P501 manual?

Hi

Sorry about the delay, the forum was down. Obviously fixed now.

I will send the manual through.

Not sure what you mean by "just stay on". If you mean leave them on all the time, I would not recommend that. It only wastes electricity. The amps performance is extremely consistent from cold to fully warmed up, so nothing to be gained sonically from leaving them on.

We very deliberately have not implemented a signal operated power control. They are simply not reliable, on or off when they shouldnt be. If you have ever tried using a sub with this feature, you will know what I mean.

The trigger input is very simple and standard. 12v input the amp goes on, 0v in the amp goes off.

Alan March wrote:
We very deliberately have not implemented a signal operated power control. They are simply not reliable, on or off when they shouldnt be. If you have ever tried using a sub with this feature, you will know what I mean.

@Alan March Surely they're far more sophisticated these days & will not exhibit the same behaviour from years past, BoXem has seemingly implemented a very reliable consistent audio sensing solution with a very high success rate, not sure why he has such disdain for the power switch though, he deems it useless in the following below,

"There is none because it's plain useless with this amp. And I am sure that none of you guys wants to pay for the cabling of a useless feature at Luxembourgian pay rate. Its is useless because the amplifier will power up and standby automatically. Even without trigger. And before some complain about their 1988 subwoofer that sometimes doesn't start automatically, our system works very well and has satisfied 99.95% of our customers since several years.
Standby is an actual standby, the main supply is completely disconnected, standby consumption is below 0.1 W."

Not really. The function and mechanism hasnt changed therefore nor has the problem.

The issue is that an input signal has to be above a certain level and for a certain length of time to prevent phantom triggers. Note that some sources actually get noisier when they are off.

So quiet music signals also won't turn the amp on. Also, even if music starts at an appreciable level, it will still take several seconds for the amp to turn on. You therefore miss the beginning of the music. This is the behaviour you still see all the time with subs and I think its pretty lame.

Is Boxems implementation reliable? Of course he will say it works. I also have no understanding of his comments about paying for trigger cabling. Its cheaper and simpler than the additional "auto" electronics that is also in the signal path.

Alan March wrote:
Hi

Sorry about the delay, the forum was down. Obviously fixed now.

I will send the manual through.

Not sure what you mean by "just stay on". If you mean leave them on all the time, I would not recommend that. It only wastes electricity. The amps performance is extremely consistent from cold to fully warmed up, so nothing to be gained sonically from leaving them on.

We very deliberately have not implemented a signal operated power control. They are simply not reliable, on or off when they shouldnt be. If you have ever tried using a sub with this feature, you will know what I mean.

The trigger input is very simple and standard. 12v input the amp goes on, 0v in the amp goes off.

The Haus-Boss (aka Mrs), sort of just want it to work ith out pushing buttons.

Do you have a trigger out on your source?

Alan March wrote:
So quiet music signals also won't turn the amp on. Also, even if music starts at an appreciable level, it will still take several seconds for the amp to turn on. You therefore miss the beginning of the music. This is the behaviour you still see all the time with subs and I think its pretty lame.

Is Boxems implementation reliable? Of course he will say it works. I also have no understanding of his comments about paying for trigger cabling. Its cheaper and simpler than the additional "auto" electronics that is also in the signal path.

@Alan March Of course the manufacturer will not speak ill of their products & will say it's wholly reliable but customers have mentioned it works flawlessly, there have never been any complaints about Boxem's auto on/off signal sensing implementation but like you said there will naturally be some delay when the amp turns on & the first couple of seconds of music will be truncated, Boxem mentions this about its sensitivity "Sensitivity of the audiosense is around -60 dBu, it takes about 2.5 seconds between detection and amplifier playing."

I know this is probably ill-advised but was curious all the same, is there any popping noises with your amps when changing the Gain switch on-the-fly?

I'm afraid to try. 😉

Someone had queried it to Boxem, "Will hot-switching between different gains while playing music cause any pops on the speakers or harm to the amp?" Boxem replied "Gain changes are pop free."

One last thing, it has been said to eliminate or minimise popping noises with amps, one must turn on your source (AVR) or pre-amp first then turn on the amp & when turning off, the amp must be powered down first then the source (AVR) or pre-amp, if you are using a 12V trigger out to the amp's 12V trigger input is it somehow detrimental then if one is concerned about these potential popping noises?

No popping noises with our amps.

BTW -60dB is audible, so it won't be switching on with quiet sounds. Plus, personally, I dont want to wait for 2.5 seconds after the music has started playing before sound starts coming out.

Alan March wrote:
Do you have a trigger out on your source?

Well I need to check it with a volt meter, as I had soldered up some cables from the place on Lockyer ave.

The mrs leave the AVR on, so I am thing I leave the mono block on to idle.
It’s cold in where you used to live, so some warmth seems OK ??

Holmz wrote:
Well I need to check it with a volt meter, as I had soldered up some cables from the place on Lockyer ave.

The mrs leave the AVR on, so I am thing I leave the mono block on to idle.
It’s cold in where you used to live, so some warmth seems OK ??

Hi

There is no issue with leaving them on permanently however, if you want to maximise the life of the electrolytic capacitors inside, it is best to switch it off.

The following applies to *ALL* electronics and products, not just the P501. Most electronics have electrolytic capacitors somewhere in their circuit. These caps are filled with a gel electrolyte. Over time this gel dries out and the cap performance reduces along while other parameters such as ESR increases. A cap will generally be considered "lifed" when its value has dropped by 20%.

A cap life is rated at its maximum working temperature (varies from 85 deg C to 125 deg C depending on design and quality). This might surprise you but the rated life may only be a few thousand hours. Heat is a big enemy. Every increase in temp of 10 deg C will half the life of a cap. Other factors such as ripple current will also affect life. Random link:
https://www.xppower.com/resources/blog/electrolytic-capacitor-lifetime-in-power-supplies

There are many parameters that go into calculating the service life of a cap, but most cap manufacturers dont provide any info for over 15 years regardless of operating conditions.

Now lets be clear, even if "lifed" it doesnt mean your product, whatever it is, will stop working. A good design will have over specified the cap, but it is just possible that product performance may be degraded.

As it is so difficult to predict cap life, it depends on design, operating conditions and environment, my recommendation is to simply turn the item off when not in use. Again, this applies to any product, not just ours. Doing so also saves electricity, your money and the planet 🙂 .

Also, the amps performance is extremely stable with temperature. There is no chance you will hear any change in sound quality between stone cold and fully warmed up. As such there is no sonic benefit to leaving them on "warmed up".

One final thing, many trigger cables have large connector bodies. You will notice that the trigger input connector on the P501 is slightly recessed. Cables that have large connector bodies therefore may not fully insert, fouling on the case and preventing operation.

Good

Bad

Oh yes just to mention that our amp connector will work with stereo (3 pin) or mono (2 pin) 3.5mm connectors. Your AVR may well do too, but are typically specified with 2 pin output connectors.

Alan March wrote:
Oh yes just to mention that our amp connector will work with stereo (3 pin) or mono (2 pin) 3.5mm connectors. Your AVR may well do too, but are typically specified with 2 pin output connectors.

@Alan March I know that D+M AVRs mention in the manual that TRS stereo trigger cables should not be used, it mentions "Use a monaural mini-plug cable for connecting the TRIGGER OUT jacks. Do not use a stereo mini-plug cable."

I believe you had mentioned the 12V trigger out on your amps are 3 pin but only the tip & sleeve are connected internally so it's effectively only a 2 pin TS input, will using a TRS stereo trigger cable still be fine with your amps if the source can use a TRS cable?

Do you know why it's ill-advised to use a TRS stereo trigger cable in some cases, it's strange that D+M recommend not to use a stereo cable?

I've noticed your earlier designs had the trigger input flush with the enclosure, now it's slightly recessed which is fine, the revision is a neater look which I prefer, is there any particular reason for the change?

If a trigger output connector is a standard design, ie a 2 way 3.5mm socket with +12v on tip and 0v on sleeve, the a stereo 3 way with the ring not connected should work just fine. The plugs are the same overall shape. The ring does nothing. I have no idea why D+M insist on a 2 way cable.

Yes, really it should be a 2 way mono cable, but stereo 3 ways are so much easier to get hold of.

As you can see we changed the whole P501 design. Really a completely new model with vastly better performance. Moved from Hypex to Purifi.

The trigger socket and xlr connectors were placed on a pcb instead of free connectors. Also as you mentioned, it was also an improved aesthetic.

Alan March wrote:
Do you have a trigger out on your source?

Needed to be enabled in the AVP/AVR, but the output is now 12V as measured and confirmed.
Even updated the S/W today just for good measure.

Finally the amps turn on and off with AVP being powered.

Excellent 🙂

Alan March wrote:
Excellent 🙂

It was surprising to see no volts at first, and there being a setting in the AVP.