#1
Hey whats up everybody..

I have a JCM 900 High Gain Dual Reverb, the sound of it is awesome but I'm definitely looking to mod it up a little bit. I want to switch out the stock tubes with JJ KT88's and the stock speakers for Celestion Golds. Right now I don't have the money to do both but I'd like to change whichever would change my sound the most for right now.

So basically would changing the tubes have more effect on the sound then changing the speakers? I know they both are detrimental but I'd like to know which will have more instantaneous effect.

Right now I have a Les Paul Studio with PH-90's in it.

I'm picking up a new American Strat within the month and switching out the pickups to the lace sensors (blue, silver, and red).

I play a lot of 90's alternative rock/rock. Smashing Pumpkins, Soundgarden, Stone Temple Pilots, also Led Zeppelin, and Tool.

Thanks for your time!
#2
woah, i wouldnt think anyone would want to do that.

can you even do that? without some modding and tech stuff?

the 88s give much bigger bass response and would whack the clean RMS watts up to 120w (if 100w) surely?

youd need to push it much harder at higher volumes to get near the same amount of gain as they dont like breaking up.

any 88 fans that know more and how it all works?
#3
Well I didn't think it was that rare of a thing to do. I'm just looking for a new sound is all.
#5
I dont much about the KT88's but when you want new pickups i'll sell you the Blue, Red, Silver set out of my strat.
Ibanez AFS75/Fender Strat Plus > Fulltone Deja' Vibe > Keeley TS808 MOD+ > Fulltone OCD > VanAmps SoleMate > Metro JTM45
#6
Thanks for the offer but I can get them brand new at base cost. By the way, how do you like them? What kind of music is it capable of? I've read a lot about them and heard they are very versatile. Why are you getting rid of them?
#7
Quote by fafinaf
Thanks for the offer but I can get them brand new at base cost. By the way, how do you like them? What kind of music is it capable of? I've read a lot about them and heard they are very versatile. Why are you getting rid of them?


i like em, a bit bright but great sounding. I'm getting rid of them because i really want to try a set of Lollar Blackface's
Ibanez AFS75/Fender Strat Plus > Fulltone Deja' Vibe > Keeley TS808 MOD+ > Fulltone OCD > VanAmps SoleMate > Metro JTM45
#9
what tubes are in it now? If it's a 6550 version, it's just a swap and bias. If it's an EL34, you'll probably need to change a bias resistor at least, and maybe more. I'm not sure of the conversion from something like a KT66, if that's what is stock. You should also check that the sockets are far enough apart to physically fit a KT88. Like dave said, it's going to add bass response, nice tightness, and almost a high fi mid and highend. You're going to lose some of that sweet midrange grind of the EL34 however if that's what's stock. If it is an EL34 amp, KT77 might be a nice inbetween alternative which wouldn't require any modding.
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Last edited by Erock503 at Apr 21, 2008,
#10
You need to make sure that your amp can push enough current to the KT88's for them to actually work. A tube will function if it's down on plate voltage, but it won't if it's down on current and KT88's are thirsty in that regard. They drink a bit more than 6550's, but if your amp already has 6550's then you should be fine.

Tonally, as mentioned there is more bass response and a tone that is generally described as more "hi-fi" (KT88's make excellent tubes for home stereo systems). The other big thing to look at is headroom, as properly running 6550's and KT88's can push as much as 50 watts each as compared to EL34's and 6L6GC's that usually only push as much as 30.

To reiterate what Erock said, KT88's are BIG tubes and it's a possibility that there isn't enough room between the tube sockets to fit them.
ESP LTD EC-256 and a Fender Deluxe VM
#11
You most likely won't be able to mod for KT88s for one reason or another- I'm guessing the transformers can't handle it, but their size could be an issue as well.
Changing the speaker will have a bigger effect on the tone anyway. Why did you pick the Gold? That's a pretty expensive speaker and I'm not sure it's the best fit for what you're playing.
#12
Go for KT77s...they will drop right in. Then again, what sound are you tending toward.
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#13
Just because you demanded seirous answers...

Tits.

That being said, I think the trouble of replacing the tube sockets and taking care of all the voltage concerns would make it more trouble than it's worth.
#14
Quote by the.spine.surfs
I think the trouble of replacing the tube sockets and taking care of all the voltage concerns would make it more trouble than it's worth.

KT88's are a standard octal base tube, which means they'll "plug in" to the same sockets as any EL34/6L6 variant. The issue with the KT88's is that the actual glass housing is a bit taller and significantly wider than the other tubes.

Voltage isn't really the issue. The KT88's draw too much current and if the transformers aren't up to the task, they go boom. I know my Soldano can't handle KT88's and it uses Mercury Magnetics trannys designed for Marshall amps.
ESP LTD EC-256 and a Fender Deluxe VM
#16
I guess my sound is more Smashing Pumpkins (gish era) What would be some good speakers then? and tubes i guess i wont worry about for now, though i think i shoudl change them soon
Last edited by fafinaf at Apr 22, 2008,