func KarplusStrongTriangle(ctx sound.Context, frequency, cutoff, decay float64) (output chan float64) {
delaySamples := uint((1.0 / frequency) * ctx.SampleRate)
wave := ctx.Triangle(ctx.Const(frequency))
input := ctx.Take(wave, delaySamples, true)
return KarplusStrong(ctx, input, delaySamples, cutoff, decay)
}