Tube Amp, Preamp upgrades -- what did you do that improved your units?

@grannyring Thanks for weighing in. Much appreciated. I've got some nice closeups of both the Line Stage and the Monoblock 60s on my system page, now:

https://systems.audiogon.com/systems/9064/edit

I'm a noobie. I wonder what more experienced people think of the stock caps which came with my amp. My feelings won't be hurt and I know this is very affordable quality gear. But, getting down to the quality of the parts, what do you see in these photos?

Thank you, all.

I upgraded my input tubes on the phone and amp. The phono got a NOS Telefunken 12AX7 and the amp got 2 x 6922 NOS Siemens. Huge increase in soundstage and much more air around each instrument. Highs are crisp and clear, not sibilant. YMMV of course.

Tubes are, i had thought, already a given. I’m thinking of alterations to the machine.

Also, learned this: the Orange Drop caps are 90 cents (.90) a piece at Tube Depot. 
https://tubedepot.com/products/orange-drop-715-series-022f-600v?utm_source=google&utm_medium=cpc&adpos=&scid=scplpCP-OD715-022-600V&sc_intid=CP-OD715-022-600V&gclid=EAIaIQobChMIsIa6_8yH9AIVeQytBh0nbQ4EEAQYBCABEgICr_D_BwE

some of us remember swapping in Orange drops into a Hafler…because they were an…upgrade… it’s all relative….

I would do what I said above with your preamp.  Replace the Alps Blue pot with the same value TKD. The potentiometer has a sticker on the back that tells you if it’s 25k, 50k, 100k etc…. Nice step up in resolution and realism. More than replacing a cap. This can be found at Parts Connextion or Hifi Collective. I think the TKD pot costs just under $100 shipped. 
Replace those white caps labeled QS behind the tubes, 2 of them, with Vcap Odam 2.2 uf.  600v. If too pricey for you use the Audience XO caps. The Odams are wonderful in every way and a nice step above the Audience. The Odam caps will cost around $100 each.  The Audience caps about 1/4 that.  
You could replace the 4 - 47uf 500v filter caps with Mundorf M-Lytic HV 500V 2-Lead Single Section Axial cap from Parts Connextion.  If the amp is 10 years or older, then consider this upgrade.  They cost some $11 each.