Posted: Fri Jun 26, 2009 10:35 pm Post subject:
Re: Digital Reverb PT2399, 5 delays...
Tim Servo wrote:
I like the method of using multiple echo units for a reverb effect.
Yes, I'd like to do something similar using 2 * MN3011s. In the analogue domain, I think it's really the way to go. Reverb is, afterall, a set of varying delays interacting with each other. _________________ What makes a space ours, is what we put there, and what we do there.
Posted: Sun Jul 26, 2009 6:38 pm Post subject:
Digital Reverb PT2399, 6 delays...
Spanish Version. English version soon.
(los acentos ortograficos son omitidos a proposito)
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Este proyecto lo cree basandome en 2 proyectos de Reverb Analogica de Maplin (ETI). Mi objetivo fue emular las características del MN3011, "3328-Stage BBD with 6 Taps". El pcb lo hice basado en el diseño de geofex, R.G. Keen, pero tiene varias modificaciones.
Mi objetivo no es crear una reverb de alta fidelidad. Mi idea es crear una reverb con un sonido especial, con un caracter sonoro poco comun.
Los tiempos de delay los escogi de manera arbitraria en base al datasheet del PT2399 y buscando tiempos semejantes al MN3011. En teoria estos no deben ser multiplos en entre si (ver el proyecto ETI reverb o el datasheet del MN3011).
El esquema base de cada modulo es el siguente:
El PCB de cada modulo:
Como es complejo medir el clock del PT para ajustar los tiempos, decidi que la mejor opción es medir el voltaje en el pin de cada modulo denominado "TIME" en el pcb (TIME DELAY). Este voltaje lo obtuve luego de ajustar la resistencia de cada trimmer segun los valores que indicaba el datasheet respecto a cada tiempo de delay. Para tener un control extra del sonido decidi hacer ajustable el ultimo modulo, el del delay más largo. Toda esta información podran encontrarla en el archivo pdf adjunto.
There is an error in the calculation of time. Failed to add the resistance of 1k of each module. An engineer friend helped me in the calculations. The correct time calculated by Lagrange Interpolation:
The example of audio with 6 modules was done with the times.
The MN3011 times, according to the following table (datasheet):
The minimum delay time to delivery of the datasheet PT2399 is 31.3 msec. Calculating by the method of Lagrange interpolation values to emulate the MN3011 are:
The correct word is "trimmer." Sorry...
Cordiales Saludos!!!
Marco. Last edited by AnalogCustom on Fri Sep 25, 2009 7:31 pm; edited 1 time in total
I'm thinking about doing a similar (module based) project using MN3205 BBDs. _________________ What makes a space ours, is what we put there, and what we do there.
I'm thinking about doing a similar (module based) project using MN3205 BBDs.
Genial! Great!!!
So we can exchange ideas. I have some ideas for the motherboard such as a stereo mix of the echoes, CV time, CV decay (VCA for feedback), CV amount (VCA for effect level), etc...
Here a block diagram of a Maplin project:
I have the schematics in a book. If you need it can be sent to your email.
I've changed my tack on this slightly.
I'm now going to breadboard just one delay with it's associated level and speed controls, and when I have that running well, I'll incorporate a second delay unit and decide on the mixing/feedback routing. Then add the third delay etc.
I think it will still end up being a number of identical modules connected to a motherboard which will hold the preamp, output summer, PSU, and feedback busses. _________________ What makes a space ours, is what we put there, and what we do there.
Thanks heaps for these last two pics.
My MN3205 experiments have led me to a place where I have 3 * 4096 stage BBD delays, and the last piece was to find a tried and tested way of mixing them together. This is just perfect!
I toyed with the idea of building what would be a DimC with long delays and keep a 3205 for a spare, but I think implementing the DimC modulation into this three delay system with cross feedback options will actually produce a more unique unit. _________________ What makes a space ours, is what we put there, and what we do there.
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