50w Plexi mods
Re: 50w Plexi mods
Don't break your arm patting yourself on the back.
Here, let us help you. Great job!
Here, let us help you. Great job!
- Bubba
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Hey, Greg!!
Did you choke your JVM, yet? I need to know whether it makes any difference at all from somebody who can actually tell. I'm considering the mod.
Haggard Musician
Re: Hey, Greg!!
Too funny. I actually just started doing it last night to my bud's JVM. His is the test mule, then mine will be next. He bought two chokes - one for him, one for me - and I'm doing the work.
So far I've got the board removed from his amp and marked/drilled the holes for the choke. Very easy so far. Plenty of room for the choke. I need to go to a hardware store today and pick up some small bolts and lock-nuts.
I'm going to do a photo-essay thing when I get to my own amp.
Rebel Yell
- Bubba
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Re: Hey, Greg!!
Excellent. I've seen various build photos and it looks to be ridiculously simple - bolt the choke to the chassis, run two leads through, take out the big white resistor near the four big caps and solder the leads in its place. Is it really that easy?Greg_L wrote: ↑Wed Mar 28, 2018 8:31 amToo funny. I actually just started doing it last night to my bud's JVM. His is the test mule, then mine will be next. He bought two chokes - one for him, one for me - and I'm doing the work.
So far I've got the board removed from his amp and marked/drilled the holes for the choke. Very easy so far. Plenty of room for the choke. I need to go to a hardware store today and pick up some small bolts and lock-nuts.
I'm going to do a photo-essay thing when I get to my own amp.
Haggard Musician
Re: Hey, Greg!!
Yes, it would appear to be that easy, but I haven't gotten that far yet, so I'm not sure. But it does seem stupidly easy. That is all there is to it. R106 is the resistor you'd need to replace.
Rebel Yell
- Bubba
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Re: Hey, Greg!!
Presumably there's a polarity to the leads? Maybe not, I dunno.
I wait with bated breath.
Haggard Musician
Re: 50w Plexi mods
I know you feel sketchy about soldering, but other than that, you absolutely can do it.
The real question is if it's even worth it. Most people seem to love a choke on their JVMs, but a lot of people have confirmation bias too. I'm going into it not expecting any kind of massive tone revelation. I'm hoping for a little less noise, maybe a little better stability in the low end and less oscillation at mega gain levels. Maybe.
Rebel Yell
- Bubba
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Re: 50w Plexi mods
I'm good at soldering, I do loads of it at work - but understanding electronics isn't my strong suit.Greg_L wrote: ↑Wed Mar 28, 2018 9:39 amI know you feel sketchy about soldering, but other than that, you absolutely can do it.
The real question is if it's even worth it. Most people seem to love a choke on their JVMs, but a lot of people have confirmation bias too. I'm going into it not expecting any kind of massive tone revelation. I'm hoping for a little less noise, maybe a little better stability in the low end and less oscillation at mega gain levels. Maybe.
I'd just like to control noise a little better, particularly as we get around a lot of different venues and their power is often not the cleanest. Loads of dimmer switches, outside neons, beer pumps blah-de-blah. I sometimes get obtrusive 50Hz noise, particularly with gain, as you'd expect. I'm not intending to do it for any particular tone benefits - I'm happy with it!
Haggard Musician
Re: 50w Plexi mods
Ah yes, that's right. Sorry. It's the wiring that stresses you out.
In theory, a choke should help a lot with that specific problem. The JVM is a noisy amp, as you know. Most of the noise is in the higher gain stages, but it's kind of noisy everywhere. I guess we'll see soon enough. I'll definitely let you know how mine goes.I'd just like to control noise a little better, particularly as we get around a lot of different venues and their power is often not the cleanest. Loads of dimmer switches, outside neons, beer pumps blah-de-blah. I sometimes get obtrusive 50Hz noise, particularly with gain, as you'd expect. I'm not intending to do it for any particular tone benefits - I'm happy with it!
Rebel Yell
- Bubba
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- Joined: Wed Jan 04, 2017 2:45 pm
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Re: 50w Plexi mods
Excellent. Fingers crossed it does the trick.Greg_L wrote: ↑Wed Mar 28, 2018 12:33 pmAh yes, that's right. Sorry. It's the wiring that stresses you out.
In theory, a choke should help a lot with that specific problem. The JVM is a noisy amp, as you know. Most of the noise is in the higher gain stages, but it's kind of noisy everywhere. I guess we'll see soon enough. I'll definitely let you know how mine goes.I'd just like to control noise a little better, particularly as we get around a lot of different venues and their power is often not the cleanest. Loads of dimmer switches, outside neons, beer pumps blah-de-blah. I sometimes get obtrusive 50Hz noise, particularly with gain, as you'd expect. I'm not intending to do it for any particular tone benefits - I'm happy with it!
Haggard Musician
Re: 50w Plexi mods
Okay Bubba, I just finished my buddies JVM, and I think you need to do the choke. It's noticeably quieter. It still hisses a little, but the low end is vastly improved and the fizz is tamed a lot. It's very chunky now. The low end is beefier without being tubby or flubby. The squealing and fizz in the high gain settings seems to be much improved. Good mod to do!
I'll get started on mine and do the pics and write-up thing.
Rebel Yell
- Bubba
- Posts: 3350
- Joined: Wed Jan 04, 2017 2:45 pm
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Re: 50w Plexi mods
Superb! Very keen to get it done, now. I've always liked the low end provided by the JVM and 4x12, but felt that it was too undefined and mushy to add any "chunk" to chugging riffs. It kind of disappeared apart from adding general weight and warmth to the band's live sound. If the hum is reduced significantly, then deep joy will be outstandifold.Greg_L wrote: ↑Wed Mar 28, 2018 6:57 pmOkay Bubba, I just finished my buddies JVM, and I think you need to do the choke. It's noticeably quieter. It still hisses a little, but the low end is vastly improved and the fizz is tamed a lot. It's very chunky now. The low end is beefier without being tubby or flubby. The squealing and fizz in the high gain settings seems to be much improved. Good mod to do!
I'll get started on mine and do the pics and write-up thing.
Excited.
Haggard Musician
Re: 50w Plexi mods
Yeah there's definitely like a "clarity" to the sound, as I'm hearing it right now. Everything just sounds better for sure.Bubba wrote: ↑Wed Mar 28, 2018 7:05 pm
Superb! Very keen to get it done, now. I've always liked the low end provided by the JVM and 4x12, but felt that it was too undefined and mushy to add any "chunk" to chugging riffs. It kind of disappeared apart from adding general weight and warmth to the band's live sound. If the hum is reduced significantly, then deep joy will be outstandifold.
Excited.
Rebel Yell