Multi-chip amplifier - Concentra, GC, PBA200, multichannel (all in one)

[veteran]

Finally some progress

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[veteran]

It's working... Now I can place them on a bigger heatsink.

An externally hosted image should be here but it was not working when we last tested it.

 

[Bassterror]

Hi

nice projekt

How good is it compared to a paralleled 2x3886 or 4780 paralleled?

I think about a little amp for my 2*10 inch subwoofer...

 

[jaudio]

What are the dc offsets?

 

[MikeW]

Is +/- 43 volts to high?

 

[jaudio]

Yes

 

[MikeW]

Your right, two out of the three chips of onechannel blew up when I connected the input. The other channel is still working. I will drop the voltage a little.

 

[halo0925]

LM3886's ?? blew up on +/-42VDC? something else is wrong I run a BPA on +/- 48VDC and have never "blown up a chip"
PS thats unloaded voltage under load the supply puts about +/-43VDC never have I had a problem even under long term high output.

 

[Scribble]

So how does it sound!?

Im very interested in this project. Looks like something i can make point-to-point. How was the DC offset?. What transformer did you use?



Thanks for your time!,
Joel

 

[veteran]

It sounds quite good - with the softness of standard GC and power consequents from parallel configuration. If you have match chips proper output offset is minimal (about 70mV).

I'm using 2x24AV transformer for this amp.

 

[PierreG]

-By jaudio-
How many paralllel module are you planning with 50 chips?

Jaudio, I will make one stereo amplifier . I just need more chips to match them. I can sell the rest.

I understand that you need to buy 50 chips to match the quantity needed for a stereo amp? 6 out of 50?

 

[halo0925]

BPA200

Why match the chips? do you match for the lowest individual offset? and if so why?it is a componding rule that applies to the DC offset, you will net gain for the lowest level of offset, but you will still have DC and higher idle dissipation, I would be curious to know what youre Idle current per chip is becuase idle current can be more of an issue then DC offset. Just take the normal 60ma per chip and mutiply by 3, I will bet ya its a lot greater then 60ma*3

 

[tschrama]

Hi, congrats on this very nice project. Very nice PCB! Are you selling PCBs. I would be very interested in 2.

regards,
Thijs

 

[samsagaz]

maybe i want some too, i want to build 2 5.1 systemss.

 

[veteran]

PierreG, I just wanted to match them proper .

I have few more boards. Contact me please for details.

 

[PierreG]

PierreG, I just wanted to match them proper .

Do you mean that you can make the board without matching the chips ?
What would append then?

 

[sasmit]

anybody got any ideas about a biamped setup using..4 * LM4780's and a 2 way active crossover..?