Posted on Mar 26 2020 06:13 AM
I don't fully understand the change of pan discussions. Does any of these effects units including the 6G15 have pre-reverb and would it be better that fiddling around with pans.
I think the 'official' term is "pre-delay", the time for the first 'reverb-echo' to arrive.
Every pan has a pre-delay, simply because it physically takes time for the 'wiggle' on the spring to travel from the input transducer to the output transducer.
The longer the spring, the longer the pre-delay.
Springs can be stretched harder or less so that in the same width pan you can have shorter and longer springs.
You can measure the pre-delay of a pan by playing/recording a click sound.
In a DAW you can then see the time interval between the dry click sound and the moment the first echo arrives.
A while ago I measured the pre-delay of some of my pans:
Type-4 long pan, 2 springs:
vintage Accutronics: 27ms / 33ms (spring 1/ spring 2)
2015 Accutronics: 30ms / 39ms
2019 Accutronics: 31ms / 39ms
2019 TAD: 33ms / 42ms
Type-8 short pan, 3 springs:
2015 Accutronics: 22ms / 26ms / 28ms (spring 1/ spring 2/ spring3)
2019 Accutronics: 22ms / 26ms / 28ms
2019 TAD: 22ms / 26ms / 28ms
Type-9 long pan, 3 springs:
2019 TAD: 33ms / 37ms / 42ms
On a further note, that first echo 'bounces' at the output transducer and travels back to the input transducer and there it bounces and travels back to the output transducer for the second 'repeat'. And again and again.
So the repeats for that Vintage Accutronics pan will be:
spring 1: 27ms, 81ms, 135ms, 189ms, 243ms, 297ms
spring 2: 33ms, 99ms, 165ms, 231ms, 297ms
For some period of time, the echos/repeats of one spring occur in between the echos of the other spring.
This contributes to diffusion and makes up for a reverb sound rather than a repeating echo sound.
This explains the advantage of using 2 long springs of slightly different length:
You get the benefit of a relatively long pre-delay by using a long spring and at the same time, the time interval between repeats is short giving a more smooth, diffuse reverb sound.
But the 5th repeat of spring1 coincides with the 4th repeat of spring2.
Depending on the difference between the delay times of the two springs you get these coincidences more often of less often.
The more often they occur the more clearly you hear distinct echos in the reverb sound.
would it be better that fiddling around with pans.
In general, adding (additional) pre-delay separates the first 'reverb-echo' from the attack of the dry sound.
It can be a (recording) trick for a less muddy or clogged up sound.
Specifically to spring reverb, people have tried adding a bit of pre-delay to make shorter pans/springs sound closer to longer pans/springs.
If you mix in some of that predelay to the dry sound you get a combination of slapback + spring reverb. Maybe this was also signature sound on older recordings which people try to replicate?
I don't know of any analog spring reverb units to have an adjustable pre-delay. It would require the addition of the entire circuit you'd find in a delay pedal, either analog (bbd) or digital.
The only unit that comes to mind is the Danelectro Spring King. But I thought they added a short predelay (PT2399S chip) to make up for the shorter spring(s) it has inside.
You can mod it to make the delay time adjustable: http://jacobkorn.de/studio/danelectro-spring-king-mod.html
I don't fully understand the change of pan discussions.
In my opinion you swap pans, not for their very minimal difference in pre-delay, but more for:
- drip: some definitely have more drip than others
- frequency response: some pans sound much brighter and others a lot darker
- decay time: even though two pans of the same brand can be labeled 'long decay' the difference can be quite large
- diffusedness: as explained above, with some pans you hear more distinct echos/repeats in the tail or decay than with others.
Last edited: Mar 26, 2020 06:19:23