Tube screamer larsen with all knobs at max , why ?

[nonoxxx]

Hello I noticed with 4 tube screamers pedal I own (2 joyo and 2 builds with musikding kit parts) , that on the four when all pots are at max the pedal is larsening , does someone know the cause ? I think it s the tone stack,but  This evening I triedto figure why but with no success.
Thanks

[mth5044]

Larsen? As in theft? Do you mean oscillating, by chance?

[Passaloutre]

I had to google it

http://www.urbandictionary.com/define.php?term=larsen?

Larsen, noun. A a large flock of seagulls swimming west for the winter.

[EBK]

Swimming?  I thought a Flock of Seagulls ran?

[pinkjimiphoton]

Hello I noticed with 4 tube screamers pedal I own (2 joyo and 2 builds with musikding kit parts) , that on the four when all pots are at max the pedal is larsening , does someone know the cause ? I think it s the tone stack,but  This evening I triedto figure why but with no success.
Thanks

voltage readings?
sounds to me like
bad solder
bad lead dress
bad ground

[Kipper4]

Since you own some commercial pedals as well as some kits. I guess your pedals are all working as expected right out of the shop.
I assume you are not daisy chaining all four tube screamers.
Tell us some more about your signal chain.
Axe? Cable? Pedal? Mixer? Effects loop? Pre amp? Amp?What?
It would seem strange that a tube screamer would oscillate just plugged axe>cable battery powered screamer> or regulated wallwart powered screamer> patch lead> amp.
Are there any issues with the mains power? The amp? Lighting ?
Have you tried them with a friends rig?
It's hard to know what's going on. Larsening is a new one on me.
I hope you get it sorted. It's so frustrating not getting the sound you want.
Rich

[robthequiet]

What if you only use three? Maybe only one of them is the culprit.

Larsen Danish pronunciation: [ˈlɑːsn̩], is a Danish-Norwegian patronymic surname, literally meaning "son of Lars" (equivalent of Laurentius). It is the seventh most common surname in Denmark, shared by about 2.4% of the population.

So Son of Screamer is really Screamersen?

[GiovannyS10]

I was really trying to help... But even using all the grammar classes that you guys posted i could not understand what is "larsening"... But anyway, just check things related with the power supply. The TS9 schematic has not protection device or filter. Maybe you are talking about oscillations caused by RF or not grounded axe... For it, just try to add a simple low pass circuit in the V+ and it should solve your problem... Hey - I am just shooting in the dark and supposing your problem... Because i had a similar problem using TS so far...

[nonoxxx]

Thanks for your replies, in fact it s not a real issue but more an interrogation about the circtuit cause the joyos (stock with no mod) are making the  same kind of  noise when all pot's are at max and all is fine while reducing the tone pot a little , and I had build a lot of pedal's ( dist,fuzz,delay )with no noise issue so I don't think it's a bad solder or something like that ( and the stock ones are making the same trebly noise when I don't play. So I am wandering'if it's something normal or not for this circuit before to go any further .

I had tested the joyo with a battery to be sure it's not due to my alimentation ( a cheap transformer with multi output).

[bloxstompboxes]

Thanks for your replies, in fact it s not a real issue but more an interrogation about the circtuit cause the joyos (stock with no mod) are making the  same kind of  noise when all pot's are at max and all is fine while reducing the tone pot a little , and I had build a lot of pedal's ( dist,fuzz,delay )with no noise issue so I don't think it's a bad solder or something like that ( and the stock ones are making the same trebly noise when I don't play. So I am wandering'if it's something normal or not for this circuit before to go any further .

I had tested the joyo with a battery to be sure it's not due to my alimentation ( a cheap transformer with multi output).

But we still don't know what "larsening" means! For the love of God and all that is holy or, screw it, unholy, tell us!

[slashandburn]

I'd prefer my pedals more Larsson than Larsen.

[EBK]

I like to think it has something to do with Gary Larson.


More seriously though, look here:
http://www.cochlea.org/en/hear/the-larsen-effect-whistle
Feedback-induced oscillation.

[duck_arse]

never mind larsening, how did the interrogation go, and what the hell is your "alimentation"?

the hoops!

[GibsonGM]

"Joyo"??

[vigilante397]

"Joyo"??

Inexpensive Chinese stuff. Nothing to trouble yourself over.

[nonoxxx]

Yes joyo are making cheap clones but really nice for the price
What I call a larsen is a trebly sound  at 3700 herz ( I check on the Eq of my sequencer)
My alimentation is a cheap behringer transformer but I tested also with a battery.
When experimenting this evening I find that putting a low pass at approximately 800  hertz after the 47 uf cap ( the vb out of the power supply ) solve the problem . But it's weird.

[blackieNYC]

I'm sure your English is better than my...   Where are you from?
Alimentation sounds like what we commonly call a power supply.  Battery test also - that's right.
A sound you can use an EQ to help find the frequency - ok, got it.
The 800 Hz low pass filter - of course it will get rid of a 3700 Hz noise.  This seems obvious.

Does the noise happen all the time or just when you play?  I can understand the distortion/drive control and the gain control, but your output volume has to be all the way up to hear the problem - is that what you are saying?

[nonoxxx]

I m French so sorry for my english lol, I try to do my best, but it s not easy for technical vocabulary.
So yes this noise happen whatever the guitar,and when all controls on the screamer are at max . My interrogation start because I noticed that on a joyo stock with no mods and on a musikding kit build
At first and I was wandering if it's normal for this circuit cause I do not have Ibanez/maxon screamer to test. When reducing the tone pot all is'fine the noise disappear.

The noise happen only when not playing , when playing it sound Ok so it,s more an interrogation than an issue but I had made stuff with a lot more distortion  without noise issue so I want to understand why

It's strange that just'filtering a little the power supply circuit just after the 47 uf cap solve the problem... ( with wall mart or battery it's the same , for what I know battery is the noiseless method for pedal alimentation and I didn't know it has to be filtered to be quiet).

[nonoxxx]

This mod with the 47 ohm resistor after the diode should do the job

[reddesert]

I think it's pretty normal for a tube screamer or other overdrive / distortion pedal to become uncontrollable with all the knobs at maximum. You're setting the pedal to have high gain at high frequencies, and usually turning the volume knob all the way up makes a volume boost that is several times over the clean signal. I don't have an original tube screamer, but my clone reaches unity volume around 3 out of 10. I can barely touch the guitar with the volume all the way up.

So the short answer is basically: there's not a good reason to do this unless you are trying to create a noise fest.