Reynaud Bliss Jubile vs Cantabile Jubile

You could swap out the Grover which I think are silver foil to something copper and maybe swap out the tubes in your Pathos.  What 6922 tubes are in there now?

I have a pair of Monster copper pair of bi-wired cables. They sound darker and a tad slower, but I’ll throw them in. I’m using a pair of 1960s Sylvania, which are an improvement over the Russian-made Electro-Harmonix that came with the unit.

But here is something I did which has improved things quite a bit. I angled the speakers slightly upward. The result was a great lessening of the overt brightness and much better integration between the top end and the rest of it.

I’d still like to see a greater relaxation of the top end compared to what I get from the midrange on down. There isn’t the bloom that there is in the midrange on down. It’s still sounding a bit constrained up there compared to the rest of the speaker’s output, but at least the top end seems to have been tamed from where I’m sitting. If I do raise myself up to me more in the horizontal center plane of the tweeters or if I stand right in front of the tweeters, the brightness returns.

I did replace the Grover Huffman silver speaker wire with the Monster Cable. It's definitely toned down the heightened top end. It's not as precise in the midrange as the Grover Huffman nor as fast, but it's not bad either. I might try to see if I can borrow some other cables to try in my system.

Depending on the vintage the Sylvania 6 volt tubes can be pretty forward and could have much more affect than  changing out speaker cables.  Mullard's would of course tone it down but expensive.  An alternative to them are Matsushita for less. Andy at Vintage Tube Services has them in stock. One speaker cable that will help tone the top end down for not a lot of money is the Dueland 12 gauge dual cable from Parts Connexion.  Add the connectors of your choice or as they recommend use bare wire. It's what I use with the Abscisse Jubile after trying four others.  Glad you found out that tilting them worked. 

i have a pair of cables made of those exact wires with klei banana ends.  my fave cable for most scenarios.  think they'd be too smooth with older reynauds i had but never tried the newer ones.  could be a good match.

sylvania tubes to me does emphasize the highs a bit.  rca is more balanced and ge is a bit smoother.