Repeated momentary loss of output on 1.06 with JCM800

Simon Godden

Simon Godden

Inspired
Since the move to 1.06, I have experienced repeated mometary losses of output using the JCM800 preset I have attached. The dropouts last between about 0.5 seconds and 3 seconds. The unit was running for maybe 30 minutes before I had an issue.

This first happened to me last week when I was using the unit through a Marshall Origin to a 2x12. At the time I thought this was an issue with the input jack on the 2x12, as when I went round the back and wiggled things it came back.

However, I now think that was coincidence, because I switched to my Line6 Powercab this week, and the same thing happened repeatedly last night. The input signal indicator on the powercab went out indicating loss of input signal. So this is with two different amplification methods, and two different cables going to them.

I can't say 100% the problem is in the FM3 yet. I have not linked it up to my studio monitors as a third test, and won't get the chance to for a couple of days now.
 

Attachments

  • JCM800 (V30's) FM3.syx
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head's up you can save a good amount of CPU by getting rid of all those Shunts and making the preset smaller. as is, you'd could fit everything in 1 row. the extra shunts use CPU. just an observation.

Screen Shot 2020-09-22 at 10.39.20 PM.png

with the rearrangement, my CPU is at about 72%, vs about 78%. i'm guessing that the drop outs could be due to CPU getting too high momentarily.
 
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chris said:
with the rearrangement, my CPU is at about 72%, vs about 78%. i'm guessing that the drop outs could be due to CPU getting too high momentarily.
Click to expand...

WIth the preset as originally posted, with all the shunts, my CPU is consistently at 71%.

That's quite a weird discrepancy in itself. My unit is without headphone jack if that helps.

The preset did originally have an unused Chorus and Filter block, taking it to just over 80% and into the red. I removed those, bringing it down to 71%. Unfortunately the dropouts still occurred.
 
chris said:
with the rearrangement, my CPU is at about 72%, vs about 78%. i'm guessing that the drop outs could be due to CPU getting too high momentarily.
Click to expand...

FYI rearranging as per your layout, and also removing the unnecessary shunt before Out 1, brings my CPU down from 71% to around 68%.
 
Also, I should have mentioned that I had FM3 Edit running all the while that I had the issues. I will try later in the week to have a long session playing without Edit open.
 
I took this to rehearsal tonight and the dropouts occurred there too. In 2 hours, I probably had 5 dropouts, lasting anywehere from half a second to a couple of seconds.

All cables were different from the ones I was using at home, so it isn't cables. I doubt it's the Powercab as it happened with my Origin last week too.

I will downgrade to 1.05 and see if the issue goes away, I have a rehearsal with a different band tomorrow night.

Obviously this is pretty major. I can't use the unit like this. I have a gig on Saturday and may be back to my AX8.
 
Simon Godden said:
I took this to rehearsal tonight and the dropouts occurred there too. In 2 hours, I probably had 5 dropouts, lasting anywehere from half a second to a couple of seconds.

All cables were different from the ones I was using at home, so it isn't cables. I doubt it's the Powercab as it happened with my Origin last week too.

I will downgrade to 1.05 and see if the issue goes away, I have a rehearsal with a different band tomorrow night.

Obviously this is pretty major. I can't use the unit like this. I have a gig on Saturday and may be back to my AX8.
Click to expand...
i'll look at this again later today. i couldn't get any dropouts.
 
If you can do without it, try deleting one of the two Delay blocks, and check if the issue re-appears.
 
yek said:
If you can do without it, try deleting one of the two Delay blocks, and check if the issue re-appears.
Click to expand...

I can do without it, it would only need me to make a specific preset for the one song that needs it. My issue is time for testing, as it can take a while for the problem to appear (it took an hour last night) and I have limited time before deciding how I approach my gig on Saturday.

This is a weird one - I don't see anyone else complaining about this type of thing on the 1.06 thread, so the implication is it's somehow hardware, but I think I've eliminated everything else, because I've used different cables, guitars and amplification methods. I haven't hooked up to my studio monitors yet though.

I think I'll get the AX8 prepped as backup, and continue trying to work out what's going on here, by trying what you have suggested, but also trying firmware downgrade and seeing if the problem goes away.
 
chris said:
i'll look at this again later today. i couldn't get any dropouts.
Click to expand...

OK thanks, this is a tough one due to how long it can take to appear. Took an hour last night. How long were you playing for?

See my answer to Yek - this is just weird. No-one else complaining about this, suggesting somehow it is an issue with my rig outside of the FM3. I'll continue to try to find out what's happening when I get time.
 
Simon Godden said:
I can do without it, it would only need me to make a specific preset for the one song that needs it. My issue is time for testing, as it can take a while for the problem to appear (it took an hour last night) and I have limited time before deciding how I approach my gig on Saturday.

This is a weird one - I don't see anyone else complaining about this type of thing on the 1.06 thread, so the implication is it's somehow hardware, but I think I've eliminated everything else, because I've used different cables, guitars and amplification methods. I haven't hooked up to my studio monitors yet though.

I think I'll get the AX8 prepped as backup, and continue trying to work out what's going on here, by trying what you have suggested, but also trying firmware downgrade and seeing if the problem goes away.
Click to expand...

@Simon Godden

Before 1.06, the FM3's second CPU could overload in some cases involving an Amp block and two Delay blocks. Firmware 1.06 fixed that and there haven't been any new reports. We're just investigating here if some rare combination of settings may still cause the 2nd CPU to overload. Probably not, but it's worth investigating. Deleting one of the Delay blocks and trying again helps with this. I understand that these kind of incidental issues are hard to track because of the required time to play.
 
yek said:
@Simon Godden

Before 1.06, the FM3's second CPU could overload in some cases involving an Amp block and two Delay blocks. Firmware 1.06 fixed that and there haven't been any new reports. We're just investigating here if some rare combination of settings may still cause the 2nd CPU to overload. Probably not, but it's worth investigating. Deleting one of the Delay blocks and trying again helps with this. I understand that these kind of incidental issues are hard to track because of the required time to play.
Click to expand...

Ah ok - sorry I thought it was a shot in the dark type thing. OK - in that case I will try rehearsal tonight with only one delay block in each preset.
 
Incidentally, just as a bit of light relief. The one song I need it for is Still In Love With You by Thin Lizzy (Live and Dangerous version), for that first solo which has a tape delay before the amp, creating quite a unique and distinctive feel to the delay.

The other guitarist's jaw dropped when I nailed that sound last night.

The sound quality out of this unit is stellar.
 
Love that live version, and it's one of my favorite live albums ever.
 
Jumping in, I’ve reported on the 1.06 thread I’ve had some odd USB and button issues.

I’m also running two delay blocks on every preset - could be a common feature??
 
peteri said:
Jumping in, I’ve reported on the 1.06 thread I’ve had some odd USB and button issues.

I’m also running two delay blocks on every preset - could be a common feature??
Click to expand...
This is my guess, at least with the sound issue. We are looking into the USB and button issues now.
 
Simon Godden said:
Incidentally, just as a bit of light relief. The one song I need it for is Still In Love With You by Thin Lizzy (Live and Dangerous version), for that first solo which has a tape delay before the amp, creating quite a unique and distinctive feel to the delay.

The other guitarist's jaw dropped when I nailed that sound last night.

The sound quality out of this unit is stellar.
Click to expand...

I had that issue with a jtm45 preset but it was fixed with 1.06

In that moment I just created a new preset copying the amp block and re-working the few effects I had.
 
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