Friday 18 August 2017

Serge WAD and the Reticon SAD1024

I did some testing of a WAD (Wilson Analog Delay) last week.
It's an amazing effects unit quite unlike anything I own.

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The sound is cleaner than my Buchla 288v ... though I like that for other reasons.

The WAD is so hard to find these days due to the rarity of its components.
.. those SAD1024 chips.

The SAD1024 is a dual 512 stage bucket brigade analog delay chip
It has 2 independent delay sections.  (1024 stages total.)
The Bucket Brigade consists of a series of capacitors that pass the analog signal
like a line of people carrying buckets of water to put out a fire.
The analog signal in each capacitor is forwarded to the next stage using transistors that act a switches.
The rate is determined by an external clock. When the audio shifts from one end of the delay to the other, the shifting and clocking functions delay the audio.


Bucket-Brigade delays have lots of problems. The most common of these issues is "clock noise",
which occurs due to the clocking function used to shift the audio through the BBD stages.
Cleaning up the clock noise is sometimes done by filtering or by using a zero-balance mixer and a dual-phase clock. 
It's difficult to say what portion of the WAD's magic is due to the SAD1024 but for the record 
these also use it:

- Ace-Tone EH-50 Delay
- A/DA Flanger *
- A/DA - HARMONY  Synthesizer
- Anderton Flanger
-  BEL ELECTRONICS  Delay/Flanger BA-40
- Boss Flanger BF-1
- Dynacord DC 300 e
- DOD Flanger 640.... 1979
- EHX EH-5100, EH7500 (Memory Man), EH-7811
- EHX Electric Mistress V1 (Flanger) (EH-5200-1-A). 1976
- EHX Electric Mistress V2 (EH5200-1-A) Flanger/Filter/Matrix (1976)
- EHX Electric Mistress V3 (EH5200-1-A-2) Flanger/Filter/Matrix (1978) 
- EHX Electric Mistress V4 (EH5200-1-B/C)) Flanger/Filter/Matrix (1979)
- EHX Electric Mistress V5 (EH5100-D) Flanger/Filter/Matrix (1980)
- EHX Electric Mistress V6 (EH5101) Flanger/Filter/Matrix (1981)  
- EHX Deluxe Electric Mistress V1,V2,V3. EH-1318 (1978), EH-5150-B,C & D (1979, 1981)***
          (V3 was black & Green)
- EHX Deluxe Memory Man (4 knob)....?? **
- EHX Memory Man Solid State Delay
- EHX Memory Man Echo/Chorus (non stereo)
- EHX Memory Man DeLuxe (EH-7550)
- EHX Echo Flanger (EH-7700)
- EHX Slapback Echo (EH-4700)
- EHX Stereo Slapback Echo
- EHX Small Clone (not all) EH4600 ****
- EHX Clone Theory (w/Edge switch)
- EHX polychorus

- KORG  some keyboards (The Trident's onboard analog flanger used the SAD 1040)
- IBANEZ  Flanger FL-305, FL-303
- LUPINE  Systems SAD1024 Delay
- MAXSON  MP-DL201 Flanger
- MONTGOMERY APPLIANCES  77 Flanger (ADA Flanger Clone)
- MXR flanger - M-117
- MXR Pitch-Shift Doubler
- Mutron flanger
- PAiA fhlanger
- Pearl F-604 - Flanger Analog Delay Effect (FADE).
- Roland - some guitar pedals
- ROLAND VP-330 Mk 1 Vocoder Plus. 
   (The Mk1 uses SAD1024D chips. The Mk2 uses MN3004 & MN3009)
- Roland RS-09 Mk 1 (The Mark 1 uses 4x SAD-512D chips.  The Mk2 uses MN3004)
- Roland RS-505 (4x SAD512D)
- Ross Flanger (Stereo delay R-80)
- Sovtek Electric Mistress (prototype)
- Tel-Ray Morley Chorus - Flanger CFL
- Vox 1902 Flanger (1981)
------------------------------------------------------------


*The first version of the A/DA Flanger used the Reticon SAD1024A (June 1977)                                        Bucket Brigade device, but the circuit was revised in May of ‘78 to use the Panasonic MN3010 chip.
This version remained in production until 1981. A/DA reissued the flanger in the mid-nineties. The new circuit also used the panasonic MN3010 BBD and had a built-in AC power cord. The production didn’t last long though. Today A/DA has resurrected the flanger and reviews are favourable.  ADA PBF Flanger (and ADA REISSUE FLANGER) use a pair of low voltage MN3204 BBDs.

Ive read that the very early c1977 SAD1024 A/DA flangers were powered by an 18VDC wall wart. (I have seen pics of some with 12VDC wall warts too... so who knows ???).
The later Panasonic MN3010 BBD chip version had an internal power supply (AC cord is permanently attached). Apparently the two versions sound very different.

**Possibly as early as 1976 Memory Man (3 & 4 knobs) pedals (eg: EH-7500 models) used three SAD1024 chips and  a CD4047 clock. Some of the later 1978 four knob EHX Memory Mans used Panasonic MN3005 chips.
The Memory Man line switched to the MN3005 chips perhaps around 1978, judging by the dates on the factory schematics for EH-7810 and EH-7850.**

***From what i can find on the net it seems that from 1999 on the Deluxe Electric Mistress had to be redesigned because its main integrated circuit, the Reticon SAD1024 BBD was no longer in production. These were V4 & V5. They used the RD5106 which is also now out of production.***

**** Its all very very confusing. This is the info I have compiled so far:
From 1979 to early 1981, EH used either the MN3007 delay chip or the RETICON SAD1024.
The sonic differences are subtle. The SAD1024 has been described as more “watery” sounding, adding a slight “boost” to the signal, while the MN3007 allows higher levels and less noise without signal clipping. The most sought after unit is the 1024 one, mostly because this was the version used by Nirvana’s Kurt Cobain on “Nevermind” and the “MTV Unplugged” sessions.
The vintage units have a clear and smaller (3mm) LED versus the red and larger (5mm) LED in the reissues. Also, the originals don’t have a dash mark (-) separating the words FULL and CHORUS.
The reissues have FULL-CHORUS (with the dash) written on it.

****

There are probably more pedals/synths that use the SAD chip. Please contact me if you know of any.


Ebay has a few of these chips but who knows the quality. Or you could "borrow" them from existing pedals though I think that's sad (no pun intended).

An alternative chip could be the MN3007. Its also a bucket brigade IC.
It is used by Boss in the DM-1 & CE-2. Also in the EMX Memory Man & Small Clone
the AD-999 by Maxon & the Analog Delay by MXR.

------------------------------
More on BBD chips
Back in the day there were 3 main manufacturers of BBD chips:
Reticon, Panasonic/Matsushita, and Philips.

Reticon (Sunnyvale California) produced the SAD 1024 under licence from Philips.(SAD = Sampled Analog Delay). Reticon stopped making these in the early 80's so if you are trying to repair or clone a WAD you will need to pay astronomical prices for NOS replacements.
Reticon also produced a single 512 stage IC (SAD512).

Panasonic/Matsushita (Japan) produced the MN30xx  and MN32xx series.
They stopped producing these in the nineties but clones abound.
Belling (Shangai) made copies of Matsushita’s MN3208 and MN3207 with the designation BL3208 and BL3207.
Coolaudio started producing clones of the MN3207, MN3208, and MN3205.
Xvive Audio began making replicas of Matsushita’s MN3005.
Visual Sound recommissioned production of MN3102/MN3207 in 2009.

The MN 30XX chips are earlier generation chips in comparison to the 32xx series.

The MN3001 appeared in November 1974.  The MN3001 is a dual 512 stage BBD, like the SAD1024.
The MN3002 is a single 512 stage IC featured in the 1975 Roland Jazz Chorus and the 1976 Boss CE-1.


The MN320xx are lower voltage and debately noisier than the 30xx series.

Philips were the inventors of BBD chips.
The BBD was invented in 1969 by F.L.J. Sangster and K. Teer at Philips Research Laboratories in Eindhoven, Netherlands. The most common version made by Philips was a 512-stage BBD named the
TDA 1022.
Around 1972. electronic keyboards such as the Dutch Eminent 310 String Synthesizer and Freeman String Symphonizer were the first to employ this new technology. Arguably, the secret to their sound lay with BBD technology. The most famous use of a 310 was by Jean-Michel Jarre on his albums Oxygene and Equinox.

The EC 280 Electronic Echo used eight Philips TDA 1022 BBDs.

--------------------
The number of stages effects the delay times.
The SAD1024 is a dual 512 stage bucket brigade analog delay chip  (1024 stages total.)
It has 2 independent delay sections. To get longer delays, both stages are cascaded together. The output of the first stage is fed into the input of the second stage and clocked through both stages at the same rate. 
In general, 128, 256 & 512 are used for shorter delays. 512 stages are really good for chorus and flanging effects.
1024, 2048 & 4096 are used in longer delay devices.

Doepfer make the Eurorack A-188 module which come in many flavours:

  • A-188-1X with 128 stages BBD (MN3006/MN3206), available only as long as quantities of MN3006/MN3206 last
  • A-188-1Y with 256 stages BBD (MN3009/MN3209), available only as long as quantities of MN3009/MN3209 last  geringer Bestand / low stock !
  • A-188-1A with 512 stages BBD (MN3004/MN3204), available only as long as quantities of MN3004/MN3204 last  geringer Bestand / low stock !
  • A-188-1B with 1024 stages BBD (MN3007/MN3207/BL3207), standard version, no delivery limitations 
  • A-188-1C with 2048 stages BBD (MN3008/MN3208/BL3208), standard version, no delivery limitations 
  • A-188-1D with 4096 stages BBD (MN3005/MN3205), available only as long as quantities of MN3005/MN3205 last
  They use Panasonic chips.

Another quite popular synth that uses the Panasonic MN3009 is the Roland Juno 106 & 60.
They use these for the chorus.
The 172 delay module in the Roland System 100m uses a single MN 3004 chip.
According to the net, the delay times are short...0 to 7ms.

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Links:
- EGRES
- muffs1
- Ken Stone - CGS208
-  Ralf Metzger - All about The Electric Mistress
- SS30m - Roland 172 delay , etc 
- Florian-Anwander

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