#1
I've been thinking a lot lately about upgrading the tubes in my JCA50H. Don't get me wrong, I love the way that the amp sounds, but I can't help but think that the cheap stock Chinese tubes are likely holding back the amps true potential.

I know a bit about tubes, but I'm def no expert; thats why I'm starting this thread

For Power tubes I'm thinking of maybe going with SED Winged "C" I've heard others say that this tube works well in the amp, and gives it a lot of bottom end.

I'm not really sure what I should look at pre-amp wise... I know these will have the most effect on the tone. I've heard that JJ's arn't that great in this amp (too muddy). Maybe some mullard's? I'm basically just looking for suggestions here.

Like I said, I really like the way the amp sounds. A little more headroom on the clean channel could be tolerated


Thanks for reading!
Guitars:
PRS Custom 24
Gibson Les Paul 60's Tribute
85' MIJ Strat
97' Snakepit Les Paul
LP Traditional 1960 Zebra
MIJ Tele
MIA Strat

Amps:
Silver Jubilee 2525
Peavey Ultra 112
Jet City JCA50H
66' Bassman
Pink Paisley Princeton RV
74' Vibro Champ
Last edited by red.guitar at May 1, 2013,
#2
You can't go wrong with SED power tubes.
JJ preamp tubes work very well in any Marshallesque amp, which that is. Try JJ ECC83S everywhere but V1. In V1 go for a JJ ECC803. The 803 is low noise and has a little more top end sparkle than the 83.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#3
Tung sol 12ax7 (bright tube) for V1 and JJ ecc83s in the rest. Dont know what to use as powertubes.

ESP LTD F-50 + Tonezone
Cort EVL-Z4 + X2N
Cort EVL-K47B

Marshall Valvestate 8100
Randall RG1503
Bugera 333
Peavey Rockmaster preamp

Line6 Pod X3
#4
All I use is SED power tubes these days and they are great.

The New Mullard 12ax7 are pretty nice, I have tried a combo of new Mullards and JJ in my Marshall DSL100 and they are pretty nice.

I would suggest getting at least 1 JAN-GE/Phillips 5751 for either V1 or the PI
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#5
as always i recommend doing preamp first to see a difference, then power amp. all at the same time masks the affect of each.

off hand the JJs and tung sol are a good choice. why do i feel jet citys are bright amps? perhaps the tung sol might be a bit shrill? its not that bright, but the JJ might compliment better...just my assumption.

more headroom? perhaps try a 5751 in V1. should drop gain too much, but may add clarity or take away the fuzz. it does drop gain, but not to the point of a problem, moreso just removes gain you didnt realize shouldnt be there anyways.
Carvin CT624
Walden G630ce Acoustic
Carvin V3M, Avatar 2x12 WGS Reaper, vet 30
(crybaby, Fairfield circuitry Comp, GFS tuner, Vick Audio 73 Ram's Head, Xotic AC booster, lovepedal trem, TC Flashback, PGS Trinity Reverb, Walrus Audio Aetos power)
#6
Thanks for all the great suggestions guys!

@ikey_ - The JCA50H is a very bright amp indeed! Infact, I usually run it with my trebel knob at zero, and the presence at less than half.

I think I will most likely go with the SED's winged "c" for the power section, and possible JJ's for the preamp, with something different in V1.
Guitars:
PRS Custom 24
Gibson Les Paul 60's Tribute
85' MIJ Strat
97' Snakepit Les Paul
LP Traditional 1960 Zebra
MIJ Tele
MIA Strat

Amps:
Silver Jubilee 2525
Peavey Ultra 112
Jet City JCA50H
66' Bassman
Pink Paisley Princeton RV
74' Vibro Champ
#7
I remember someone saying that Jet City has a very thick, loose bass. If that is true then thats why JJ may not be ideal for V1, JJ ECC83S had clearly darker sound compared to Tung Sols I have now in my Valveking.

ESP LTD F-50 + Tonezone
Cort EVL-Z4 + X2N
Cort EVL-K47B

Marshall Valvestate 8100
Randall RG1503
Bugera 333
Peavey Rockmaster preamp

Line6 Pod X3
#8
Oh just so you know SED are no longer making tubes, so you may want to buy a quad if you plan on keeping the Jet City for a while, or prices are sure to rise even more than they are now.
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#9
Quote by Robbgnarly
Oh just so you know SED are no longer making tubes, so you may want to buy a quad if you plan on keeping the Jet City for a while, or prices are sure to rise even more than they are now.


Thanks for pointing that out. I may just do this

So I think I'm going to go with 2x SED's for my power section, 4x JJ ECC83S for v2, v3, v4, & v5 and then a JJ 5751 for v1.
Guitars:
PRS Custom 24
Gibson Les Paul 60's Tribute
85' MIJ Strat
97' Snakepit Les Paul
LP Traditional 1960 Zebra
MIJ Tele
MIA Strat

Amps:
Silver Jubilee 2525
Peavey Ultra 112
Jet City JCA50H
66' Bassman
Pink Paisley Princeton RV
74' Vibro Champ