Fender Blues deluxe problem- please help diagnose

[Eg303]

My Blues Deluxe (older mid 90's model) is making some strange noises. The amp makes a distinct airy electronic sound at a certain pitch (the C# on the second second string 2nd fret, and all other places that exact tone can be played).
The note comes through, then the electronic sound + the note then just the note again when plucked and the note is held out. It seems only to be a problem when the note is played agressively.

Any idea's?

Thanks,
Kyle

 

[Eg303]

Re: Fender Blues deluxe problem- please help diagnose

Should be noted- the problem exists on both inputs as well as the dirty channel.

 

[WhoFan]

Re: Fender Blues deluxe problem- please help diagnose

odd.... are you sure it's not your guitar? Maybe the G String ringing out above the nut?.... just wondering.....

 

[ES350]

Re: Fender Blues deluxe problem- please help diagnose

Is the reverb on when this happens?

 

[Eg303]

Re: Fender Blues deluxe problem- please help diagnose

it happens with reverb on or off.

The sound is almost like something vibrating on plastic, but at a higher pitch.

Also, tried it with a few different guitars just now, and the problem is always that note except for at the actual 2nd string 2nd fret, so only on 3rd string and 6th fret, 4th string and 11th fret, 5th string and 16th fret, ect

 

[Fresh_Start]

Re: Fender Blues deluxe problem- please help diagnose

Have you tried swapping out tubes one at a time? Maybe one has gone microphonic and only resonates at that specific frequency. You'd only need one preamp tube and one power tube to test this.

This is probably painfully obvious to you, but have you tried moving the amp around - maybe even to another room?

About reverb, what happens if you unplug the return cable from the reverb tank to the amp? (That ought to at least eliminate the reverb portion of the circuit)

Just a thought,

Chip

 

[Eg303]

Re: Fender Blues deluxe problem- please help diagnose

I've moved the amp around, but not to a different room in a while.

I'll try that reverb idea tonight, and then I guess the next step is to get one of each tube an get to switching. Anyone know if the Blues Deluxe is fixed bias, off the top of their heads?

BTW- enjoying this cool weather we are finally getting, Fresh Start?

 

[Gearjoneser]

Re: Fender Blues deluxe problem- please help diagnose

It sounds like it could be 'cone cry.' That's when you hit one particular note on the guitar, and it reacts strangely with the speaker and cab's resonant frequency. It's fine on all notes except for that one.

If you've got another cabinet sitting around, unplug your combos speaker leads and alligator clip them to a speaker cable into your other cab. See if it still does it.

 

[Eg303]

Re: Fender Blues deluxe problem- please help diagnose

If "cone cry" prooves to be the problem, would the solution simply be a new speaker?

 

[Eg303]

Re: Fender Blues deluxe problem- please help diagnose

A little more info...

After spending a bit more time looking for these spots, I have now found 2 more tones at which the amp makes the electronic buzzing sort of noise.

Also, the power tube were replaced with matched set from Groove tubes in 2005, 2 of the preamp tubes are original but one was repaced with a Groove tube.

 

[stevie ray]

Re: Fender Blues deluxe problem- please help diagnose

have you ruled out your guitar being somehow linked to the problem?

 

[WhoFan]

Re: Fender Blues deluxe problem- please help diagnose

my Classic 30 combo's chassy and cab buzzes on some notes... could it be something inside the amp vibrating? in my C30's case most people believe it's the tube sockets rattleing on the metal chassy

 

[Eg303]

Re: Fender Blues deluxe problem- please help diagnose

I tried it with a few different guitars, and they all have the problem on the same notes.

There is a volume drop while the sound is happening

If it is a tube, would preamp or power be the more likely culprit (I'd much rather get by replacing one little preamp tube than buying another match-set and having it biased)

 

[Eg303]

Re: Fender Blues deluxe problem- please help diagnose

Also- the Groove Tube power tubes in there now are rated at "10", if I needed to purchase new power tubes, would I be alright just getting another set of the same GT's rated at "10" and popping them in? (I checked and the amp is fixed bias, if that changes the answer)

 

[Fresh_Start]

Re: Fender Blues deluxe problem- please help diagnose

Also- the Groove Tube power tubes in there now are rated at "10", if I needed to purchase new power tubes, would I be alright just getting another set of the same GT's rated at "10" and popping them in? (I checked and the amp is fixed bias, if that changes the answer)

One 12AX7 - Tung Sol, Shuguang (Chinese), EH, or JJ - would be a relatively cheap diagnostic tool, plus you'll probably find better tone with any one of those in the V1 spot even if the problem isn't a tube.

Replacing the power tubes is tougher since you've got a fixed bias amp with no adjustment. (It's too late at night to go into that - read Aiken's Tech Notes.) If any of the other ideas - especially cone cry or cabinet harmonics - are eliminated and it's not a preamp tube, you may need new power tubes. Again, you can do better than Groove Tube's re-labelled bottles anyway.

And yes, it's a great relief to have summer FINALLY end... in October. If I had to sit through one more college football game in 90+ degree heat, I was going POSTAL. Instead, yesterday was perfect

Chip