Gold lion tubes

Scooter, not to be a rude, because they are.. Those thing were manufactured a few different places, by a few different factories.
The production runs are from the 50s until current. The OLD ones use to turn orange when left in the sun. Newer ones that have the orange tint to them. There are a LOT of fakes, believe it or not.

So you know the fakes are probably BETTER than some of the new reissue. LOL I’m not kidding either. HIGH failure rate, and 10% matching if your lucky.. The best on the market today if you can afford it, is PSVANE. Second, Solvex (EH), for the money, and matching.. GL is way down on the list for SQ, reliability, and cost, you’re buying a name, but it sure not high quality.

Listen in Mono before you spend money, They are not known for sounding good in mono. Have to make sure they are matched RIGHT to the speakers, or they just make more noise, but not quality, for sure. LISTEN first, before you spend your money.

If you really want to hear the MC275 come alive, GE 6550, tungsol, 1955-65
A 6550 is a better valve, for mids and highs.
Bass duty in the mix, KT88s, BUT, again I don’t use valve amps for BASS duty.

Regards

Just buy two matched sets of either EH or JJ 6550's. Both companies make quality tubes at affordable prices.

Not crazy about his personality, but- when Kevin Deal speaks about a tube’s reliability and presentation; I listen!    ie: https://upscaleaudio.com/products/gold-lion-kt88      I’ve personally compared a quad the Russian/New Sensor, GL/Genelex KT88 repops (from Brent Jessee, with 50 hours on them), to a quad of my last mid-Seventies, GE 6550As (a quad in each monoblock main amp, system in Mono, GEs still testing well into, "GOOD" range for GM and emissions).      The tone, mids and highs were virtually identical, but- just slightly less dynamic in the bottom, with the GLs.      I’ve now had an octet of KT88 repops in my system for over a year and have thoroughly enjoyed their imaging, sound stage, tonality, dynamics and reliability (ie: zero bias drift), over that time.      If you’re still shopping for tubes: contact any reputable tube monger (ie: Upscale Audio, Brent Jessee Recording, TC Tubes, etc) for the facts/to avoid fakes.       Of course, if you can still afford them; nothing’s going to outperform a good testing compliment of original, NOS Genalex, GE, Sylvania or Tung-Sol pentodes

The ones I have the band on outside ring is orange not red it’s the we’re the names is I seen ones in both colors at upscale and other sites 

Hay rodman99999, you ever head to head, left channel/right channel, with a MC275? GL KT88 left bank, GE Tungsols, 6550s in the right?

I have, seems like ALL the 6550 valves have better mids and highs, and the KT88s have better bass, low mids, stay pretty flat until 14-16khz and a 2-4 db roll off.
I still hear above 16Khz with no boost, and below 30hz with -6 db.
Looking at a graph, a KT88s a slight smile on the left side (20-200 hz)
flat until 14-16k the -1-2 db @ 14-16khz UP. Bell's palsy look, left smile, right frown.

6550s, climb from bottom to top ever so slightly,
-3 db @ 25hz and +2 db 16khz +3 db @ 18khz

When I use a GE, I like Tellies and RCAs in the pre position.
With KT88s I like Sylvania's, they brighten the tops a bit..but don't
boil my ears.

Sylvania power valve and Sylvania preamp valves, WAY to bright.
Serous ear boiling combo in a Mcintosh push pull setup.

I want to try a set of EL34s and KT88s in PSVANE, 2 sets of 6. 
They are some expensive valves, I REALLY like their signal valves.
Guy here on AG said to try them, I was pleased, but $$$$$$ WOW, expensive...

Regards