I share with you the following tweaks that have positively affected the sound in my system (YMMV). For my Analog Front-End which utilizes a Technics SL-1210 MKII (A) Had my tonearm rewired with Cardas wire that was terminated to external RCA jacks on the back of the turntable which affords me the ability to use cables of my choice (B) Disabled the strobe (C) Added a separate Power Supply (D) Added a Silicon Trough (E) Replaced the rubber mat with a Funk Firm Achromat (F) Purchased a VPI Center Weight which insures the Achromat and record become "One". (G) Purchased an Allnic AUT-2000 Step-Up Transformer whose design mimics the Kondo of Japan SUT. (H) Purchased the Alpha series SoundString cables which come out of the turntable and into the SUT and Audience AU24e cables which come out of the SUT and into the Harman Kardon Citation 1 Pre-Amp. (I) Replaced the technics headshell with a Sumiko headshell. (J) Finally, every month I use the Cardas Record Sweep which obstensibly degausses my system and demagnetizes my Denon DL-103r. All interconnects,speaker cables, and power cords are SoundString except where noted.
For my Digital Front-End, which utilizes a Proceed CDD Transport and Monarchy NM24 Dac, I share the following tweaks. (A) Purchased a Creative Cable Concepts Silver Bullet digital cable that connects the Proceed Transport to the Monarchy NM24 dac (B) Purchased a Monarchy AC- Regenerator that I set at 120Hz and powers the Monarchy NM24 Dac (C) Replaced the Wima capacitors in the NM24 Dac with Mundorf Supreme Silver/Oil which utilizes an oil-impregnated Silver-metalized Polypropylene wound in a special counter-inductance winding. (D) Replaced the Jan Phillips tubes in the Dac with NOS 1965 Siemens Halske tubes (E) Removed the Monarchy Upsampling DIP from my Digital chain and now only play my cds in their native format of 16 bits and 44.1 kHz which along with the Creative Cable Concepts Silver Bullet digital cable gives them a more organic, natural, closer to vinyl sound (F) Every month, I use the $20.00 Ayre "Irrational But Efficacious" CD version 1.2 System Enhancement Disc. The main tool on this disc is track seven, a five minute glide tone, that when played through your system at a moderately low listening level will obstensibly enhance transparency, clarity, soundstage, musical layering, and Micro/Macro dynamics. Ayre Acoustics says the following: While we don't have conclusive proof of the mechanism involved, we suspect that it functions by demagnetizing residual fields that build up in your components over time. The tracks on this disc were created digitally with 88.2 kHz, 32-bit resolution. Enhanced resolution transfer to the 44.1 kHz, 16-bit CD format was performed using 0.5 bits of dither with a triangular probability distribution function for maximum fidelity.(Whatever that means) For what it's worth, when I had a Teac 2300SX Reel To Reel tape player, I would demagnetize the tape heads on that unit regularly and it did ameliorate the sound quality.
With regard to acoustic treatment to my listening room, I have done nothing outside of extensive experimenting with finding what I now consider the optimum sounding position for my Focal Utopia Diva Be speakers with the elements that exist in my listening environment.
I may very well be a victim of the "Placebo Effect". I may very well have been conned with what some would consider Snake Oil, Voodoo, and Irrational BS. However, after every listening session, I always come to the same conclusion: these tweaks are unequivocally Efficacious.