Hot Rod Tube Amp

upgrading the Fender Hot Rod Deville and Deluxe
In our relentless pursuit of tone, musicians like us may search for vintage effects pedals because we think they sound better, buy expensive low-noise cables, and stay up late listening to old Pink Floyd LP’s thinking “how did they make it sound so good?” Everyone has a specific sound they are trying to achieve and everyone’s is different. If you’re serious about warm tone and lots of volume, then eventually you’re going to want a tube amplifier.

There are lots of options out there for any budget, but one of the best amps you can get for the money is the Fender Hot Rod Series. The 40 watt Deluxe and the 60 watt Deville are some of the worlds best selling amps because of their good tone and their fair price, but many people don’t know that they can be easily modified, and the tone will be improved upon dramatically.

what the Deville has to offer

The Deville comes with some nice features: footswitchable clean, drive, and “more drive” channels, reverb, 3-band EQ, individual volume controls, presence and drive dials, a brightness switch for the clean channel, an external speaker jack and an effects loop. I found the Deville, with its 2×12 speaker cabinet, to be pretty good on the clean channel. Clear true notes and a fairly even tone, but this required the bass to be turned down all the way. It seems that the tube/speaker combination in this amp was producing a ton of bass, and this was causing the speaker to lose mids and highs. Part of the problem lies in the two Eminence 12 inch speakers. I suspect that in order to fit this amp into a particular price bracket they cut costs with the speakers. Another problem with the clean channel was that it had to be turned up really loud to reach the “sweet spot,” the point where the tubes start producing a natural overdrive.

The drive channel is a little disappointing. It’s flabby and heavy on the lows and lacks sparkle, I would usually run my Ibanez Tube Screamer pedal in the drive channel to give it a little more life and help cut through the mix on stage. I found the “more drive” channel to be unusable, it just sounded cheesy.

Anyone who has used this amp knows that this thing is LOUD. I play in a garage band and on stage I would find myself keeping the volume in check to avoid drowning out the other players (this thing can even overpower a loud rock drummer). The 6L6 tubes give this thing a ton of headroom, which left me wondering, “do I really need 60 watts?”

The circuitry in the 60 watt Deville is identical to the 40 watt Deluxe. One of the major differences is that with the Deluxe you get one twelve inch speaker, it’s intended to be a good all around combo amp for small bars and clubs and practicing, the Deville gives you a little more volume and an extra speaker.

replacement parts

I decided to go through with a speaker/tube replacement and to rebias the tubes, in this article I’ll show you how to do it yourself. Keep in mind, you can also do this kind of upgrade with the 40 watt Deluxe.
First I decided to go with a JJ 6V6 tube kit from Eurotubes.com. According to their website using 6V6 tubes cuts the power down to 30 watts and lowers the headroom. I chose the “normal clean channel – High Gain lead channel” kit, that would give me a little more growl where before it was lacking. The kit comes with two matched power tubes, and three ECC83S tubes for the preamp. Interestingly enough, If you are putting 6V6 tubes in a Deluxe it will cut the power down to 30 watts as well. It may seem strange that both the 60 watt and the 40 watt amps will produce 30 watts with 6V6’s, but Eddie Pletka from Eurotubes explains:

“The Deville really isn’t going to make 60 watts of clean power and the deluxe (in stock trim) can actually make more than 40 watts. It’s all relative and with the 6V6’s you’re going to be at about 30 watts. None of this is exact and keep in mind even a difference of 10 actual watts hardly makes a difference in the amps physical ability to move air.”

Update 12/02/09

I have since replaced all three preamp tubes with the original fender 12AX7 tubes. These tubes are made by Sovtek in Russia and I believe they sound warmer and more even in the gain channel. The ECC83S tubes from Eurotubes have too much gain for my taste and tend to sound brittle.

For speakers I wanted something with a vintage style alnico magnet, for its smooth compression and the sweet tone, rather than a harsh and aggressive ceramic magnet. I read that the Jensen P12N is a popular speaker in a lot of old amps and is well liked. I heard some good things about Weber speakers and i know that they do a pretty good job reproducing that old tone, so I ended up buying a pair of the 12A125-O rated at 8ohms and 30 watts. These speakers are well matched for the tubes and gave me much brighter mids and highs and transformed the amp from a docile sloth to a snarling beast. If you are looking for something with a little less breakup and cleaner tone, or If you’re looking for a single 12 inch speaker for the Deluxe I would recommend the 50 watt 8 ohm 12A150-O. You can also check out their British Series for tone similar to Marshall amps.

I don’t know what kind of effect this mod will have on your warranty, but if you are like me and bought your amp used and it’s over five years old then the warranty has expired anyway. The good thing about this mod is that it can be reversed just as easily to return it to its original state. Save the boxes your speakers came in just in case some day you want to sell the old ones online.

suggestions on how to do it yourself
If you don’t know what you’re doing, then don’t open up the amplifier, it could save your life!

The first thing you need to do when performing this upgrade is drain the filter caps. Even when the amp is not plugged in it can carry enough voltage to kill you. If you don’t feel comfortable working on amps then take it to a professional, if you’re not qualified to work on an amp then don’t open it up in the first place!!

To drain the power caps simply turn on the amp and let it warm up with standby in the “on” position, then turn the power off while the standby switch is still in the “on” position. This lets the tubes drain the power naturally. Remove the back cover and test the voltage with a multimeter at the third pin of the power tube as shown in the picture, you should see voltage draining off. You can also individually test the filter caps using the method shown, they are the big gray things that look like AA batteries and say 350V and 500V on the side, the negative end is marked on the side of the filter cap with an arrow pointing to the end.

When you are sure there is no voltage remaining you can remove all of the tubes by gently grasping the end and wiggling them straight down.

Remove the speaker cable. Remove the entire amp assembly by removing the screws in the cabinet, careful, it’s heavy!
Remove the speakers by unscrewing the Phillips head screws.

Carefully install the new speakers with the screws. Hand tighten in an X pattern. I found that the upper speaker will not fit between the amp assembly and the cabinet with the bell cover on, simply pull the bell cover straight off the speaker and it will fit perfectly. Reinstall the entire amp assembly into the cabinet, I find it’s easier to work with when you turn the cab on its side.

Hook up the speaker wires (the wire with the little white letters is the positive, it should have a spot of red paint on the connector as well) and install the new tubes in their appropriate locations. I like to spray some DeoxIT pot and switch cleaner on the tube pins and then pull them in and out of the assembly to clean the connections this keeps the amp sounding clean and free of crackle. Once the tubes are installed, leave the back cover off so that you can bias the tubes.

Biasing the Deville with 6V6 tubes
Turn the power on and wait for the amp to warm up. The bias pot is a little blue potentiometer in the middle of the circuit board (see red arrow) with a slot for a screwdriver in the middle. Remember to only have one hand inside the amp at a time, that will keep deadly voltage from passing through your heart if you touch something inside the amp. With a plastic handled screwdriver turn the pot all the way in each direction and then all the way to the other to get a feel for the pot, then set it somewhere in the middle. Turn the standby switch to “on,” then test the bias with a multimeter. The bias test point is marked in the photo and is clearly marked on the circuit board. According to Eurotubes.com you should bias the Deville at 30 to 35mv and the Deluxe at 40 to 45mv when using 6V6 tubes.

Secure the back cover and the amp is ready to play. Enjoy!

how it sounds

Everyone has a different idea of what’s good, but I’ll give you my honest opinion of how this setup sounds to help you decide what might be right for you. When I set the EQ at treble 10, bass 4, middle 7, presence 8, it seems to have a pretty even tone on the clean channel. It sounds warm and bluesy and has nice breakup when you get above 3 on the volume dial, it’s still a loud amp but not bone shaking like it was before. I do notice a little bit of distortion coming from the speakers but I kind of like that raw sound. If you desire tone that’s cleaner, try a pair of 50 watt speakers.

The overdrive channel is closer to a Marshall tone now, with aggresive growl and a nice sparkle to it. I’ve always liked Marshall amps for overdrive but thought they were just a bit thin. The Fender has warmth and low-end where the Marshall is lacking. I also noticed that this amp sounds better at low volume than it did before, making it nice for practicing at home.

remember how before I said the “more drive” channel was unusable? It’s now the thunder of the gods. I no longer need to use my Tube Screamer pedal, I just use the “more drive” channel to achieve my heavy rock sound. The High Gain kit from Eurotubes really did the trick, there is a noticeable increase in overdrive. I usually keep the drive around 7 or 8 and experiment with the presence between 8 and 11 to find the best sound. Experiment with your own sound and have fun with it, you’ll probably learn something along the way.

useful links
Weber Speakers
Eurotubes
Harmony Central forums
Telecaster forums
Fender amp and guitar info

Potting Pickups

Wikipedia defines microphonics as “phenomenon where certain components in electronic devices transform mechanical vibrations into an undesired electrical signal (noise).” The desired function of a guitar pickup is to turn the vibration of the strings into electrical signal. The pickup is basically magnetic pole pieces wrapped with thousands of coils of copper wire, if the copper wire or any other metal part in the pickup vibrates against itself it creates a screeching noise through the amplifier. Microphonics are not our friend, but they can be minimized by dipping the pickups in wax.

The process is fairly simple, but certain safety precautions have to be taken to avoid being burned by the hot wax or catching fire. Wax and the vapors it puts off are extremely flamable and should never be in the vacinity of open flame, that’s why you can’t melt the wax over your kitchen stove, and never try to heat it in the microwave. Use good ventilation.

The first thing you’ll need is a deep fryer designed for home use, these can be fairly inexpensive and all that is required is that it has an adjustable temperature setting. You will also need a thermometer that measures at least up to 150 degrees.

You will also need about a pound of canning paraffin wax and one-quarter pound of beeswax, you can find these at a hardware store or a hobby shop, call first though because this is not always something stores keep in stock.


Set your deep fryer to somewhere around 150 degrees (mine only has settings for 0-225-300-350-390, so I set it somewhere between 0 and 225 and watched the thermometer.) According to Lindy Fralin, a professional pickup winder, the mixture should be four parts paraffin to one part beeswax, so drop in one pound of paraffin and one-quarter pound beeswax.

When the wax is completely melted and the temperature is consistantly 150 degrees you can drop in the pickups, try to keep them from touching the bottom of the pot because that can be hotter than the wax, so put the pickup in the fryer basket or on top of a layer of marbles a the bottom of the pot.

Let the pickups set in the hot wax for about 10-20 minutes and pull them out. Set them somewhere to cool and when they are cool enough remove the excess wax with a soft cloth. They are ready to install and should play with very little noise.

The Big Muff Guitar

In today’s world of commercialism, capitalism, MTV and Apple, it’s easy to forget that modern rock and roll was built on the accomplishments of people who were inventive, thrifty, creative, innovative, and POOR AS DIRT. Usually people who have the least are able to make the most out of what little they have. These are the people who come up with the best ideas. Les Paul, possibly the most influential man in rock and roll built his first guitar called “The Log,” a 20 pound guitar made of a 4×4 piece of wood with incredible sustain. He showed his idea to the Gibson president and was laughed out the door. They later came back to Les and asked him if he would help in creating what would later be the famous guitar named after him. They made millions. In this article I’ll show you how to build a guitar for practically nothing.

The Tools
A lot of people don’t know that you can build a guitar with simple hand tools. Some tools you might find useful are:

an electric drill/driver
a hand saw
a soldering iron
a wire cutter
a wire stripper
pliers
sand paper
wood glue
wood clamps
a ruler
a pencil
a big pot of coffee

The Body
The body is simply a resonator, this can be a gourd, a coffee can, or an old hubcap. Cigar box guitars are popular to build right now and old cigar boxes can be picked up cheap on eBay. They are also likely to be hand built from fine woods like mahogany, cedar, spruce, rosewood and other beautiful sounding woods. For my guitar I’m using a 6″x8″x4.5″ wooden box that came with my Big Muff guitar distortion pedal. It is made of laminated wood, not as ideal as a cigar box, but it will do the trick.

I drilled 4 holes in the top: two sound holes, a pickup hole, and a hole for the tone control. I also drilled a hole in the body for the instrument cable jack.

I drilled 4 holes in a little piece of wood and glued it to the back of the body. This is the tail piece where the strings will be anchored.

Electronics

You may decide not to use electronics in your guitar. I chose to wire up some spare parts I had lying around. A pickup can be any old single coil you find on eBay from a Strat or a Tele, you can get one for like 10 bucks. A 250K pot will run you about $5 on eBay or a guitar electronics store. Don’t forget the capacitor on the tone control. Wiring diagrams can be found at this link:

http://www.guitarelectronics.com/category/wiringresources/

The body is done!

The Neck

Guitar necks are commonly made from mahogany or maple, I made mine from a 3/4″ thick by 1.5″ wide by 15″ long scrap of redwood. A very soft wood. Glue a piece of wood to the end to make an “L” shape and reinforce with a little triangle. Glue and clamp overnight to make a strong bond.

The headstock is made from a piece of redwood slightly wider than the neck, with holes drilled for the tuners, and with a 23 to 45 degree angle sawed at one end. I drilled a small hole in the neck and the headstock where they join and inserted a dowel for strength.

The neck and headstock are glued (no clamping required, let it dry overnight) and a little piece of wood is notched for each string and glued to the end of the neck.

Frets
Some cigar box guitars are built with no frets at all and played with a slide. I wanted the option to play with fingers so I added frets. It doesn’t matter how long your neck is, measure from the nut to the bridge of your guitar, this is your “scale length,” or the vibrating portion of the string. Decide how many frets you want (I used 18) and follow the link to the fret calculator below:

http://www.stewmac.com/FretCalculator

Now mark with a pencil on the neck where each fret will go. I found the metric system more accurate in this instance.


Time for a small tangent in our article. A couple of years ago, my roommate’s bicycle was mangled when it was sandwiched between a pickup truck and a V12 Mercedes-Benz. No one was hurt, but the bicycle was completely destroyed save for a single wheel. the bike was left injured in the front yard overnight and was promptly stolen! I hung on to this wheel for no reason in particular and now I’m going to cut up the spokes to use as frets on my guitar.


Use a saw to cut notches in the neck where the frets will go.


Cut the spokes with a heavy-duty wire cutter and glue them to the fretboard.

Come Together

I chose to bolt my neck to my body so that I can take the whole thing apart and replace pieces if I wish. You can also choose to run the neck through the entire body for superior tone!


Hmmm what to use for a bridge… a bent, rusty nail, perfect! Watch out for tetanus. Under the tail piece you see a little black wire that is connecting the strings to the back of the tone pot through a tiny hole in the body so that the guitar is grounded through you while you are playing it! Goodbye hum!

So now you are ready to start playing. Go find a few friends to jam with, start a band, become famous! Maybe even Gibson will offer you a contract to build guitars for them. Keep dreaming punk! Go have fun!!