Archon 25 waterfall noise

[fingermystrings]

Hello everyone,

I have a PRS Archon 25 Combo with a May 2018 build date. Around a year or so ago, I noticed thet my amp would make a loud waterfall sound after playing on the lead channel for an hour or so. It goes away after I turn it off for some time. I assume some component is getting hot over time and is causing the sound. When I turn it back on later, the noise is not present. When it's not making thet sound, the amp is dead quiet.

I tried replacing all of the tubes and biasing, unplugging everything plugged in to the amp (so it's not the loop nor my pedals) including the footswitch, swapped cables, and i even bought a power conditioner. I brought it to a local amp tech who could not replicate the sound for some reason, and I sent it to PRS two times already.

When PRS first got the amp, they said they were able to replicate the sound and claimed to repair it, charging me for the fix. They also swapped all of the tubes and biased them (so two sets of new tubes, so far). I received the amp and that same day, the sound came back. So I sent it back to PRS, and now they claim they cannot replicate the issue. They swapped the tubes again and sent it back, saying that they believed the issue was resolved.

The noise came back the first day I got it back. It reliably occurs for me after about an hour or so of playing, every day since I've received my amp back. I just don't get it. They were able to make the noise occur the first time I sent the amp to them, so it's not just my set up nor is it the wiring in my house. But now I'm out the cost of the repair, the cost of a set of tubes, the cost of a power conditioner, and I've been without my amp for a couple of months, and the noise still occurs. It's so loud and obnoxious that my amp is unuseable when its happening. A noise suppressor won't help because I have to turn the threshold too high to eliminate the noise and it sounds very bad when I do this. I can't let any notes ring out either or ill hear the noise suppressor kick on.

I just want my amp to work so I can play out of it. It's my only small tube amp, and the noise is making it harder to pick up my guitar and play everyday. I paid good money for it and I take good care of my equipment. I don't gig with it, and I don't abuse it. I don't know what else I can do. I contacted PRS again, but they have not responded, and now it feels like I'm on my own with this issue. What can I do at this point? When the amp is working, I love the tone it puts out, both dirty and clean. Very few amps can achieve this. But then the noise occurs and I have to turn the amp off. It's killing my drive to play. Has anyone dealt with an issue like this on their Archon and have been able to resolve it? I don't want to get rid of this thing, but I might have to, especially since I csnt seem to get any resolution on this matter, no matter who I turn to for help.

Thanks for reading.

 

[Bogner]

I Am Sorry To Hear Of This. A Good, Proper, Very Experienced Tech Is A Very Hard Thing To Find. I Would Hope That PRS Would Be Able To Sort The Issue Out And Make Sure They Thoroughly Test Your Amp To Ensure It Doesn't Continue Making The Noise Or Else The "Repair" Is Anything But.

Based On Your Description I Am Unable To Properly And Intelligently Decipher What The Problem May Be Without Actually Hearing It. It May Be Beneficial To Record The Sounds (Before, During And After) For Reference. This Would Likely Be Helpful To Provide Ahead Of Time To Anybody You May Consider In Repairing It. Are You Located Near Proper Tech's Or A Major Touring Stop Town? Usually Those Places Have Somebody Capable In Many Instances.

A Couple Of Questions...Does The Amp Take About The Same Amount Of Time To Repeat The Problem Each Time? If You Cranked The Controls (Gain, Volume, Etc) Does It Change The Behavior Or The Time It Takes For The Problem To Appear? If The Amp Is On Standby For The Time It Takes For The Problem To Occur Before You Take It Off Standby, Does The Problem Occur Immediately Or Does It Still Take The Usual Time For It To Appear?

 

[Prina]

I Am Sorry To Hear Of This. A Good, Proper, Very Experienced Tech Is A Very Hard Thing To Find. I Would Hope That PRS Would Be Able To Sort The Issue Out And Make Sure They Thoroughly Test Your Amp To Ensure It Doesn't Continue Making The Noise Or Else The "Repair" Is Anything But.

Based On Your Description I Am Unable To Properly And Intelligently Decipher What The Problem May Be Without Actually Hearing It. It May Be Beneficial To Record The Sounds (Before, During And After) For Reference. This Would Likely Be Helpful To Provide Ahead Of Time To Anybody You May Consider In Repairing It. Are You Located Near Proper Tech's Or A Major Touring Stop Town? Usually Those Places Have Somebody Capable In Many Instances.

A Couple Of Questions...Does The Amp Take About The Same Amount Of Time To Repeat The Problem Each Time? If You Cranked The Controls (Gain, Volume, Etc) Does It Change The Behavior Or The Time It Takes For The Problem To Appear? If The Amp Is On Standby For The Time It Takes For The Problem To Occur Before You Take It Off Standby, Does The Problem Occur Immediately Or Does It Still Take The Usual Time For It To Appear?

+1

Sorry to hear that. I'm no expert myself but I'm interested because my Archon 25W combo is about a year newer than yours.

Hopefully, some of the other amp experts on the forum will comment

 

[Stephen J.]

If a noise suppressor kicks it out, it sounds like it is something before or at the input of the amp. If you pull the cable from the input, does that stop the sound?

 

[fingermystrings]

If a noise suppressor kicks it out, it sounds like it is something before or at the input of the amp. If you pull the cable from the input, does that stop the sound?

This is with the suppressor in the loop. It makes the sound even if nothing is plugged into the amp. I have a video of this I can upload as soon as I sort out how..

 

[fingermystrings]

I Am Sorry To Hear Of This. A Good, Proper, Very Experienced Tech Is A Very Hard Thing To Find. I Would Hope That PRS Would Be Able To Sort The Issue Out And Make Sure They Thoroughly Test Your Amp To Ensure It Doesn't Continue Making The Noise Or Else The "Repair" Is Anything But.

Based On Your Description I Am Unable To Properly And Intelligently Decipher What The Problem May Be Without Actually Hearing It. It May Be Beneficial To Record The Sounds (Before, During And After) For Reference. This Would Likely Be Helpful To Provide Ahead Of Time To Anybody You May Consider In Repairing It. Are You Located Near Proper Tech's Or A Major Touring Stop Town? Usually Those Places Have Somebody Capable In Many Instances.

A Couple Of Questions...Does The Amp Take About The Same Amount Of Time To Repeat The Problem Each Time? If You Cranked The Controls (Gain, Volume, Etc) Does It Change The Behavior Or The Time It Takes For The Problem To Appear? If The Amp Is On Standby For The Time It Takes For The Problem To Occur Before You Take It Off Standby, Does The Problem Occur Immediately Or Does It Still Take The Usual Time For It To Appear?

I have video clips of the sound that I have provided to the techs who have worked on my amp. I'm going to post clips here as soon as i sort out how.

There is a tech in my area (Boston area) who is frequently recommended and I used him at first. I have not looked for any other locally after he suggested I contact PRS. I got my amp back from PRS about a week ago, and I have not had much time to address this ongoing issue because I am a student.

The amp has been fairly consistent lately with how long it takes fo the sound to occur. This is with various setting in volume (I can't crank too loud because it's a home environment, and I have neighbors.

I will check if leaving it on standby still makes the noise occur and report back.

 

[fingermystrings]

It didn't seem to occur when on standby. But it also didn't take very long to show up after turning standby off. Turning it back on standby for a bit and turning it back on seems to get rid of the sound temporarily, but not for long. Now I'm letting it sit with the amp on with nothing plugged in at all (except the speaker). Nothing in front, nothing in the loop. Not even the footswitch... let's see what happens...

Edit: Yeah, it came back on within 10 minutes...

Here's a video clip..

https://imgur.com/a/z5zPwhz

For reference, this is how quiet it should be

https://imgur.com/a/ym0Ps3y

 

[Davey]

Is it just on the lead channel?

This problem sounds like dirty or loose tube socket pins. Most likely pre amp section.

If it makes noise In both channels check V1. If it is just the lead channel check V2 or V3 and clean each of those sockets. If they're clean or you've cleaned them and it still makes noise, try retensioning the sockets.

It happened on my 100 watt Archon head and sounded like a waterfall. I retensioned V1 and it has been quiet since.

If you are comfortable working around amps, you can remove the rear panel and pre amp tube retainers. Fire up the amp and when it begins to make noise, wiggle each pre amp tube and see if it changes or goes away. You can also check/wiggle the power tubes as well.

When retensioning sockets, that involves discharging capacitors as you don't want to be poking around inside an amp with charged caps.
Since working on live amps is dangerous.
If you are not comfortable working on a live amp or don't know, then absolutely take it to an amp repair shop. Don't risk life or limb if you aren't comfortable. Have them perform this test to eliminate possible loose tube sockets.

Let us know what you find out

 

[fingermystrings]

Is it just on the lead channel?

This problem sounds like dirty or loose tube socket pins. Most likely pre amp section.

If it makes noise In both channels check V1. If it is just the lead channel check V2 or V3 and clean each of those sockets. If they're clean or you've cleaned them and it still makes noise, try retensioning the sockets.

It happened on my 100 watt Archon head and sounded like a waterfall. I retensioned V1 and it has been quiet since.

If you are comfortable working around amps, you can remove the rear panel and pre amp tube retainers. Fire up the amp and when it begins to make noise, wiggle each pre amp tube and see if it changes or goes away. You can also check/wiggle the power tubes as well.

When retensioning sockets, that involves discharging capacitors as you don't want to be poking around inside an amp with charged caps.
Since working on live amps is dangerous.
If you are not comfortable working on a live amp or don't know, then absolutely take it to an amp repair shop. Don't risk life or limb if you aren't comfortable. Have them perform this test to eliminate possible loose tube sockets.

Let us know what you find out

It affects both channels, though it's not as obvious in the clean channel. When the issue starts, if you switch over to the clean channel you can hear it faintly. I've already tried cleaning my tube sockets unfortunately. It didn't seem to do anything. I've also tried knocking on the tubes with wooden chopsticks, trying to slightly jiggle the power tubes, and nothing seems to happen. The sockets don't seem loose to me either, though i suppose if only one terminal was loose, i probably wouldn't be able to tell . I'll take a look and retension them when I get a chance.

I also called PRS directly and left a message with the service manager. I've only heard good things about their customer service, so I really hope they help me out on this. It sucks only being to play for an hour or so at a time.

 

[Davey]

It affects both channels, though it's not as obvious in the clean channel. When the issue starts, if you switch over to the clean channel you can hear it faintly. I've already tried cleaning my tube sockets unfortunately. It didn't seem to do anything. I've also tried knocking on the tubes with wooden chopsticks, trying to slightly jiggle the power tubes, and nothing seems to happen. The sockets don't seem loose to me either, though i suppose if only one terminal was loose, i probably wouldn't be able to tell . I'll take a look and retension them when I get a chance.

I also called PRS directly and left a message with the service manager. I've only heard good things about their customer service, so I really hope they help me out on this. It sucks only being to play for an hour or so at a time.

Ok so if you checked both preamp and power tubes by lightly tapping and no changes occurred, that's not outcome determinate. It's just an easy way to see if the identified problem changes when tapping.

If the noise is on both channels, it would almost certainly be your V1 preamp tube. Most noise will often come from the V1 input position. That'll be the closest one to your input jack.
I re-read your original post and you stated you have already swapped tubes so you have already done the next step.

The next thing is check that V1 preamp tube socket. I know you cleaned it, but just one loose tab in that socket and you'll get noise.
I can't say for sure if that's it or not, but if I were troubleshooting my own amp, that would be my next step to rule out before moving on.

I wanted to come back with an edit.
Please make sure you are comfortable working inside an amp. High current can still be stored in parts of the circuit and can kill you if you don't know what you are doing.
Just want to be clear on that.
If your not comfortable, find a friend or amp tech who has experience.
Sorry this happened to you. It sucks, but you'll get it figured out.

 

[fingermystrings]

Ok so if you checked both preamp and power tubes by lightly tapping and no changes occurred, that's not outcome determinate. It's just an easy way to see if the identified problem changes when tapping.

If the noise is on both channels, it would almost certainly be your V1 preamp tube. Most noise will often come from the V1 input position. That'll be the closest one to your input jack.
I re-read your original post and you stated you have already swapped tubes so you have already done the next step.

The next thing is check that V1 preamp tube socket. I know you cleaned it, but just one loose tab in that socket and you'll get noise.
I can't say for sure if that's it or not, but if I were troubleshooting my own amp, that would be my next step to rule out before moving on.

I wanted to come back with an edit.
Please make sure you are comfortable working inside an amp. High current can still be stored in parts of the circuit and can kill you if you don't know what you are doing.
Just want to be clear on that.
If your not comfortable, find a friend or amp tech who has experience.
Sorry this happened to you. It sucks, but you'll get it figured out.

I'll take a look when I get a chance and update this thread. Thanks for the help so far! I will be sure to exercise the necessary precautions and take the steps to drain the capacitors before working on the amp.

By the way, PRS responded and said they think it might be some sort of interference. I'm not convinced on that considering the pattern of malfunction I've been seeing. The fault is quite consistently showing after operating the amp for some time, and it goes away in the same manner each time (turn off the amp/switch to standby for a period of time). I suspect heat or capacitance is a factor here...

 

[Davey]

I'll take a look when I get a chance and update this thread. Thanks for the help so far! I will be sure to exercise the necessary precautions and take the steps to drain the capacitors before working on the amp.

By the way, PRS responded and said they think it might be some sort of interference. I'm not convinced on that considering the pattern of malfunction I've been seeing. The fault is quite consistently showing after operating the amp for some time, and it goes away in the same manner each time (turn off the amp/switch to standby for a period of time). I suspect heat or capacitance is a factor here...

I just want to rule out loose sockets and make sure there is good pin contact. V1 is always suspect with noise. Its happening in both channels which could also be after the channels merge so check V5 or the phase inverter tube and sockets. I would check them all to be safe and rule them out.
I use a small dental pick and gently push the sockets closer together. Just a little nudge, not much.

Before we get into more complicated troubleshooting. Let me ask, does the volume or tone knobs change anything when this happening? I presume not, but report back if it does.

After the sockets, we'll see if that cures the issue. If not, then I would lean toward a heat issue (as you state). Some component or solder joint that is affected by the heat after the amp warms up.
You can sometimes identify the issue by waiting for the problem to occur then carefully spray freeze spray to cool amp components and solder joints. If spraying a part or solder joint causes the issue to go away or come back you've located the problem. You'll have to remove the chassis from amp shell and have a good work station to do this. With the amp seperated from chassis, you can also do the chopstick method by putting pressure on components to see if you can find a weak or loose connection/wire/solder joint.

Again this is dangerous work, probing a live amp. Do so only if your confident and know how to do it safely.

Also because it's a combo, try installing some high temperature preamp "tube o-rings" to prevent excessive vibration or tube noise.

I'm just going down my list of checks to try and isolate your issue. I'm sure PRS would have done something similar when they checked it out as any amp tech would.

 

[fingermystrings]

After viewing the videos i posted here, PRS agreed to take another look into the issue, so I will be sending my amp off to them again when I get a chance to. I'm hoping they find the issue this time. Electrical issues can be tricky, but I also don't want to have a compromised experience with my amp.

I will update as I get more info. Thanks again to all who posted.

 

[fingermystrings]

So I finally received my amp back from PRS. They claimed they replaced some diodes that were reading out of spec, as well as a resistor and a capacitor. It also received new tubes. Unfortunately, I cannot comment on whether or not this resolved the waterfall issue, because now I have a new set of issues. First, the tone knobs on the clean channel act as volume controls. I do not recall this being the case in the past, though I don't ever really go all 0 with my tone controls. Second is the lead channel sounds very thin and doesn't get very loud. I can dime all of the knobs and comfortably talk over the sound level if produces. This is occurring in all set up situations, including with the guitar plugged directly into the amp with no pedals and nothing in the loop, with or without footswitch.

I was hoping this was going to be a positive update. I was excited when PRS emailed me back and said they had finally fixed the noise issue and everything was back to normal. They told me they even gave the amp to the designer of the archon's circuit to diagnose the issue. I don't know what to do anymore. The last time they had my amp, they had it for 3 months. Now it's gotta go back again? It's a defined configuration of a collection of electrical components. How is it this hard to get a permanent repair? I'm not in a good mood at all.

 

[Stephen J.]

Horrible news. Sorry you have had such bad luck with it.

 

[Steve's addiction]

The mid tone knob on my Mesa turns the volume off if I set it to 0. Maybe the PRS is set up the same?

 

[Davey]

So I finally received my amp back from PRS. They claimed they replaced some diodes that were reading out of spec, as well as a resistor and a capacitor. It also received new tubes. Unfortunately, I cannot comment on whether or not this resolved the waterfall issue, because now I have a new set of issues. First, the tone knobs on the clean channel act as volume controls. I do not recall this being the case in the past, though I don't ever really go all 0 with my tone controls. Second is the lead channel sounds very thin and doesn't get very loud. I can dime all of the knobs and comfortably talk over the sound level if produces. This is occurring in all set up situations, including with the guitar plugged directly into the amp with no pedals and nothing in the loop, with or without footswitch.

I was hoping this was going to be a positive update. I was excited when PRS emailed me back and said they had finally fixed the noise issue and everything was back to normal. They told me they even gave the amp to the designer of the archon's circuit to diagnose the issue. I don't know what to do anymore. The last time they had my amp, they had it for 3 months. Now it's gotta go back again? It's a defined configuration of a collection of electrical components. How is it this hard to get a permanent repair? I'm not in a good mood at all.

Ugh!
That is frustrating. So sorry this has happened to you.
Where to start. There is so many things it could be, too many to list here...tubes, solder joints, defective parts, bad/dirty pots, damage during shipment, etc

Do the obvious and easy stuff and do a quick check of your tubes and make sure they're all seated as one could have jarred loose in shipping. Clean each tube socket again
Try a quick shot of De-Oxit into each pot just to make sure they're clean.
If that doesn't work, sadly you're probably going to need to return it as anything the PRS tech did could have come loose, bad part or even a new issue cropped up during shipping.
So frustrating. I would ask to exchange it for another one as this one is just having too many issues.
Sorry bud, probably not what you want to hear.
Good luck and keep us updated.

 

[fingermystrings]

Ugh!
That is frustrating. So sorry this has happened to you.
Where to start. There is so many things it could be, too many to list here...tubes, solder joints, defective parts, bad/dirty pots, damage during shipment, etc

Do the obvious and easy stuff and do a quick check of your tubes and make sure they're all seated as one could have jarred loose in shipping. Clean each tube socket again
Try a quick shot of De-Oxit into each pot just to make sure they're clean.
If that doesn't work, sadly you're probably going to need to return it as anything the PRS tech did could have come loose, bad part or even a new issue cropped up during shipping.
So frustrating. I would ask to exchange it for another one as this one is just having too many issues.
Sorry bud, probably not what you want to hear.
Good luck and keep us updated.

I played around with the tubes and nothing changed. I jiggled them a bit and nothing. Ive tried contact cleaner at least a dozen times.

It seems the issue is on the preamp side. I have stereo outputs in my loop (i stereo out of my boss ce5). One of the outputs I fed into the input of another amp and that amp couldn't amplify the signal coming from the archon (lead channel) either. It's thin and the volume is very low. Meanwhile the clean channel is fine and gets amplified by both amps power sections. After I established this, I tried swapping v2 and v3 and nothing changed. I also tried v1, v5, and v6 for kicks, and still no changes. I've emailed PRS, and let them know what is happening, along with voicing my dissatisfaction, so I assume I will hear back on Monday as to what the next steps are. At the very least I think PRS will need to repair these new issues.

I don't think it's as simple as exchanging amps because the archon 25 is discontinued. I am also not interested in exchanging for a mk2 archon, which would likely be at a cost since this isn't a warranty claim.

If I have to swap out my amp, it will be from another manufacturer. But I am not satisfied with what's available on the market. I like the fact that the archon, while being a fire breathing high gain monster, is also versatile and, most importantly, has an very high quality clean channel. I am not aware of another small high gain full tube amp that can achieve this. But I also need my amp to WORK PROPERLY, and I am so done with using a katana amp as a backup after sending in the archon yet again to resolve something that stemmed from a single issue. Each time I send it in they keep my amp for at least a month.

 

[Davey]

I played around with the tubes and nothing changed. I jiggled them a bit and nothing. Ive tried contact cleaner at least a dozen times.

It seems the issue is on the preamp side. I have stereo outputs in my loop (i stereo out of my boss ce5). One of the outputs I fed into the input of another amp and that amp couldn't amplify the signal coming from the archon (lead channel) either. It's thin and the volume is very low. Meanwhile the clean channel is fine and gets amplified by both amps power sections. After I established this, I tried swapping v2 and v3 and nothing changed. I also tried v1, v5, and v6 for kicks, and still no changes. I've emailed PRS, and let them know what is happening, along with voicing my dissatisfaction, so I assume I will hear back on Monday as to what the next steps are. At the very least I think PRS will need to repair these new issues.

I don't think it's as simple as exchanging amps because the archon 25 is discontinued. I am also not interested in exchanging for a mk2 archon, which would likely be at a cost since this isn't a warranty claim.

If I have to swap out my amp, it will be from another manufacturer. But I am not satisfied with what's available on the market. I like the fact that the archon, while being a fire breathing high gain monster, is also versatile and, most importantly, has an very high quality clean channel. I am not aware of another small high gain full tube amp that can achieve this. But I also need my amp to WORK PROPERLY, and I am so done with using a katana amp as a backup after sending in the archon yet again to resolve something that stemmed from a single issue. Each time I send it in they keep my amp for at least a month.

OK, well it's not power tubes then if clean channel is functioning properly.
Didn't know it was a MkI Archon, so yeah, no deal on an exchange or warranty issue.

I would think PRS would take it back and fix the new issues.
I agree with you on the clean channel crystal cleans which most people overlook in the Archon.

 

[fingermystrings]

New update! This one should be more positive. I received my amp back from PRS yesterday. They had told me that a wire carrying audio from the lead channel had deteriorated inside the jacket. During shipping, the strands of the wire completely disconnected. They were able to locate and replace the wire.

I kept the amp on all day yesterday and all morning and afternoon on the lead channel and it's dead quiet. Like, crazy quiet considering how much gain these things pump out. I'm hoping this persists and I can rule the issue resolved.

PRS as a company is a class act. Sure, this whole situation caused a lot of grief and headache and dragged on for a very long time, but such is the nature of electrical issues. They didn't give up on my amp or send me away like a crazy person when they were having trouble getting the issue to show itself. They paid for every shipping label, and in the end, I only paid a grand total of $150 for the repair(s). Im pretty sure they lost money on this. My amp is a modified 2018 build (v30 speaker, so barely modified, but still), purchased second hand from Reverb; they still stood behind their product. It's really hard to find companies like this these days...