https://www.amazon.com/gp/product/B07558DPKN/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1
I bought the above Sound level meter which give out peak reading.
It tuned out that peak db is around 85 db at my listening chair.
From time to time I got over 90db but I found the sound to be too loud.
But last night I recorded 105db while playing
https://www.amazon.com/Bernstein-Suite-Candide-Meditations-Divertimento/dp/B00000JXY1 .
There is some behind story for this.
About one week ago after swapping some IC cables, I started hearing ground hum.
At first I guessed that there must be some problem with IC cables but not.
Thus I pulled back two big 2KW isolation transformers that I had kept for 20 years.
I had not used them for last 7 years since they are heavy and taking lot of space.
With those two isolation transformers in Line Magnetic SET amplifier and power supply of Lansche 4.1 speakers, 80% of ground hum disappeared.
I bought one more 450W isolation transformer from Amazon and set it up with my EMMlab DAC2 and now almost 90% of ground hum are gone.
The amazing thing is that some digital sheen is also gone after setting up three isolation transformers.
I bought 2 packs of 20 magnetic cores.
https://www.amazon.com/gp/product/B07BWC5ZTW/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1I put them on digital, IC and speaker cables.
Now I can play music above 100db without ear aching hardness.
The only drawback of magnetic cores is that it may sound less open or slightly less dynamic.
But I am comfortable with the round and musical sound after putting three isolation transformers and 30 magnetic cores.
2 packs of 20 magnetic cores cost me 24 $ including tax.
This is the best value tweak that I had done on my system.
Thomas
