Fender Hot Rod Deluxe and Deluxe III Basics

1-23-13-The Fender HRD Basic Mods

In my previous post, I stated that I'd give you the "Basic" mods I've done, that don't include any circuitry modifications.

1) Change the Speaker: A lot of the amp's "Tone" is a result of the speaker. So, you can change the overall tone by changing the speaker. You can get books on preferred 12" guitar speakers for various amps. My personal preference is the Celestion Vintage 30, a 60 Watt, 8 ohm, 12” speaker. My playing style is geared towards Classic Rock, and I've found I like this speaker best. As with many Mods or changes, subjective personal preference will rule. You may have to do some web searching & reading to find the speaker you think is right for you, and you’re playing style. I know other guys that prefer the Celestion G12T-75 speaker.

NOTE: Changing the speaker requires removing the amplifier chassis from the cabinet. Not for the faint of heart. You have to loosen the six screws holding the chassis in place about 1/4", and then insert the spreader tool. I created a tool that spreads the chassis apart about 1/8", to help the chassis lift out without tearing up the grounding foil around the inside of the cabinet. Once the cabinet is spread with the tool, carefully remove the six screws, starting with the lowest on the sides, and holding onto the chassis carefully so that it doesn't drop into the cabinet on the speaker. The speaker magnets can attract that chassis, so hold on tight, and keep it as far away from the speaker as possible as you lift it out of the cabinet. It will be awkward because of the uneven weight of the transformers mounted on the chassis.

2) Change the speaker Cable: Most all amps and speaker cabinets come prewired with 18 gauge wire. This is great for a table lamp, but if you want to get ALL of the low frequency transferred from the amplifiers output to the speaker itself, you want to use 16, 14, or even 12 gauge cable. I bought a box of crimp on 12 gauge spade connectors, and a spool of 12 gauge, oxygen-free cable, and I make new speaker cables for almost any amp, or speaker cabinet I buy. I also have heavy-duty ¼” jacks that I use on the amplifier end of the cable. In my case, I made the cable long enough, so that if I ever want to use just the speaker in my Fender HRD, I can unplug it from the amp in the back of the cabinet, extend the cable to another amp beside, on top, or below my cabinet. (~3-4 feet).

3) Different Tubes: You can change your tone with different tubes. I like the JJ/Tesla 6L6 power tubes (V4 & V5), biased to ~67mA. (65 – 70MA).

-V1 is the first preamp tube, and will have the most effect on tone.

-V2, middle small tube. I installed a good JJ 12DW7 - this tube is a 12AX7 on one side and a 12AU7 on the other side. The 12AU7 side is the side of the tube that handles the Drive/More Drive sections. The Drive/More Drive channels are definitely more pleasing and usable over the stock amp. That tube helps tame some of the horrible gain increase when switching from the Clean channel to Drive/More Drive, also.

-V3 is the Phase Inverter (PI), to the 6L6 output tubes.

My Tubes:

I am currently using the following tubes, and I’m happy with the tone & the overall performance of the amp for gigging. I hand-picked each of the three small tubes, and this was the combination that worked best for me:

-V1 = Groove Tube 12AX7; -V2 = JJ  12DW7; -V3 = Mullard  12AX7A; -V4 & V5 = JJ  6L6.

4) Redress Wire Harness: You’ll also notice in the pic below, that I redressed the wire harness from the power transformer and the output transformer. This is something pretty standard that all of the custom mod shops do when you send your amp in for custom mod upgrades.

Wire Harness as Shipped from Factory