Official original Marshall JVM appreciation thread

[laxu]

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.

 

[cragginshred]

Why didn’t it just come that way to start with?

Great question,.. Jose made a lot of $ in the 80's fixing harsh Marshalls

 

[spawnofthesith]

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

 

[laxu]

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?

 

[Karl Houseknecht]

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.

 

[laxu]

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.

 

[Karl Houseknecht]

I guess there's no mod or fix to this

They fixed it on the Satriani model with a good series loop at instrument level. Why Marshall hasn’t updated their flagship since discontinuing the HJS is baffling.