You are here

Strymon Dig

Dual-channel Digital Delay
Published January 2016
By Jack Ruston

Strymon Dig

Not all digital delay pedals strike the right balance between convenience and quality. How does this one fare?

A few years ago, searching for a nice delay effect, I’d borrowed several pedals from my local guitar dealer. All the usual suspects were present for my studio tests but almost all suffered from one or more of these problems: the dry sound of the guitar seemed ‘pingy’ and ‘plastic’; the delay sounds just weren’t very appealing; or the pedal broke during testing. The single exception sounded great... but it was an analogue pedal and functionally too limiting for my requirements! While returning my pile of pedals to the shop, though, I was invited to try a new arrival, the Strymon El Capistan, and I’ve never looked back. It has a permanent place in my box of tricks and it seems to find its way onto every project! I’ve tried a few Strymon pedals since then and the standard has been universally high so, when invited, how could I not agree to have a look at the their latest delay?

Can You Dig It?

The Dig is a dual-channel digital delay pedal that’s capable of modelling the unmistakable character of 1980s rack-mounted digital delay units. It features 24-bit 96kHz A-D and D-A converters, and 32-bit floating point processing via SHARC DSP chips. Interestingly, though, the Dig also features modes for 12-bit PCM audio and ‘Adaptive Delta Modulation’ (ADM), of which more later. The all-analogue dry path introduces no latency, and there’s a choice of analogue buffered (trails mode) or true bypass. The two delay lines can either interact with each other or operate independently. Delay times range from 20 milliseconds to 1.6 seconds (or 40ms to 3.2s, courtesy of the half-note delay setting). The maximum input level of +8dBu means the unit will happily accept line as well as instrument signals.

The Dig, which is housed in a pale pink, brushed-aluminium casing, is one of Strymon’s smaller pedals. It features five knobs, two mini switches and two clickless foot-switches. Strymon get around the issue of space with the same sort of dual-function control system as on other pedals in the range — holding down the two foot-switches simultaneously changes the function of each of the knobs.

The audio inputs and outputs are via quarter-inch jack sockets. A TRS input socket accepts instrument level (TS), unbalanced line level (TS — but you can certainly use a balanced TRS connection if it’s convenient), or, via a jumper change, a stereo signal combined to a single TRS jack. There are also left and right outputs on TS sockets (again these work fine with TRS jacks connected straight to an interface), and there’s a TRS expression pedal input, allowing control over any knob. This can also accept an external tap-tempo foot-switch, as well as Strymon’s own Tap/Favorite switch (a separate product).

Controls

The effect is activated using the right-hand foot-switc —, which is slightly counter-intuitively labelled Bypass, because the accompanying LED lights up when the pedal is on. The left foot-switch controls a tap-tempo function but can also be held down to engage ‘circular repeats’. The three-position Type switch selects between the pristine 24-bit 96kHz digital delay, ‘ADM’ and 12-bit settings. The Mod switch engages the modulation effect, again with three positions (Off, Light and Deep).

The delay settings are mostly set using the aforementioned five knobs. The Time control allows manual, continuous setting of the delay time for Delay 1. Repeats governs Delay 1’s feedback, as you’d expect, while Mix determines its wet/dry blend, or output level when in wet mode. Time 2 acts like a switch in its primary function, setting the time for Delay 2 in the form of a rhythmic subdivision of Delay 1 — you can choose between triplet, eighth, ‘golden ratio’, dotted eighth or dotted quarter. Mix 2 controls the wet/dry blend for Delay 2, or again, output level when in wet mode.

Things start to get more interesting when the secondary functions for these five knobs are brought into play, by holding down both foot-switches simultaneously. Time becomes a Delay 1 subdivision of the tap tempo value (set by tapping the left foot-switch). This works in the form of a three-way switch. Moving the control to anywhere in the left third of its travel sets dotted eighths, the middle third (anywhere from about 10:30 to 1:30) gives you quarter notes, and the right third, half notes. Time 2 is now a two-way switch: anything to the left represents ‘Sync Mode’, enabling time sync and subdivisions between the two delays, while anything to the right selects ‘Free Mode’, turning Time 2 (primary) into a manual, continuous time control for Delay 2 — in this way you can have the two delays either correlated to each other, or completely independent. The secondary function for Repeats is the feedback control for Delay 2. If you turn this fully clockwise in secondary function mode, you link the feedback for the two delay lines, which will then both be affected by the primary Repeats control. The Mix knob doubles up as a Filter control, progressively darker on the left–hand side of its travel, flat at 12 o’clock, and brighter as you move around to the right. Finally, Mix 2 becomes another three-way switch, called Config. This selects between Series mode on the left, Ping Pong in the middle, and Parallel on the right. In Series mode Delay 1 feeds into Delay 2, and both are centre-panned (but the overall result can be spread in stereo with the Mod functions). In Ping Pong, both delays alternate repeats between each side of the stereo output, and in Parallel, Delay 1 goes to the left, and Delay 2 to the right.

Digital Warmth?

The 24-bit 96kHz mode is obviously designed to be modern, quiet and pristine. It provides a clean, high-resolution, high-bandwidth delay with a hint of dynamics that allow the delay to sit nicely with the analogue dry signal. The repeats are uncoloured and artifact-free. The other two, ADM and 12-bit, are intended to recreate the character of early digital rackmounted effects. Strymon have published a white paper detailing their research into this vintage technology — it’s available to view on their web site (http://sosm.ag/strymon-dig-whitepaper) and is an interesting read for audio geeks, but here’s a short summary for the less technically inclined...

As you can see from the rear panel, the Dig supports dual-channel operation, and can be used with an external expression pedal.As you can see from the rear panel, the Dig supports dual-channel operation, and can be used with an external expression pedal.The ADM mode employs a one-bit, high–sample-rate conversion technique that evolved from telecommunications voice coding. The conversion and supporting signal conditioning, limiting, and pre-emphasis/de-emphasis combine to create a percussive wide-band delay that adds more character as input dynamics increase. The 12-bit mode, as the name implies, uses the 12-bit, 32kHz PCM conversion that was made possible by the monolithic IC chips developed in the late ‘70s. Pre-emphasis/de-emphasis and compansion combine with the converters to produce a warm-sounding delay with a sense of dimension. While nobody cares about white papers when they’re listening to a record, or at a gig — all this stuff is very academic if it doesn’t sound good — this sort of technical analysis is an indication that Strymon have developed a thorough understanding of the technologies involved, so it comes as no surprise that they’ve done a fantastic job: it sounds really good. There’s something familiar, comfortable and just ‘right’ about these sounds. (I notice the same thing every time I plug in the El Capistan.) I have no idea whether this is the result of excellent technical analysis or good taste and tweaking. Perhaps it’s both. Whatever the reason, there’s a good feeling to be had when using this mode!

The ADM repeats have a slightly splatty grain as they attack, adding a punchy edge. The 12-bit sounds are darker and, again, grainy in a good way. In terms of vintage sound character, both modes sound authentic, although there’s an added bonus: the welcome absence of obvious noise.

The 24/96 delay is clean but in a beautiful way. It has none of the deliberate artifacts associated with the other two modes but, at the same time, it sounds somehow ‘organic’ and again just feels right. I suspect that this is the dynamics processing at play here, which serves to weave the delay around the dry sound in a natural, unfussy way. The modulation spreads things out, with the ‘deep’ setting capable of providing some really obvious ‘bendy’ movement when the gentle drift of the light setting isn’t enough for you. The ability to have the delays working in series or parallel vastly increases the potential — it’s something you can experiment with for hours, and keep finding new angles. It doesn’t have to be complicated: you can roll Delay 2 out and stick with a simple mono delay if you want. But, for me, this pedal is at its best with both delays running and the feedback dialled up — that’s when it begins to do things that your average delay pedal can not.

It’s not just the sound of the algorithms that makes Dig a worthy addition to your pedal board, though. Unlike with some delay pedals, the analogue dry path does exactly what you’d hope — there’s no latency, no loss of tone, no nasty, piezo-like, pingy attack of the sort which affects so many digital pedals at all price points. The Dig is ‘Made In America’ and it feels like it: the build-quality, finish, reliability and feel of the controls is exemplary. The click-less foot-switches are firm enough to press with your foot, but not difficult to press and hold down with one hand as you adjust secondary functions.

The controls may appear conventional and simple... but dig into the manual and you’ll discover that each has a  hidden secondary function.The controls may appear conventional and simple... but dig into the manual and you’ll discover that each has a hidden secondary function.The pedal worked well in my tests when fed with a balanced line-level signal, and when feeding balanced inputs on an audio interface. You have to watch the input level if you’re running +4dBu signals — I found myself backing it off a bit to create more headroom — but you can certainly use it in the studio without the help of a dedicated reamp facility. Another nice touch is the ‘wet mode’, which allows the Mix controls to become independent level knobs for each of the two delay lines, with no dry signal passed to the outputs. That’s very useful for studio work.

Downsides?

There’s an awful lot to like about this pedal, then, but are there any negatives? I also own a Strymon Mobius, which is a larger-format pedal. While I prefer the smaller form-factor of the Dig, comparing those dual-function controls with the menus of the larger models, it does present a more challenging learning curve: the secondary functions aren’t marked on the unit, which means they must be learned, and it’s not just a simple matter of what knob does what — with some controls effectively becoming switches, the different positions within those switches also need to be remembered. Of course, given the law that no front-panel markings will ever be legible in the dim light of a gig, most of us tend to learn our pedals anyway, but it’s worth noting that there are things that can’t just be ‘worked out’ without reference to the manual.

There’s another pitfall for the unwary associated with the dual-function controls. When holding both buttons down to access a secondary function, you need to be careful first that you are definitely holding both down, and second that you’re not still moving the control when you release them: the risk, should you fail to do that, is that you accidentally change the value of the primary function. Equally, some users will always find that although rotary encoders such as these can be used for multiple functions, they suffer from the problem that the position of the knob may no longer reflect the value associated with the control’s primary function. (It may look as if your feedback is set to ‘full’ but it may just be that it’s ‘linked’.) There will always be those who prefer to see at a glance where a control is set, and they may want to think hard about whether this is for them. Overall, though, I prefer this method of operation; it’s a useful way to enhance the functionality of the product while still letting a pedal be a pedal. I can’t think of a better way to implement it, while also retaining the simplicity and relative affordability. Yes, you could have rings of lights around the encoders, different colours representing each function, a dedicated switch for moving between primary and secondary control and so on. But there’d be a danger of mission creep — where would you stop? Some users would always want more visual feedback (it’d be nice if the right–hand LED could flash the Delay 2 time!), but others none. Strymon have already struck a sensible balance.

Dig For Victory

I love this pedal. It sounds fantastic, and once you invest some time in understanding it, it’s actually very easy to use. It balances flexibility and functionality, with complexity and cost, and if you’re looking to fill a Dig-sized space on your pedal board, I can recommend it without reservation.

Alternatives

There are so many delay pedals on the market that it’s difficult to make any sort of comprehensive list of alternatives. A shortlist would likely be made up of units made by Eventide, TC Electronic, Boss, Electro-Harmonix, and possibly other Strymon models, among others.

Audio Examples

I created some sound files that give just a flavour of what the Dig can do. The files are listed on the SOS web site, with a brief description of the mode and settings used. All files are 24-bit/48kHz WAV format, and are separated into a dry mono source file and a 100-percent wet stereo return, to allow you to listen more critically to the delays alone. They’re as recorded, with no normalisation or processing.

sosm.ag/jan16media

Published January 2016