Taming the Archon loop noise at lower volumes.

Black Plaid

Other Alan!
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Ok, I admit it, I don't always play my Archon at 100 dbA, sometimes there are other people in the house.

Like most other people, I noticed the noise as soon as I added a reverb to the amp in the loop. The more pedals I added, the noisier it got (haven't sprung for a switcher yet).

Yet when I was playing loud, it was never a problem, the noise floor was negligible.

It turns out the master volume on the amp is before the effects loop.

This means any inherent noise from anything in the loop is amplified at full volume.

I hadn't seen this mentioned anywhere in my searches on the issue, so I thought I'd post it here.

The workaround is to have a volume pedal at the *end* of you effects chain. Crank the Master on the amp up pretty high, and use the volume pedal (or another volume controlling device) as the volume to the amp.

It's a bit hokey and I am going to look into modding the amp to have the master volumes *after* the loop, but's solved my problems at least.

Anyone else tried this?
 
IF your Archon was built after the “fix” it will not be noisy. If it is, it is 100% the fault of A) the tube that drives the loop, or B) your pedals and/or pedal power supply.

There is a reason that in 4 million threads at TGP, people are complaining about “noisy loops” yet the amp makers never seem to be able to “fix” them. It’s because most of the time, nothing is wrong with them.

There is no standard for input and output level and impedance for pedals. Oh yeah, there’s +4 and -10 but there’s a lot more to it than that. Basically, manufacturers can make their pedals with or without input and output buffers, and with any input impedance and any output impedance they want. When you take a non filtered, non-regulated power supply and start pushing 3,4,5 pedals with it... you are basically asking for trouble.

There have been guys at TGP SWEAR “these are the exact same pedals I’ve used with 5 other amps and never had a problem, so it’s the loops fault!” Only to actually troubleshoot the chain and find one pedal causing the issue. Or, that switching the order of two pedals fixed it. Or that there was a ground loop with the amp and the pedal power supply. Or... and the list goes on.

My 2 Channel Custom 50 had a noisy loop... which was fixed magically when I ran all my loop pedals on batteries. Not practical, but it proved my pedal board supply was the issue. Replaced it with a better one and the loop got quiet. My Archon has a little noise with my pedalboard supply, but if I put the loop pedals on a different supply (the new one) there’s no noise at all.

Basically, not being a jerk, but 9 times out of 10, it’s not the loop and IF it’s the one time it is, a nice new loop tube should fix it. And, no way I’d put a volume pedal in the loop, crank the amp and lower the volume with a volume pedal.
 
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And, no way I’d put a volume pedal in the loop, crank the amp and lower the volume with a volume pedal.

What is your reasoning here?

I can put a meter on it and report back, but I think the only problem would be a slightly too hot input going to the pedals, which would happen regardless of if I was attenuating at the end of the loop and playing with the volume up.

I'm not saying it's the loop, it's where the master volume is located in the signal chain.
 
What is your reasoning here?

I can put a meter on it and report back, but I think the only problem would be a slightly too hot input going to the pedals, which would happen regardless of if I was attenuating at the end of the loop and playing with the volume up.

I'm not saying it's the loop, it's where the master volume is located in the signal chain.
That the master on this amp is better than that would be, IMO. And, cranking a master only to attenuate the amp right before the power stage, wouldn’t be my choice of solutions for noise in the loop. I’d find the problem and fix it, and use the master as intended. Troubleshooting a loop isn’t that difficult, or course depending on just how many pedals you have in the loop. But I’d identify and fix the problem. Any kind of volume control in the loop is a hack that I’d never resort to on an amp with a master. IMO it’s only for amps that need to be cranked to sound good, but are way too loud. This amp has a very good master.
 
Ok, I honestly didn't think there was anything wrong with the loop, but will look into it.

What are good ways to determine that there is a problem in the loop?

If I engage the loop switch with nothing in it, should there be any change in noise or level?

Mine jumps from 40 db with the switch off to 65 with it engaged, even without anything in the loop, or the loop jumpered.
 
There is nothing wrong with cranking the master and adding a loop return volume control. That keeps the signal hot as far as possible, generally good practice for best SNR.

What is the manufacture date on the back panel of the amp? Before or after November 2014?
 
There is nothing wrong with cranking the master and adding a loop return volume control. That keeps the signal hot as far as possible, generally good practice for best SNR.

That's exactly what my thought was.

What is the manufacture date on the back panel of the amp? Before or after November 2014?

It reads 11/15, so should be well after the loop update.
 
There is nothing wrong with cranking the master and adding a loop return volume control. That keeps the signal hot as far as possible, generally good practice for best SNR.

What is the manufacture date on the back panel of the amp? Before or after November 2014?
Isn't this just putting a "master" right before the Master? That's why I don't see the point.

And, IF there is even one pedal in your loop that is clipping, the hotter the signal you send, the more likely it is to happen. But, that said, it would apply the same to cranking the gain and turning the master down, so again I don't see that as the issue, and if it is, it's pedal related because it's going to be the same whether you attenuate with the master or the volume pedal.

Your amp was made after the update. If you don't want to troubleshoot the loop first, replace the loop tube with a known good quiet tube. If that doesn't work. start on the loop. Remove all pedals. Then put only a straight cable from loop out to loop in. Then if you have extra patch cables, replace one cable at a time in the loop (just like you were rolling preamp tubes looking for an issue). Then one pedal at a time. And lastly, change the order of the pedals to see if it's a pedal interaction causing the issue.
 
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Mine jumps from 40 db with the switch off to 65 with it engaged, even without anything in the loop, or the loop jumpered.

I'm an idiot, that noise was switching channels, not the loop.
face-palm_1f926.png
(I find the dearth of emoji support on this site disappointing)

The loop is dead silent, the pedals have internal noise regardless of being attached to my isolated output power supply or not.

The extra noise is definitely from pedals inherent noise being amplified by a 100 watt amp regardless of input signal.

Which is why the noise floor is negligible when running loud.

So the real fix truly is to optimize your signal to noise ratio by running the loop as hot as possible (without overloading the items in the loop unduly) and using a post loop control for volume.
 
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aha! So I fixed it! ;) That will be a bench fee of $50 plus tax.

Which I'll waive IF you don't put a volume pedal in the loop!

:p:p:p
 
I'm an idiot, that noise was switching channels, not the loop.
face-palm_1f926.png
(I find the dearth of emoji support on this site disappointing)

The loop is dead silent, the pedals have internal noise regardless of being attached to my isolated output power supply or not.

The extra noise is definitely from pedals inherent noise being amplified by a 100 watt amp regardless of input signal.

Which is why the noise floor is negligible when running loud.

So the real fix truly is to optimize your signal to noise ratio by running the loop as hot as possible (without overloading the items in the loop unduly) and using a post loop control for volume.

Happens to us all!
 
Happens to us all!
I'm a recovering caboholic. I turned the Mark V on one day and heard a little static noise for a few seconds, and turned it off. Just switched over and played the Archon, since I only had about 20 minutes. Couple days later I was ready to check the V out to see what the problem was. Turned it on... nothing. switched channels, rolled knobs, nothing. Turned it back off. That night, got on Doug's Tubes web site pricing replacement power tubes since I had plenty of new pre tubes. ALMOST checked out, but was waiting for a paypal on something I'd sold, so I could order a few other tubes while I was ordering.

The next day, I turned the Archon on and was playing through the Mesa 2x12 vertical recto cab... which was normally attached to the Mark V. I had forgotten that I switched cabs. There was nothing wrong at all with the V... except there was no cab plugged into it. And that normally would create problems, but it was OK. I didn't have it on for long. I was ticked that I'd forget to plug another cab into it when switching cabs to avoid running one with nothing hooked up.

That's not nearly as funny though, as the night I went in without my glasses on and it took me a couple minutes to figure out that I had no sound because I was plugged into another amp than the one I had on to play. :cool: And that one I've done more than once.
 
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Isn't this just putting a "master" right before the Master? That's why I don't see the point.

It actually makes the master a loop send control and the added one a loop return/master.

Noise is not critical. SNR (signal to noise) is the key. Everything the signal runs through adds noise. You want to get the clean signal amplified up early and keep it at as high a level as possible until you get to the end of the chain, and drop the signal level there if needed. That keeps the signal as much larger than the noise as possible.

Clearly you have to watch out for clipping the loop pedals, but you probably can run the signal in the loop quite hot before that happens, making the overall amp volume too high.

I routinely use my loop effects (G System) to set the master volume. That way I can set the amp master to optimize the FX send level.
 
I'm a recovering caboholic. I turned the Mark V on one day and heard a little static noise for a few seconds, and turned it off. Just switched over and played the Archon, since I only had about 20 minutes. Couple days later I was ready to check the V out to see what the problem was. Turned it on... nothing. switched channels, rolled knobs, nothing. Turned it back off. That night, got on Doug's Tubes web site pricing replacement power tubes since I had plenty of new pre tubes. ALMOST checked out, but was waiting for a paypal on something I'd sold, so I could order a few other tubes while I was ordering.

The next day, I turned the Archon on and was playing through the Mesa 2x12 vertical recto cab... which was normally attached to the Mark V. I had forgotten that I switched cabs. There was nothing wrong at all with the V... except there was no cab plugged into it. And that normally would create problems, but it was OK. I didn't have it on for long. I was ticked that I'd forget to plug another cab into it when switching cabs to avoid running one with nothing hooked up.

That's not nearly as funny though, as the night I went in without my glasses on and it took me a couple minutes to figure out that I had no sound because I was plugged into another amp than the one I had on to play. :cool: And that one I've done more than once.

I've made both of those mistakes too many times to be proud of. Or embarrassed by.

Last year at a show, I saw a guy frantically checking his guitar and amp at the beginning of a song. Climbed behind the amp and tried some things. Came around front tried some more. Went back to his pedal board - and discovered his tuner mute was still on.
 
I have owned plenty of amps in 35 years but never had loop noise issues.
Thiwnia my first go at this.
Love the amp however!!!!!

I used a 5751 to lower the loop noise. It's not really any iasue on thr gain channel, it's only on thr clean when you hear the hiss and noise in the background.
I've also tried about 25 pedals and no pedals, just a patch cable.

The 5751 helps a lot but it also lowers the volume of the amp when engaging the loop, so I just turn up my delay and chorua output volumes to compensate.

I would love if PRS had included a loop send level.

It seems the master volumes feed the loop as others have said. The volume drop is not there on clean, only on gain, and isn't as noticable at band volumes. It stinks the 5751 drops the volume a bit.

I ended up going back to a JJ ECC83S because I didn't like the volume drop, and the loop hiss is not as bad at gig volume as people say. I did find that the one stock loop driver JJ tube had noise issues and it really cleaned up after replacing.

The hiss is a I'll there but I don't let it bother me, plus I can always go back to the 5751 if I see the need.

I heard of guys replacing the PI tube with low gain tubes as well.
 
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