Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Anyone here use attenuators?

As I understand it, my 861v4 uses a hybrid digital/analogue volume control for its analogue outputs.
I use an ID40 card for music purposes from a Roon, which I believe uses 64 bit precision to maintain data. All of my outputs are via OA13 balanced cards to analogue amps.

Does anyone know:
- is the 861v4 using its own built in volume control and if so what the level of precision the digital part of it is?
- does the ID40 bypass the built in volume control and apply its own 64bit digital
- has anyone tried or uses an attenuator such as the Rothwell XLR 10db, to reduce the reliance on digital attenuation?

My active 'speakers have level switches (+4dB, 0dB & -10dB) and I run them all at -10dB, so my G68SL XLR outputs are run 10dB higher for the same in room loudness.

In theory, this should give an additional 10dB of noise rejection in the cables to the 'speakers, plus run the volume control on the G68 10dB closer to the 0dBFS.

Whether it makes any difference is moot, but makes me feel better...

Looking at the block schema of the used DAC chip I think this happens in the digital domain in the second DAC stage but that is an assumption as it can also probably be done by one of the DSP boards.

An interesting question, to which I’ve never seen a clear answer, is the precise volume levels on processors and endpoints where the analogue stage kicks up or down a step (i.e., at which volume levels there is zero digital attenuation/gain).

Of course, this might be different for each endpoint, and in the case of a processor would likely be affected by the attenuations carried out during speaker calibration… but let’s say in Direct, which I believe bypasses all that.

You can still apply room correction to the direct mode if you want to, at least that is what i do to solve an acoustic issue in my room.

Have tried various Rothwell balanced and non balanced devices but quite some time ago. I don’t recall that I felt the need to use them from my (then owned) 861V4 to analogue actives.

I did however use when I had an analogue pre amp in the system, which by design intent was in consideration of those who wanted a pre amp next to or very close to their listening seat; I recall up to the ability to drive long cable lengths with no fuss (25m and beyond ??)

Anyway the Rothwell’s did the job and gave me extra control on the volume pot in terms of range setting sensitivity, loud went from 9 o clock to 12 o clock, with the attenuators in place. I think I was using balanced -20dB devices for that.

This is going back nearly 10 years.

A pair of -10dB Rothwells arrived today.
Only a couple of tracks in, so I’ll be careful about too overtly positive, but initial impressions seem good.

From a volume perspective, the implications are that I’m now running at 80 for what I’d say is a pretty full on “loud but not deafening” experience.
Assuming the 861 uses a digital volume, it does mean the potential for precision “might” have improved.
I think I’ll see if I can grab a pair of 20dB versions too.

If you look at these HFNRR measurements on an 861v1, there is some insight into how the 'hybrid' analogue/digital volume control works. It's helpful to read the relevant part of the measurements blurb which accompanies the graph. It's not very simple as to where you might choose to attenuate for normal listening levels... Perhaps 75, and then avoid going over 94 max. to avoid potential digital clipping?

Whether the same applies to later versions of 861, or 568, or the two-channel endpoints, who knows.

In an 861 this is further complicated, I assume, by the fact that in multichannel use, speaker level calibration has occurred, which means a certain amount of digital attenuation has already happened...

That’s a very interesting link, my thanks for that.
Following a good hour of some listening, I’m sold on the use of the attenuators.
The most striking element being that background noise appears lower, meaning that instruments and vocals are better defined in their location and clarity. Bearing in mind how much we spend on gear, this feels like a good price to value relationship.