Deluxe Modification

[Prometeo Archuleta]

I'm a big fan of the VOX style Cut Control because it's a great way to "trim the ice pick". Early in-the-circuit tone controls affect the substance of the overdrive tone. High freqs generate overdrive harmonics that fill in the top end. If you turn down a normal tone control to reduce ice-pick highs you'll kill all the harmonics too. A cut control allows you to trim off very high ice pick highs without removing all the high frequency overdrive harmonics. All high gain amps should have early and late tone controls for this reason. You can just leave the cut control on full high and you have a normal amp circuit.

The Vox Cut Control connects the two power tube grids with a 220k audio pot and 4.7nF (.0047uF) capacitor to allow variable high end cut. In a push-pull amp the guitar audio signals on the two power tube grids are 180 degrees out of phase with one another so mixing them together nullifies the signal, kind of like mixing matter and antimatter. The capacitor limits the effect to high frequencies but if you jumper around the cap the pot becomes a Trainwreck Type-3 Master Volume.

I like this very late tone tweak because it pairs well with an early tone control or stack. Use the early tone control to get the overdrive tone and substance you want then use the Cut Control to fine tune the tone. The Cut Control affects only the power tubes.

High volume settings or using boost, delay or reverb pedals can push the phase inverter into extreme and odd sounding 'double frequency' blocking distortion. This unpleasant distortion is the reason why the 5E3 is known as not being pedal friendly and why high gain preamp mods are not popular--any boost in preamp output can push the phase inverter into nasty distortion. By adding this resistor the 5E3's sweet preamp tube distortion won't get chopped up in the phase inverter.

I believe a better solution to the phase inverter distortion problem is to forget the grid stopper mod and simply replace the 1M grid leak resistor with a 1MA pot to create a PRE Phase Inverter Master Volume pot which will allow you to fine tune the grid stopper & grid leak resistor sizes to really control phase inverter distortion. By turning down the master volume by about 1/3 you do the same thing as adding a 470k grid stopper and 470k grid leak to the phase inverter. The nice thing about this master volume is when it's set a max the 5E3 circuit is unchanged from stock.

Turn cab upside-down and brush a light coat on the tweed, then do the sides. When brushing, make sure to keep globs/pools of lacquer away from the tweed seams. Because the seams will act like a wick, and suck in the lacquer, giving a dark blotch. Soooo, brush very carefully. If you go too thick, it will make a black/grey blotch in the tweed.

Use a larger first filter capacitor, up to 33F is ok even with a 5Y3GT rectifier tube. This will reduce hum and beef up the low end and help prevent 'farting out.' It will also reduce power supply sag and make the amp a little more punchy.

Lower all the coupling cap values from .1F (100nF) to .022 to reduce bass which will reduce the 'farty' lows and make the amp more agreeable with high output guitar pickups and effects pedals. The famous AB763 blackface circuit used .022uF for the Vibrato Channel and .047uF for the Normal Channel. You can also do this only on one channel and then run humbucker guitars on that channel. Doing this also will reduce blocking distortion.

Replace all the signal resistors (especially input, plate load, grid leak and grid stopper resistors) withmetal film resistors like the Vishay RN65 for less noise (hiss). Most 5E3 kits use period correct carbon composition resistors but metal film resistors generate 1/10th the noise of carbon comp. In reality resistor hiss is usually drowned out by filament heater hum and power supply ripple so this won't be a dramatic improvement but every little bit helps with noise suppression. If you want to be thorough then replace every resistor except these three: the higher watt rated voltage dropping resistors (between the first filter caps) and the power tube cathode resistor. R.G. Keen recommends metal film for all signal resistors except for the 5E3's 56k plate load and 56k tail resistors of the V2B phase inverter. Those two 1/2 watt carbon composition resistors would ensure "vintage" carbon comp tone without generating excess noise.

Building a 5E3 amp head? Consider a hybrid head/combo with the addition of a little 6" Eminence 620H hemp coned speaker to your head amp. The 620H is an inexpensive but great sounding speaker that punches above its weight. It requires no additional cabinet size and it adds very little weight. You'll always be able to practice with it and people freak out when a meaty tone emanates from a "speakerless head amp."

Wish your tweed amp had reverb and tremolo like the blackface amps? This is a great way to add it, with my favorite pedal of all time, the Strymon Flint. It does everything from adding a little warmth and thickness to full up 60's surf. The "Color" control is a very usable tone knob. The '61 harmonic tremolo setting is a really nice bonus that sounds very much like the very complicated harmonic tremolo circuit. Try this surf setting and you'll have a blast:

The Humdinger is an adjustable heater artificial ground. A 100 or 250 ohm, 1 watt or greater linear pot is used to adjust the resistance value between ground reference and the two heater wires to even out their voltage and minimize 60Hz heater hum. You simply adjust the pot by ear for least hum. If you don't notice a change in hum when adjusting the Humdinger then just set it in the middle of the pot travel to equalize the resistance for each heater wire. Remove your current 6.3v center tap before installing a Humdinger.

For cathode biased amps you can connect the Humdinger's ground wire to a power tube socket cathode pin (pin 8) or to the hot side of the cathode resistor (as shown in the next section) to elevate the heater reference voltage. A voltage elevated Humdinger can eliminate more heater hum than any other type of heater real or artificial center tap.

If your power transformer has a 6.3v center tap, instead of grounding it to the chassis you can elevate the heater circuit ground reference voltage by connecting the 6.3v center tap to the tube side of the power tube cathode resistor. This elevates the heater ground reference by the voltage on the cathode which is around 17 volts in the 5E3. The elevated heater ground reduces the voltage difference between the heater filaments and the tube cathodes which helps minimize 60Hz heater hum.

This is my take on the best possible layout for a standard 5E3 chassis. This is a basic 5E3 circuit, there are no modifications that will affect the tone. I have deleted the totally unnecessary Standby Switch andGround Switch/Death Cap.

The split ground bus with a separate power amp and preamp ground bus is the current standard that DIY amp builders use. That's what I show in the 5E3 layout at the top of this webpage but most electrical engineers will tell you a single point grounding scheme should be the quietest. The original 5E3 used a brass plate under the input jacks and pots that acted as the whole amp's ground bus but corrosion between the steel chassis and brass plate can cause problems in the long term.

Since the 5E3 puts out around 12 watts of power a speaker rated for 20 watts is adequate. It seems the most popular 5E3 speaker is the20 watt Weber 12A125A which is a Fender tweed vintage style 12" AlNiCo (Aluminum, Nickel and Cobalt magnet) speaker with a 1.25 inch voice coil for a very reasonable $113. It gets great reviews and gives probably the most authentic 50's Deluxe tweed tone. I installed one in an extension cab and it really does sound like a tweed Deluxe should.

If $113 is too rich for your blood check out theWeber Signature AlNiCo 12 and 12S speakers at $58. Some people actually prefer them over the 12A125A. The Signature speakers are also reported as being less efficient than the 12A125A so they won't be quite as loud. The Weber 12A150 (larger 1.5 inch voice coil) and 12A125S (1.25 inch voice coil but with slightly different voicing) are also popular for the 5E3. If you do go with Weber I recommend you have them do their free speaker break-in service for you so they will sound great right out of the box.

Other favored 5E3 speakers are the Eminence Patriot Cannabis Rex (ceramic magnet) $90 and Tone Tubby Alnicos, all with cannabis cones. TheEminence Canis Major is the AlNiCo version of the Rex but it's relatively expensive at $190. The vintage British voiced Eminence Red Fang AlNiCo is also well liked and very loud with a sensitivity of 102.5dB but expensive at $190.

I went a different route and installed a 15" JBL E130 re-coned with hemp byA. Brown Speaker Repair. It's a very accurate, efficient and loud speaker which makes it ideal for gigging. The hemp cone tames the brittleness of the standard E130 and just sounds freakin' great. The downsides are I get no speaker breakup and the amp is freakin' heavy.

Yeah, Howard Davis for sure. Perhaps also Ron from RONsound. He repairs them, but I'm not sure if he mods as well. I've sent him an email about whether he'd be willing to fix the volume drop of my Mistress - as a comparative quote to Howard.

I may be wrong but I think Howard Davis designed the Deluxe Electric Mistress only (not the non-deluxe, which is I believe what Gilmore used, modded or not). The non-deluxe electric mistress I think existed before he joined EHX, though he may have been behind the addition of the filter matrix to the mkII 18v version. Also, IMO the EM isn't that metallic at all - certainly not like a Boss BF-2. It sounds great but for the huge volume drop after a dirt pedal. Doesn't sound anywhere near as good if placed before one, where the volume drop isn;t really that noticeable.

c80f0f1006