Pre-amp for active digital / analogue speakers

[andrew]

This does look pretty neat.

Agreed - a one box solution with, importantly for me, option for time delays on the main speakers to improve integration with subs. (My hope is that ultimately the 8c DSP will support this time alignment between sub output and main speakers)

 

[Strictly Stereo]

I'd be interested in hearing the feedback from such a test

I have done a few tests here and in customers' homes. Using a very neutral-sounding DAC or analogue preamp the difference is inaudible compared to a digital source. When we tried an older analogue preamp (a Sugden design from around 1990), the system picked up some of the "flavour" from the preamp.

As to the AES output requirement, you can easily connect a standard coaxial S/PDIF output to an AES input using an impedance transformer. This provides a whole lot of extra front end options. This Neutrik one costs under £50 and can be plugged straight into the back of one speaker. You then run standard 110 Ohm AES to the second speaker.

 

[gingerbeer]

The adapter above is AES/EBU to BNC.

Is it a case of then having a second adapter to get to coaxial spdif? (or alternatively a cable with bnc on one end and coax on the other). ?

 

[Blumlein 88]

The adapter above is AES/EBU to BNC.

Is it a case of then having a second adapter to get to coaxial spdif? (or alternatively a cable with bnc on one end and coax on the other). ?

Yes. These below are even the proper 75 ohm rating. Most BNCs are 50 ohm.
https://www.amazon.com/VCE-Gold-Pla...1530330432&sr=8-4&keywords=rca+to+bnc+adapter

 

[Strictly Stereo]

The adapter above is AES/EBU to BNC.

Is it a case of then having a second adapter to get to coaxial spdif? (or alternatively a cable with bnc on one end and coax on the other). ?

By "coaxial" I was referring to the cable, rather than the connector, but yes this adapter uses BNC. Some of our products have BNC connectors and others have RCA connectors. You would use RCA to BNC or BNC to BNC cables as required to connect up to other equipment.

 

[Dialectic]

In my system, I use a cheap Hosa Toslink-to-AES adapter to connect to the 8Cs. (The reason I'm using Toslink and the Hosa has to do with BACCH processing.)

Did I notice any degradation as compared to a direct connection from an AES interface? No, none at all.

 

[Deleted member 2348]

These below are even the proper 75 ohm rating.

These adapters might have a 75 Ohm rating, but the plug certainly is a 50 Ohm BNC plug. 50 Ohm BNC has a ring of dielectric material inside the outer contact while 75 Ohm BNC comes without this ring (simply google for "bnc 50 75" images). Futhermore the outer contact of these adapters is poor because the metal ring is not slotted.

Fortunately this doesn't matter too much because the wave impedance of the RCA phono connector is not specified at all …

 

[RayDunzl]

These below are even the proper 75 ohm rating

Curious, looked, didn't find.

At what frequency are they 75 ohms?

 

[sergeauckland]

When I worked In TV, bringing a 50 ohm BNC cable on-site was a sacking offence!!!
50 ohm BNCs are the work of the devil, and should be kept away from decent people, and limited to RF engineers.

(thus spake an audio man)...........

S.

 

[andrew]

I have done a few tests here and in customers' homes. Using a very neutral-sounding DAC or analogue preamp the difference is inaudible compared to a digital source. When we tried an older analogue preamp (a Sugden design from around 1990), the system picked up some of the "flavour" from the preamp.

View attachment 13465

That’s really helpful. I’m super tempted to use an AV Pre-Pro with balanced analogue out to the 8c for day to day TV / movies and the on-board Roon endpoint for music. Your findings lend weight to this being a suitable setup but it will be a matter of getting over the audio nervous re a to d to a. The other issue will be the suitability of the app or box at simply switching between the inputs

 

[Kal Rubinson]

When I worked In TV, bringing a 50 ohm BNC cable on-site was a sacking offence!!!
50 ohm BNCs are the work of the devil, and should be kept away from decent people, and limited to RF engineers.

And the 75ohm BNCs were verboten in the neurophysiology labs.

 

[NWCgrad]

Two good candidates for feeding the D&D 8c a digital signal with attenuation are the Lynx Hilo and the Grace Design M-905. Both would serve as pretty capable preamps.

For less expensive digital attenuation from a computer via remote the Weiss Engineering INT204. This unit is a USB to AES/EBU (unidirectional) interface that can also do DSD to PCM conversion (DSD files played to the INT204 result in conversion to PCM at a, selectable, sampling frequency and word-length). So the D/A Converter in the 8c becomes a DSD capable DAC.

 

[Dialectic]

Two good candidates for feeding the D&D 8c a digital signal with attenuation are the Lynx Hilo and the Grace Design M-905. Both would serve as pretty capable preamps.

For less expensive digital attenuation from a computer via remote the Weiss Engineering INT204. This unit is a USB to AES/EBU (unidirectional) interface that can also do DSD to PCM conversion (DSD files played to the INT204 result in conversion to PCM at a, selectable, sampling frequency and word-length). So the D/A Converter in the 8c becomes a DSD capable DAC.

That's a lot of money for a volume knob. I was worried about not having a physical volume knob, too, when I got the 8Cs.

But I learned to stop worrying and love software volume control (in the 8Cs themselves for setting an upper limit on volume level; in Roon, Foobar, JRiver, etc. for small adjustments in conventional setups; and in BACCH for those of us who have attained enlightenment).

 

[andrew]

That's a lot of money for a volume knob. I was worried about not having a physical volume knob, too, when I got the 8Cs.

Yes the web-app is fine for me but not the family - agree, though, that these are expensive options.

Re: D/A/A/D/A: Current set-up for A/V is HDMI to TV with optical out (48kHz) to mini-DSP 22DD which sends volume adjusted 96kHz AES to 8c. The A/V alternative looks like HDMI to Pre-Pro with balanced analogue output to 8c (which then does A to D). I'm thinking that the latter would be better bet as it avoid the noisy TV / downmix to 48kHz etc. and advice seems to be that 8c A/D is clean. Any views as to whether this is correct?

 

[Kervel]

Maybe I'm late to the party, but the CD player by Audiolab 8300CDQ has many digital inputs and outputs, including AES/EBU out, and a remote control.

Edit: AES/EBU seems only connected to the CD player--not the other inputs. Thus, the search continues. Thanks mssngpeces

 

[mssngpeces]

Maybe I'm late to the party, but the CD player by Audiolab 8300CDQ has many digital inputs and outputs, including AES/EBU out, and a remote control.

I thought the AES/EBU out was only working for the CD player and not while using the the other digital inputs (ie: using USB input won't output anything from the digital output)?

 

[Kervel]

I thought the AES/EBU out was only working for the CD player and not while using the the other digital inputs (ie: using USB input won't output anything from the digital output)?

Ow, did not know that! I checked the manual but it did not say anything related to your point--do you have a source? I also wonder whether the volume control applies to the AES/EBU output (alternatively, it might just output the full digital signal).

 

[mssngpeces]

Ow, did not know that! I checked the manual but it did not say anything related to your point--do you have a source? I also wonder whether the volume control applies to the AES/EBU output (alternatively, it might just output the full digital signal).

One thing to note is that the CDQ version DOES NOT have the AES/EBU output (only the 8300CD version has).
Source: I have the CDQ, but I sent it to Audiolab to update its firmware, so I can't test the volume control right now.
If I remember correctly, only when using the CD player did the SPDIF/Toslink out work. I assume it's the same with the 8300CD and the AES/EBU output.

 

[prestigetone]

Is anyone using the Lake People DAT RS 05? That seems to be a good option but at that price I might as well go the RME ADI Pro route. Frustrating that there arent more options for this type of converter given how many digital speakers are on the market now. My girlfriend will want a physical remote for volume control, but D&D says to use the speakers as there is a more direct signal. Has anyone found a stellar solution?

 

[Purité Audio]

I use the RME and send ( and attenuate) a digital signal to the 8Cs, it is a versatile bit of kit and as you say there aren’t too many other options at the moment.
Keith