# Vintage tube amp - cranking volume



## GuitarsCanada (Dec 30, 2005)

What are some of the possible issues that could arise from cranking the volume on a vintage amp. Case in point my '67 Fender Super Reverb. Cranked it way back about a year ago and now it sounds like crap. Clearly blew something. Wondering if there is a particular item or items that would be target for such a thing. Tubes, trannny, etc. It is working, just sounds terrible.

I was holding out for Wild Bill to take a look at it but he has been out of commission for a long time. May have to find someone else to take a look at it but was wondering if anything sticks out based on the volume crankage.

Buzzing kind of noise now and basically sounds like crap


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## bcmatt (Aug 25, 2007)

The first thing I think of is the speaker. They can sound buzzy when they are blown. Did you tear a cone? Do you have another speaker cab you can plug in to to compare against?


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## GuitarsCanada (Dec 30, 2005)

bcmatt said:


> The first thing I think of is the speaker. They can sound buzzy when they are blown. Did you tear a cone? Do you have another speaker cab you can plug in to to compare against?


No, speakers are good. They are a new set of 4 that I put in there. I also switched them out just to be on the safe side. All is well on the speaker side. Something internal to the amp for sure. All original on the guts side, so I am wondering of something gave out that would be connected to the cranking up of the volume.

Also note that it sounds the same on both channels, the normal and vibrato inputs and all jacks. There are two per side. Does not matter where you plug in, same issue


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## mrmatt1972 (Apr 3, 2008)

Could be the tubes were old to begin with and you blew one. That sometimes takes out a resistor, sometimes not. you may be running one one tube only. Here's a helpful link: Tube Amplifier Debugging Page

I'd take it to a local tech (and why not Wild Bill, he's probably working and has no time to post) for a diagnose and repair, that's a nice amp.


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## GuitarsCanada (Dec 30, 2005)

mrmatt1972 said:


> Could be the tubes were old to begin with and you blew one. That sometimes takes out a resistor, sometimes not. you may be running one one tube only. Here's a helpful link: Tube Amplifier Debugging Page
> 
> I'd take it to a local tech (and why not Wild Bill, he's probably working and has no time to post) for a diagnose and repair, that's a nice amp.


I talked to the wild man a few months back, going through some personal issues. I think he is still tinkering but way off the normal pace. I will take a look at that page. I have some tubes laying around. I switched out the rectifier and power tubes before this happened. The others are old and have not been changed in some time. I will take a look at that as well. Beyond that, I would not know what to look for if I opened it up so it will need to be looked at.


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## jimihendrix (Jun 27, 2009)

Wild Bill is still alive and kicking...he worked on one of my vintage amps about a month ago...P.M. me for his new contact number...


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## keto (May 23, 2006)

I'd throw the old power tubes in just long enough to power up and test then back out, as it will have been biased for the new ones.

Preamp tubes, no precautions necessary beyond a power down as you probably know. Take 1 known good one and put it in each position in turn.

Is there a great loss of volume along with the fuzziness?

Have you looked at the guts to make sure it's not something really obvious like a blown up capacitor? Or a solder joint come loose, which is another really good suspect?


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## GuitarsCanada (Dec 30, 2005)

keto said:


> I'd throw the old power tubes in just long enough to power up and test then back out, as it will have been biased for the new ones.
> 
> Preamp tubes, no precautions necessary beyond a power down as you probably know. Take 1 known good one and put it in each position in turn.
> 
> ...


I went through my stock of tubes. I am short on any replacement 12ax and 12at so I just ordered up some. I put in a matched set of GT 6L6 and that made a distinct improvement. I am thinking it may have something to do with the reverb. There is a 12at I beleive that works with that. So I will put in all new tubes and see where this leads us. Basically, at this point she sounds not bad a low volumes. But the bass end is rough. The smaller tubes have not been changed in a very long time so fix or not its not wasted money.


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## GuitarsCanada (Dec 30, 2005)

So now all tubes have been replaced. Sounds a bit better but still not back to normal. So speakers are good, all brand new tubes. Has to be something internal. Its time for an amp tech. I am out of home remedies


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## gtrguy (Jul 6, 2006)

GONE


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## GuitarsCanada (Dec 30, 2005)

gtrguy said:


> Filter caps...


A distinct possibility. Its time to call in the pro's


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## WCGill (Mar 27, 2009)

Unfortunately this is one of those things that's pretty hard to diagnose at a distance. With high volume, comes high current which always stresses components, esp. screen resistors if they're old and carbon comp. Then again it could be a few other things. A tech is in order.


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## GuitarsCanada (Dec 30, 2005)

I am on my way to see wild bill right now


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## CSBen (Mar 1, 2011)

Before pushing it, did it sounded fine say 75% of the way up? Or did you only play it with the volumes on the lower range?

Lots of variables at play here, but nothing that can't be fixed!


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## GuitarsCanada (Dec 30, 2005)

CSBen said:


> Before pushing it, did it sounded fine say 75% of the way up? Or did you only play it with the volumes on the lower range?
> 
> Lots of variables at play here, but nothing that can't be fixed!


She sounded great up until the point that I dimed it. Then that was it. I dropped it off to Wild Bill the other day. Awaiting the verdict


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## nonreverb (Sep 19, 2006)

May have taken a screen resistor out when you blasted it initially. Does it sound harsh and low in volume?


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## GuitarsCanada (Dec 30, 2005)

nonreverb said:


> May have taken a screen resistor out when you blasted it initially. Does it sound harsh and low in volume?


Harsh yes but volume wise it is still the same


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## GuitarsCanada (Dec 30, 2005)

Just spoke with the Wild Man. My amp is ready for pick-up and Bill says it sounds sweet. Apparently we had a few filters caps blown. He replaced them all and tuned it up. Looking forward to flipping it on tomorrow


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## gtrguy (Jul 6, 2006)

GONE


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## parkhead (Aug 14, 2009)

when I get a vintage amp I intend to crank I do the following 

check the condition of the factory speaker & possibly install one or more 
modern new speakers & box the nice vintage ones for preservation
I tend to leave vintage celestions ... while vintage jensens will not survive the crank 


check all the filter caps and routinely renew them if I am going to gig or crank the amp

check the tubes and in some cases leave the old vintage power tubes if they are robust types kt88, 6550, 5881 
if they are EL84 el34 or 6v6 I replace them with brand new jjs


at this point you are good to go 

I look at it like taking a vintage sports car to track day 

if you dont bleed and service the brakes change the oil and adress a few other little issues 
you will be paying a lot more to fix what you break 

if the vintage piece gets occaisional trophy play around the house use you may choose to leave the original bits in place 

p


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## GuitarsCanada (Dec 30, 2005)

parkhead said:


> when I get a vintage amp I intend to crank I do the following
> 
> check the condition of the factory speaker & possibly install one or more
> modern new speakers & box the nice vintage ones for preservation
> ...


Solid advice there. She is getting old and like Bill said, some things will eventually go. So now its pretty well set for the next 40 years


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