Surround Master V3 has landed (news, discounts etc)

[ClassicalSurroundFan]

Quick question about the SM3 DAC specs, as I want to prepare the best audio files I can for it without going overboard. Will it accept a 96k signal? If so, would it then down-sample the input for processing? In other words, would there be any theoretical difference at the output if the input signal had been 48 or 44.1?

 

[jaybird100]

It can accept s stereo signal up to 96/24.

 

[ClassicalSurroundFan]

It can accept s stereo signal up to 96/24.

Thanks, but does it downsample that signal in processing? I’m guessing that’s what they mean when they say “Processing Sample Rate 24-bit 48kHz.” I think I answered my own question.

 

[bill114]

I discovered that if both the analog and optical inputs are connected simultaneously, the SM will not output any sound. I found this while trying to input the optical output of my CD player while having the analog inputs connected from my preamp.

 

[chucky3042]

I discovered that if both the analog and optical inputs are connected simultaneously, the SM will not output any sound. I found this while trying to input the optical output of my CD player while having the analog inputs connected from my preamp.

I passed that onto Dave the Bitch as we both did not test for that!!

Dave's reply was
"
Ugh. If it's not one thing.....that's freaking weird. No sound from either input?

It's just a hard mix..maybe the optical d/a does something weird impedance-wise?"

 

[chucky3042]

I passed that onto Dave the Bitch as we both did not test for that!!

Dave's reply was
"
Ugh. If it's not one thing.....that's freaking weird. No sound from either input?

It's just a hard mix..maybe the optical d/a does something weird impedance-wise?"

My reply back to Dave was:

"I blame you"

Dave replied:
"
I blame me too.

I mean...it was offered as an alternative input, but....still.

I'm sure I had it running on the desk at work with both plugged in. Sigh.
Do I need to be distracted by this today or can it wait?"

I replied:
"Distractions are BANNED"

 

[bill114]

No worries, guys. Just thought I'd pass my finding along. I'm content using the analog inputs. I LOVE the SM!

 

[chucky3042]

No worries, guys. Just thought I'd pass my finding along. I'm content using the analog inputs. I LOVE the SM!

Dave just said....................

The optical input via the PCM5102 goes through an opamp buffer before hitting the op-amp mixer circuit, but the RCA is a direct line into the mixer with 10K input impedance. I'm sure I did it correctly, though I'm wondering if the ground connection from the RCA is upsetting the ground level of the d/a, maybe there needs to be ground isolation for the rca input? Except the d/a analog stage is referenced to analog ground. I wonder....if maybe the chip doesn't like the ground reference shifting after it has been powered up.

 

[chucky3042]

Dave just said....................

The optical input via the PCM5102 goes through an opamp buffer before hitting the op-amp mixer circuit, but the RCA is a direct line into the mixer with 10K input impedance. I'm sure I did it correctly, though I'm wondering if the ground connection from the RCA is upsetting the ground level of the d/a, maybe there needs to be ground isolation for the rca input? Except the d/a analog stage is referenced to analog ground. I wonder....if maybe the chip doesn't like the ground reference shifting after it has been powered up.

and another question

OR....hmmm - is he connecting the rca and optical to the same piece of equipment? If it's outputting on optical and rca at the same time, the optical signal gets inverted, then they get mixed - 100% cancellation or near to it if the signals are close together....

 

[Soundfield]

Dave just said....................

The optical input via the PCM5102 goes through an opamp buffer before hitting the op-amp mixer circuit, but the RCA is a direct line into the mixer with 10K input impedance. I'm sure I did it correctly, though I'm wondering if the ground connection from the RCA is upsetting the ground level of the d/a, maybe there needs to be ground isolation for the rca input? Except the d/a analog stage is referenced to analog ground. I wonder....if maybe the chip doesn't like the ground reference shifting after it has been powered up.

Using a mixer seems very odd Chucky. I was surprised there wasn't a little selector switch on the back panel but assumed it worked on an either / or basis and that the optical input took priority (i.e. if it detected an input signal on the TOSLINK connector the RCA inputs were disconnected). Not sure under what circumstances I'd ever want to mix two sets of inputs.

 

[chucky3042]

Using a mixer seems very odd Chucky. I was surprised there wasn't a little selector switch on the back panel but assumed it worked on an either / or basis and that the optical input took priority (i.e. if it detected an input signal on the TOSLINK connector the RCA inputs were disconnected). Not sure under what circumstances I'd ever want to mix two sets of inputs.

A 1 mixed with a zero is still 1
Switches cost money and are a source of failure

 

[Soundfield]

A 1 mixed with a zero is still 1
Switches cost money and are a source of failure

Guess I don't understand how your mixer is supposed to work then - if there's a signal on the RCA inputs and on the Toslink they don't get added together?

 

[chucky3042]

Guess I don't understand how your mixer is supposed to work then - if there's a signal on the RCA inputs and on the Toslink they don't get added together?

Going back to Bill114's original post it looks like its only letting one through. But in the original design philosophy we decided right or wrong that users tend to play one device at a time (at least I do)

 

[Soundfield]

in the original design philosophy we decided right or wrong that users tend to play one device at a time (at least I do)

I guess that's where we part company then - If I had a V3 (and I've thought of adding it to my stable of SM's!) my DAB/Tuner internet radio with (TOSLINK out) for example is permanently on, so I'd have to remember to switch it off before I could use the RCA inputs. I guess the horrible noises that would result from two randomly mixed signals would remind me but....!
I love your products Chucky but that just seems like the wrong approach here.

 

[bill114]

Update: It appears that the issue was either my not fully seating the optical cable into the SM or an issue with the supplied optical cable itself.
There is sound output with both inputs connected. I'm going to get another optical cable to see if it's less touchy.
My apologies for the confusion. My Idea is to play my CD player via optical and all of the other sources via analog.
I suppose it's an issue of pre-mature posting!

 

[par4ken]

Going back to Bill114's original post it looks like its only letting one through. But in the original design philosophy we decided right or wrong that users tend to play one device at a time (at least I do)

I agree, that's why in my home projects I like to use a mixer circuit for the inputs, no noisy or intermittent switch contacts to get in the way!

 

[quattro64]

I'm curious which DAC ICs are used in the SM? Is the max resolution 24bit 48khz? Also, could I build a DIY 9v battery power supply for it?

more DIY questions, is the output opamp based and are they in sockets?

and are the leds integral to the circuit? They seem a bit bright... :-|

 

[ClassicalSurroundFan]

I'm curious which DAC ICs are used in the SM? Is the max resolution 24bit 48khz? Also, could I build a DIY 9v battery power supply for it?

Just asked above about resolution. 48 is the max, but it can downsample from up to 96 (or presumably 88.2). Good question about the power supply. I wonder if that might lower the noise for recording.

 

[quattro64]

Thanks, 48khz isn't bad considering 99% of the digital music I feed it will be below or at that res, I do imagine though that feeding vinyl through it could sound a bit better if it were 96khz. Though I wonder how perceptible it would actually be with the extra channels?

Yes I think a battery supply might be the best way to avoid any powerline noise issues.

 

[chucky3042]

I'm curious which DAC ICs are used in the SM? Is the max resolution 24bit 48khz? Also, could I build a DIY 9v battery power supply for it?

more DIY questions, is the output opamp based and are they in sockets?

and are the leds integral to the circuit? They seem a bit bright... :-|

https://www.ti.com/lit/ds/sles197c/...38295&ref_url=https%3A%2F%2Fwww.google.com%2F