I think the "Quatour" is more like what I need, thanks. A bit of tone control etc. will do the job very nicely. I will buy decent speakers to match.

With this project, you can use the speakers you like. 4Ohm speakers will deliver more power for the same operating voltage, since more current is needed. This project already uses 4Ohm speakers, so any of these are supported without the need of doing recalculations. Of course, I have the enclosure calculated for use with Visaton FR10 4OHM speakers. You will probably have to calculate the enclosures for your speakers, if you choose different ones.

I see the project requires 13.5V, will this be an issue if I supply 12V? I can use 2X12V Gelled Cells and regulate the voltage but would prefer not to.

No problem there, since the project requires a minimum of 9.80V. Just make sure that the voltage doesn't get lower than that (probably it won't, since you are using the battery cells from your boat).

 

Due to an error only detected during the final testing stage, the PCB had to be redrawn. The final version is available for download.

Please, refer to by blog for more details.

 

Hi

I've looked but can't find the new PCB?

Cheers
Andrew

 

Hi Andrew,

The new PCB drawing is attached to the opening post. You should look for "PCB.pdf".

 

As you noticed, this project had a major rebuilt, since as it was, the project would give a lot of distortion. The new PCB was tested and now the amplifier works as it should.

Also, I've changed the name to "Quattuor", the correct translation in Latin for four.

P.S.: Refer to my blog "Stone Age TTL" for details.

 

I'm aware I have promised in the previous post that it would be the final revision. However I have made several changes meanwhile, since anomalies were detected during the real testing phase. It was detected that the amplifier had a tendency to oscillate when reproducing bass sounds and the LM1036 would introduce some noise. I've solved these issues in a great extent, as better they could be solved. The LM1036 still introduces some noise, but since the gain reduction will be made after the LM1036 and not before, this revision will have about a reduction of noise about 17.9dB when comparing with the previous one.

 

In the attached file you can see the front and back views for both the left and right speakers. The edges on the front face are meant to be beveled with a 10mm radius round bevel.

You can however use your imagination and do or improve the design by yourself.