Synergistic Red Fuse ...

Al, thanks for your response to my question on "pushed-value" SR Blacks in my AC input.  Of note, the front-panel display on each amp now reads at 120-121V, whereas at lower fuse ratings, the line voltage was at around 117V.  The operating range of the ARC 210's is 105V-130V.  
I'm glad you asked about the REL subs and Neutrik SpeakOn wiring.  The Neutrik plug is the NL-F4C, a four-terminal plug supplied with the REL's.  When I went to mono block amps and a sub for each amp, I followed the advice of my High-End retailer here in Mpls. For Magnepan speakers, I am using the 4 ohm speaker output terminals on the ARC 210s. I have connected both SpeakOn red and yellow (+) wires onto the 4-ohm (+) terminal of the amp and the black (-) wire to the 4-ohm (-) terminal on the amp. I left these wires in their original places on the Neutrik plug end. And where do I have the Neutriks on the REL input terminals?  I have left them in the unbalanced high-level inputs a long time ago.  This is the input recommended for a stereo amplifier.  The balanced high-level input is described in the REL manual as being used for  bridged-mode amplifiers. Thinking this was not my situation, I have ignored that input all these years. although the REL manual goes on to say, "Monoblock amplifiers may or may not be bridged output." Perhaps I should be using the balanced inputs on the REL's?
Regards, Joe 

I suspect it might be best to write failures like this off to, "that’s the way the cookie crumbles." 🍪 Failure to obtain expected results can occur - and have occurred - for just about every device ever conceived. And these failures to achieve expected results often generate a certain amount of angst and confusion, especially when they occur for something that's got a lot of buzz going for it. 🐝 Like the Black fuse or the new Blue fuse. There are many perfectly good reasons why these failures can occur; and those reasons have been thoroughly covered by your humble scribe ad infinitum.

geoffkait ...

The new BLUE fuses are so good in my system that its hard to believe that someone can install one and not hear the difference over a stock fuse. Perhaps the fuse is defective? Try another fuse? Hidden agenda? What??

Frank

I have to a agree with Frank’s last post. Given the pedigree of @veerapaneni components, i am finding it hard to understand as well. I was able to hear immediate improvements over a stock fuse in my system.

May be he was expectating improvements equivalent to those that comes from a equipment upgrade :-)