← Delay
2.5 Numeracy
Topic 2.5 Numeracy · 1.12 Delay

Tape & Heads

In an Echoplex, the delay isn't a number — it's the gap between the record head and the playback head. The tape carries each hit from one to the other, and the distance is the delay time.

● Live · TR-1600
Tape transport · AUDIOTECH TR-1600120 BPM · 7½ ips
Head distance — what the formula looks likeQUARTER · 500 MS
500 ms
Erase
Record
Playback
0
250ms
500ms
750ms
1000ms
60,000 ÷ 120 × 1 =
500MS
4-on-the-floor at 120 BPM
1Kick
2Snare
3Clap
4Rim
5Vox
6Pluck
Tempo
120BPM
Note value
Whole
2000ms
Half
1000ms
Dot · 1/4
750ms
Quarter
500ms
Dot · 1/8
375ms
Eighth
250ms
1/8 Trip
167ms
Sixteenth
125ms

Try thisHit the snare pad and watch a glowing flux mark fly across the rail from record to playback. Drag BPM down — playback slides right, the bracket widens, the wet hit arrives later. Pick an eighth — the head jumps left, the gap halves. The maths and the geometry are the same idea.

What you learned

  • Derive delay time in ms from BPM using the formula 60,000 ÷ BPM × note value
  • Apply the formula to dotted, triplet, and standard note divisions accurately
  • Distinguish dotted (×1.5) from triplet (×2/3) note values without confusion
  • Use tap tempo to find a song's BPM by ear
  • Interpret tempo-sync settings on hardware and plugin delays
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