JVM 410H FX LOOP HEADACHE

[SLTR]

So...

For some reason or another I cannot get the serial loop to work using pedals, and I cannot get the parallel loop to work at all.

So far I have eliminated any cable and pedal issues (Through the front of the amp everything is fine) I have only tried the OD2 channel but i don't see why switching channels would make a difference.

My FX chain is as follows:

Guitar - BOSS TU3 - Jrockett Archer - Phase 90 - AMP INPUT - SERIAL SEND - TC Corona - TC Flashback - TC HOF - SERIAL RETURN

Also, I have tried running the guitar directly into the back of the return on the serial loop which was a success (so this must mean the serial loop is working?) however pressing the 'FX LOOP' button on the front of the amp makes no difference. What i don't understand is when I come to try plug everything up properly, pedals in the loop I get absolutely nothing from the amp at all unless I bypass the serial loop.

P.S. It's going to be difficult to source some replacement tubes at the moment because of the coronavirus.

 

[Lance Chambers]

Are you the first owner of the amp? Did you try resetting the amp (and six button controller) to the original factory specs?

Any resolution?

 

[paul-e-mann]

So...

For some reason or another I cannot get the serial loop to work using pedals, and I cannot get the parallel loop to work at all.

So far I have eliminated any cable and pedal issues (Through the front of the amp everything is fine) I have only tried the OD2 channel but i don't see why switching channels would make a difference.

My FX chain is as follows:

Guitar - BOSS TU3 - Jrockett Archer - Phase 90 - AMP INPUT - SERIAL SEND - TC Corona - TC Flashback - TC HOF - SERIAL RETURN

Also, I have tried running the guitar directly into the back of the return on the serial loop which was a success (so this must mean the serial loop is working?) however pressing the 'FX LOOP' button on the front of the amp makes no difference. What i don't understand is when I come to try plug everything up properly, pedals in the loop I get absolutely nothing from the amp at all unless I bypass the serial loop.

P.S. It's going to be difficult to source some replacement tubes at the moment because of the coronavirus.

power/batteries to the pedals? The pedals plugged in the right direction? Do all pedals work out front?

 

[Matt_Krush]

where is the Mix Level 'knob' set on the serial loop?
And, make sure the switch is out (for -10dB/Pedal)

If its all the way left (at zero) you will not have any effect being mixed.
Conversely if it is all the way right (at Max) it will also not mix any effect (I dont get this, but thats the way mine is).
Set the knob at 3-'clock and adjust mix level.

Do not use the serial loop on the power-amp section for pedals. That is at Line Level, not instrument level signal.
the Serial Loop in the power amp is always on.

the Parallel/Serial loop in the preamp section is only on if the Effects loop button is presses (lit red) on the face of the amp.

 

[Sapient]

Isn't there a tube that affects the ..effects loop send/return? Mine didn't work either but did after a tube change. I'm no pro with this tough and I believe it's something I just gazed over reading.

 

[Detlef]

If you switch the Corona or for that matter any other TC Electronic device with the internal DIP switch to the kill dry position you won't hear anything unless the device is switched on. Rather stupid design which complety defeats the purpose of that switch. Is that the case? I asume if you use the FX loop you know how to connect cables etc.

 

[Matt_Krush]

A Tube, yes there is...it would be V9 according to Marshall & schematics. Any 12AX7 will do.

Keep in mind that we always call V1, the first preamp tube signal hits. Then move sequentially through the signal chain.
This is not the same convention Marshall used on the JVM series.


Below is the naming convention Marshall uses for the JVM series.



We'd typically call V6 in pic above V1, and move sequentially to V5 (which remains V5- the Phase Inverter), then the powertubes would be V6-V9.

 

[Lance Chambers]

OP disappear on us?

He certainly doesn't post much. Only two messages in two years.

 

[SLTR]

Resetting the amp is an interesting suggestion, I’ll give that a try as well as the dry/wet mix knob tweaking.

Having given the amp another quick go this morning I’m getting monumental tone suck/volume dip when enabling the parallel loop which would lead me to believe it is a tube.

Thanks for all the suggestions about wiring the pedals the correct way, you’d think I’ve had figured that out!

 

[Matt_Krush]

start with one pedal at a time...then add another...another..

 

[SLTR]

So turns out JVM’s and phase 90’s don’t get on at all... problem solved, phase 90 will have to live out the front. FX loops on these things are terrible considering how great the rest of the amp is.

 

[Lance Chambers]

I own it, but have not tried a Phase 90.

 

[SLTR]

I’ve ran one in front for years but wanted to see the difference in the loop. Worth a try I’d be interested in what results you get

 

[MonstersOfTheMidway]

So turns out JVM’s and phase 90’s don’t get on at all... problem solved, phase 90 will have to live out the front. FX loops on these things are terrible considering how great the rest of the amp is.

I think you are describing what most long time JVM owners know: some pedals sound better/work better in the "SERIAL/PARALLEL EFFECTS LOOP" than others. I can't recall specific past claims about the phase 90, but I wouldn't be surprised if you tried the same effect made by a different company where results would different and more to your satisfaction.

Assuming that you JVM is functioning properly, I suggest trying a different brand of phase effect to see if the sound quality improves. TC Electronic makes great pedals that sound great in my 410H "SERIAL/PARALLEL EFFECTS LOOP" (I haven't tried all TC effects, but the ones I've tried all sounded great). You can also try brands like Line6, Fractal, and Eventide. Some brands and models might be pricier than others but maybe you can borrow one first from a friend.