View Full Version : Blues Deluxe Mods for BIG Improvement

06-12-2011, 01:20 AM
I just joined and this is my first post...I hope it's useful to other Blues Deluxe fans.

I'm a long-time acoustic and acoustic-electric player and I also build and service tube audio gear, so admittedly I'm coming from a hi-fi place....

Over the years I've owned and quickly traded several electric axes, then last year I got a killer deal on a new Fender Blues Deluxe Re-Issue and an Epiphone Sheraton II. There was no comparison to the wooden planks and transistor amps I had tried in the past and I'm now plugged in for good.

Since I professionally modify audio electronics I didn't waste much time getting inside the Fender. I was struck by a couple of things related to quality control that were easily repaired. I also corresponded with John Fromel and purchased his mod kit, which replaces the linear-taper master volume pot with a correct audio taper pot, improves the tone circuitry, replaces the input jacks with off-PCB Switchcrafts, replaces the resistors in each tube's grid stopper circuit with carbon comps and stiffens the power supply filtering. John also sells a re-capping kit and this amp really benefits from better capacitors, but rather than using his caps I chose some pricier audio caps for the low-voltage radial electrolytics; he uses Nichicons, which are decent, but I went with Elna Cerafines, which are outstanding (though I can't say if they sound better for this application, I used 'em because they were on hand). For the high voltage axial electrolytics I used German F&T's, the same ones as John.

A few other points:

1) The Molex ribbon cables connecting the three PCBs are extremely brittle and not great conductors. Even though I was very careful during disassembly two entire cables snapped off completely--I only flexed them once or twice, and then very carefully. I'm glad they broke off entirely, actually, since one or two of the conductors could have been damaged and I wouldn't have noticed. They're a setup for problems and I replaced them with point-to-point 22awg OFC Teflon-insulated wire.

2) Shortly after buying the amp I plugged it in and heard a god-awful hum. I traced the problem to the reverb tank. I had only touched it while storing the footswitch in its Velcro cradle inside the case, near the end of the tank. The RCA connectors at the reverb coax terminations are the cheapest I've seen--low-quality thin steel with no spring tension (making them grip the female RCA's very loosely) and one of the center pins broke off as I inserted it; it's very thin metal with an inert filling. I installed Eichman bullet plug RCA jacks and have had no problems since.

3) I noticed several cold solder joints and one leaky coax connection, which I re-soldered. The transformer leads are bound by cable ties and poorly dressed, which WILL cause inductive hum. I re-dressed all the leads so each set crosses the others at right angles rather than in parallel. I replaced the two 5W 470-Ohm ceramic power resistors with 5W Mills wire-wound non-inductive resistors (these get hot and I'll probably replace them with 12W Mills'). I installed snap-on EMI filters at both ends of the AC power cable.

I have a large stash of tubes gathering dust, so I replaced the three Russian Groove Tube 12AX7C preamp tubes with matched Amperex 12AX7A's (made in Holland). These are expensive tubes and I hope they survive the rigors of guitar amplification, but they provide a much more detailed and balanced sound and tame the somewhat overly-bright top end of the stock amp.

After the Fromel mods, my own additional tweaks, re-tubing and re-wiring, the amp sounds much more balanced and is (almost) completely quiet...I previously had a ground-loop hum that came and went, and disappeared when I touched any metal part on the amp or guitar with a finger. There was a lot of background hash, especially on the drive channel. I can now crank the volume of both the clean and drive channels to maximum with the guitar plugged in and all I hear is a slight background hiss that's unnoticeable standing a few feet away. Try that with your stock amp and see what you get (part of my problem was the bad coax solder joint on the PCB and the cheap reverb RCA plugs so it might not be as significant with a different amp).

In many audio tube amp upgrades you get into a tail-wagging-the-dog situation: Significant improvements in one area reveal problems in others. I learned that guitar amps are no exception--in this case, the stock Gold Label Special Edition speaker (made by Eminence) just ain't up to the job. The lower bass notes sounded flat (as in out-of-tune flat...it was hard to distinguish one bass note from another). The mids were great but the highs struck me as rather muddy. I did some checking around with other techies and learned that the stock speaker often has a problem with a loose magnet/voice coil fit, which explains what I was hearing. After several hours of research, talking to a local pro and listening to endless YouTube sound clips I ordered an Eminence Patriot Series Cannabis Rex 12" ($90 shipped).

Being an electric axe newbie I didn't discover Weber speakers until after ordering the Cannabis, and I may end up installing a Blue Dog or Legacy 12 Weber instead. I'lm considering mounting one speaker or the other in an extension cab, giving me a wider range of tonal selection with the Blues Deluxe. From the name I thought the Cannabis was either a metal-shredder or a Grateful Dead tribute, but it's called that because the cone is made from hemp.

If it doesn't work out I can either list it on Ebay or roll it up and smoke it.

My styles are jazz and blues, which suit the Cannabis Rex well. It's a detailed, slightly bassy speaker that's more suited to acoustic-like sounds than overdrive (some use it as a keyboard speaker) but it's still at home with electric blues and jazz. The hemp cone tends to mute shrill highs. Its SPL rating is 102dB, meaning it's extremely efficient and loud.

It's a good match and it suits my particular tastes, but if you want to check out something truly cool look at Weber's new customizable Legacy 12--you specify the magnet weight (up to 80oz), cone resonance, dust cap, impedance and power rating, and they custom build you a speaker for $130. I'm horny to hear one and would like to hear from anyone who has. http://www.tedweber.com/

Installing the Fromel modification and re-cap kits is within the capability of anyone who knows how to solder, de-solder and use a DVM or continuity tester. It's very easy to break the ribbon cables connecting the three printed circuit boards so be careful (I recommend replacing them with separate wires). The traces on the circuit boards are thin and rather easily lifted when removing the old parts (I solder every day and had to repair three traces I buggered) so make sure you test for continuity with every replaced part. Just take it slow, pay attention to detail, ALWAYS remember to discharge the capacitors before you touch anything or test for voltage/continuity and Don't Panic. If for some reason you get in over your head any competent service tech can rescue you with two hours of bench time, tops.

I'm not knocking the Blues Deluxe (much), I chose it over every other amp I checked out at an area Guitar Center and other music stores, and then found it for sale at a web store in Florida where I paid $599 including shipping to Washington State (this was the same as the local price for a Blues Jr). The additional cost for parts and the speaker was about $225. I bought it already knowing that I'd be rebuilding it--I wouldn't have chosen a tube amp I couldn't easily upgrade, though I hadn't planned to replace the speaker. The amp is good off the shelf, but with the modifications I've described it comes to the level of boutique amps costing a lot more.

It's also a great match for the Sheraton II and other Gibson ES335 clones, or an actual Gibson. I bought the Sheraton after briefly owning an Epiphone Dot Deluxe, planning to upgrade it with '57 Classic Humbucker PUPS. I was surprised to find that I like the stock pickups just fine so that plan's on hold. I don't think that my playing ability will ever exceed the capability of the amp and guitar to deliver the real goods and I spent less than $1300 on the whole shebang, not bad for pro-quality sound. Both the amp and the natural-finish Sheraton have turned the heads of gigging musician friends with years of experience and four or five times as much money tied up in their gear. Playing it is more fun than I've had on the guitar in years (after 30 years on acoustics finding cheats for bar chords it's so easy that it seems to play itself...I dig having such a light touch).

That's my ten cents on the Blues Deluxe.

06-12-2011, 05:36 AM
That's my ten cents on the Blues Deluxe.
Welcome to TGP! I didn't make it past the third paragraph of your lengthy post, but I had a blues deluxe in the 90s and just replacing the crappy stock tubes and a bias adjustment did wonders for this amp.

06-13-2011, 12:04 AM
Thanks for the welcome...I'm more of a technoid than a real musician but at least I understand your screen name, I think. It's a chord progression but there's no signature or style that I recognize...you've gotta realize that I've been faking open B on acoustic for years, it's hard to grab in a hurry with four fingers so I cheat. I'm cursed with the ability to play DGDGBD in my head but my fingers won't cooperate with my brain. My Sheraton is helping me develop, things happen on a decent electric axe that don't click on classical or dreadnought guitars. Then the opposite is true as well. I recently upgraded my tired Yamaha nylon string with a Kremona Sofia, made in Bulgaria and verrry sweet, solid cedar top/African mahogany body. I paid more than I could afford but you can't touch it for twice the bucks with other makes. There are a lot of good geetars coming out of China right now, I've got a jumbo Epiphone Masterbilt AJ500RE acoustic-electric that's an upgrade from my pricier acoustic Guild. Solid spruce top, rosewood back & sides and eSonic II pups/preamp, piezo at the bridge and magnetic at the neck. I play it miked or plugged into a Roland AC90 or the Blues Deluxe and I dig it. Here's a piece of rock&roll trivia I came across: Keith Richards' lead on Jumpin' Jack Flash is an overdriven classical guitar, according to Richards himself. I don't know where you're coming from musically but as I mentioned in my post I've owned electrics before and didn't get serious until I scored the Sheraton II semi-hollow and the Blues Deluxe. I could never coax much out of wood planks, though I listen to a ton of Satriani, Roy Buchanan, Hellecasters and the like. Right now I'm working on my personal version of Third Rock From the Sun after hearing Stevie Ray's homage to Hendrix. I'm closing in on 60 and couldn't tell you what's blues, R&R, jazz, classical, Soul or even country anymore, there's only music that's good and music that sucks (and nothing in between). I wasn't at Woodstock, I was in southeast Asia at the time but I did see Jimi, the Doors, the Airplane, the Byrds and the Beatles play live in my youth.

06-13-2011, 05:30 AM
All Fender PCB amps seem to suffer from cold solder joints and piss poor flow soldering. I have an original '94 Blues Dlx, and over the years have completely resoldered the entire thing. It's a tank now, but before the complete resolder - it was a buggy mother that would hum, buzz and cut out without warning or reason.

Im surprised more jazz player dont use these amps, they are by far the 'warmest' sounding amps I've ever used.

06-13-2011, 01:30 PM
Yeah, I had problems from day one too. I contacted Fender service with a list of complaints and only got a spiel about how professional they are in component selection and construction, though they did send me a full retube set including two different pairs of matched 6L6's rather than make me ship the amp to CA. The tubes didn't fix the problems but at least I got something for my trouble.

I decided to void the warranty and work it over myself and I'm really glad I did--it's not the same amp at all but it's still, as you say, very warm and kind of organic-sounding, for want of a better word. I dig owning a Blues Deluxe that's unlike any other. I put a lot of study into the tone circuit mods and still expected it to require additional tweaking but I lucked out, the cap values I chose are spot on. As I mentioned, I come from an acoustic headspace and if not for the Blues Deluxe and Epi Sheraton I wouldn't be plugged-in at all. I was looking for something with personality and warmth, and the simple tube amp with tank reverb and this particular guitar are like a matched set, it'd be a shame to sell them separately (if I ever sell) because I think of them as a single instrument, if that makes any sense.

My Sheraton does a decent job with jazz or blues, I think it's the best of the ES-335 clones and a good platform for upgrading. I chose it over a Joe Pass Emperor II at the same price--I don't know if you've seen or played an Emperor but it's a dedicated jazz machine; a Gibson-style hollow body about 4" deep (you can play it unplugged) with dual humbuckers and a trapeze tailpiece. Nice, but I've already got five acoustic and acoustic-electric steel and nylon-string guitars and the whole idea was to apply what I've learned to a new type of instrument. I'm finding it fun, relaxing and so much easier on my aging hands that it's irritating going back to acoustic...I always thought bar chords were SUPPOSED to hurt and now I know they don't have to.

When I've settled into electric some more and found my style I'll probably sink some bucks into new pickups. As of now I just don't know much about electric guitars, how to achieve a particular sound or even what I want that sound to be. I've owned and upgraded a couple of Strat and Tele clones over the years but this is a whole different level.

I've been looking at Stewart-Macdonald's Golden Age pups, there's a wide selection and all are said to all be pro quality (though I've never heard them and don't know anyone who uses them). Gibson '57 PAF humbuckers are the standard upgrade but just like the amp, I want my guitar to sound a little bit different than anyone else's...I do all my own electronic and luthier work, for better or worse it gives me a sense of ownership in my sound and technique.

Sorry to drone on for so long...it still feels like winter here in western WA, I'm a little stir crazy and my new dog doesn't like electric guitar or drums at all.

What guitars/pups do you play?

06-13-2011, 09:07 PM
Taz, thanks for the detailed post. I have ann HRDx, and many of the same fixes apply. You didn't mention a simple one, where you add a jumper to the Mid control to allow the tone stack to be zeroed and get zero output. This allows more tonal range. Also, you should check the bias, if you didn't already.

06-13-2011, 09:11 PM
+1 on bias -- my HRDlx was COLD. retubed and rebiased it in 5 minutes and it made a huge difference

plus I got jim at omega to mod it

06-14-2011, 08:24 AM
Good points xtlan, I forgot to mention them. That mid jumper goes across pins 2 & 3 of the mid pot, you can use a cut-off resistor lead and solder it across the holes at the bottom of the pot just above the PCB. Even if you've got your original 6L6's chances are that the bias has wandered some, and is further affected by the mods (which included replacing the metal film resistors at the grid filters with carbon comps--this affects the cathode bias). My home line voltage tends to stay at around 121V, higher than the 117V design standard used by most manufacturers, resulting in higher voltages at all the power transformer outputs. If you're a gigging musician you might want to use a Variac and DVM and set the bias with the power input at around 118V. I use a line conditioning power filter (Furman PL-8C) for the amp and my stack which maintains a constant 120V regardless of what's coming out of the outlet, so I can set and forget. I recommend using a good line-conditioner and soft power-up with all high-gain tube amps, it corrects any ground faults, gives quieter operation and is much kinder to your tube filaments. They're not cheap ($150+) but you'll thank yourself later.

06-14-2011, 08:32 AM
2 BIG improvements to my Blues Deluxe

NOS Tung Sol 5881s
Weber C12B