Fixing hot rod deville amp...help!

[jimistone]

I have a Fender Hot Rod Deville amp, that I love for the most part. I have a problem with it though.
When you first turn it on it breaks up even on clean at low volume. It's not a good sounding break up, it sounds like crap....kind of like im using a bad guitar cord or the input jack on my strat is shorting out and not getting a good connection. After it warms up an hour or so...it's fine and I won't have a problem for the rest of the night.

So far:
I have eliminated the guitar or the guitar cord as the problem...it does it with any guitar and cord.
I have replaced the tubes and rebiased,
and I have replaced all the plate load resistors.

I would email Justin (the hot rod deville guru) but on his website he said he is back in shcool and not taking any emails.

Any suggetions?

 

[David]

I have a Fender Hot Rod Deville amp, that I love for the most part. I have a problem with it though.
When you first turn it on it breaks up even on clean at low volume. It's not a good sounding break up, it sounds like crap....kind of like im using a bad guitar cord or the input jack on my strat is shorting out and not getting a good connection. After it warms up an hour or so...it's fine and I won't have a problem for the rest of the night.

So far:
I have eliminated the guitar or the guitar cord as the problem...it does it with any guitar and cord.
I have replaced the tubes and rebiased,
and I have replaced all the plate load resistors.

I would email Justin (the hot rod deville guru) but on his website he said he is back in shcool and not taking any emails.

Any suggetions?

You can buy my rivera?

 

[TheGuitarMan]

I thought that's how the distortion on the hrd was supposed to sound...

j/k

My first instinct was the power tubes, but you replaced them. It's always best to let it warm up for 30 minutes before playing anyway.

Sorry I couldn't help. Maybe the guys at the Fender Forum or somebody in the Seymour Duncan Forum's Amp section could help you?

 

[Thatupstateguy]

Sometimes, depending on how often the tubes have been replaced,..... the solder joints on the tube sockets get loosened up slightly,.... and after they warm up for 20 minutes or so,... make better contact due to heat expansion,....

I would just wiggle the tubes a bit after it is turned on,.. to see if you get any noise by just doing that,.....

If not,.... check some of the other connections ,... vibration from sound sometimes causes soldered connections to loosen up after some time....

If those are all good,... follow the above suggestions about the Fender Forum....


Steve

 

[Valley Arts Kid]

jimistone,

I had the same problem with mine. I took it to the local warranty service center and the tech found some shoddy soldering and fixed it.

 

[jimistone]

Thanks guys,

I just let the damn thing warm up for an hour and it's fine for the night....I guess that will be my plan of action as long as it works.

 

[ggunn]

Thanks guys,

I just let the damn thing warm up for an hour and it's fine for the night....I guess that will be my plan of action as long as it works.

My SVT had a similar prob. When I first turned it on, it would hiss and crackle until I slapped it, and in a minute or two it would do it again, over and over until it had been on for half an hour or so. As time went by, however, the half hour turned into 45 minutes, then an hour... I took it in to a tech, and he found some cold solder joints and touched them up. Now the amp is fine.

 

[Anfontan]

Dont wait for something to happen~

It's got to be a bad solder joint in there as the tubes gotta really be cooking for an hour to make the metal expand enough to reconnect. I would get it looked at soon-as you wouldn't want it to fry something expensive, like a transformer!

 

[Dani Pace]

When you changed the tubes did you clean the sockets? Tube sockets are contacts too and should be cleaned every time tubes are changed. Corrosion and carbon build up makes for bad conections, often heard as crackle or breaking up. A shot of Deoxit might cure your problem, if not it's a good bet that there is a weak (cold) solder joint someplace.

 

[jimistone]

When you changed the tubes did you clean the sockets? Tube sockets are contacts too and should be cleaned every time tubes are changed. Corrosion and carbon build up makes for bad conections, often heard as crackle or breaking up. A shot of Deoxit might cure your problem, if not it's a good bet that there is a weak (cold) solder joint someplace.

How do you locate a weak solder joint (out of the huindreds of solder joints in that amp)?

 

[boingoman]

How do you locate a weak solder joint (out of the huindreds of solder joints in that amp)?

Best bet is to just reheat all the suspect joints- it's quicker than looking for one specific bad spot. Try cleaning the sockets first like Steve said, though. Reheat the tube socket joints and all the parts attached, like grid resistors. Also reheat all the joints in the power supply and bias supply. Those are the places to start.

Sometimes they are easy to see. They will even be broken. Cold solder looks dull and grainy, as opposed to shiny.

You can also use a magnifying glass (I'm not kidding), it will show cracks in solder joints and boards a lot quicker than you can see them with your eyes.

You can sometimes find crappy joints by running the amp out of the chassis, and poking around with a wooden stick with the volume up a little.

A can of compressed air can do the trick. With the amp out of the chassis, let it heat up. Then spray suspect parts (not tubes, probably ). They will cool down, and sometimes the problem will come back. This can lead you to the problem joints.

 

[Outlaws]

How do you locate a weak solder joint (out of the huindreds of solder joints in that amp)?

Ever seen polished up stainless steel? Good. Now look for something foggy. That would be cold soldering.

In the beginning of my pedal building days, that was the first and most common problem of malfunctions.

 

[Dani Pace]

Solder joints should remain shinny for years, cold solder joints have a dull gray appearance and sometimes look like they have a powder or dust coating on them. A quick reheat will often solve the problem, sometimes a joint has to be cleaned then resoldered.

 

[Outlaws]

Solder joints should remain shinny for years, cold solder joints have a dull gray appearance and sometimes look like they have a powder or dust coating on them. A quick reheat will often solve the problem, sometimes a joint has to be cleaned then resoldered.

Desolded and then resolded is the only real fix IMO. Cold solder joints never seemed to ever look like they should when I tried to fix them without starting over. I got them to work....not saying that won't happen....just saying they never looked like something other than a cold solder.

 

[Anfontan]

I like to think that solder should not be thought of as glue holding the circuit together, the best connection is a component lead connecting to the metal trace on the circuit board or another metal component lead. A cold solder connection often can be isolated from the circuit, and reheating will not correct it.

 

[ggunn]

I like to think that solder should not be thought of as glue holding the circuit together, the best connection is a component lead connecting to the metal trace on the circuit board or another metal component lead. A cold solder connection often can be isolated from the circuit, and reheating will not correct it.

Most cold solder joints occur when the solder has not flowed from one metal contact to the other, but they are touching. Initially, it appears as if nothing is amiss, but as dirt or oxidation migrates into the seam between the contacts, electrical continuity gets intermittent. Usually, reheating to flow the solder will correct this unless the contacts have physically separated.

 

[Scooter B]

I found a tube amp repair tech site that has lots of good info so if you don;t get it figured out here you may try;

http://p210.ezboard.com/bampworkshop