finally finished GC LM3886

[Bedi]

This is my final version Amplifier GC LM3886.Power supply is separate from the amplifier, and the amplifier box containing the speaker protection, remote volume control and input selector.

[Dan_Steele]

How does it sound? I used the same conenctions for my mono blocks and the cables are a nightmare for producing inteference, I have to play around with the position a lot to reduce the hum. Going to get rid of them altogether over the summer and hopefuly will sort it.

Enclosure looks great!

[Bedi]

It sound pretty good, but the hum is present when the maximum volume without attached inputs.I must say that I have not watched much of the position of cable and is perhaps the reason but the remote volume control can also cause the same problem.Thanks!

[AndrewT]

maximum volume control AND inputs disconnected is not a normal operating condition. If it does not blow itself up nor damage the speaker then ignore this.

[Bedi]

Thanks,AnrewT

[Razor_x]

It looks beautiful

Do you have any schematic of remote volume control circuit? That is what I am working on so any help would be nice. I presume you used microcontroler and digital potentiometer?

Oh, now I see we are both from Croatia, are you active on Croatian forum elektronika.ba?

[cwteoh]

some body told me... if you redure the cable length between PSU and the main board... you got better sound...

[AndrewT]

Hi,
if you reduce the loop area and the inductance between the transformer and the rectifier, the PSU will perform better.
If you reduce the loop area and the inductance between the rectifier and the smoothing capacitors, the PSU will perform better.
If you reduce the loop area and the inductance between the smoothing capacitors and the amplifier then the amplifier can benefit from the improved performance of the PSU.
If you can reduce the parasitic effects of PCB and layout in any of these PSU and Amplifier assemblies then overall performance is likely to be improved.

The length of the cables has a significant effect but that can be quite minor in comparison to all the parts that could be wrong in the layout.

[abraxalito]

Originally Posted by cwteoh

some body told me... if you redure the cable length between PSU and the main board... you got better sound...

You'll do even better still if you run multiple grounds between the PSU and main board. In particular, a separate ground for the input RCA, another for decoupling returns, yet another for speaker return (assuming not a bridged design) and finally another one for signal ground (the feedback network ground return). If you do this, the cable lengths won't matter so much and the sound stage will in general get deeper, highs will be considerably sweeter. At least that's my experience from playing with amp grounding.

[cwteoh]

I really like your design... I just got no idea how I want to get it started.