S23 - Active Cardioid Loudspeakers

Cardioid loudspeakers have desirable traits when place in a room. However they are normally difficult to design and build. 

Using S19 platform two alternating channels are converted to monopoles, which provides the acoustic sum as Cardioid.

Follow the build discussions here at DIYAudio.


Outdoor polar response measurement result (7/9/14)




20khz - 800hz

800hz - 50hz


- The perfect Cardioid was never formed fully
- Forward directivity is maintain from 20khz down to 600hz. -6db less rear radiation or better. 
- Then it transtition to a weak dipole to Omni. The transition is smooth and not abrupt.




Epiphone Les Paul


I had developed fascination with Epiphone guitar. The one that I bought was the Les Paul Standard Pro. It basically means a version of Les Paul with the newer 'Pro' pickup. I can pull the knobs and make them single-coils (like Fender Stratocaster). It makes cleaner sound but picks up EMF hum as a compromise. The colour is 'Wine Red'


Few years ago Epiphone produced the 'Valve Junior' Amplifiers. They are simple tube amps and was very popular for modders. The one that I got is known as 'V2' and is in pristine condition as shown below.



Although the amp is only 5 watts, the 8" loudspeaker is of high efficiency type, like normal guitar speakers. So they play VERY loud. I had to build a plug-in attenuator above so not to disturb the house/neighbours.


Distortion pedal, also by Epiphone! was added in May 2014.

The guitar community is very large and friendly (ie. mylespaul.com). I learnt few new terms like GAS (guitar acquisition syndrome), NGD (new guitar day), etc. There are endless discussions on tone for example. It's not unlike the HiFi scene and one can easily go down the slippery slope.

I have promised myself: 1 guitar, LOTS of practice !