Harmonic ouchness (video)

[Honk]

Anyone recognize this piercing harmonic problem?



At first I thought it was guitar related, a bad bridge or pickup maybe, but other guitars do it too, so I guess it's down to amp or cab. The plain strings emit a painful harmonic overtone, strongest when played open but also there when fretted, which seems to match the highest couple of harmonics you can get from around the 2nd fret. Open top E is the worst. Ouch. The rest of the tone I love. Has been my adored main amp for five years.

Can tubes cause this?

The head is a 50 watt Splawn, feeding two EVM-12S (not 12L) speakers. No pedals. Pretty harmonically aggressive setup, but I don't think it should be doing this. Seems it crept in gradually. Hard to pinpoint when it began. Help!

 

[guitarspaz]

Does it do it with other guitars? Can you hear it unplugged. If you can eliminate the instrument, I'd say might be a speaker problem. Try a different cab if you have access to one. I had a similiar problem with a nasty G overtone. Turned out to be a speaker problem. Not sure what exactly but replacing the offending speaker fixed it. Hope you get it sorted out and it's not too pricey.

 

[Rockyrollercat]

Sounds like fret buzz to me.

RRC

 

[BigDar]

pre-amp tube?

 

[DrunkleJoe]

How about the nut? String to deep in the groove and fretting out...

Oh I see you have tried other guitars and found the same issue. Can't be all fretting out then.

Check tubes just to rule them out. Preamp first. You have known good ones sitting around to replace some spots or move around the ones you have in it?

 

[walkers]

I had a similar issue on my tele, and it wasn't until my daughters violin teacher mentioned that her string was producing a false harmonic and needed to be changed. I threw a new e string on and it was gone...

Not sure if that's it but it's worth a shot.

Edit: just saw it was happening on other guitars, still worth a shot

 

[GT100]

May be "Stratitis"?
Where the pickup(s) are too close to the strings.

Lloyd

 

[Honk]

Thanks for the suggestions so far, fellas.

It does indeed happen with other guitars. They sound good unplugged. Will test with a few more today, just in case. I think it may happen with other speakers. I'm quite a speaker junkie, and I think this issue slowly emerged regardless of the several combinations I've used in even just the last six months.

Preamp tubes: I have some pretty beat JJs I could swap in, just to see. It has newish Tung-Sols in there right now. I would *love* if this were a tube issue. My fear is it's some technical fault, like a leaky cap or something, that would be hard to pinpoint and repair.

I don't believe it's stratitus, GT100, which in my experience is more of a dissonant warble or trembling type sound from string pull.

Really appreciate you all having a listen. I love this amp and what it does for me. It's distressing to have picked up this strange problem. Anyone who recognizes it, please chime in.

 

[freaksho]

yeah, that's weird. i'd try isolating everything you can to narrow down the possible causes then post the question in the Amp Technical area.

 

[Evansexcellent]

Check your pick hand position. Is it resting on a string? If so strings could be hitting pickup or causing harmonic.

 

[Honk]

Sadly, I think I've excluded all external causes now. Tested much in the last couple of hours.

• Tried more guitars. Scale length, string gauge, bridge type, no matter.

• Plugged the head into my combo's speaker (open backed, single EVM-12L) and, although it sounded awesome, same horrible icepick harmonic on B and E strings.

• Different speaker and instrument cables (why not.)

• Switched out preamp tubes. Sure reminded me quick why I was happy to take those JJs out last time, but didn't affect the problem.

• Changed power tubes for some old standbys. Same deal.

• Tried the pick thing, Evan, just in case. Even floating my hand, it happens.

Suppose, as you say Freaksho, the Tech area may be my next stop, although I was paging through the archives last night with various searches and I'm not certain I'll understand what they say.

 

[freaksho]

sorry to hear that, man. though you may be out of your league in the Tech forum (i am too) they could at least verify that a trip to a tech is necessary.

 

[teleluvver]

If you are satisfied that it is not guitar, speaker or tube related, then you should take it to a tech. This does not mean that you are facing an expensive problem. A good amp tech can find the problem, and will only replace and/or fix what needs fixing.

 

[trailrun100s]

I realize this is stating the obvious, but have you called Splawn? It's their amp, who better to talk to...

Good luck...

 

[Honk]

I did talk to Splawn a couple of times yesterday. Just check-your-tubes kind of stuff. Although it kept happening when I switched in some old used-up Mullards, so it's happening on two sets of power tubes, Scott still wants to rule them out, so I will likely order some today.

Thanks again for listening and weighing in, folks. I'm still hoping someone out there will recognize the issue and give me an aha moment.

 

[Zingeroo]

Sounds like ghosting to me.

 

[trailrun100s]

I did talk to Splawn a couple of times yesterday. Just check-your-tubes kind of stuff. Although it kept happening when I switched in some old used-up Mullards, so it's happening on two sets of power tubes, Scott still wants to rule them out, so I will likely order some today.

Thanks again for listening and weighing in, folks. I'm still hoping someone out there will recognize the issue and give me an aha moment.

Have you tried playing the exact same notes but on the G string instead? Just to see if it has to do more with frequency of the specific note than the B and E strings themselves...

 

[Mark Robinson]

What is in the path between the guitar and amp? Just a cord?

Go to just one cord if that is not the case.

Clean the cord ends etc. Could be bad contact. It sounds "front endy" to me like a crappy digital scum on the note. Is your cell phone or any other phone gear nearby?

 

[jkamp20]

funny thing a similar thing happened to me.....it was my ceiling fan. Went away when I turned off the fan. weird.....

 

[Zingeroo]

GHOSTING.