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The Circuit
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In layman’s terms, a discrete opamp is similar to the IC chip version. It does the same thing, just in a simpler fashion that some feel is more responsive and less “sterile” feeling and sounding. It uses two FETs facing each other followed by a bipolar transistor. There are two of these types of gain stages in the BD-2, controlled by a dual gang 250k pot wired as a variable resistor. Just like the IC opamp circuits, there is a resistor/capacitor pair going to ground that will also help set a frequency to clip. This pair will also help set the gain, though they are fixed values in the BD-2. R31 and C22 are the pair for the first stage, while R15 and C9 are the pair for the second stage.
We know that EQ before clipping determines the clipping feel, tonality, and response (distortion/overdrive) quite dramatically. For example, if we want a fuzzier type of distortion, we want to increase the bass before it is clipped. Then, we clip the signal as much as possible without creating a lot of noise or oscillations.
R31 and C22 in this first gain stage set a frequency of just a hair over 700hz. This is a normal frequency for most overdrives and distortion. If you want more fuzziness, increase this cap to .22uf (microfarad) or larger. If you want a tighter crunchier type of tone, make the cap smaller. If you plug in these values to my calculator at indyguitarist. com/filter.htm you will see the frequencies you can affect.
 BD-2 tonestack (left) and Traditional Fender tonestack (right) |
After this first gain stage, we go through what first looks like an odd tone filtering stage. It is actually a Fender-type 3-band tonestack with fixed values (with the treble on 0 and the bass and mid on 10). This is a really cool thing to mess with if you want to go hog wild, because you can add trim pots in place of R37 (use a 250k trim pot for treble), R50 (use a 1M trim pot for bass), and R51 (use a 25k trim pot for mids). In addition, you can change the ‘slope’ resistor, R36, to a 33k, C34 and C35 to a .022uf, and change C26 to a 470pf in order to get more of a Marshall type of tonality before the signal is clipped. When you are replacing these resistors with trim pots, just connect one hole to pin 1 on the trim pot, and the remaining resistor hole to pin 2 on the trim pot. Leave the third lug untouched.
The BD-2 EQ before clipping looks like this due to this filter:
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Notice how there is a ton of bass present? That is before the majority of the clipping is happening, so it’s no wonder the pedal sounds fuzzy when the gain is turned up!
A good mod at this location is to make R50 a 100 ohm, and change R36 to a 47k. That will give you a much flatter EQ response.
After that the signal is clipped by diodes connecting to ground (D7, D8, D9, D10) with two diodes on each side and fed into another discrete opamp. This opamp is nearly identical, except the frequency response is a little different. There is more gain in the bass (set by R34 and C24, frequency is about 72hz) but it works exactly the same. Notice that since the bass is boosted yet again here it’s really no surprise that the BD-2 would be so fuzzy with the gain turned up.
C17, R25, and C19 form both a highpass and low-pass filter, which will get rid of some high harmonics about 5k or so, as well as to get rid of some of the bass content that was created by boosting the lows so much previously.
From here, the signal goes through a fairly standard tone control very similar to that of an old Fender tweed Princeton. It acts as a high-pass filter with the tone knob turned up, and a low-pass filter with the tone knob turned down. So, you increase the highs as you turn up the tone, and lose some bottom end once you are past about halfway or so. Changing C100 will change what high frequencies are filtered with the tone control up, and changing C101 will change what frequencies are filtered with the tone control turned down. The volume control is next before going into the next stage—the EQ stage.
The next stage is a simulated inductor, which is boosting the bass content at about 120hz or so by 6dB. Even though there are diodes in this stage (D1 and D3), they aren’t really clipping much at all like diodes usually do in an overdrive or distortion circuit—it is actually more to protect this opamp from being slammed with a loud and hard signal. It also does a little bit of filtering as well as help to output a low impedance signal. Changing these diodes to a different type will give a little bit different “feel.” However, it becomes a little less compressed if you use LEDs, and becomes a bit more compressed and filters out a bit of the highs if you use germanium type diodes. This is probably due to varying degrees of harmonics being ever so slightly clipped.
If you want to mess with the EQ, there are several ways to do it. You can try changing the cap sizes of C9 and C16, or changing R21. Changing the caps can get you many more frequency options just by subbing in various values. Increasing the resistance lowers the frequency and decreasing it raises the frequency to a point. You might even try subbing a 5k trim pot here just for fun!
From here it goes into the switching circuit and then to an output buffer. Even when it’s in bypass the pedal is going through three discrete buffers.
A lot of folks just want to know, “What do I change to make it sound better?” In that case, I’d recommend several different options. The Blues Driver mod that I probably do most often is the Brent Mason modification. This mod is very easy, and only requires changing a few parts. It was a modification that I did in response to Brent Mason’s request for better tone from his blues driver. It will give you a meatier, more “round” sound and excels at low to mid gain:
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Another popular mod is the “Tweed” mod—designed to give you a bit more of the “woolly” tones from an old Fender amp.
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All of these parts can be found at my favorite parts supplier, Small Bear: smallbearelec.com.
All in all, this is a great palette to work from for great tones. Let me know what you think—you can find my contact information at: wamplerpedals.com
Brian Wampler is an author, effects designer/builder, and operates IndyGuitarist Custom Effects: indyguitarist. com and wamplerpedals.com. His books include How to Build Effect Pedals, How to Modify Effect Pedals, and Advanced DIY Effect Pedals, and are available at indyguitarist.com.
Gibson originally launched the EB-6 model with the intention of serving consumers looking for a “tic-tac” bass sound.
The Gibson EB-6 was announced in 1959 and came into the world in 1960, not with a dual-horn body but with that of an elegant ES-335. They looked stately, with a thin, semi-hollow body, f-holes, and a sunburst finish. Our pick for this Vintage Vault column is one such first-year model, in about as original condition as you’re able to find today. “Why?” you may be asking. Well, read on....
When the EB-6 was introduced, the Bass VI was still a glimmer in Leo Fender’s eye. The real competition were the Danelectro 6-string basses that seemed to have popped up out of nowhere and were suddenly being used on lots of hit records by the likes of Elvis, Patsy Cline, and other household names. Danos like the UB-2 (introduced in ’56), the Longhorn 4623 (’58), and the Shorthorn 3612 (’58) were the earliest attempts any company made at a 6-string bass in this style: not quite a standard electric bass, not quite a guitar, nor, for that matter, quite like a baritone guitar.
The only change this vintage EB-6 features is a replacement set of Kluson tuners.
Photo by Ken Lapworth
Gibson, Fender, and others during this era would in fact call these basses “baritone guitars,” to add to our confusion today. But these vintage “baritones” were all tuned one octave below a standard guitar, with scale lengths around 30", while most modern baritones are tuned B-to-B or A-to-A and have scale lengths between 26" and 30".)
At the time, those Danelectros were instrumental to what was called the “tic-tac” bass sound of Nashville records produced by Chet Atkins, or the “click-bass” tones made out west by producer Lee Hazlewood. Gibson wanted something for this market, and the EB-6 was born.
“When the EB-6 was introduced, the Bass VI was still a glimmer in Leo Fender’s eye.”
The 30.5" scale 1960 EB-6 has a single humbucking pickup, a volume knob, a tone knob, and a small, push-button “Tone Selector Switch” that engages a treble circuit for an instant tic-tac sound. (Without engaging that switch, you get a bass-heavy tone so deep that cowboy chords will sound like a muddy mess.)
The EB-6, for better or for worse, did not unseat the Danelectros, and a November 1959 price list from Gibson hints at why: The EB-6 retailed for $340, compared to Dano price tags that ranged from $85 to $150. Only a few dozen EB-6 basses were shipped in 1960, and only 67 total are known to have been built before Gibson changed the shape to the SG style in 1962.
Most players who come across an EB-6 today think it was a response to the Fender Bass VI, but the former actually beat the latter to the market by a full year.
Photo by Ken Lapworth
It’s sad that so few were built. Sure, it was a high-end model made to achieve the novelty tic-tac sound of cheaper instruments, but in its full-voiced glory, the EB-6 has a huge potential of tones. It would sound great in our contemporary guitar era where more players are exploring baritone ranges, and where so many people got back into the Bass VI after seeing the Beatles play one in the 2021 documentary, Get Back.
It’s sadder, still, how many original-era EB-6s have been parted out in the decades since. Remember earlier when I wrote that our Vintage Vaultpick was about as original as you could find? That’s because the model’s single humbucker is a PAF, its Kluson tuners are double-line, and its knobs are identical to those on Les Paul ’Bursts. So as people repaired broken ’Bursts, converted other LPs to ’Bursts, or otherwise sought to give other Gibsons a “Golden Era” sound and look ... they often stripped these forgotten EB-6 basses for parts.
This original EB-6 is up for sale now from Reverb seller Emerald City Guitars for a $16,950 asking price at the time of writing. The only thing that isn’t original about it is a replacement set of Kluson tuners, not because its originals were stolen but just to help preserve them. (They will be included in the case.)
With so few surviving 335-style EB-6 basses, Reverb doesn’t have a ton of sales data to compare prices to. Ten years ago, a lucky buyer found a nearly original 1960 EB-6 for about $7,000. But Emerald City’s $16,950 asking price is closer to more recent examples and asking prices.
Sources: Prices on Gibson Instruments, November 1, 1959, Tony Bacon’s “Danelectro’s UB-2 and the Early Days of 6-String Basses” Reverb News article, Gruhn’s Guide to Vintage Guitars, Tom Wheeler’s American Guitars: An Illustrated History, Reverb listings and Price Guide sales data.
Originally released in the 1980s, the Victory has long been a cult favorite among guitarists for its distinctive double cutaway design and excellent upper-fret access. These new models feature flexible electronics, enhanced body contours, improved weight and balance, and an Explorer headstock shape.
A Cult Classic Made Modern
The new Victory features refined body contours, improved weight and balance, and an updated headstock shape based on the popular Gibson Explorer.
Effortless Playing
With a fast-playing SlimTaper neck profile and ebony fretboard with a compound radius, the Victory delivers low action without fret buzz everywhere on the fretboard.
Flexible Electronics
The two 80s Tribute humbucker pickups are wired to push/pull master volume and tone controls for coil splitting and inner/outer coil selection when the coils are split.
For more information, please visit gibson.com.
Gibson Victory Figured Top Electric Guitar - Iguana Burst
Released in 1983, the Roland SDE-3000 rackmount delay was a staple for pro players of the era and remains revered for its rich analog/digital hybrid sound and distinctive modulation. BOSS reimagined this retro classic in 2023 with the acclaimed SDE-3000D and SDE-3000EVH, two wide-format pedals with stereo sound, advanced features, and expanded connectivity. The SDE-3 brings the authentic SDE-3000 vibe to a streamlined BOSS compact, enhanced with innovative creative tools for every musical style. The SDE-3 delivers evocative delay sounds that drip with warmth and musicality. The efficient panel provides the primary controls of its vintage benchmark—including delay time, feedback, and independent rate and depth knobs for the modulation—plus additional knobs for expanded sonic potential.
A wide range of tones are available, from basic mono delays and ’80s-style mod/delay combos to moody textures for ambient, chill, and lo-fi music. Along with reproducing the SDE-3000's original mono sound, the SDE-3 includes a powerful Offset knob to create interesting tones with two simultaneous delays. With one simple control, the user can instantly add a second delay to the primary delay. This provides a wealth of mono and stereo colors not available with other delay pedals, including unique doubled sounds and timed dual delays with tap tempo control. The versatile SDE-3 provides output configurations to suit any stage or studio scenario.
Two stereo modes include discrete left/right delays and a panning option for ultra-wide sounds that move across the stereo field. Dry and effect-only signals can be sent to two amps for wet/dry setups, and the direct sound can be muted for studio mixing and parallel effect rigs. The SDE-3 offers numerous control options to enhance live and studio performances. Tap tempo mode is available with a press and hold of the pedal switch, while the TRS MIDI input can be used to sync the delay time with clock signals from DAWs, pedals, and drum machines. Optional external footswitches provide on-demand access to tap tempo and a hold function for on-the-fly looping. Alternately, an expression pedal can be used to control the Level, Feedback, and Time knobs for delay mix adjustment, wild pitch effects, and dramatic self-oscillation.
The new BOSS SDE-3 Dual Delay Pedal will be available for purchase at authorized U.S. BOSS retailers in October for $219.99. To learn more, visit www.boss.info.