Delay vs reverb

If you can count the repeats, it is delay. If you cannot, it is reverb. Delay repeats your signal at a set interval; reverb produces a dense cloud of very short reflections that simulates a space. Buy a delay first if your amp already has reverb — which most amps do — because delay is the capability you are actually missing.

They get conflated because both make a guitar sound less dry and both are described as adding 'space'. Mechanically they are the same idea at different scales, and that scale difference changes everything about how you use them.

02The same mechanism at different scales

Reverb is what happens when sound bounces off surfaces in a room and arrives at your ear thousands of times, at intervals of a few milliseconds, each quieter than the last. Your brain does not hear individual reflections — it hears a space.

Delay is the same idea with a handful of reflections at intervals long enough to hear separately. At 500 ms you hear discrete repeats; at 50 ms you hear a slapback; below about 30 ms you stop hearing repeats and start hearing comb filtering, which is where chorus and flanger live.

03Which to buy first

• Your amp has reverb you like — buy the delay. You are missing a capability rather than upgrading one.
• Your amp has no reverb — buy the reverb. A completely dry guitar sounds unfinished in a way delay does not fix.
• You play in a band with a lot going on — delay, and used sparingly. Reverb fills space a band has already filled.
• You play alone, or ambient parts — reverb, and a lot of it. This is the context reverb was made for.
• You want rhythmic effects locked to tempo — delay with tap tempo, which means a digital pedal.

04Running both, and in what order

Delay first, then reverb. Each delay repeat then gets its own reverb tail, which is organized and predictable. Reverb into delay means the delay is repeating an already-reverberated signal, which piles up quickly and loses definition.

Both belong after your drives and, if the amp has one, in the effects loop. Distorting a delay repeat is the single most common cause of 'my delay sounds muddy' — see pedal order.

05The power cost of adding either

This is where the decision has a practical consequence beyond the pedal price. BOSS publishes 100 mA for the DD-8 and 95 mA for the RV-6. Adding either to an all-analog board multiplies the total current draw several times over, and adding both is often the point at which a daisy chain starts to hum.

Budget for a supply at the same time as the pedal. The power arithmetic guide has a worked example, and isolated vs daisy chain covers when the cheap option stops being adequate.