Trigger cable lowers temperatures & power consumption

[Axel]

A trigger cable allows the companion/slave to enter a deeper sleep in standby mode, there is no change in “playback” behavior. In standby its very noticeable, my slave was always warm to touch (ie, burning money), with a trigger cable it gets cold (after a few hours). The system wakes up from standby a little quicker too: as a soon as the main wakes, it triggers the companion to wake. It’s worth doing for sure. The only cost is a cheap 3.5mm headphone cable, and 5 mins playing with the configurator.

Does the companion go completely cold after a few hours? If so, how is this different from fully off mode? I prefer the amps to stay warm in standby mode as it means less thermal shock to the components on startup.
On my valve driven guitar amps, standby is used to make sure that the valves are up to temperature and ready to go as soon as the amps are switched "on". On my 440s, having them warm in standby mode means they are up to operating temperature that bit quicker.

[daniel.avasilichioaei]

Does the companion go completely cold after a few hours? If so, how is this different from fully off mode? I prefer the amps to stay warm in standby mode as it means less thermal shock to the components on startup.
On my valve driven guitar amps, standby is used to make sure that the valves are up to temperature and ready to go as soon as the amps are switched "on". On my 440s, having them warm in standby mode means they are up to operating temperature that bit quicker.

No, companion unit is not cold. It has the same temperature as the master unit. Without trigger cable it has higher temperature than the master unit.
It gets cold if you unplug it from the mains, but not on stand by or power off.

To me, difference between stand by and power off it is a misstery (except for display behavior). I was not able to find technical details about this...

[deviousalet]

I can understand how the trigger cable improves companion startup time, standby/sleep power consumption, and therefore temperature. By allowing better communication between amps via the trigger cable the companion can use less power waiting for information through the inferior interlink channel (RCA-RCA or RCA-XLR).

I don't fully understand how the trigger cable improves other aspects, but I can understand how the companion could enter a deeper sleep mode if it takes less power to wait for a signal from the trigger cable than interlink cable. The benefits go beyond low-power states though. Experimentation shows that the trigger cable lowers power consumption, and therefore temperature, while active. I've measured this many times on Devialet 400, 440, and now 1000. I'd enjoy figuring out why both master and companion use less power when active if triggered.

I started this thread to tell others that by simply connecting a cheap 3.5mm cable they can use less power for the same function. The lower temperature is simply easier to see than power consumption. Some people feel that lower temperature improves sound quality (thus the experimentation with orientation and even case mods). Others prefer the sound at higher temperature (thus wasting power by leaving their amps on when unused). I clearly have a bias, but only wanted to provide information.

Let's be clear that the trigger cable improves things in all states: on, standby, and sleep (Devialet's have no real off mode). If you doubt this, measure it. If my measurement techniques are in error I'm happy to have help improving them.

I'm glad to see even Devialet becoming clearer about the benefits of using the trigger cable. At this point it seems uncontroversial that using the trigger cable brings benefits.

I wish that Devialet would allow use of the trigger cable when using the RCA-XLR interconnect, but at least they've improved the sound of the RCA-RCA interconnect. When I experimented with my D400 the RCA-XLR connection clearly sounded better, but with my D1000 Pro CI and the latest firmware the opposite was true. Each system may be different that way, so it would be nice to get the benefits of triggered operation with either interconnection.

I'm very interested in everyone's experience about what differences the trigger cable makes. Thanks for reanimating this thread.

[thumb5]

Speculating a little, but not too wildly:

• It's likely that the processor(s) on the companion could go into a very low power state from which it could be woken on receipt of an interrupt; I doubt the S/P-DIF inputs (whether on RCA or XLR connectors) can generate interrupts on a transition, but it would be trivial to do this using the trigger input which I guess is just a discrete digital signal (aka GPIO).  In other words, the master just has to send a high-to-low or low-to-high transition via the trigger cable to wake up the companion from its deep sleep.
  
• The configurator might not support the trigger cable when the master/companion connection is via RCA-XLR because that configuration is inherently asymmetrical, as the XLR connector is an input only.  This means that the companion can't transmit data from any of its inputs to the master so the companion inputs can't be used.  That would make the trigger cable redundant if you consider its primary purpose to be related to input switching (rather than waking up the companion).
  

[deviousalet]

Thanks for the interesting informed speculation!

Now that Devialet has started to recognize that the trigger cable has benefits other than allowing use of companion inputs it would be nice if they recognized that in software: allowing the use of triggering for power states without requiring a companion input to be active. Then they could allow use of the XLR connector too. Devialet has only recently come around to admitting that the trigger cable lowers power consumption and temperature, but I appreciate their progress while hoping for more.

[mdconnelly]

Updated my config, inserted trigger cable and it works like a charm. Thanks @daniel.avasilichioaei for getting us started down this path.

[flohmann]

Thanks all, I updated my summary post to reflect what you've reported (that temp diff applies to all mono units).

Do we have consensus that the temp difference applies to the "on/playback" state (as well as "standby")? Seems @"alaw" and @deviousalet have differing views on that.

[daniel.avasilichioaei]

Updated my config, inserted trigger cable and it works like a charm.  Thanks @daniel.avasilichioaei  for getting us started down this path.

I'm glad you succeeded.

In fact, the merit is not mine: everything started from this post https://devialetchat.com/Thread-440-Pro-...0#pid91480, which belongs to Jean-Marie. Thanks to Jean-Marie I started this investigation. Also, the support team from Devialet played an important role, as they certified and confirmed the solution from a technical point of view.

[daniel.avasilichioaei]

Thanks all, I updated my summary post to reflect what you've reported (that temp diff applies to all mono units).

Do we have consensus that the temp difference applies to the "on/playback" state (as well as "standby")? Seems @"alaw" and @deviousalet have differing views on that.

I cannot confirm or deny the impact on the operating temperature. Both before and after using trigger cable, I did not see a temperature difference of more than 1 degree between master and companion. At the same time, in my tests I did not follow the absolute values of the operating temperature (both units warmer or colder).

[hardcore]

I wish that Devialet would allow use of the trigger cable when using the RCA-XLR interconnect, but at least they've improved the sound of the RCA-RCA interconnect. When I experimented with my D400 the RCA-XLR connection clearly sounded better, but with my D1000 Pro CI and the latest firmware the opposite was true. Each system may be different that way, so it would be nice to get the benefits of triggered operation with either interconnection.

I'm very interested in everyone's experience about what differences the trigger cable makes. Thanks for reanimating this thread.

I've tested my dual-mono to see how the sound changes with and without the trigger cable. It definitely sounds different with vs without it. I prefer the sound without the trigger cable - it sounds smoother and the soundstage is more 3-dimensional, especially using the RCA-XLR interconnect. With the trigger cable it sounds a little sharper but less airy.

The sound difference happens even *without* changing the configuration - basically just connecting the cable creates another electrical path between master & companion units. My theory is the trigger cable adds another potential ground loop path between the master & companion. I minimize that possibility by using galvanically isolated inputs and outputs: WiFi instead of Ethernet, XLR input on Master, RCA-XLR to companion, RCA output to subwoofer has a Jensen SUB-2RR isolation transformer.