The Boominator - another stab at the ultimate party machine

Not enough contacts on that switch to both rearrange the batteries and cycle power on two amplifiers. Tried it several times and ended up leaving one of the amplifiers on. It had to be the 24v amplifier because of voltage tolerance.
Here the 12v amp runs off the battery to the left and the 24v amp runs off both batteries in series. But i would like to run the 12v amp off both batteries in parallel, is this possible?
Added to the 12v amp:
DC-DC Buck Step-Down Converter 8-40V to 3-30V 8A Switching Power Supply Module | eBay
There's probably other ways to step down the 24v for running the 12v amp--just make sure the efficiency ratings are in the 90%'s so you don't get much waste heat from your converter.
Edit:
Maybe it would make more sense to use just 24v amplifiers?
 
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I couldn't see your attached photo.

The switch can be arranged so that only one amplifier is on.
Unfortunately, the small signal line has ALSO connected the ground of the RCA jacks together. oops! Now you have a ground loop. So, set both amplifiers with the RCA jacks (input edges of the boards) touching and run a unified ground at that spot. When there is only 1 ground, then there's no ground loop.

For for charging, the 24v amp (maxes at 40v) can withstand the charger, but the 12v amp (max 14) cannot. So, have your switch simultaneously turn on both the charger and 24v amp simultaneously, and likewise the charger is disconnected if the 12v amp is on. The arrangement shown uses a ~24v CCS charger for charging both batteries simultaneously.
 

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I couldn't see your attached photo.

The switch can be arranged so that only one amplifier is on.
Unfortunately, the small signal line has ALSO connected the ground of the RCA jacks together. oops! Now you have a ground loop. So, set both amplifiers with the RCA jacks (input edges of the boards) touching and run a unified ground at that spot. When there is only 1 ground, then there's no ground loop.

For for charging, the 24v amp (maxes at 40v) can withstand the charger, but the 12v amp (max 14) cannot. So, have your switch simultaneously turn on both the charger and 24v amp simultaneously, and likewise the charger is disconnected if the 12v amp is on. The arrangement shown uses a ~24v CCS charger for charging both batteries simultaneously.

Can you see this photo?
An externally hosted image should be here but it was not working when we last tested it.


I dont quite understand what your saying about the RCA jacks?

The batteries will be easily removable and charged externally, so that shouldn't be a problem. Then it can play 12v music at Roskilde festival, while i charge the other battery at my work ;)
But cool idea, might use it, thanks :)

I have already bought 2 amps, would like to see if i can get something out of them, before investing in a 3rd...

EDIT: I got the switch the wrong way around in the diagram.
 
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The batteries will be easily removable and charged externally, so that shouldn't be a problem.
Aha! Just buy a 12v battery and attach it to the 12v amp.

Attach your 24v battery to the 24v amp.

Now, you can remove amp+battery as a swap-able unit.
Both amplifiers aren't present simultaneously.

P.S.
Use the dpdt switch to protect your 12v amp, block overvolting from charger, via preventing charge-while-run.
 
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You cannot have 2 amps connected to the speakers at the same time. Period.

Remember there's output filters in these amps, these will affect the impedance and frequency response of the system.

Ok...
I remember reading about someone building a boominator with 2 amps earlier in this thread. If i recall correctly it was someone from Camp Fri Ost, but i may be mistaken. Maybe i should just stick to the 12v amp, and use the 24v for a future project.

Aha! Just buy a 12v battery and attach it to the 12v amp.

Attach your 24v battery to the 24v amp.

Nice out of the box idea, but it will cost me a battery more, and half the battery life in 12v mode. :/
 
Ok...
I remember reading about someone building a boominator with 2 amps earlier in this thread. If i recall correctly it was someone from Camp Fri Ost, but i may be mistaken. Maybe i should just stick to the 12v amp, and use the 24v for a future project.

Yes. They have 2 different amps. And they change between them. They cannot be connected at the same time.
 
Hi. We finally had the time to look at our Boominator from this years Roskilde + 2-3 other occasions. Standard built; AMP6-basic, HP-10W, some recommended tweeters (don't remember the exact brand/version), an amorphous solar panel, and two parallelled CT leader 7,2ah 12v batteries.

1. The batteries seem to be dead. They both measure 0,9v across. I read somewhere that a solar charge controller wasn't needed. Guess we should have checked up on that. So we need a solar charge controller. Any ideas?
2. For some reason, the amp has decided to stop working. We have tested everything, and with an external power supply, the amp doesn't draw ANYTHING. So i guess after the batteries stopped working, the amp was connected directly to the solar panel. Which could potentially damage it. What is the best way to test for this?
3. This isn't the worst thing, considering that we plan to move to a bigger amp. The HP-10W can go up to 100W each, which means the amp can be anything up to 2x200W, right? Of course that would be overkill. We just want to be able to play a little louder than the AMP6-basic. Is there anything you could recommend that fits with our current setup?

Thanks for this year!
 
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4. We also attached a 12v car cigarette female plug for charging cellphones and iPods. It is connected in parallel with the amp. However, the (smart)phones and heavier iPods took an insanely long time to charge. It didn't seem to depend on the amount of battery charge or sun strength. Does anybody have a solution?

Damn we are noobs.
 
Hi. We finally had the time to look at our Boominator from this years Roskilde + 2-3 other occasions. Standard built; AMP6-basic, HP-10W, some recommended tweeters (don't remember the exact brand/version), an amorphous solar panel, and two parallelled CT leader 7,2ah 12v batteries.

1. The batteries seem to be dead. They both measure 0,9v across. I read somewhere that a solar charge controller wasn't needed. Guess we should have checked up on that. So we need a solar charge controller. Any ideas?
2. For some reason, the amp has decided to stop working. We have tested everything, and with an external power supply, the amp doesn't draw ANYTHING. So i guess after the batteries stopped working, the amp was connected directly to the solar panel. Which could potentially damage it. What is the best way to test for this?
3. This isn't the worst thing, considering that we plan to move to a bigger amp. The HP-10W can go up to 100W each, which means the amp can be anything up to 2x200W, right? Of course that would be overkill. We just want to be able to play a little louder than the AMP6-basic. Is there anything you could recommend that fits with our current setup?

Thanks for this year!

The 100w rating of the HP10w is the thermal handling, the driver only has 3mm of xmax so its mechanical displacement limit is far lower.. I wouldn't use anything bigger than an amp9 if you want your woofers to survive - and even that will push them to limits :)
 
The 100w rating of the HP10w is the thermal handling, the driver only has 3mm of xmax so its mechanical displacement limit is far lower.. I wouldn't use anything bigger than an amp9 if you want your woofers to survive - and even that will push them to limits :)

Ah okay. Well, i guess we will go for the AMP9-basic then. Do you know if it has the same configuration options as the AMP6-basic in terms of preamp? If i remember correctly, there where two resistors that could be placed in different positions to obtain different levels of preamp. Does the AMP9-basic have the same possibility? Then we could limit the max output in a non-reversible way. And what should that value then be?
 
1. The batteries seem to be dead. They both measure 0,9v across. I read somewhere that a solar charge controller wasn't needed. Guess we should have checked up on that. So we need a solar charge controller. Any ideas?
2. For some reason, the amp has decided to stop working. We have tested everything, and with an external power supply, the amp doesn't draw ANYTHING. So i guess after the batteries stopped working, the amp was connected directly to the solar panel. Which could potentially damage it. What is the best way to test for this?
3. This isn't the worst thing, considering that we plan to move to a bigger amp. The HP-10W can go up to 100W each, which means the amp can be anything up to 2x200W, right? Of course that would be overkill. We just want to be able to play a little louder than the AMP6-basic. Is there anything you could recommend that fits with our current setup?
Thanks for this year!
It is unlikely that a solar panel small enough to fit a boominator could hurt a battery big enough to run a boominator, but you do at least have a schottky series with the solar panel so it doesn't run down the battery, right? However, accidentally forgetting the amp and leaving it on can run the batteries down below safe minimums. Battery chargers typically run higher voltage during charging, plenty enough to fry your average t-amp unless it were disconnected. Most battery chargers are really terrible and it is hard to find one with adjustable voltage. This sort has a dial and you just give it DC from a laptop cord a solar panel, whatever, set the dial to match the battery voltage and you're good. Really fairly copasetic, but if left connected long enough, unpowered, it could also run down a battery. Motocycle maintainer is another fairly accessible and decent sort of charger but they're not adjustable and guarantees somewhat wrong voltage.

2 X 50 Watt 6 Ohm Class D Audio Amplifier Board - TDA7492 50W Stereo Power Amp from Sure
That amp has a wide voltage range and fairly unlikely to harm it with a charger, although it shouldn't be used full blast at more than 20v while driving a 4 ohm load. It also has selectable gain for when louder is wanted despite driving it from an iphone or digiplayer. For actually getting more power without getting more clipping, you'd need a higher voltage battery, range 18v to 24v. These won't be the convenient size little low amperage batteries, but rather the big black square rechargables that run computer backup batteries. You'd also need to double your 12v solar panel and put them in series to charge the 24v array. Most of the time it will probably be run down slightly and provide that approximately 20v the amp needs. However, I suggest that you set the gain low enough that the amp is not going to clip. They also have the TK2050's if you've got enough battery power for it. Look for a selectable gain feature so that the bigger power can actually do something.
 
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Received my 24v amp today! :D
An externally hosted image should be here but it was not working when we last tested it.


But what kind of plug do i need to fit the input socket? I thought it was a simple fan header, but no, it's smaller :/

Are the two pots on each side of the input socket, the L and R input gain?

EDIT: I just did a test, it is loud! But even at 12v the driver cones were moving very violently, way more than the xmax of 1mm... If it is doing this at 12v, i hate to think what will happen at 24! But i am guessing that putting the speakers in the cabinet will help?
 
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But what kind of plug do i need to fit the input socket? I thought it was a simple fan header, but no, it's smaller :/
Most of the econo builds from China have headers like that. I've definitely fought with a few. The braided shield of a good quality stereo audio cable does not go down the hole. My solution was to use the center pin and cut off the other two. Solder the ground to the center pin and solder the left and right underneath. Spreading the job out like that may make just enough room to do it. You're going to need flux. And maybe one of those LED headlights to get a good bright view of the tiny area.

P.S.
The potentiometers on the Muse are DC offset trim per left and right. No idea what the trimmers are for on your board, but if you play with them, be sure to measure the output for DC offset.
 
Most of the econo builds from China have headers like that. I've definitely fought with a few. The braided shield of a good quality stereo audio cable does not go down the hole. My solution was to use the center pin and cut off the other two. Solder the ground to the center pin and solder the left and right underneath. Spreading the job out like that may make just enough room to do it. You're going to need flux. And maybe one of those LED headlights to get a good bright view of the tiny area.

P.S.
The potentiometers on the Muse are DC offset trim per left and right. No idea what the trimmers are for on your board, but if you play with them, be sure to measure the output for DC offset.

Ok thanks. I have soldered all 3 cables on the bottom of the board (I just used some cables salvaged from a 120mm fan, sounds fine).

Ok, i have no idea what DC offset is, so i will just leave the pots alone ;)