The Boominator - another stab at the ultimate party machine

I hope they arrive monday, otherwise they'll certainly be there tuesday.

I do have a circuit design for OEP A262A7E (1:1+1:1) for a dual primary and paralelled secondary setup. This would need a 47nF cap and a 1,8K resistor.

And for the NTE-4 it would have to be like I posted earlier...

I must say that the OEP tranny surprised me by the price/quality ratio they offer. If you were to order these then order the MU-metal shielding casing along with it, it's an accessory.

The scope images above were from the OEP, but not with the most ideal resistor value (1,6K) yet, later on I placed them on a piece of experimental board and added the correction network in SMD components...In SMD I did have 1,8K in stock, this made the square wave even better!
 
Hi Everybody,

I finally got around to testing my amp 9 basic and I cannot get it working. The setup is:
• I am using an ipod as input with a 3.5mm to rca cable.
• The outer barrel of each rca socket is connected to the outside pins of j1 and the centre of the rca to the inside pins.
• J1.1 and j1.2 are paralleled and j1.3 and j1.4 are paralleled for stereo use.
• The cap near the supply input is connected to the diode as noted in the forums.
• Jumper j2.1 and j2.3 are closed. No other J2 jumpers are closed.
• I am using a lab power supply set to around 13v.
• Each of the speaker outputs is connected to an P Audio HP10 4 ohm speaker.

When I power on there is a very slight click from the speakers. Then nothing. The chip heats up very quickly, I am holding my finger on the back of the chip and power down once it gets hot to touch.

Is there a debugging or troubleshooting guide somewhere? What voltages should I be reading where? I have access to an old oscilloscope and a DMM.

Thanks in advance for any help you can give me.
 
Hi,

Bad news! :(

What resistance do your speaker outputs measure? I mean at power off and separate, not paralleled...

Are you sure you paralleled the right points?

Are there any status leds on or off?

What DC do you measure at the outputs? (perhaps clip on a small heatsink to test this)

Follow the inputs with a DMM towards the blue caps and from the blue caps towards the inputs on the chip. Do this too with the speaker outputs. Measure for continuity and shorts Between them...

Can you shoot some pics?

PS, trannies have not arrived yet...
 
Hi V-Bro,

Should I be starting a new thread for this? Anyway for now I will leave it here. So the outputs are not bridged/paralleled at all, only the inputs. Each of the 4 outputs goes directly into one of the HP10 drivers. I’ve attached some photos.


Setup.jpg


Bottomview.jpg


InputConnection.jpg


Inputconnections.jpg
[/IMG]

P1000806.jpg


Topview.jpg


switchesonmutedilAM.jpg



For the test setup I had switches connected to awake and mute and was using the little back bridge connector on AM mode. I know my soldering skills are not the best but I am almost certain I haven’t crossed anything. Can you see anything obvious?

Is there a “boot order”, ie bridge AM, power on, awake on, wait 5 sec, mute off, music on. Or something similar?

I will attach a heatsink as soon as I get home and do some more testing.
 
Yes, I think it's better to continue this in a thread at 41hz forum.

I do see a few things that are perhaps thye cause of your amp not working, for instance some blobs of solder where the resistors are near the sleep and on/off jumpers.

On top of that you're not running in class D, you should close the third jumper there (look at the bottom of the PCB and read the assembly instructions once more) , though:

DON'T jumper this one with the amp on!!!!!!!!!!!!!!!!!!!!!!!!!!

Then there are solders on the output filter caps (the glossy red ones near the speaker outputs) that should not be done so rich, hold the board against a strong lamp and you'll see the copper around these pads should NOT make contact to these pads! Try and clean your solders up a bit better, then polish up the board with pure (99%!!) alcohol and some paper or even better with some printed circuits cleaner.

I'm pretty sure this amp is still alive, with a faint heartbeat though....
 
PS. the mod with the cap to diode wire isn't necessary any more with the latest board revisions.... have another look with a strong lamp...

The strong lamp method is sadly a far too much overlooked very helpful tool to troubleshoot and make a good diagnosis of a PCB and the soldering, plus it gives yourself a good 'insight' of the circuitry ...
 
Aside from amp problems, how's progress on the cabinet side? Do try to start construction or at least think the assembly order out well beforehand, as you don't want to end up with a cabinet that's half assembled a few hours before you have to leave the house. I've tried it and it's not recommendable.
 
Hey Saturnus,

Amp troubles have grown into amp disasters. I think the amp 9 is a write off for this trip at least so the only option will be the amp 6B pushing into 8 ohms. Not sure if I’m going to get the volume we need from it, but I think it is still worth a try. Because the amp 6 kit was missing one of the 3.3uF low ESR caps I cannot get it set up and running until I give up completely on the amp 9, because I will have to steal the cap from that amp.

As for the rest of the work, all timbers are cut and trial fit. End walls with ports are completed. Because I am using the piezos, I have cut and joined the four pairs and they are ready to mount. Braces and speaker magnet hole align and all is looking ready for joining. I have been putting it off because I am using the speakers on the bench for testing the amp 9. I’d take some pictures but I’m not doing the woodwork at my place. I’ll get some later today.

I’m really bummed about this amp 9, lesson learned though; set aside more time for these things and take more care soldering PCBs. I had almost given up on taking the boombox completely last night, but I think I will give it a go with the amp 6 and see how it sounds.

Thanks again for all your help and advice Saturnus, and everybody!
 
It'll work fine on the amp6basic into 8 ohms, no worries, maximum output will be lower but more than enough for most people. You can always finish the amp9basic for another time and get better tweeters and so on.

Remember, I have been developing the Boominator over 8 years so far and it's still a work in progress although I'm closing in on the definitive version with the latest version being the 5th cabinet design, and having improved at least something every year.

For me each cabinet design lasted 2 years, the first year using it as designed, and the second year tweaking something. Then take the lessons learned and back to the drawing board for the next version.

I've just begun making the next version. Lessons learned from previous years has taught me to begin design and getting the materials about 6 months in advance.
 
HAH! Funny design!

A nice efficient amp to run on batteries? AMP6-B like in the original Boominator.

http://www.41hz.com

For more power you could also go for an AMP9-B but that would consume a fair bit more...

Oh and about the NTE-1 measurements, I've been sitting here at home coping with the flu for the past two weeks and I don't have the equipment here at home... , sorry....but I haven't forgotten about it!
 
From reading this thread in detail, I am considering the following:

2 amp modules from 41hz:

amp 9 basic - driven with 24v (4 channels enabling me to run my mid-tops 2 way active, stereo.

amp 11 LV - driven also on 24v for the sub.


are there any other off the shelf modules that I should consider? cheaper is always better!



batteries I am considering some 12v 14Ah from Haze, as these are available for just under £20 each. My plan was to combine the two batteries in series giving a 24v supply.. I can always double up to give a longer run time. (i.e run 4 batteries)
 
For your purpose I'd recommend the amp9basic to start with and take things in steps.

Start by having the amp run on a single battery for 12V and use one channel for each satelitte and two channels paralled for the sub.

Now if you're not satisfied with that performance you can just add another battery for 24V on the same setup.

If you're still not satisfied you consider adding another sub or another amp for the sub and have the speakers run active on the amp9basic.

It is always my philosophy that one should plan ahead and look for a setup that they can improve on later in steps and not try to do all at once because you might be happy with a smaller setup than you originally planned. And potential problem solving is a much less daunting task.

Also understand that going from 12V to 24V, you'll need 4 batteries in series/parallel on 24V to have the same battery life as a 12V setup has on one battery.