All 9V blocks are not created equal. Here's what to look for to avoid hiss, hum, and crackle.
(Originally published April 22, 2020)
At the dawn of the guitar-effects age, powering pedals was relatively simple. If an effects pedal didn't take a standard 9V battery like your AM transistor radio, it plugged into the wall like your avocado-green toaster. Forever dissatisfied, guitar players eventually grew weary of changing batteries, and plugging stuff into the wall was kind of a drag, too.
As the industry was looking to eliminate its batteries and Edison plugs, the effects purveyor Boss went a long way to standardizing pedal power by putting a 2.1 mm coaxial power jack on all their pedals, and while their market dominance made the 1/8" jack on certain Ibanez and Pro Co pedals outliers, even they couldn't stick to one standard for long as they transitioned from 12V ACA spec pedals to 9V PSA spec pedals.
Once that growing pain subsided, it was relatively peaceful on the pedal-powering front for many years, and the standardization allowed companies to produce power supplies that let players power all their pedals simultaneously and without harming a single battery. Some supplies had a single output with daisy chains to fan out power to multiple pedals. Some were isolated, offering an individual power port for each pedal and eliminating daisy-chaining all pedals in a parallel fashion. Isolated supplies were a huge development in pedal-powering history, so let's dig in there before wading further into the power morass of today.
In this context, isolated power supplies are those supplies that are essentially a series of separate power sources in one enclosure. Each supply stands on its own with no direct connection to any of the other supplies, and, as such, the effects they power have no direct connection to one another through their respective power ports.
There are several reasons power supply isolation can be anything from favorable to crucial. First, some pedals have a positive-ground scheme, where the audio ground of the effect is connected to the positive terminal of the battery, usually due to the type of transistors used in the pedal's circuit.
Isolated power supplies are those supplies that are essentially a series of separate power sources in one enclosure.
While fuzz pedals are often set up this way, most pedals have a more conventional negative-ground scheme. If you parallel connect the power of a positive-ground pedal to a negative-ground pedal, and then connect their audio grounds together with a patch cable, you'll cause a power supply short, and neither pedal will get power. The power source will complain, too! Isolated supplies mimic a battery as each device gets its very own power source to use independently of any other device.
Crosstalk is another reason for isolation. Some pedals don't play well with others when powered in parallel. Like so many playground bullies, tremolos and vibratos can tick and pop while overdrives and DSP effects with switch-mode supplies and high-speed processors can whine, and they can torment their boardmates with their glitches. These deficiencies might not bother the offending pedal, but the trash they put on their power supply ports gets leaked to other connected devices that may not be able to reject the noise quite as well. Isolation breaks the link and prevents such crosstalk.
The last reason for isolation we'll list here is ground loops. In general, for guitar rigs, it's best practice to have just one ground path. Typically, that one path should be the ground connections of all of your patch cables extending in a line from guitar's output to amp's input. Daisy-chaining power creates other ground paths that make closed loops from one section of your signal flow to another. These ground loops can make your rig more susceptible to hum pickup in the presence of electro-magnetic fields. If you have daisy-chained pedals both in front of an amp and in its FX loop, and dozens of feet of cable between them, the associated ground loops can become very large and produce a great deal of noise. Using an isolated supply disconnects the links that make the loop, and the induced hum can no longer be sustained.
With isolation addressed, power supplies remained relatively unchanged for many years. Then, digital-signal processing became cost-feasible for common use in guitar-pedal effects. We'll dig further into their high-current demands and how they've complicated the power supply marketplace in my next column.
The PG Koll High-Rise review.
RatingsPros:Great touch dynamics and responsiveness. Great capacity for note detail. Growling, not overbearing, midrange presence. Cons: Fans of “transparent” boost may not favor the slight mid-bump. Street: $225 Koll High-Rise kollguitars.com
| Tones:  Ease of Use:  Build/Design: Value:  |
As a guitar builder, Saul Koll deftly walks a line between original and familiar. With his first stompbox, the High-Rise boost and overdrive, Koll strikes a balance between sonic surprises and functional accessibility. And though it’s simple on the surface, superb dynamic sensitivity and a wide range of tone colors make the High-Rise very versatile for a two-knob drive.
The High-Rise’s flexibility derives, in part, from how well the boost (steel) and drive (concrete) sections of the circuit work independently of each other. But they also interact to create many extra tone variations.
The clean-to-nasty range is occasionally reminiscent of a Klon—though the High-Rise has a touch more character and mid-range presence, and feels slightly more feral at high-gain settings. The slight mid-bump is typically most pronounced with single-coils in clean boost settings. But at higher gain settings, the extra mids translate to crackling explosiveness and great touch dynamics.
The pedal’s sensitivity to guitar volume and tone attenuation add more possibilities: You can essentially re-create unfettered guitar/amp tones—but with a touch of extra high-mid octane—by reducing guitar volume. Simple it might be, but the High-Rise is practical and thrilling, and for players that value economy and streamlined control of dynamics, it’s possibly the only gain solution they’ll need.
Test Gear:Fender Telecaster, Fender Telecaster Deluxe with Curtis Novak Wide Range pickups, Fender Vibrolux, Fender VibroChamp
The PG Jam Pedals Delay Llama Xtreme review.
RatingsPros:A powerful, versatile, and very-well-conceived delay pedal that spans great sounding traditional analog echoes and stunning weirder fare. Cons: A little noise with some common wall-wart style power adaptors. Street: $339 Jam Pedals Delay Llama Xtreme jampedals.com
| Tones: Ease of Use: Build/Design: Value: |
In simpler times, delay pedals lived in a world split by the analog-digital divide. On one side, there was the warm, dark, vintage-y flavor of analog. On the other, the clean, sometimes complex, multi-functional potential of digital. These days, however, digital control blurs the delineations between these worlds, and pedals like the Delay Llama Xtreme, reviewed here, make the most of the reduced barriers between sweet analog tone and digital’s capacity for effect manipulation.
Extrapolating from the delectably rich analog foundation of the original Delay Llama, the Delay Llama Xtreme adds a boatload of functionality—including tap tempo with three subdivisions, and effects including vibrato, tape age, random delay times, and pitch shift (which even delivers a 5-mode sequencer). There’s also an increase in maximum delay capability from 600 ms to 800 ms, user-created presets, a hold-oscillation function, and more.
Triple Trio
The analog heart beating inside the Xtreme’s 5.8" x 4.8" x 1.5" enclosure is made up of three 3205 BBD chips. And the core of the Delay Llama Xtreme’s functions remains the three conventional and familiar knobs the original Delay Llama uses for delay time, repeats, and level. But below these controls lurks a trio of mini-toggle switches. “TRLS” (or “trails”) retains the delay trails when the pedal is switched off and activates buffered bypass. You can switch to true bypass in the lower position, which, of course, also lops off delay trails when the pedal is disengaged. “KD”or “kill dry” mutes the dry signal as it passes through the circuit, delivering processed signal exclusively only at the pedal’s output. The tap-divisions switch creates quarter-note, eighth-note, and dotted-eighth divisions of your tap-tempo selection.
The three non-latching footswitches along the bottom of the pedal serve varied roles. The leftmost is a simple bypass. The center switch enables selection of the presets. It also enables selections from the four extreme modes—vibrato, tape-age, random, and pitch-shift—when used with the “alt” push-button just to the right of the footswitch. The rightmost footswitch is for controlling the tap tempo, but also engages the self-oscillation function when you press and hold.
An abundance of connectivity options further underscores the versatility of the Delay Llama Xtreme. Standard in and out jacks allow mono connection only. But while the lack of stereo output will be limiting to a small percentage of players, the three additional side-panel jacks enable expression pedal control of delay time, remote preset selection, and remote tap tempo, which open up many other expressive possibilities. Internal trimmers, meanwhile, enable alterations to the maximum repeats and the maximum decay of trails.
Repeat Performance
Given the plethora of functions available, it would be near impossible to explore every possibility in a review of this length. (Thankfully, the excellent owner’s manual is thorough and concise.) But by pairing the Delay Llama with a selection of guitars and amps well as a Fractal Axe-FX III, I discovered a genuinely thrilling and inspiring bonanza of sound-sculpting possibilities, not to mention scads of downright tasty traditional echoes for the player who wants to keep it simple.
The pedal’s traditional echo sounds are superb—warm with just a little grit that is a fantastic match for the wobbly “tape age” setting. The added delay time is a striking reminder of how long eight-tenths of a second can feel, too. The repeats knob ushers in self-oscillation pretty fast. You can consider the first half of its range a standard repeats control, but the second 50 percent of its range is primed for exploring the wild textures of oscillating echo. Things really get interesting when you explore the xtreme settings in depth, however.
For my tastes, the xtreme settings are most useful when providing lush enhancement to traditional echoes. This approach is best exemplified by the sounds of the tape-age setting, which adds random pitch fluctuations to the repeats and can be set from subtle to extreme. A touch of vibrato also works beautifully to dress up otherwise traditional delay settings when you want a more predictable touch of wavy atmosphere. The award for most fun, however, might have to go to the random setting, which will rarely be deemed practical for Sun Studios slapback sounds, but should delight sound sculptors that like to build towers of chaotic texture from irregular repeats. The award for “most likely to rob you of hours of hypnotically blissful noodling,” however, goes to the pitch-shift function. It can mimic synthesizer sequencer sounds in many modes. But it can also be dialed in for five distinct, specific pitch-shift intervals including a fifth up//fourth down, a second up/second down, and a ninth up/seventh down. It’s both trippy fun and an extremely creative composition tool.
The Verdict
The Delay Llama Xtreme admirably extends the capabilities of the simpler original Delay Llama. But it’s capable of much more adventurous tones and is bound to impress any fan of delay’s outer limits. Altogether, it’s a bountiful bundle of conventional delay delights as well as a texturalist’s dream come true.
Watch the Review Demo: