[doggie]

I have a Sonic Impact amp that I have moved to a more spacious chassis and am running on a 12v 3.4AH battery. It works great and powers my AKG K-1000 phones really well. Right now I have a SPST switch which allows me to choose between "amp on" and battery charge. I see two problems with this. If I forget to turn off the amp and let the batteries run out then the SLA will not like that. Second I cannot leave the amp running all the time as I do my gainclone. To my ears most equipment sounds better if left on and if not then requires at least 20 minutes to get to even 90% of what it can do.

My question: is anyone out there wiring their charger to simply be on all the time? In other words, amp is on with charger working while music is being played? Is there a technical downside to this? Obvously I would have to decide for mysef if there is a sonic tradeoff.


Thanks a lot.

Paul

[Vinnie R.]

I have a Sonic Impact amp that I have moved to a more spacious chassis and am running on a 12v 3.4AH battery. It works great and powers my AKG K-1000 phones really well. Right now I have a SPST switch which allows me to choose between "amp on" and battery charge. I see two problems with this. If I forget to turn off the amp and let the batteries run out then the SLA will not like that. Second I cannot leave the amp running all the time as I do my gainclone. To my ears most equipment sounds better if left on ...

Hi Paul,

Glad to like the SI with the AKG K-1000s.  This is a great combo, but gets even better if you connect 4 to 8 ohm loads in parallel with the speaker outputs (the TA2024 wants a lower impedance than what the 120 ohm K-1000s provide).

Regarding connecting your charger all the time, I don't think this is a good idea:

First, the voltage across the battery during charge is often higher than the 12V battery.  It can be as high as 14.75V.  This is NOT GOOD for the TA2024 chip.

Secondly, you are defeating the purpose of having battery power when you do this because the charger is quite noisy (not nearly as clean as a linear AC-DC supply that you can buy for around $30).  The noise from the charger will feed into your amp.

Third, I don't know if the charger/battery will like you drawing current from it at the same time it is trying to put current into the battery.  Please be careful with this    

If battery power is not for you (an inconvenience), the next best thing is a good linear requlated power supply.  My guess is that you will notice a decrease in sound quality vs using a 12V SLA.  

Regards,

[doggie]

Hi Vinnie,

Thanks a lot for the response. I know that you have looking into this a lot I will keep it switched and just develop some good battery tending habits

I do already have a 5 watt Mills resistor across each output. Next step is to add some better inductors.

I have one other question. Right now I am just switching the positive battery lead between board and charger with a SPST switch. Do you think that there is anything to be gained from getting a DPDT and switching the negative terminal also. As it stands now the inputs are being grounded to the chassis because the negative leg of the charger jack is continous with the chassis.

Thanks,

Paul

[Vinnie R.]

Hi Vinnie,

Thanks a lot for the response. I know that you have looking into this a lot I will keep it switched and just develop some good battery tending habits

I do already have a 5 watt Mills resistor across each output. Next step is to add some better inductors.

I have one other question. Right now I am just switching the positive battery lead between board and charger with a SPST switch. Do you think that there is anything to be gained from getting a DPDT and switching the negative terminal ...

Paul,

I use a SPDT to switch between ON and CHARGE.  As far as I can tell, there is no reason to switch the GND, as this just adds another connection in the power path.  

You can GND the RCAs and negative terminal of the battery all to the enclosure (I am assuming that it is metal).  Just DO NOT ground the negative terminals of the speakers!  

Good luck,

Vinnie

[doggie]

Paul,

I use a SPDT to switch between ON and CHARGE.  As far as I can tell, there is no reason to switch the GND, as this just adds another connection in the power path.  

You can GND the RCAs and negative terminal of the battery all to the enclosure (I am assuming that it is metal).  Just DO NOT ground the negative terminals of the speakers!  

Good luck,

Vinnie

Thanks Vinnie.