Power on issue AP16+

[dwgsparky]

Hi , Newbie questions.

First.... What a GREAT product. Exactly what we needed for our setup. Put it in its box, wired it up, added files to the SD card and it worked fantastic right away (once I figured out the file convention in WIN7)

2 questions,

(a) When I preset the volume (25%) and turn on the power I get a thump from the speakers. Is there a way to prevent this ? can I add a capacitor / filter etc. to the supply to reduce this? I have an on/off switch in my box.

(b) My system is going onto a mobile vehicle as a guided tour and so it would be very useful to adjust the volume manually along the route, can I add remote volume control ideally in the form of a 2 gang pot with on / off switch to help with (a) above? or is there a better way.

My application only uses the AUX01-07 files and an Ambient file and uses the speaker output from the AP16+

I understand the STATUS LED but what is the function of the 3 orange LED's when the board is operating?

Thank you

Dwgsparky

[JonnyMac]

The power-up thump is an amplifier phenomenon that won't go away with this amplifier design; it's caused by energy flowing into a de-energized system. We've done everything we can to mitigate the thump. This not something specific to the AP-16+, it a happens with almost all power amplifiers.

We have recently added pads near the volume pots on the boards so that you can add an external volume pot (to use, you must set you onboard pot to max volume). This requires soldering so do so very carefully.

There are LEDs for each regulator (2) and one for relay activity.

[dwgsparky]

Hi JonnyMac
Thanks for the fast reply.

I have a new board with the pin holes near the volume controls. So I want to add a set of headers and plug my external volumes to the headers. presumably I use all 3 wires to the 5k pot? is this correct?
Do I need to disable the onboard pot or just turn it to full?
Do I need a standard pot or a log pot.
Is it possible to use an extra pot as a balance control?
Thats it, no more questions.


my soldering skills are good enough for this job!!

Thank you

[JonnyMac]

Use a 10K-25K audio taper (log), set the onboard pots to max.  The only clean way to control balance is through software control of the board, I think it would be a mistake to try to wire up addition pots to create a balance control. You would be inserting additional components into the signal chain which may have undesirable results.

[dwgsparky]

Hi JonnyMac

Thanks for the advice, you are the expert and I can live with no balance control. 
I want to put the on / off switch and the twin volume together on one twist on/off / volume which should help reduce the amplifier thump problem as well.

The sound quality from this unit is great. Its getting very popular in this office... everyone keeps coming with more ideas for its use, (more work for me!!)

Best regards
dwgsparky

[JonnyMac]

You need to make sure that you switch is capable of handling at least 3 amps -- when the volume is high a lot of current will be flowing through it.

[IMTim]

I was going to ask if an external volume control could be added.  There have been times it would have been easier to adjust the volume this way.

Thanks,

Tim

[dwgsparky]

Thanks JonnyMac 3 amp switch (or relay) it will be.

I like this product and I like your customer service, great.