Choral Generator - part 3 -NLC

 

This is part 3 of my build of the Choral Generator module from nonlinear circuits..

 

It's a BBD based triple chorus generator.

It is inspired by the Choral generator in the ARP Omni

 The earlier parts are here:

88. Choral Generator - Build notes - part 1  

      Choral generator - NLC - build notes - part 2 

 

Some NLC words of wisdom

 

Experimental raw materials of an experimental nature for art, hobby, industry, science and religion

 Life is one big experiment.

Nothing is guaranteed.

 

Headers to join the two PCbs

 

Trimmers

 

 

The toggle switches can be ON-ON or ON-OFF-ON. These select positive or negative feedback, or off if using the ON-OFF-ON type. The REGEN pot can simply be set to 0 if you don’t want feedback and have used ON-ON switches.

I'll be using just On-On switches

The  B100k pots - linear

 

The BBDs... finally arrived and they work

MN3207

 

"As is, a signal patched into in 1 will be fed thru all 3 BBDs and arrive at out all, so the 3 BBDs operate in parallel as is done on the ARP Omni. The best effect is to modulate them with a 3 phase signal"

Alternatively, the three circuits can be used individually; patching to the inputs will break the internal routing.

 

 

 It's done

 

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Links

+ Wiki

+ BOM

Choral generator - NLC - build notes - part 2

 These are a continuation of my build notes for the NLC choral generator.

It's a BBD based on the choral generator of the ARP omni

 

This is part 2 of the build

 

Part 1 is here:

88. Choral Generator - Build notes - part 1 

I was waiting on the 

LM13700MX/NOPB

These are out of stock at mouser

So ordered on ebay

Finally arrived. Is the chip shortage even effecting these simple opamps?

LM13700 & TL072

 

 

BC847 & 857 trannies

 

 

signal diodes and rectifiers

 

More resistors.

note, there are a few resistors marked with an asterix on the pcb.

Replace the three 150k* on the PCB with 82k, this is noted in the BOM.

Replace the three 33k* with 15k

There are a few more resistors marked with an asterix:

18K*, 22k*, 47k*

 

If the * are not mentioned in the build guide, just ignore them. They are leftovers from the prototype.

 

 Install caps next.

10k trimpot 3 Tayda: A-586 

100k trimpot 6 Tayda: A-587

 

Some NLC words of wisdom.

I love these messages from Andrew.

I have no idea as to the source.. shoot me an email if you know.

 

To be continued.......

Choral Generator - Build notes - part 1  

    

      Choral Generator - part 3 -NLC 

Links

+ Wiki

+ BOM

MXR Stereo Chorus - M205

 The MXR dates from around 1983. Its very heavy.

 It's a great sounding pedal

The era of BBD based delays & chorus appears to have just been very short . Between 1976 and 1983 ?
So this comes from the very end. It appears that pedal companies all released digital  based delays in the 1980s killing the demand for the BBDs.

..

Uses a Reticon SAD4096.... super long delays.

 The SAD4096 is super rare. It's a general purpose 4096 bucket (2048-sample) n-channel BBD. It's useful where a long delay is required. (2ms to 250msec). The delay is controlled by the clock frequency.

The RC4558 is a texas Instruments General purpose dual Op amp.
The MCI458p is also an op amp

The SCL4013 is of course a CMOS logic chip. Dual flop flop.
The CD4013 provides an excellent clock source with their Q and -Q outputs.

MXR Time delay

Picked this up on Ebay.
I am addicted to Reticon bucket brigade chips. So couldn't pass this one up.

Heavy, and built like a tank.
This one dates from around 1981 to 83.

M206/Series 2000
Serial No. 206-001729

The seller described it thus:
"This is a supremely luscious vintage analog delay. Thick, decadent delay repeats you could cut with a butter knife. Forget that Panasonic/Matsushita malarkey: Reticon did it right."  Yes !!!!

Reticon SAD4096 bucket-brigade delay chip with in'n'out running through a NE571 compander. It's socketed as are the op-amps (MCI458p)

NE571N Compander

....SCL4013BE ... CMOS chip ,,, its a dual D-type flip flop

 Built with love in beautiful Rochester

Ibanez FL-303 pedal

Vintage Ibanez FL-303 Flanger.
Picked this up the other day on Reverb.

 Great sounding pedal. Runs on two 9V batteries.

speed (or rate), width (range or depth)
Regen : The regen (intensity or enhance) knob feeds some of the delay output back into the input.
It intensifies the flanging effect

 The delay Chip is a Reticon SAD 1024. My favourite BBD IC.

The MCI4013. ... CMOS Dual D-type Flip flop. ?

SN72L022P .... I think it's a dual general purpose low power op amp, using the standard pinout for a dual op amp (same as a TL082, LM358, etc.)

For more on SAD 1024 BBD - Bucket Bridge devices

Doepfer Module A-188-1

Still on the search for the perfect Bucket Brigade Device module.
I just purchased these two on Ebay.
The A-188  series of Doepfer Eurorack modules are great value. They use the Panasonic BBD chips and as always with Doepfer, the build quality is excellent.

The A-188-1 X uses a MN3009. Its a 256 stage IC. These are getting hard to find.

The A-188-1 Y uses a 512stage BBD.

This module happens to be using a newer Panasonic MN3204 IC. These 32xx ICs are lower voltage than their 30xx cousins.

You can read the manual here:
http://www.doepfer.de/A1881.htm

EHX - Deluxe Electric Mistress - Version 1 - EH 1318A

A very early Electrix Mistress, deluxe.
I think this dates from 1978.

This uses the SAD 1024 Bucket Brigade chip.

The marking in pencil is a reference to a later version ? Version 2 or 3 used the EH 5150 PCB.

The EHX Delux mistress is a early flanger.

Flangers have been around for ages .. since the 1940/50s.
Les Paul in 1945 ??
They originally used two tape recorders ... one running slightly out of sync / slower than the other.
From what I've read, the first flanger using an bucket brigade delay ICs was the Eventide instant flanger FL201 in 1976 This beauty had CV controls that allowed modulation of the effects using modular synths.
The  Eventide used two Panasonic MN3001s clocked at 2.7 MHz.

Eventide today make a software version of this classic rack effects unit.

The PCB is labelled EH1318 A which makes it a Version 1 from 1978.
Notice the curled knob with pointer.

The IC's are: 1x LM78L, 1x 4558, 1x SAD1024A, 1x LM324, 1x LM311N, 1x 4013BE
with one transistor ... a 2N5087.

Links:
 + Metzgerralf - V1 pics
 + How the Flanger works - detailed
 + Reverb - Eventide FL201