Help me thicken up my peavey JSX

[Bearitone]

I've had my peavey JSX for awhile now and i like it but its really thin, overly bright, and harsh sounding when I crank it.

I was wondering what preamp and power tubes I could put in to really thicken and darken it up.

Its such a tight amp I know it could be way darker without it sounding bad.

I have the stock EL34 power tubes in there and I want to switch to some kind of KT 77's or 6l6's but any suggestions would be great. I just want DARK and THICK

 

[RustInPeace]

JJ E34L's add a lot of low end into a power amp section, check them out!

 

[Senior]

2nd for JJs. My Windsor came with them stock, and I had a hell of a time when I changed them the first time, because everything I tried was way too bright and had too much of the EL34 "edge".

JJs are like an EL34 that has been hanging out with 6L6s too long, and is starting to pick up their habits.

 

[Bearitone]

EDIT: So E34L, not EL34?
Should I just switch to JJ 6l6's instead then?

and what about preamp tubes? also JJ?

 

[sage]

When I had the JSX, I ordered the KT77 + high gain preamp tubes from Eurotubes. Shipping was quick. Results were incredible. Like, turned the whole thing into a different amp.

 

[TheWarAgainstTime]

KT77's or 6l6's and all JJ preamp tubes

 

[Endnote]

I put 6L6s and KT77s in my JSX (along with JJ 12AX7s in the preamp). I preferred the 6L6s over the KT77s and feel that they darken the tone to an extent. But I also think that it was somewhat subtle. The amp has a very bright voicing. I think the tubes will make a difference, but it might not be enough.

 

[FILTHnFEAR]

I put KT77's in mine, but it was still too harsh. Though I do have a mix of preamp tubes in there also. Not all JJ's. Need to try that before I put 6l6's in.

Then again, I'm pretty sure that something is wrong with my head. Maybe hot plating? Not sure. The tubes become extremely hot shortly after turning the amp on, even though the volume is low. Like loud tv volume kinda low. 2 of the tubes are glowing blue.

Not to hijack the thread, but does anyone know if that's what might be happening in my case? Really kind of bumming me out.

 

[Bearitone]

I just got off the the phone with a guy at Eurotubes and he recommended the JJ 6ca7 tubes for the power section. I can't quote him from verbatim but he basically said it would help shave of some of the high end and thicken up the lows.

I've never heard of someone running these in anything before, but I guess I'll experiment.

 

[RustInPeace]

Eurotube guys are top notch. I think Senior is a bit confused... JJ is a brand so they make 6L6, EL34, E34L, Kt66.. etc.

The E34L is like the EL34 but with more bottom end bloom. There are good descriptions on the Eurotubes site.

 

[RustInPeace]

Also make sure to bias your amp properly when you get new power tubes in. I bought one of the bias testers from Eurotubes for $25 and its paid for itself.

 

[Kstring]

All with JJ pre amp tubes in:

EL34: harsh but cut through really well.

6l6: Got rid of some of the harshness and added some bass but not much difference from EL34.

6CA7: The best of both the EL34 and 6l6 but it also took away some of the natural tightness of the amp if that makes any sense.

KT77: My favorite tubes in my JSX when I had it, added bass made the mids less honky and tamed some of the high end harshness.

But the JSX is also really picky with cabs speakers and EQ settings so id mess around with some of that too.

 

[witeter]

JJ 6L6 or KT77's will help.
Make sure the send and return knobs on the back of the amp are turned to max.
Include an EQ in the loop (i used to use the MXR 10 band).
Hope this helps

 

[GoldDragon]

To the OP:
Its like you describe a different amp than the one I own. I would not consider the JSX tight for a metal amp, it has some bloom and its fat, not particularly fast. And while it has less bass response than the 3120/XXX, it still has an active EQ and a ton of gain which means it easily does big, fat metal. Or you could scoop out the mids if thats your thing. Compared to the XXX, its like the JSX has "5" less bass. I like to keep the bass around the middle on the JSX, where with the XXX I would roll it mostly out.

The 6L6 is sounds bigger and more American than the EL34s, and they suit the amp better, imo. Anything you do with the preamp tubes will be a drop in the bucket compared to what the active EQ gives you in adjustment.

My advice about the JSX is that while it sounds OK at practice level, it is a different amp at stage volume. If your master and channel volume are not both at at least "5" then you are not hearing what the amp is designed to do.

The preamp circuit is pretty vanilla Peavey, if you want different tones out of the amp, your best bet is different speakers. If you want more heft then Celestion GT75s are probably what you want.

 

[grogarage]

ever tried an MXR 10 bamd eq?

 

[KailM]

^^Ditto to that. I have one and it made more difference on my 6505+ than any other upgrade, including speakers, tubes, and any other pedals. You can basically do whatever you want with a MXR 10-band in the loop. I was able to completely eliminate high-end fizz on my 6505+ by cutting the highest slider by 6db. Add a little to the 125 hz slider and it will increase the amp's "thump" without making it muddy. Basically, everybody should own one.

 

[jonsick]

I would never have described the JSX as overly tight or trebly. Unless you're using too much gain and presence.

Try dialling both back first. I loved my JSX when I had it. But it is easy to make it sound bad with a rubbish EQ setting!

 

[MikeSweeney]

thicker strings too can help maybe a vary short delay

 

[Bearitone]

To the OP:
Its like you describe a different amp than the one I own. I would not consider the JSX tight for a metal amp, it has some bloom and its fat, not particularly fast. And while it has less bass response than the 3120/XXX, it still has an active EQ and a ton of gain which means it easily does big, fat metal. Or you could scoop out the mids if thats your thing. Compared to the XXX, its like the JSX has "5" less bass. I like to keep the bass around the middle on the JSX, where with the XXX I would roll it mostly out.

The 6L6 is sounds bigger and more American than the EL34s, and they suit the amp better, imo. Anything you do with the preamp tubes will be a drop in the bucket compared to what the active EQ gives you in adjustment.

My advice about the JSX is that while it sounds OK at practice level, it is a different amp at stage volume. If your master and channel volume are not both at at least "5" then you are not hearing what the amp is designed to do.

The preamp circuit is pretty vanilla Peavey, if you want different tones out of the amp, your best bet is different speakers. If you want more heft then Celestion GT75s are probably what you want.

I dont know. I play on the green channel of my 6505, bass at 6, resonance nearly maxed out, and I love it. But then I switch to my JSX and woah! Its freakin bright and harsh, and doesn't have that resonance (big sound) i get from the 6505.

Maybe you guys are right and I really just need to sit and toy with the controls. I'll sit down for awhile longer with it and really comb through all my options and report back.

As far as me calling the amp super tight: To me it feels tighter than the 6505.

 

[Bearitone]

^^Ditto to that. I have one and it made more difference on my 6505+ than any other upgrade, including speakers, tubes, and any other pedals. You can basically do whatever you want with a MXR 10-band in the loop. I was able to completely eliminate high-end fizz on my 6505+ by cutting the highest slider by 6db. Add a little to the 125 hz slider and it will increase the amp's "thump" without making it muddy. Basically, everybody should own one.

^^^ i'll give that a shot!