Question about Music

1 Answer

My 1967 fender super reverb amp starts popping and cutting out on high volume after it's played for about 15 minutes.The 2 6L6GC tubes flicker a soft blue light while this is happening. If you turn down the volume, it stops popping and cutting out, until you turn it up again.

Posted by on

  • Anonymous Mar 21, 2014

    where is the serial number

×

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Music Master
  • 5,603 Answers

IF the blue is on the GLASS envelope, that is just phosphouresence in the glass and not a problem. The harder you drive the tube, the brighter this will get. The electron beam heading toward the plat of the tube leaks past the plate and hits the glass. ot to worry if the blue is on the glass.

IF the glow is magenta/purple in between the internal electrodes, the tubes have gotten gassy and need replacing.

From your desciption, I would suspect a capacitor is going bad someplace in the unit OR the vibration has loosened a connection someplace. Input jacks are VERY common problem for intermittent noises like this. The jacks get destroyed because the musicians FAIL to restrain the intrument cables and yank them sideways. Loop the cable through the handle to help avoid the problem.

Posted on Feb 01, 2010

Testimonial: "Thank you for your time. I appreciate it most sincerely."

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

No reverb on my fender ps 160 Vocal amplifier


Here is a link to the schematic drawing
http://www.prowessamplifiers.com/schematics/fender/ps160.pdf

items to check are
1-the footswitch and plug
2-the reverb unit ,usually found at the bottom of the box
3-the reverb unit is plugged in to the amp
4-V6 a 7025 valve
5- the reverb switch is in the on position

Hope this helps

Len

Oct 14, 2014 | Music

1 Answer

The reverb channel on my fender twin feeds back


Not sure of how it is feeding back. Two possibilities... the reverb tank in the cabinet is no longer shock mounted. The other is your guitar can "hear" the speaker... make sure you are away from the amp. With the reverb on, the feedback stability is less than with it off so make sure your guitar is away from the amp. Acoustic guitars are more sensitive to this than solid body ones.

May 10, 2011 | Fender 65 Twin Reverb 85W 2x12 Tube Guitar...

1 Answer

Fender vibrolux. Very (loooud) loud hum/buzz All tubes but the 6l6's removed. History: bought this amp as a repair project. replaced all caps. originaly the amp was quiet but but had very little volume...


Here is the schematic:

http://elektrotanya.com/fender_vibrolux_6g11_schem.pdf/download.html

Check the quality of the DC bias as being free of ripple.across teh 25 mfd/50v cap filtering the bias.
If much ripple there, replace the cap. Also the .05 bypass on the swinger of the intensity control.

This should be an easy fix, but you might need an oscilloscope to diagnose it quickly... or just parallel caps across these to see if it kills the hum.

The main high voltage filter caps are also suspect as well as the bypass of power to the ealier inverter stage a 16mfd/450v

There are lethal voltages in this so use great caution when troubleshooting... the caps hold a nasty charge.

Feb 06, 2011 | Fender Custom Vibrolux Reverb Tube...

2 Answers

Fix Reverb unit on Fender Hot-Rod Deluxe Amp


Could have broken a spring in the reverb tank, or a wire connecting it to the amp, or the reverb driver tube, or a few other things, but those are the most likely in this situation. Thats what I'd check first. Give it a little slap and if it vibrates like normal, your spring is probably ok, you can still open it up and double check though. Check your wires. Then pull your reverb driver tube and replace it. If that doesn't work, it is probably in the circuit somewhere, and you should not work on your amp unless you know what you are doing. They store large amounts of electicity in the caps and they can kill you.

Apr 24, 2010 | Fender Hot Rod Deluxe Guitar Combo...

1 Answer

Hi, I've owned a Fender Hot Rod Deluxe since '01. Around '06 I started having problems like crackling sounds when on but guitars volume was all the way down. Loss of volume here and there. While amp was on...


In YOUR amp, take a pencil and tap teh sides of the tubes GENTLY, listening for any crackling... note SOME microphonics is normal in the preamp stages.

Since retubing it fixed it once, it is likely either a tube was bad OR a pin of a tube wasn't quite making so replacing the tubes cleaned it and made it work. Tubes DO go bad, especially when they are vibrated like in these amps... BUT don't just replace the lot, try to find which is at fault..

On your friends unit, LIKELY an electrolytic bypass capacitor for one of the reverb preamp stages has dried out and needs replacing.

Apr 23, 2010 | Fender Hot Rod Deluxe Guitar Combo...

1 Answer

About a month ago while on a gig, I noticed that the amp was cutting out when I played solos at a high volume. I play at barely half volume now, and if I go any louder, the same thing happens, it cuts...


Not likely preamp tubes. If they cut out they would fade slowly then come back slowly...

First check for marginal input jack. These take a beating and get loose and poor contacts. The vibration can cause the contact to be lost.

Also volume controls can get marginal...

Try to catch it in the act and tweek things to find someting that is affected.

Another common problem is contacts on jacks meant for effects inserting. These pass the signal through switch contacts when nothing plugged in and those contacts are "junky" to say the least.

Mar 08, 2010 | Fender Hot Rod Deluxe Guitar Combo...

1 Answer

The BOSS FDR-1 produces a popping sound when played


This is a common problem with this pedal experienced by allot of people. My best advice would be to sell it and put the money toward a real Fender tube amp and some good pickups. If you're trying to go cheap check out some Line 6 modeling stuff.

Oct 08, 2009 | Boss Music

1 Answer

FENDER CYBER TWIN AMP SOUNDS GREAT WORKS GREAT BUT WHEN YOU CRANK THE VOLUME A LITTLE LOUDER THAN NORMAL THE AMP GET STATIC OR DISTORTS OR POPS AND CRACKS. COULD THE TUBES DO THIS?


First make sure you have the TRIM knob positioned correctly. When playing loud the Red Led should just blink a bit so you know you're not overloading the preamp and Digital sections. The Twin Reverb Patch is a clean place to start so select that first. On this amp it's a good idea to set the MASTER to 5 and use the VOLUME control at as low a setting as you can. The GAIN control should be set under 4. You better sound crystal clear on this setting. Try turning up the volume to see how loud you can get without breaking up. It's a guitar amp so there will be some grainy distortion but it should be very light. I bet you get through this test without much trouble. After that you need to be very careful about what settings you're using since many of the presets may not mesh with your guitar pickups. You should concentrate on tweaking one highgain setting and learn about how the controls interact. The amp is so much more complicated than a 10 knob standard guitar amp. Most people need to put in some time to get a handle on it.

As far as the tubes go, typically they can get microphonic which was a problem with versions 1.1 and 1.0 of this amp so check that. Fender had a Cyber twin upgrade kit way back to fix this but if you have version 1.2 or 1.3 that's not it. Problems with this amp are typically caused by control setting more often than an electronic problem but this reponse should get you started figuring it out.
MYREL

Jul 13, 2009 | Music

Not finding what you are looking for?
Music Logo

Related Topics:

396 people viewed this question

Ask a Question

Usually answered in minutes!

Top Music Experts

Michial Gueffroy

Level 3 Expert

1138 Answers

Vito Vacirca Jr.

Level 2 Expert

140 Answers

kakima

Level 3 Expert

102366 Answers

Are you a Music Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...