HPA-LSP40seThe first big decision was one case or mono blocks? After 5 min of thought, mono blocks it was.Listening to these amps is very pleasing to the ear. They certainly have that 'wow' factor.No background noise and very detailed sound. Low & mids are very powerful and highs are clean.When married up with the correct speakers and pre amp you can quite easily create a live sound stage sound.Have tested these amps on speakers ranging from $1.5K to $8K with very impressive results.The only problem with these amps is that they show up any weakness in the rest of your system. I had to upgrade my pre amp to realise the full potential of these mono blocks and what a difference it made!The final problem you'll have after building these amps is kicking your friends out.....Well done Anthony.Next project HPA-nxV500.Regards,AnthonyMelbourne, Vic

Firstly, what I am hooking the amp up to? The pre-amp is based around Rod Elliot's project 88 pre-amp that uses the Burr-Brown OPA2134 op amps. My speakers are also home made using Scan-Speak units, 18W8456 Kevlar bass unit and D2905 treble unit and a 4th order Linkwitz-Riley cross over (Volt air-cored inductors and Expotus capacitors).The amp itself is built using the SPS-80 switch mode power supply from ColdAmp electronics, set at ± 75v. The mains input is filtered and all connections are gold plated, obviously. The box is just a 2U rack mount case, and looks pretty empty.Lets start with the silence. Switch off the pre-amp so that the input is shorted and stick an ear into the bass cone. Nothing, not a sound. I guess it would be surprising if there was any mains hum from the ColdAmp PSU, but I have to check that I have switched...

Here is Juan's excellent 7 channel amplifier. This amplifier has been a very long term project for Juan. He started buying modules for this amplifier from me over 1 year ago, It uses five NX150 modules for the main surround sound channels and two NX400NL modules for the Subs.