Official original Marshall JVM appreciation thread

main thing to watch for is if anyone has hacked some mods and made a mess of it.

I think because they can be picked up for reasonable prices sometimes they get treated a bit worse than a “boutique” amp. They’re often great prices here but usually a bit more beaten up cosmetically too.
The one I'm looking at has had a few mods done, but they seem to be some of the simplest and most sensible of the mod list (Plexi, C83, negative feedback mods). Otherwise looks super clean.

These are absolutely not boutique around here, pretty common amp with fairly set prices, which is why I've considered buying one a few times already.

I'll see if it's still available next week when I have a car to use.
 
So, I'm kinda considering picking up a used JVM410 head. They aren't priced too bad over here.

Other than being large and heavy, what are the bad parts of these? I know there's a lot of easy mods to tweak them.

Loop isn’t the best

I actually got better results when I switched to using the other loop that supposedly I wasn’t supposed to use for my applications lol
 
Loop isn’t the best

I actually got better results when I switched to using the other loop that supposedly I wasn’t supposed to use for my applications lol
I guess you mean the loop marked preamp out/poweramp in? How does it work with the fx you use? Since I mostly use Strymon/SA which should be able to take line levels, I should be fine.

Is the main issue with the regular fx loop that it does not go fully series even with wet mix at 100%? Does this cause phase issues or what?
 
Since I mostly use Strymon/SA which should be able to take line levels, I should be fine.
Maybe. I’ve been able to clip the Timeline and BigSky with hot signals like you can get in that poweramp insert loop. Be mindful of your channel volumes by keeping them at 10:00 or lower and you should be okay.

Is the main issue with the regular fx loop that it does not go fully series even with wet mix at 100%? Does this cause phase issues or what?
Yes. You can get phase issues.
 
Maybe. I’ve been able to clip the Timeline and BigSky with hot signals like you can get in that poweramp insert loop. Be mindful of your channel volumes by keeping them at 10:00 or lower and you should be okay.
The older big box Strymons don't seem to have the instrument/line level setting that is found on the newer pedals, including the BigSky MX. While the FAQ says the old ones should accept up to +8 dBu signal, maybe the line level setting on newer pedals helps?

Yes. You can get phase issues.
I guess there's no mod or fix to this, other than using it as a parallel loop, which gets kinda annoying if it's not a single multifx box but multiple pedals since you want kill dry in there somewhere.
 
After smashing the UAD Lion sim, I spent some time with the JVM OD1 channel today and did some captures. ToneX and NAM came out extremely close to the OG amp. I'll eventually do a full pack but I don't want to rush it / get annoyed / feel like I need to redo it. These are +13dBu captures.

Samples


NAM
https://tonehunt.org/AmpsPedalsPickups/6b8be5f7-f030-4503-a89b-965e5bfb3f2f

ToneX

Thanks for the NAM captures!

I was able to use these to get an idea what I would get with the JVM. It sounds great, I think I would like it!

But I ended up saving a bunch of money, because I can dial my BluGuitar to sound pretty close. Not identical, but this was a quick "dial by ear, play a sloppy track" test.

Can you guess which is the JVM?

 
Thanks for the NAM captures!

I was able to use these to get an idea what I would get with the JVM. It sounds great, I think I would like it!

But I ended up saving a bunch of money, because I can dial my BluGuitar to sound pretty close. Not identical, but this was a quick "dial by ear, play a sloppy track" test.



Can you guess which is the JVM?

Do you work for Blug?

You bring it up ALL the time.🤣
 
Thanks for the NAM captures!

I was able to use these to get an idea what I would get with the JVM. It sounds great, I think I would like it!

But I ended up saving a bunch of money, because I can dial my BluGuitar to sound pretty close. Not identical, but this was a quick "dial by ear, play a sloppy track" test.

Can you guess which is the JVM?


First one has a bit more girth so probably the Bluguitar 💪. It’s just us nerds that sweat the difference, so much real world overlap both sound great
 
Thanks for the NAM captures!

I was able to use these to get an idea what I would get with the JVM. It sounds great, I think I would like it!

But I ended up saving a bunch of money, because I can dial my BluGuitar to sound pretty close. Not identical, but this was a quick "dial by ear, play a sloppy track" test.

Can you guess which is the JVM?


I like the 1st one better, more girth, more gain, less pokey in the upper mids. Could just be how things are dialled in though. I'd also prefer them without the room sound on it I think
 
I like the 1st one better, more girth, more gain, less pokey in the upper mids. Could just be how things are dialled in though. I'd also prefer them without the room sound on it I think
That's the BluGuitar. It ended up a bit different and could be probably dialed even closer with some tweaks. But I think they are close enough in the same ballpark that it doesn't make a whole lot of sense to buy a JVM. Even though the separate channels each with their own EQ would be nice. The BluGuitar works best as a switchable voicing single channel amp, or at most a dual channel clean/drive amp.

Room reverb was mainly to make them sound more pleasant into my headphones, I'm still working out how to get the best results out of the UA Sound City when used as room reverb. Not the best option for comparing for sure.
 
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