in Roon, but I do still like spinning discs too!

Anyway, I like the idea of a adding a pre-amp to my main set-up (as I am always slightly nervous, rightly or wrongly, that the speakers will be fed 100% power without a dedicated pre-amp), with a separate DAC which also has the possibility of running room correction filters.

In terms of the pre-amp, I have a few on my short list, the Topping Pre90 (I could pair it with my Topping D90 DAC), Schiit Freya S preamp, Hypex DIY preamp kit and the Benchmark LA4. I would want a good remote too.

In terms of the DAC, I have been looking at the Minidsp SHD (I can then move my RME back to my desktop), as this has Dirac included, so I could measure my room and do my own room correction, which could be applied to both the Roon and CD inputs.

Is this a sensible approach, e.g., passive pre-amp + DAC with room correct? Is there any other kit I should look at? I am in the UK, so would prefer to buy locally for warranty etc.

With MiniDSP SHD you're limited to IIR filters and will not be able to correct in the time domain. It doesn't have FIR filter capability (only reserved for Dirac) and neither does RME. MiniDSP Flex or 2x4HD are limited to max 2048 taps per channel which is not great for low frequency corrections. If you can find an OpenDRC-DI, they have 6144 taps capacity per channel at 48kHz with which you can do some descent phase correction (i.e. crossover, box/port). None will come close to what you can do in Roon DSP with a NUC.

 

[tonapo]

With MiniDSP SHD you're limited to IIR filters and will not be able to correct in the time domain. It doesn't have FIR filter capability (only reserved for Dirac) and neither does RME. MiniDSP Flex or 2x4HD are limited to max 2048 taps per channel which is not great for low frequency corrections. If you can find an OpenDRC-DI, they have 6144 taps capacity per channel at 48kHz with which you can do some descent phase correction (i.e. crossover, box/port). None will come close to what you can do in Roon DSP with a NUC.

Thanks for the info!

 

[MaxwellsEq]

I'm obviously out of my depth here but why do you need preamp with playing digitally? can't you feed the data directly to the DAC?

You might want to search for threads about DACs suddenly going to max output. In its pure state a DAC should always be at 100%, some DACs have attenuators to allow volume control, but these are under the control of software functions, which can have bugs and behave erratically. A classic active preamplifier has a mechanical potentiometer instead. It can also have gain as well as attenuation.

Despite being fully aware of this risk, I fed a DAC directly into a Power Amplifier for several years and never had a problem.

 

[tonapo]

You might want to search for threads about DACs suddenly going to max output. In its pure state a DAC should always be at 100%, some DACs have attenuators to allow volume control, but these are under the control of software functions, which can have bugs and behave erratically. A classic active preamplifier has a mechanical potentiometer instead. It can also have gain as well as attenuation.

Despite being fully aware of this risk, I fed a DAC directly into a Power Amplifier for several years and never had a problem.

Thanks @MaxwellsEq. I think it is this point that resonates most with me, I would not want that to happen, and so it is the main reason I would prefer a preamp in the chain.

I was reading @Kal Rubinson review of the pre90 which was really helpful, and he also compared the pre90 with the Schiit Freya here (albeit the tube version, but it does have three modes, and I would probably use in its passive mode, which the schiit freya s also has, so should be comparible.). And we already know both units measure well. Topping here and schiit here.

I would like the Benchmark LA4 in an idea world, but that might have to wait for a while so I think the choice before me is the Topping pre90 or the Schiit Freya S. There is an open, but not used unit supposedly going back to Schiit in the UK, that I could buy, or wait 2-3 weeks for a new unit. The topping is available now from a few retailers. I could accomodate the topping more easily in my rack. Both have remotes, but I think neither remote is perfect. Both units are around £600 (£690 for new Schiit). Decisions, decisions...

 

[ninox]

So what did you end up doing? Are you happy?

 

[tonapo]

I ended up purchasing a Topping pre90, and run it wtih my topping D90. The M23 is in low gain mode. I have convolution files loaded in Roon from Home Audio Fidelity. There were a few teeting problems, first one was to do with the Topping controller, which I could not get on with, but I ended up using a Logitech remote for volume control and this improved things no ended. I generally control Roon or plex via an app on my phone or tablet, with volume control on the Logitech as mentioned. Streaming duties are undertake by a raspberry pi 4 running ropieee over wired ethernet. I still control the Cambridge Audio for CDs when I want to play directly. Sounds great.