Had this for best part of ten years and recently found it in a box in my office. Being inquisitive and wondering 'is there actually anything in it' I popped the top off.
So question is, what are the bits in here? and do they actually deteriorate over time? Was it ever worth plugging in (or close to) my music system.
All I know is the X2 caps stop the switches on my Duals from arcing and putting pops and bangs through the system. Not sure if the blue discs are surge resistors (voltage dependent resistors), but I've seen these around bridge rectifiers (mainly small ones run near the limit I suspect).
Hanging on in quiet desperation is the English way...The time has gone, The song is over, Thought I'd something more to say...
May have some value next to a fridge that is causing clicks on through a ring main. I'm not sure if Isotek are more about sales banter than reality. Anyway I think they are just pricey mains filters, the above product being at the affordable end. They appeared as an adjunct of the Original Hi-FiForSale which operated through a monthly? catalogue as well as web site selling accessories of dubious value in many cases. I remember ordering something from them and it actually came direct from the supplier/manufacturer. My conclusion they were a no added value reseller. The accessories division disappeared but Isotec which sold via the catalogue continued along with the website for personal equipment sales - the later changed hands I believe some time after. Man behind all this was Keith Martin. He originally came to my attention as John Turton's assistant at Audiophile International and continued the UK business after John migrated to California. At some point he jumped ship and business changed hands before eventually folding having been run allegedly by a relative of the Tube Technology owner from their premises (I lost money on an unfulfilled order over this). Anyway Keith moved on to web design and did a site for Vivante. He seemed to jump ship again setting up the aforementioned Hi-fiForSale.com amid allegations by the original Vivante owner (Steven Carr) that he took the customer list with him.
The X rates caps are between Live and Neutral. The Y rated ones between Line and Earth and Neutral and Earth. The VRD will be between L-N, L-E and N-E. The VDR's are designed to be a high resistance below a applied voltage then pass current above that voltage. In general its a noise and spike absorber.
"but I've seen these around bridge rectifiers"
More likely to be ceramic caps in that position. They look very similar.