Part 1, Part 2, Part 3, Part 4

Part 4 - Testing and Use

The construction was not finished in the deadline I set - but only because the second transformer had not arrived yet. The deadline was the day I move back up to Colchester to start my second year at university. To bring the amplifier into a working order, I put in some temporary wiring to connect the front amps to the original transformer so I had the entire unit all running off one 80VA transformer. It worked quite well like this and actually went surprisingly loud considering the serious restraint it had. I couldn't wait to hear how loud it would go when the second transformer would arrive.

On the travel up to Colchester, the bumps and forces was a good test to see how the amplifier would survive movement. All those weak soldering joints would be found. When it got there, the front amps did not work. A few weak joints meant that the occasional wire inside had fallen loose and no longer created the circuit it needed too. So there and then I had to dig out the soldering iron and get it all working again.

After that, I gave it a few proper listens at lower volumes (because I was still a transformer short). The sound quality was very good and I was quite happy with its performance. Still, a few issues that were bugging me though, like a low constant hum which I hoped wouldn't be there and the bass didn't have much "get-up-and-give" as I had also hoped it would.

When the new transformer finally arrived back at home, I made a trip home with my amplifier and the soldering iron again to actually install it. Whilst it was in the workshop that is my bedroom again, I also re-did some of the wiring I was unhappy with.

When the new transformer was in, it needed a test again. I did overlook a slight issue though... I left all my speakers back in Colchester. Using Dad's surround sound speakers was also going to be difficult because the living room was being re-decorated and stuff was all over the place - with the speakers being in a hard to reach corner.

Team effort however and the speakers were retrieved for testing. Rather nicely, it all worked, and I opened the volume up whilst playing Athlete - One Million. The surround effect through most of the song was very nice (good tone) and the bass rift at the end opened up well with good response. Not bad for an improper test condition.

More weak joints revealed themselves on the way back to Colchester - so when I wired it up, I have lost the front channels again. This time the broken wire was causing a short on the power leads for the front amps. The fuse blew without me realising, but the rest of the electronics was safe.

After a while, I caught sight of the problem and fixed it by re-soldering and putting a new fuse in.

Now I could finally give it a proper test :)

I spent hours with lots of CD's and MiniDiscs choosing many different varieties of tracks and listening carefully. Since the re-wiring, the hum was reduced (hurrah!) and the new transformer and a bit of speaker re-positioning allowed that bass to open up and shine through. Surprisingly, I get better low frequency response then I do high frequency, but I think I need to tweak those speaker positions a bit more.

The setup as it was at my university home in 2004:

You can see our little entertainment system, complete with 24" CRT TV, VCR, DVD and a PC. And, of course, the surround sound amp and speakers play what I believe to be a very important part to it all :)

Not an ideal set-up, but the fireplace and funiture forces it into a corner setup.

Finally, here are a few views of my completed amplifier:

Front

Back

Top

Right Side

Left Side

Housed on the entertainment desk and operating!

Thanks for reading :)