For multi-channel it would be better to sense the input resistance or include a dip switch I think. A 3 way dip switch for auto-on sensitivity would also be useful (hi/lo/disabled)
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3e Audio A7 [TPA3255 PFFB Stereo] Finished Amplifier - User Impressions | Owner's Thread
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Guddu
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Mine goes to standby as well…. Wakes up when volume on ZD3 goes over 25.
I have ZD3 connected to A7 on xlr, but Volume 25 is barely listenable sitting 3 meters.
Speakers are Ascend Sierra-lx, not efficient class.
Seems like this it’s normal behavior then!
@3eaudio - does it sound right?
I would say that the Sierra-LX show pretty much average sensitivity. The higher the speaker's sensitivity, the more the problem will kick in.
If you were listening at say 0.5 m distance instead of 3 m distance the SPL would be 15 dB higher (with everything else unchanged).
OK ... I would call that extremely low volume with the WiiM Ultra volume control set to 10.
At least your hearing seems to be fine.
Piotr
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I'd love to crank up the volume a bit, but I value my life too much to risk waking my wife, who's sound asleep in another room with the doors firmly closed.OK ... I would call that extremely low volume with the WiiM Ultra volume control set to 10.
At least your hearing seems to be fine.
@Guddu @harkpabst @Piotr @mcdn @SMen and etc.
thanks all for your feedback and chime in,things won't be so perfect at the beginning but we keep learning and improve.
regarding the audio sensitivity,do you have experience what level set will be more convenience for most of the people? 1mV or something like that? i can ask team to do a quick evaluate test.
thanks all for your feedback and chime in,things won't be so perfect at the beginning but we keep learning and improve.
regarding the audio sensitivity,do you have experience what level set will be more convenience for most of the people? 1mV or something like that? i can ask team to do a quick evaluate test.
For 2Vrms as max input (unbalanced), your current choice of 2mV is -60dB. I would suggest -70dB and -50dB. Any lower then -70dB and you get into problems with input noise triggering the input. So yes, 1mV and 4mV. Doubled for balanced inputs.
Hey, my 2 A7 monos (vol bypass, -<XLR -<fosi ZD3) also have the same unwanted behavior of switching off at lower listening levels (still reasonable) that I need and want to be able to use. Not absolute levels of course but switching off at ZD3 vol setting 28-35 depending on input (speakers spec'd 88 db/w). Also disappointed with this, particularly as they sound very good when they are on -- but I've had to remove them from my system.
2 - 4 mV is too much. My amp with audio sense has a sensitivity of less than 1mV and works perfect for me, even to watch movies. The designer (member of ASR) says though that was not easy to make it so sensitive and avoid other issues like getting triggered when you switch on another appliance etc. like some claim the fosi do.
You scared me a bit. This morning I checked on my set and with the volume set to 10 (Wiim Ultra) it was definitely too quiet. I know that this is a rather subjective matter, but in my case I would have to sit with my ear next to the speaker. The acceptable level (although still too quiet for me) is 15, and then the Sub (SVS SB-1000) does not turn on and the A7mono have no problem with this. I did not have time for longer tests in the morning (work), but the amplifier played for about 15-20 minutes non-stop and did not turn off, so in my case this defect, if you can call it that, will not be a problem.
To add a bit of detail - ideally you would have some hysteresis so "on" is triggered at e.g. 2mV, but the off timer isn't triggered unless the input level drops below 0.5mV. This is what I do with my own amps but I have a microcontroller in there to manage things and appreciate it's not that easy to do cheaply with analog circuits.
KSTR
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Standby level sensors are a most tricky affair, it is very hard to find a sweet spot that works for most scenarios.
IME, one needs several things:
- restricted bandwidth, notably down low, to avoid nuisance triggering from mains hum (when upstream gear goes into standby, signal conductors often go open circuit and thus become prone to pick up hum)
- integrating behavior, a single event, even when large (like a turn-on thump from upstream gear), shall not trigger
- hysteresis, so that turn-off threshold is quite a bit lower than turn-own threshold
- hold time that keeps the unit active for some time even after turn-off threshold has been reached
- and preferably, adjustable overall threshold, like in three steps 10dB each, as mentioned by @mcdn .
- finally, the sensing circuit must not affect the main signal (learned that the hard way ;-)
Doing all that with an analog circuit is quite a challenge. Low power uC with some proper analog front end is much more convenient and may even result in lower BOM cost.
There is a reason why many gear has moved to 12 triggers, then only one device, the source, usually digital, can implement the control in the best, simplest and most reliable way.
IME, one needs several things:
- restricted bandwidth, notably down low, to avoid nuisance triggering from mains hum (when upstream gear goes into standby, signal conductors often go open circuit and thus become prone to pick up hum)
- integrating behavior, a single event, even when large (like a turn-on thump from upstream gear), shall not trigger
- hysteresis, so that turn-off threshold is quite a bit lower than turn-own threshold
- hold time that keeps the unit active for some time even after turn-off threshold has been reached
- and preferably, adjustable overall threshold, like in three steps 10dB each, as mentioned by @mcdn .
- finally, the sensing circuit must not affect the main signal (learned that the hard way ;-)
Doing all that with an analog circuit is quite a challenge. Low power uC with some proper analog front end is much more convenient and may even result in lower BOM cost.
There is a reason why many gear has moved to 12 triggers, then only one device, the source, usually digital, can implement the control in the best, simplest and most reliable way.
OP
Guddu
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I double checked again just now and my A7 isn't going to standby when ZD3 volume is set to 30.
If you can, pls give it a try with 30 on ZD3 for 10 min and see how it goes.
ZD3 that I have is going to Amazon, one of my friend gave it to me for some quick checks before he send it back as he didn't like it.
I won't be able to check volume levels from ZD3 further, so had to ask you to try.
Thanks
Hi all,
I already nearly decided to buy a A7, as it had a 12V Trigger in the first reviews.
Did / could anyone test, how the A5/A7 reachts if it is connected to a switchable power supply?
If you switch off power with the amp being "on", will it then restart when power is switched back on?
This could be a workaround, as i.e. audiophonics offer 230V switches working with a 12V Trigger.
Thanks
Juergen
I already nearly decided to buy a A7, as it had a 12V Trigger in the first reviews.
Did / could anyone test, how the A5/A7 reachts if it is connected to a switchable power supply?
If you switch off power with the amp being "on", will it then restart when power is switched back on?
This could be a workaround, as i.e. audiophonics offer 230V switches working with a 12V Trigger.
Thanks
Juergen
Last edited:
Thanks - that is cool.
I my case, the Wiim Ultra will not reliably toggle a Master - Slave power strip, as the difference in power consumption between Standby and On is too low.
In cases where the auto On/Off of the A5/A7 does not work reliably, you could then use the 12V trigger of the source and connect that to a power switch, for example this: https://www.audiophonics.fr/en/diy-...v-230v-slave-power-supply-device-p-10661.html
thanks
Juergen
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