Upgrading a Bandmaster filter caps question Srague Atom versus Illionois brand

[Slobrain]

Hey folks

I was thinking about upgrading the filter caps in a 67 Fender bandmaster head that I bought used some years back. The output tranny was replaced using a Classictone 50 watt OT which was a big improvement over the stock tranny. Right now its got the Illinois brand filter caps 100/450 and they are ok but I find wanted to ask opinions about the Sprague Atom 80/450 versus the Illinois brand 100/450 and see if anyone feels the Sprague is much better? especially at high volume, retaining good clarity thru the sound spectrum.

Reason I ask is that I run this head with a Marshall 2x12 cab with G12t-75s and when pushing the amp it seems the bottom sort of drops and gets a bit mushy at high volumes, I have brand new Sovtek 5881s in it and biased correctly. At lower to medium hi volume the amp sounds great.

I guess what I wanted to ask if beefing up the power supply with better caps like the Sprague Atom versus Illinois brand does anyone really hear that big of difference? The diodes in the PS are 1n4007 But I think maybe I could put in some 1n5408s instead but that would probably be overkill...

Thanks

Slo

[The Dude]

Theoretically, lowering the capacitance would give you more sag. The higher the cap value, the longer it will hold a charge. So, if your goal (the way I read your post) is less sag, you'll want to go with a higher value cap rather than lower. I would think cap value would be more important than brand. There will be others here with more "real world" experience.

[Zouto]

I got best results with F&T caps (e.g.F&T Electrolytic Capacitor 100uF / 450V ). I had some issues with brand new dried up Atoms, so F&Ts are my first choice. You could also sub the diodes with UF types (UF4007 or UF5408 etc.).
Zouto

[soundguruman]

I would not use Illinois because they are made in China, Have short life, and I don't like the way they sound.

The best sounding ones are F&T, I think.
Capacitors | Antique Electronic Supply

Atoms are good, you need fresh ones. Old capacitors go stale. Don't buy NOS capacitors.

5408 instead of 4007 is OK, but you don't need it.

[guitician]

That's funny because I recently bought a bunch of 1972 Sprague 22uf/250V made in Hong Kong that are great! I realize that this is a special case, and your mileage will vary.

[guitician]

Oh, and if the caps work, don't replace them, it's an old wives tale that they die with age.

[Slobrain]

Thanks for the info fellas, I will probably go ahead and get some F&T caps to beef up the PS on this amp. I used the F&T on a Marshall 50 upgrade a few years back and they worked well. Illinois brand are cheap but I guess they have gone down in quality over the years. I can remember some years ago New Sensor couldn't get them for awhile due to some problem with the manufacturer so who knows what was going on back then...downgrade of materials maybe???
I really like the tone of the Bandmaster but it doesn't come close to the volume and oomph the Marshall 50 watter can do...

Cheers

[Enzo]

NewSensor probably couldn;t get them because they were demanding a lower price than IC wanted to well them for.