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 2x12 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