When a business traveler leaves his amp on at home for a month, can Jeff save his once-glorious tone?
Last year I plugged into a Fender Vibro- King at my local used gear store and absolutely fell in love with the tone; the “fat” boost sounds playing magic with the P-90s on my Les Paul Jr. Anyway, I ended up trading three guitars and a handful of pedals for it, and walked out of that store lugging that behemoth of pure tone behind me.
For the next few months, I found that the sound of my Vibro-King inspired me to play every day. Sadly, I had to fly out of the country on business for a month, and when I returned home I realized that I had left my Vibro-King on the entire time (I knew I should have replaced that non-working jewel bulb right away). When I plugged into it, the sound fizzled and then stopped. I replaced the slow blow fuse with another and turned the amp back on. That glorious sound returned, but it was short-lived as the amp fizzled and then stopped working once again. I have tried many different types of fuses as prescribed by the Fender user manual, but the same scenario always occurs.
Can you help me? Can you me tell how I can get my beloved Vibro-King working dependably once again? I miss her so.
Thank you so much for any help you can provide.
Gregory Fischer
Hi Greg,
I’ve seen this situation before. It sounds like your amp is suffering from abandonment issues due to your extended travel abroad, and this is its attempt at payback. Oh wait … that theory was from my psych class!
Okay, I’m kidding of course. While there’s no way that I can be sure of what’s causing the fuse to blow, here are a couple of possibilities. The first—and probably only—user-repairable item I would suspect would be the output tubes. I’m going to break the following down into two steps, as it will make the explanations of multiple causes easier to define.
Step 1: Remove the output tubes (the 6L6/5881 tubes), replace the fuse and turn the power switch on. Let the amp idle in this state for as long as a typical time would be for the fuse to blow. If the fuse has not blown, move on to the next step.
Step 2: Turn the standby switch on, and again let the amp idle for a while. If the fuse has not blown in the typical amount of time then chances are that the output tubes are shorting after they’ve been on for a while. This is really not an atypical symptom of output tubes, and could easily have happened regardless of whether or not you left the amp on for all that time. Have the tubes replaced and biased and you should be back in business.
Now, if you did experience the fuse blowing at any point in the above procedure then the amp will need to be serviced by your local experienced tech, and here are the possible causes:
A fuse failure during Step 1 would more than likely point to either the mains transformer itself, or one or both of the primary capacitors (220uf 285V) in the power supply being electrically leaky, which would eventually cause an increase in current draw enough to cause the fuse to blow. In attempting to isolate one cause from the other, I would first disconnect the 220uf caps from the circuit. With the standby switch off, turn the amp on and let it idle for a reasonable amount of time. If the fuse continues to fail I would be forced to suspect the mains transformer. While the transformer in these amps is a pretty substantial unit, it is a possibility since transformers in most consumer goods such as these are manufactured for “intermittent use” and not “constant use.” I’m pretty sure that leaving the unit on for a month would fall into the latter category. If the fuse did not fail during this mains transformer test, I’d revert to suspecting the primary capacitors in the power supply. I would definitely replace both caps since the malfunction of one can place a serious overvoltage condition on the other.
If the fuse eventually failed during Step 2, I would suspect either the output transformer or any of the other six filter capacitors (22uf 500V) in the power supply. First, disconnect the primary center tap lead (red) of the output transformer from the circuit. If the fuse does not fail, this could point to an output transformer with a winding that is eventually arcing and shorting to another winding or to the case, which is at ground potential. If the fuse does still fail, we’re more than likely left with the diagnosis of failing secondary filter caps. Unless one shows distinct signs of being stressed (pressure relief vent protruding), or is physically blown (you can’t miss that one!), I would replace all of them.
Hopefully this will return the amp to being the “King of Your Tone.” If not, maybe you’ll have to sweet talk it and ask for forgiveness … and buy it a new light bulb!
… ‘Till next time.
Jeff Bober
Jeff Bober, Godfather of the low wattage amp revolution, co-founded and was the principal designer for Budda Amplification. He can be reached at pgampman@gmail.com.
Stompboxtober continues! Enter below for your chance to WIN today's featured pedal from LR Baggs: The Align Series Reverb! Come back each day during the month of October for more chances to win!
LR Baggs Align Reverb Acoustic Reverb Pedal
The Align Series Reverb was built from the ground up to complement the natural body dynamics and warmth of acoustic instruments that we love so much. The circuit seamlessly integrates the wet and dry signals with the effect in side chain so that it never overwhelms the original signal. We shaped the reverb with analog EQ to reflect the natural voice inherent in acoustic instruments. Additionally, the tone control adds versatility by sweeping from warm and muted to open and present. The result is an organic reverb that maintains the audiophile purity of the original signal with the controls set in any position.
Cort Guitars introduces the GB-Fusion Bass Series, featuring innovative design and affordable pricing.
Cort Guitars have long been synonymous with creating instruments that are innovative yet affordably priced. Cort has done it again with the GB-Fusion Bass series. The GB-Fusion builds upon Cort’s illustrious GB-Modern series and infuses it with its own distinctive style and sound.
It starts with the J-style bass design. The GB-Fusion features a solid alder body – the most balanced of all the tonewoods – providing a fantastic balance of low, mid, and high frequencies. The visually stunning Spalted maple top extends the dynamic range of the bass. A see-through pickguard allows for its spalted beauty to show through. The four-string version of the GB-Fusion is lacquered in a supreme Blue Burst stained finish to show off its natural wood grain. The five-string version features a classic Antique Brown Burst stained finish. A bolt-on Hard maple neck allows for a punchier mid-range. An Indian rosewood fretboard with white dot inlays adorns the 4-string Blue Burst version of the GB-Fusion with an overall width of 1 ½” (38mm) at the nut, while the GB-Fusion 5 Antique Brown Burst features a Birdseye Maple fretboard with black dot inlays and an overall width of 1 7/8” (47.6mm) at the nut. Both come with glow in the dark side dot position markers to help musicians see their fretboard in the dark. The headstock features Hipshot® Ultralite Tuners in classic 20:1 ratio. They are cast of zinc with aluminum string posts making them 30% lighter than regular tuners providing better balance and tuning accuracy.
Cort’s brand-new Voiced Tone VTB-ST pickups are the perfect J-style single coil with clear and robust bass sounds and classic warmth. The GB-Fusion comes with a 9-volt battery-powered active preamp to dial in the sound. With push/pull volume, blend knob, and 3-band active electronics, players can access a wide array of tones. The MetalCraft M Bridge is a solid, high-mass bridge. It provides better tone transfer and makes string changes easy. Strings can be loaded through the body or from the top giving players their choice of best string tension. The MetalCraft M4 for 4-string has a string spacing of 19mm (0.748”) while the MetalCraft M5 is 18mm (0.708”). Speaking of strings, D’Addario® EXL 165 strings complete the GB-Fusion 4. D’Addario EXL 170-5SL strings complete the GB-Fusion 5.
Cort Guitars prides itself on creating inventive instruments musicians love to play. The GB-Fusion Bass Series is the latest and greatest for musicians looking for a stellar bass guitar that is not only economical, but has the reliable robust sound needed to hold up the back end in any playing situation.
GB-Fusion 4 Street Price: $699.99
GB-Fusion 5 Street Price: $849.99
For more information, please visit cortguitars.com.
Here’s a look under the hood of the funky rhythm-guitar master’s signature 6-string.
Hello and welcome back to Mod Garage. Since we’re still celebrating the 70thbirthday of the Stratocaster, this month we will have a look under the hood of the Fender Cory Wong model to see just what’s so special about it. (I can tell you—it’s special!)
Guitarist, songwriter, and producer Cory Wong is renowned for his solo work, his band Fearless Flyers (with Mark Lettieri, Joe Dart, and Nate Smith), and collaborations with artists such as Vulfpeck, Jon Batiste, and Dave Koz. His playing style is deeply rooted in funk rhythm guitar, with a heavy dose of rock and jazz. Well-known for playing a Stratocaster, his signature model was released in 2021, and it’s a unique offering. If you want to build your personal Cory Wong Strat, here is your shopping list, starting with the primary structure:
• Alder body, scaled down to slightly smaller than a regular Stratocaster, with Fender American Ultra body contours
• Maple neck with a rosewood fretboard with rolled edges, modern Fender American Ultra D neck profile, slightly larger headstock, 25.5" scale, 10" to 14" compound radius, 22 medium jumbo frets
• Locking tuners with all short posts, a bone nut, and two roller string trees
• Vintage-style 6-screw synchronized tremolo
• Hair tie around the tremolo springs (which mutes them to enhance the rhythm tone)
• .010–.046 strings (nickel-plated steel)
“While these are all interesting features, resulting in a very comfortable guitar, you don’t need to copy every detail to transform one of your Stratocasters into a Cory Wong-style Strat.”
For the physical build, as you can see, Wong and Fender created a real signature instrument to his specs and wishes. While these are all interesting features, resulting in a very comfortable guitar, you don’t need to copy every detail to transform one of your Stratocasters into a Cory Wong-style Strat. My personal favorite of these is the hair tie for muting the tremolo springs. A lot of my funk-playing customers are doing similar things on their Strats to get a dry sound, and they’re using all kinds of funny things in there, like foam, rubber bands, and pieces of cotton, as well as hair ties.
Now, let’s have a look at the electronics:
• Seymour Duncan Cory Wong Clean Machine SSS pickup set
• Standard 5-way pickup-selector switch with classic Strat switching matrix
• 250k master volume pot with a 90/10 audio taper and Fender treble-bleed circuit PCB
• 250k tone pot with a 90/10 audio taper and Fender Greasebucket tone control PCB for only the neck pickup
• 250k audio push-push tone pot with Fender Greasebucket tone control PCB for only the bridge pickup; the push-push switch overrides the 5-way switch and defaults to middle + neck pickup (in parallel) as a preset
• Middle pickup is without tone control
Let’s break this down piece-by-piece to decode it:
Pickups
The pickup set is a custom SSS set from the Seymour Duncan company with the following specs:
• Overwound hum-canceling stacked bridge pickup with a 3-conductor wire and shield in permanent hum-canceling mode (red wire taped off), bevelled alnico 5 magnets, approximately 14.5k-ohm DCR
• Overwound middle single-coil, RWRP, beveled alnico 4 magnets, approximately 7.1k-ohm DCR
• Overwound neck single-coil, bevelled alnico 4 magnets, approx. 7.0k-ohm DCR
The pickups are voiced for clear highs, which perfectly suits Wong’s funky playing style and tone. While a lot of pickup companies will have pickups in that ballpark, it will be difficult to put together a full set that really works as intended. The Duncans in the Cory Wong Strat are available as a balanced set, so if you want to get as close as possible, I think this is your best bet.
5-Way Pickup Selector Switch
Nothing special here, just the standard 5-way switch with two switching stages that is wired like a classic Stratocaster:
bridge
bridge + middle in parallel
middle
middle + neck in parallel
neck
The upper tone pot is assigned to the neck pickup, while the lower tone pot is connected to the bridge pickup, leaving the middle pickup without tone control.
Master volume pot and treble-bleed circuit.
The 250k master volume pot is a standard CTS pot with a 90/10 audio taper found in all U.S.-made Fender guitars. The volume pot has the treble-bleed circuit from the Fender American Pro series, but uses a ready-to-solder PCB from Fender instead of individual electronic parts. The PCB is available from Fender individually (part #7711092000), but I have some thoughts about it. While using a PCB makes a lot of sense for mass production, it has some downsides for us mortal human beings:
• Soldering on PCBs requires some training and also special soldering tools.
• The PCB is quite expensive, while the individual electronic parts are only a few cents.
• The PCB uses ultra-tiny surface-mount parts, so it’s very difficult to repair or mod it to your personal taste.
I don’t think we need a PCB for adding a treble-bleed circuit, so let’s do this project using conventional electronic parts. The treble-bleed PCB contains a 1200 pF capacitor with a 150k-ohm resistor in parallel, plus another 20k-ohm resistor in series. Using individual parts, it looks like this:
Courtesy of single-coil.com
In general, a treble-bleed circuit will help you to combat the “volume vs. tone problem” when using passive single-coil pickups. When you turn down the volume (even just a bit), the high end or treble loss is not proportionate. In other words, a small cut in volume creates a far greater loss in your guitar’s treble response. Using a treble-bleed circuit is an easy way to get rid of this problem, as long as it is calculated carefully.
ONLINE ONLY: If you want to find out more about treble bleed circuits please have a look here: https://www.premierguitar.com/diy/mod-garage/treble-bleed-mod
Next month, we will continue with part two of the Cory Wong Stratocaster wiring, bringing it all together, so stay tuned!
Until then ... keep on modding!
This four-in-one effects box is a one-stop shop for Frusciante fans, but it’s also loaded with classic-rock swagger.
Great, lively preamp sounds. Combines two modulation flavors with big personalities. One-stop shop for classic-rock tones. Good value.
Big. Preamp can’t be disengaged. At some settings, flanger effect leaves a little to be desired.
$440
JFX Deluxe Modulation Ensemble
jfxpedals.com
When I think of guitarists with iconic, difficult-to-replicate guitar tones, I don’t think of John Frusciante. I always figured it was easy to get close enough to his clean tones with a Strat and any garden-variety tube amp, and in some ways, it is. (To me, anyway.) But to really nail his tone is a trickier thing.
That’s a task that Jordan Fresque—the namesake builder behind Sault Ste. Marie, Ontario’s JFX Pedals—has committed significant time and energy into tackling. His Empyrean is a five-in-one box dedicated to Frusciante’s drive and dirt tones, encompassing fuzz, boost, and preamp effects. And his four-in-one, all-analog Deluxe Modulation Ensemble reviewed here is another instant Frusciante machine.
The Frusciante Formula
Half of the pedal is based off of the Boss CE-1, the first chorus pedal created. The CE-1 is renowned as much for its modulation as for its preamp circuit, which Boss recently treated to its own pedal in the BP-1W. The other half—and the pedal’s obvious aesthetic inspiration—is the Electro-Harmonix Deluxe Electric Mistress, an analog flanger introduced in the late ’70s. Frusciante fans have clamored over the guitarist’s use of the CE-1 for decades. The Chili Peppers 6-stringer reportedly began using one in the early ’90s for his chorus and vibrato tones, and the preamp naturally warmed his Strat’s profile. Various forum heads claim John dug into the Electric Mistress on tracks like “This Is the Place” off of 2002’s By the Way. The Deluxe Modulation Ensemble aims to give you the keys to these sounds in one stomp.
JFX describes the DME as “compact,” which is a bit of a stretch. Compared to the sizes of the original pedals its based on? Sure, it’s smaller. But it’s wider and deeper than two standard-sized pedals on a board, even accounting for cabling. But quibbles around space aside, the DME is a nice-looking box that’s instantly recognizable as an Electric Mistress homage. (Though I wish it kept that pedal’s brushed-aluminum finish). The knobs for the Mistress-style as well as the authentic Boss and EHX graphics are great touches.
The flanger side features a footswitch, knobs for range, rate, and color, and a toggle to flip between normal function and EHX’s filter matrix mode, which freezes the flange effect in one spot along its sweep. The CE-1-inspired side sports two footswitches—one to engage the effect, and one to flip between chorus and vibrato—plus an intensity knob for the chorus, depth and rate knobs for the vibrato, and gain knob for the always-on preamp section. The DME can be set to high- or low-input mode by a small toggle switch, and high boosts the gain and volume significantly. A suite of three LED lights tell you what’s on and what’s not, and Fresque even added the CE-1’s red peak level LED to let you know when you’re getting into drive territory.
The effects are wired in series, but they’re independent circuits, and Fresque built an effects loop between them. The DME can run in stereo, too, if you really want to blast off.
I Like Dirt
The DME’s preamp is faithful to the original in that it requires a buffered unit before it in the chain to maintain its treble and clarity. With that need satisfied, the DME’s preamp boots into action without any engaging—it’s a literal always-on effect. To be honest, after I set it to low input and cranked it, I forgot all about Frusciante and went to town on classic-rock riffs. It souped up my Vox AC10 with groove and breadth, smoothing out tinny overtones and thickening lead lines, though higher-gain settings lost some low-end character and overall mojo.
The chorus nails the wonky Frusciante wobble on “Aquatic Moth Dance” and the watery outro on “Under the Bridge,” and the vibrato mode took me right through his chording on 2022’s “Black Summer.” On the flanger side, I had the most fun in the filter matrix mode, tweaking the color knob for slightly different metallic, clanging tones, each with lots of character.
The Verdict
If you’re a Frusciante freak, the Deluxe Modulation Ensemble will get you within spitting distance of many of his most revered tonal combinations. If you’re not, it’s still a wickedly versatile modulation multitool with a sweet preamp that’ll give your rig instant charisma. It ain’t cheap, and it ain’t small, but JFX has squeezed an impressive amount of value into this stomp