Demagnetizing JADIS JA200 Monoblock Power Amplifier




Demag JP200

First of all I would like to thank to my friend Mr. MPC for allowing me doing this trial in his audio system.
 Mr. MPC's audio system configuration are as follows : 

CD/SACD Transport    : dCS Paganini
Master Clock                :  dCS Paganini
Upsampler                    : dCS Paganini
DAC                               : dCS Paganini
Power Amp                   : Jadis JA-200
Speaker                        :  B&W 802
Date of Trial                : Feb 13th 2019

In this trial I was only focusing on demagnetize Jadis JA-200 monoblock power amp, because Jadis is one of my favourite power amp.
Demagnetizing process done at all tube and power transformer of JA-200. Actually I'm also interest on demagnetizing JA200 output transformer, but unfortunately its transformer located inside solid metal case so I can't do that.
The interval time I used was 120S or 2 minute for each tube array  and power trans.

Afer demagnetizing finished, I got the same result as I ever did to other tube amp belong to my other friend Mr. N ( link is here )
Depth and stereo image become deeper,  wider , and also tonal become more detail.
But there is a unique discovery I found at this trial, namely the ambient noise/his much more reduced after demagnetization proceess done.
This amp has been using by Mr. MPC since 2010 and from that time until now (Feb 2019) he never replace existing  power tube, in other word all power tube has been working there for almost 10 years. So It is no wonder if I can hear noticable ambient noise when I stand about 2 meter from loudspeaker, I quess this ambient noise caused by reduction of electron emission occur inside those tubes.
But after demagnetization  all that ambient noise much reduce until certain level that I can not hear from 2m position as before.


Demag JA200 tube

Demag JA200 Power Transformer

JP 200 PTrans
Demag JA200 Power Transformer

JADIS JA200 Monoblock Power Amp

dCS Paganini system

B&W 802