Dsl20 Ringing/singing Harmonic

[coyoteblue]

I recently bought the DSL20 and after a week a ringing/singing high note comes through when I use the bridge pickup of my Jazzmaster. It's most noticeable when playing an open G string, and when combined with the B. I changed strings to get a wound third and it makes no difference. I don't hear the ringing in my other amp, a Deluxe Reverb. I exchanged the V1 tube and still the ringing. I was surprised to see a tube ring on the V1, and no others...is that normal? Any advice would help before I return the amp.

 

[Kinkless Tetrode]

Most likely a microphonic tube. It is often the v1, but since you swapped it out with no change, try the others.

Any noise or RF interference picked up by V1 is amplified on down the line. That is why a shield is placed over V1. On amps that have an extra tube for high gain, such as the Vintage Modern, there might be a shield on V2 as well. Back in the day- JCM800s- they put shields on all the preamp tubes, but some claim that the shield itself caused a change in the purity of tone, so it is now only used only where needed.

 

[SkyMonkey]

Is that a "wolf tone", i.e. the opposite of a dead spot on the guitar neck?
Most acoustic guitar amplifiers have extra controls for a 10dB notch in the EQ, and a frequency knob to position the notch. This helps reduce feedback when amplifying an acoustic guitar.
You may be experiencing some sort of microphonic equivalent from the bridge pickup. It may only be peculiar to the DSL with that guitar. Can you try a different guitar through the DSL to test?

 

[coyoteblue]

Thanks for the suggestions. I'll follow through with tubes and another guitar.

 

[paul hancher]

Is that a "wolf tone", i.e. the opposite of a dead spot on the guitar neck?
Most acoustic guitar amplifiers have extra controls for a 10dB notch in the EQ, and a frequency knob to position the notch. This helps reduce feedback when amplifying an acoustic guitar.
You may be experiencing some sort of microphonic equivalent from the bridge pickup. It may only be peculiar to the DSL with that guitar. Can you try a different guitar through the DSL to test?

what he said. is the bridge pickup potted? does it have a cover? adding or subtracting one or more of these elements could make a difference.

 

[ampmadscientist]

I recently bought the DSL20 and after a week a ringing/singing high note comes through when I use the bridge pickup of my Jazzmaster. It's most noticeable when playing an open G string, and when combined with the B. I changed strings to get a wound third and it makes no difference. I don't hear the ringing in my other amp, a Deluxe Reverb. I exchanged the V1 tube and still the ringing. I was surprised to see a tube ring on the V1, and no others...is that normal? Any advice would help before I return the amp.

The Jazz master is accidentally causing (something called) sustain.
There's probably nothing really wrong.
It's producing something that I usually do on purpose.

It's a positive feedback loop. Strings>pick-up>Amp>speaker> then the sound wave travels back to the guitar and re- triggers the strings.

However you may not have expected this from a Fender Jazzmaster.

The DSL has a lot more "gain" than a Deluxe Reverb, that's why the Deluxe won't do this.

 

[Mitchell Pearrow]

I recently bought the DSL20 and after a week a ringing/singing high note comes through when I use the bridge pickup of my Jazzmaster. It's most noticeable when playing an open G string, and when combined with the B. I changed strings to get a wound third and it makes no difference. I don't hear the ringing in my other amp, a Deluxe Reverb. I exchanged the V1 tube and still the ringing. I was surprised to see a tube ring on the V1, and no others...is that normal? Any advice would help before I return the amp.

To the forum new brother, as you can see your other new brother’s are on the job, and I can only repeat what they have said! Cheers Mitch

 

[mistercoffee1]

Don’t dismiss power tubes. I had the same sort of sound, and finally fixed it with a power tube swap.

 

[Chris-in-LA]

OP might also be hearing extra vibration coming from the length of string above the nut. Try strumming above the nut, you get high ringing notes.

 

[punchingboy]

OP might also be hearing extra vibration coming from the length of string above the nut. Try strumming above the nut, you get high ringing notes.

If that's the case, I would wrap a ponytail Holder right above the nut. I use them on all my guitars. Much quieter that way.

 

[coyoteblue]

Thanks for all the suggestions. The odd thing I just noticed is that this ringing sound occurs mostly with an open D chord, or when playing the open B and G together, but not on their own! This might suggest that ampmadscientist may be correct in saying the issue is the feedback loop created between guitar, pickup and higher gain amp becoming noticeable at certain frequencies. I will check intonation as well. I will explore further.

 

[purpleplexi]

Can happen with single coils if the pickups are set close to the strings.