[EC]

I'm just curious as to why the "good" pre / pro's make clicking noises when locking onto or releasing a digital bitstreams such as PCM, DTS, DD etc. I assume these clicking noises are mechanical relays in the unit


I hear these clicking noises on my Bryston SP 1.7. Used to hear these on an Acurus ACT-3 I previously owned. If I recall the Krell Showcase makes these clicks as well when I auditioned it.


I didn't hear these clicking noises on a Rotel RSP -976 I previously owned and don't hear them on my NAD T-760 receiver if I recall.


This is a generalization from my experience but it seems that the lower priced gear don't make clicks but the higher end gear does.


Why all the clicking? Mechanical switching in the signal path? Doesn't bother me but enquiring minds want to know.

 

[Diode1]

Quote:

Originally posted by EC .Why all the clicking? Mechanical switching in the signal path? .

Yes

Some pass the click to the speakers for those without a muting circuit in the pathway when the circuit is closed/made and power flows.

 

[rich wu]

I would guess that lower cost units use solid state such as integrated circuit switches rather than relays since they are cheaper and easier to implement. An IC switch doesn't perform as well as a mechanical relay.


Rich

 

[mitchius]

I don't know why but my B&K ref30 does it. Other than that (and the lack of upgrades) I love it.


Mitch

 

[cskates]

The Tag AV32R clicks, or rather did click, when changing surround mode or muting. A few years ago a software change was made so that you can configure it to use mechanical relays for muting or mute through software, there's no difference that I can hear (besides no clicking!).

 

[AKA-Chuck G]

My Sony TA-E9000es clicked like Fred Astair. The Aragon Soundstage is quite as a church mouse.

 

[Brian Corr]

So if it clicks and has a "THX" logo, it must be good!

 

[jerrich]

The Pioneer 811 (&711?) also click up a storm when switching inputs. I was surprised that such old fashioned technology was still in use. I had a Teac open reel recorder in the 60's that was full of relays. What's old is new again. JR

 

[BGLeduc]

My Sony EDP800 clicks as well, but it is purely mechanical, not something that is passed through the analog outs. Relays to be sure.


BGL

 

[dsmith901]

If by "click" you refer to the noise inside the preamp of a mechanical relay, yes that is a good thing - my Citation 7.0 makes that click when engaging the 2 channel bypass. But if you mean the signal noise that to me sounds more like a small "pop" from the speakers when switching digital inputs, no that is not a good thing IMO because it means signal noise that, if loud enough, can damage speakers. Usually it is not loud enough to damage your speakers, but it is very annoying, and to me it represents a poor circuit-ground design.


Dsmith

 

[Mad Chemist]

My Lexicon MC1 doesn't click and I'm thankful it doesn't. I've owned some pre/pros that clicked (as in a mechanical relay in the pre/pro) everytime I changed the channel. At the speed I channel surf, I was sure that I was going to fry that relay at any moment.

 

[goldear]

DSmith brings up an important distinction between relay clicks and noise associated with changing modes and sources...and locking on to a digital signal. My Proceed AVP and MC-1 were silent in the relay department but when it came to skipping tracks with a DTS CD, there would be the occasional pop or momentary signal loose until it locked on. This could also occur when changing a DVDs audio format from say DD to DTS on the fly. Some manufacturers use a mute circuit, but in that case, sometimes you miss the fist few milloseconds of the disc. I think companies are doing better now, as my Halo so far has none of these problems.

 

[dsmith901]

I should add that the processor or receiver is not always at fault as the cause of system noise through the speakers. I had those noises in my system until I switched out a Chiro amp for a Bryston and the noises went away. The Chiro was a nice sounding amp but had a "dirty chassis" that induced noises in the system's circuitcs. So if you have that kind of noise emanating from your speakers when you make input changes or turn-on/off, try a different amp and see if it makes a difference. Also check for bad cables/connections, as that can also cause popping noises.


Dsmith

 

[EC]

Quote:

Originally posted by dsmith901 If by "click" you refer to the noise inside the preamp of a mechanical relay, yes that is a good thing

Yes, this is exactly what I mean. You could have your power amp turned off or your speakers disconnected and this will have no bearing on the clicking. On the Bryston SP 1.7 even when you switch the sources it clicks also but I believe this is from the relays trying to detect a new bitstream for that source. As with your Citatation when it clicks when you switch to 2 ch bypass, the Bryston I know has relays in the signal path for 2 ch by pass so it truly bypasses the DACs.


I get the click when the DVD does it layer change and loses it bitstream for a second. Recently I was watching either one of the Die Hard movies or the Fugative in DTS. Here is what happened:


Put the DVD in the player (Pioneer DV37) hear some clicks can't remember what it locked in as on the menu. Using the DVD's menu I choose DTS 5.1 and then play the movie. Clicks and it locks into DTS 5.1. The DTS trailer starts, the one with the piano strings. Clicks and locks into DD 5.1. Next the THX trailer comes up. Clicks and locks into DTS 5.1 and the movie starts.


I did D/L the Krell Showcase manual when I was deciding between the Bryston and the Krell. The Krell has an option / setting where it will keep the current "format / bitstream" setting eg DD 5.1 for 20 seconds so it won't have to resync from layer changes or pauses.


Thanks all for your responses. It is interesting to know what clicks and what doesn't click out there and the reasons why.

 

[PlasmaSquid]

Quote:

Originally posted by dsmith901 If by "click" you refer to the noise inside the preamp of a mechanical relay, yes that is a good thing - my Citation 7.0 makes that click when engaging the 2 channel bypass. But if you mean the signal noise that to me sounds more like a small "pop" from the speakers when switching digital inputs, no that is not a good thing IMO because it means signal noise that, if loud enough, can damage speakers. Usually it is not loud enough to damage your speakers, but it is very annoying, and to me it represents a poor circuit-ground design.

Dsmith is correct. Too much "pop" to the speakers can be annoying if it's very audible and, depending on the magnitude of the pop, potentially damaging to your speakers. Clicking that's just mechanically audible is fine and good.


Pops/clicks can be induced digitally also, in the case where the sample value makes an "unnatural" transition. For example, in the case when a large scale value is suddenly muted to zero, or other such large sample value transitions.