Effects 101: Analog(ue) Delay - What's what and what matters?

If any of your buddies wear flannel and smoke American Spirits, you’re well aware that analog is superior in every possible application, including delay.  But there’s a lot more to it than that.  There are several flavors of analog delay available, each with its own characteristics, quirks and limitations.  So before diving in, how about a little background on the options available?

Analog Tape Delay

Considered by many to be the holy grail of delay – the reality is that tape delay is pretty heavy on the romance, pretty low on the everyday usability.  Maintenance, noises, inconsistency plague these units.  They are absolutely not for the beginner – there’s a very steep learning curve.  Owning and maintaining a tape delay is very much like properly caring for a record player – only more complicated.  But, they are undeniably cool and sound unlike anything else.

The way these units operate is not horribly unlike the cassette players of the not-so-distant past.  What separates the delay units from pure listening devices, is the number of heads.  A typical tape delay unit will have a path featuring a record head, at least one playback head (the distance between the record head and playback head determines the delay time – for variable delay times, multiple playback heads are needed and you switch to the head that produces the desired time) and an erase head.  More modern units may feature recording/erasing on the same head (fairly certain the Fulltone unit works this way).  Basically, the guitar signal comes in, gets amplified, gets recorded, gets played back, gets amplified, is sent to the amp.  Meanwhile, the tape keeps spinning, subsequent passes through the playback head are not sent through the input amplifier, which causes the repeat volume to gradually decrease and fade away.

tape delay

There are a lot of variations to that basic form.  As already mentioned, there may be multiple playback heads at varying distances from the record head.  Other units may have playback heads that can be moved, allowing for varied delay timing.  Many delay units feature a low pass filter or capacitor, as the infamous “tape hiss” was so loud on some poorly made units.  Others will have a high pass filter, as delay times rarely matched the tempo of the music, only passing the higher frequencies would keep musicians/audiences from noticing the guitar/organ being off beat.

Tape delays come in tube and solid state varieties and as you’d expect, you’ll likely save a lot of money with solid state.

Analog BBD Delay

Ah – the mighty bucket brigade!  BBD (bucket brigade device) delay is pretty common technology for the modern analog delay world.  It’s been around since the 60’s and almost was completely lost to digital technology.  However, the semi-recent rebirth of analog effects has brought the technology back.

The general concept here, which I will not attempt to draw as I’m incapable of making a respectable circuit diagram, involves the guitar signal going through a series of capacitors. Capacitors exist to hold the electrical charge for brief moments, essentially slowing the signal down.  Depending on the clock rate, the signal exits the BBD and is fed back in with the original signal.

These delay pedals can be very noisy, as the clock adds noise at each tick.  Also, the quality of the audio signal degrades as it passes through delay stages, so the echo sounds a lot less like the original sound as repeats go on.  Finally, some purists or electronics nerds will point out that these aren’t exactly analog.  When a charge is not held in the capacitor, it’s essentially off.  This variable state is a foundation of digital technology.  We’re getting into some heavy stuff though and I don’t want to start sounding too dumb… so let’s move on.

Which delay is right for me?

I have to be a bit of a prick about this one… if you’re asking this question, it’s definitely not tape.  Beyond that, I think there is definitely a lot of good stuff in the digital delay realm.  There are more and more digital units that do a very good job replicating analog sound, and you can get all the delay time you want.  However, the analog delays always have fun characteristics about them which make them appealing.  I really think this is an area where it makes sense to try several options and go after the one that sounds best to you and fits your needs.