dbx 900 Series Racks & Modules

In the early 1980s dbx introduced the 900 Series, a modular processing system using a 3U chassis with builtin power supply. Sound familiar? Yes, it’s one of the progenitors of the 500 rack system

One of the few manufacturers that supported the dbx 900 Series was Aphex – now a player in the 500 Series market with both racks & modules

The 900 Series had (at least) two racks

  • FS900, 1U, two-module, self-powered rack
  • F900A , 3U, eight-module, self-powered rack

Compatible modules included

  • 902 De-Esser
  • 903 Compressor
  • 904 Noise Gate
  • 905 Parametric Equaliser
  • 906 Flanger
  • 907 Stereo Gated Compressor Slave
  • 911 Type I Noise Reduction
  • 941A Type II Noise Reduction
  • 942A Type II Noise Reduction
  • 929 Hiss Reducer
  • 993 Mixer module
  • Aphex Compellor 9301
  • Aphex Dominator II 9721
  • Aphex Expressor 9651
  • Aphex Aural Exciter
  • Aphex Equaliser
  • BBE 702

 

I have a number of 900 Series items in my workshop queue and will update this page when I have photos and more information

Preservation Sound has more info on the 900 Series plus a download link for the original marketing material. More info here

A few forum links & threads for research:

The DBX 900 Series

https://www.gearslutz.com/board/so-much-gear-so-little-time/68346-dbx-900-frame-modules.html

https://www.gearslutz.com/board/so-much-gear-so-little-time/9762-dbx-900-rack-compression.html

 

Dynamite!

Valley People Dyna-Mite

A piece of outboard gear that really caught my attention on an early session at Eden Studios was the Valley People Dyna-Mite. Housed in an ugly beige plastic case it stacked two channels of Dynamite in a very small package. Despite looking like a toy, the Dynamite proved to be a huge-sounding device capable of eye-widening compression. A year later, working at Sarm East, I discovered the epically-wonderful Allison Research Gain Brain, a masterpiece of savage compression & distortion

Later on I discovered the shared heritage of these two items and the story of their creator, Paul Buff. His story has been written about online already and there’s a longer piece here, and more here, so no need to duplicate it

Significant pieces of Valley gear, in approximate chronological order, include:

 

Allison Research

Photo Credits: © Universal Audio & © The Telos Alliance

On the bench: dbx 160X Compressors

dbx 160X stereo pair with sequential serial numbers

dbx 160X stereo pair with sequential serial numbers

I am working through a delivery of ten dbx 160Xs from the USA. They have been refurbished with new UK power plugs (Euro plugs available on request), pots & switches cleaned and metering aligned. All are in good shape with just a few knob caps required to make them spot-on. As usual with vintage kit they have age-related marks and are not cosmetically perfect

I have made up three stereo pairs – one pair with sequential serial numbers, one with close serial numbers and a third pair which are selected to match age & condition. Links below

On the bench: Valley International 440 Compressor

I have another great Valley compressor in for a 220 voltage swop & power supply recap. Just arrived from the USA, it’s in really tidy condition. These compressors sound amazing – if you’ve never owned one, I can recommend any Valley unit as the ultimate antidote to boring compressors

When it’s ready you’ll find it here. Email if you need more info

Valley 440 on the workbench

Valley 440 on the workbench

On the bench: Orban 622B

Orban 622B

I’ve just taken delivery of a really tidy Orban 622B equaliser. These are great, useable 4-band equalisers with per-band bypass switches like a Klein & Hummel. The example has all-original knobs & switches and looks like it’s been tucked away in a box for the last thirty years

I’ll be refurbishing this with new caps, upgraded power supply and replacement of the troublesome Tantalum caps with electrolytics. When it’s ready it’ll be listed here. Update soon!

Hail the Effectron!

I’m a bit of a Deltalab fan. The first one I used was an Acousticomputer – it was rubbish, but very entertaining rubbish. The later Effectrons really hit the spot and, even now, are great tools for warping & twisting sounds

I am collecting Deltalab & Effectron info together on this page so check back for updates!

Some items have a PDF link to a user manual or catalogue or a schematic

Product links & Info

 

Effectron

Super Time Line

Other Deltalab kit

 

Random weblinks

 

Preservation Sound

http://www.preservationsound.com/?p=2088

TapeOp forum

https://messageboard.tapeop.com/viewtopic.php?t=59090

https://messageboard.tapeop.com/viewtopic.php?t=83894

Music Electronics Forum

https://music-electronics-forum.com/showthread.php?t=3678

DeltaLab Effectron, I, II, III ADM (Blue) Digital Delays From The 80’s (what I know so far)

Youtube Demos

 

Youtube demo (weird noises mainly)

 

Period adverts

 

Effectron – PDF

Effectron II – PDF

Effectron Ad 1 –

Effectron Ad 2 –

Effectron I - II - III features

Effectron I – II – III features

Effectron Ad 2

The Dolby Trick – Hardware Setup

I had an enquiry recently about how to setup a 361 to perform “The Dolby Trick”. This is the basic setup:

Audio routing

  • DAW (effects send, bus, etc) —> audio interface —> Dolby “line in”
  • Dolby “to rec” output —> audio interface —> DAW channel line in

Send the signal to the Dolby & record the output. You’ll need to compensate for the audio interface latency

Dolby 361 back panel

 

 

 Hardware setup

  • Set NR in and Rec on (white & red buttons pushed in)
Dolby 361 with Modified Cat 22 Dolby Trick Card

Dolby 361 front panel

 Notes

If you’re using a standard Cat.22 Dolby A card the output of the 361 will be the encoded signal – ie the original signal plus the processing. This means balancing the effect will take a bit of juggling with levels to get the effect you want

For a deeper effect & easier use a modified Cat.22 is a useful tool

How it works

As you reduce the level going into the Dolby the effect will increase. Dolby A encoding uses a multiband expander so more level = less effect, the inverse of a compressor, and the inverse of the decode process. For the Dolby Trick there is no decode process, just encoding

The NR in / out switch should give an obvious effect if you monitor the return signal. If you hear no effect, reduce the level into the Dolby

Theory

Dolby A passes the audio signal through a four-band compander. A sidechain determines the level of encoding for each band. In the encode process the sidechain-generated signal is summed with the audio, to create the encoded signal, and recorded to tape. On playback the sidechain recreates the encoded signal and subtracts it, decoding the signal

As a compander, Dolby A raises low-level signals during recording and lowers them again on playback. This has the effect of reducing tape noise by the same amount. There’s a lot of subtlety in the details – in the way the bands are chosen, the amount of expansion & compression and how these are optimised for maximum perceived effect and minimum artefacts

Hardware

The 361 (and earlier 360) are hardware interfaces with no audio electronics but with input & output transformers. They have the power supply and switching to route audio to and from the Cat.22

The Cat.22 has audio electronics, input & output stages, sidechain and four bands of processing on one card. It’s all Class A, transistor-based circuitry

The separation of audio path and support hardware was a highly significant move. It meant Cat.22 noise reduction cards could be used in other hardware interfaces such as the M16 & M8 multitrack units and film playback systems. It also allowed the next generations of noise reduction, Dolby SR, to use existing interfaces

Ray Dolby was a clever guy, a true audio pioneer

On the bench: Yellowhammer

Yellowhammer is a distortion box designed for studio use. It’s at second prototype stage and is being road-tested by a number of producers & engineers

It’s a passive device which uses transformers, diodes, inductors & capacitors to generate distortion & filter the results. All the controls interact, making it a little unpredictable, but it’s easy to navigate once you start using it

The next prototype will be a rackmount version though I think there may be demand for a freestanding unit like this one

For more information or to arrange a demo, email yellowhammer@bn1studio.co.uk 

To hear the Yellowhammer in action, upload your sound samples via WeTransfer to upload@bn1studio.co.uk and we’ll run them through the Yellowhammer

Yellowhammer prototype 2 Sketchup drawing
Top panel layout & drilling template
Input XLRs & transformers being test-fitted
The green-fading-to-yellow paintjob didn’t pass inspection
First set of knobs, before lettering
New knobs & lettering in place – now ready for testing

On the bench: Symetrix 501

This pair of Symetric 501 compressors has just arrived from the USA. They will be tested, switched to 220 VAC and recapped before being listed in the shop

These are great-sounding VCA compressors with a big reputation. They have a switchable sidechain, switchable auto attack/release, stereo link switch and a separate limiter

The 501 came in a couple of versions: early models used the TA-101 VCA – designed by Paul Buff of Valley People fame – whilst later models used a dbx 2181 VCA. I have one of each in stock

On the bench: TC Electronic 1220 Stereo Equaliser / Preamplifier

I’ve just finished recapping & testing this TC equaliser / preamp. It’s a useful, musical-sounding eq with a decent amount (20 dB) of gain in hand. Each channel has two bands of EQ, ±20 dB gain control & bypass switch

This 1220 is in nice condition and still has all the original knobs & switches. It’s in the shop now

TC Electronic 1220

This has the usual TC Electronic upside-down PCB

TC Electronic 1220

Simple EQ section with no electrolytic capacitors

TC Electronic 1220

Power supply and input / output on one board, recapped with Panasonic caps, bipolar for the audio section. PSU bypass caps are on the other side of the board

On the bench: McMartin LR1004C Limiter / Compressor

This McMartin LR1004C Limiter / Compressor came from a radio station in the USA and dates back to the 1970s. The limiter is based on a diode bridge, like the Neve 2254, and the compressor is switchable. Both sections sound awesome when crushing drum tracks – sound samples to follow

I’ve recapped the unit & will replace the power transformer so it can be used on 220 Volts. The attack & release pots are inaccessible so I’ll move them to the front panel & source some suitable knobs

Note the lovely horizontal meter – proper meters like these are an endangered species now and have become diabolically expensive

The LR1004C will be in the shop when ready

Under the hood

McMartin LR1004C Limiter / Compressor

Guts shot

McMartin LR1004C Limiter / Compressor

70s orange plastic compressor in/out rocker switch

McMartin LR1004C Limiter / Compressor

Matching power switch

McMartin LR1004C Limiter / Compressor

Neve-style horizontal meter shows GR or output level

McMartin LR1004C Limiter / Compressor

Compressor board and line output board

McMartin LR1004C Limiter / Compressor

Lots of space for attack & release pots to be added

Audio test files

Drum room test audio file processed through Alesis Micro Limiter and a modified Alesis Micro Limiter

This test is anything but definitive: levels have not been matched and it’s extremely hard to match settings on these units

Original file

File through modified Alesis Microlimiter

File through unmodified Alesis Microlimiter

Misc SR-JV80 links & info

A growing collection of miscellaneous info about Roland SR-JV80 synths such as the JV-1080

Links

Roland synth modules for sale

http://www.bn1studio.co.uk/product-category/keyboard-modules/

 

SR-JV80 expansion boards for sale

http://www.bn1studio.co.uk/product-category/keyboard-modules/sr-jv80-expansion-board/

 

List of expansion boards

http://www.bn1studio.co.uk/roland-sr-jv-80-expansion-boards/

 

Compatibility Guide for expansion boards

http://www.bn1studio.co.uk/roland-sr-jv80-compatibility-guide/

 

Roland main SR-JV80 page

https://www.roland.com/hu/search/?q=SR-JV80

 

Don Solaris

http://www.donsolaris.com/

 

Gearslutz Favourite SR-JV80 expansion boards poll

https://www.gearslutz.com/board/electronic-music-instruments-and-electronic-music-production/poll-3400-whats-your-favourite-roland-sr-jv80-expansion-board.html

 

Nathan Sheldon patches

http://www.nathansheldon.com/xp-80/patches.html

 

Soundprogramming.net page

https://soundprogramming.net/synthesizers/roland/roland-sr-jv80-expansion-boards/

Dolby Noise Reduction

Professional Dolby Noise Reduction

Dolby A noise reduction (NR) was used on millions of 16- and 24-track 2″ multitracks and 2-track masters. It’s a 4-band compander which boosts levels on recording, and compensates on playback, thereby reducing noise

Dolby SR, the successor to Dolby A, offered around 10 dB more noise reduction. Tapes encoded with SR require an SR card for decoding

Domestic Dolby Noise Reduction

Dolby B was a domestic NR commonly used on cassette recorders. In many ways a simplified version of Dolby A, B was s single-band NR system, boosting high frequencies on record and reducing them on playback. As with Dolby A, B required accurate level & frequency response matching for best results. It had the happy by-product of making B-encoded tapes sound brighter on non Dolby-equipped playback systems

Dolby C and Dolby S were later domestic systems

Professional Dolby hardware

Dolby hardware separates the host and NR card. The host typically provides audio input / outputs (via transformers on the 361), power supplies and remote switching whilst the NR card performs audio functions only

Dolby produced hundreds of card types for audio, film, broadcast & etc. In single- and dual-channel models these fell into two main categories, first- & second-generation models.The noise reduction specification (A, SR, etc) remained constant across hardware generations but cards & hosts are not interchangeable between generations as Dolby changed connector standards

First-generation hardware (supports Cat 22 (A) and Cat 280 (SR) cards)

  • 360 – single-channel interface in 1U
  • 361 – single-channel, updated version of the 360
  • 362 – dual-channel in 1U, electronically balanced, front-panel trims
  • 365 – dual channel in 2U, electronically balanced, front-panel trims

Second-generation hardware (supports Cat 350 (SR), Cat 450 (A) and Cat 300 (SR / A) cards

  • 363 – dual-channel in 1U, supports SR & A

For multitrack systems Dolby produced the ubiquitous M16 (16-channel) rack and the later 8-channel expansion. The M16 used standard Cat 22 cards with separate Cat 44H i/o interface cards. The M16 was superceded by the 24-channel XP24 SR rack

 

More info from Sound on Sound

Reverb

Reverbs & Effects for sale are here

Page under construction


Before there were digital reverbs there were reverb plates, springs, mechanical reverbs  and – of course – reverb chambers

A reverb chamber is a simple idea – take an empty room, fit a speaker and a pair of microphones and create natural reverb. It’s simple in theory, and hard to do in practice, but there were (and are) some great chambers in larger studios

The plate reverbs was invented by EMT in 1957 and used a suspended steel plate with a transducer and a pickup (later, two pickups for “stereo”). The transducer energised the plate and reverberation was created by the sound waves travelling around the plate. Plate reverbs are still in use, and in production, 61 years later

In the late 1970s EMT began research into digital processes to quantify & generate reverberation. This led to the 1976 EMT 250, still one of the most feted reverbs in the world

The other pioneering reverb company at that time was Lexicon in Waltham, Mass. Lexicon and EMT had one thing in common – Dr Barry Blesser, a founder of Lexicon and designer of the 250 for EMT.

EMT had a background in broadcast and high-end audio products whereas Lexicon was a typical high-tech company which grew in the shadow of MIT

 

Reverb Top Ten

  1. Lexicon 480L
  2. Lexicon 224XL
  3. EMT 240
  4. Lexicon 224
  5. EMT 250
  6. AMS RMX16
  7. Lexicon PCM70
  8. EMT 244
  9. Quantec QRS/L

Modifications, Upgrades & Recapping

Modifications

We do a number of modifications including a high-pass filter mod for the Cloud CX335. Email workshop@bn1studio.co.uk for details

Transformers

We can source output transformers for dbx compressors. We can supply dbx 160X or dbx 160XT compressors with the transformer fitted or retrofit a transformer to your dbx. Email workshop@bn1studio.co.uk for details

Recapping

We can recap most pieces of gear. Equipment we’ve recapped to date includes:

 

In Preparation

We have quite a list of gear in prep. When it’s complete it will be for sale in the shop. Till then you can fin it on our In Prep page

Equalisers

Equalisers for sale are listed here

In theory, equalisation is one of the simplest audio tasks. That doesn’t stop there being thousands of EQs to choose from, using hundreds of different approaches to a couple of of basic topologies

The earliest equalisers were used to flatten the frequency response of fixed telephone lines. They were typically LC (Inductor / Capacitor) equalisers followed by a valve gain make-up stage. They were designed for permanent equalisation and would have a fixed HF boost matched to the line

The advent of equalisation in sound recording and cinema audio playback led to variable equalisers like the legendary Pultec EQP-1A. The development of transistors led to equalisers with more frequency bands and greater flexibility


Cost is a big factor. Cheap EQs can work well but are likely to be limited in flexibility and precision. They are also unlikely to be easy & enjoyable to work with

At the other end of the scale, high-end equalisers like the GML 8200 and Massive Passive offer great flexibility, accuracy & repeatability – at a price

The middle ground is where the price / performance ratio works best. Great affordable, usable EQs include

Equaliser Top Ten

  1. GML 8200
  2. Pultec EQP-1A
  3. Massive Passive
  4. Neve 8108 console EQ
  5. Klein & Hummel UE400

Honourable mentions

Shop Update January 2018

Here’s to a successful New Year!

Incoming 2018:

* Empirical Labs Distressor EL8X (pair)
* Empirical Labs Fatso EL7X (stereo)
* MXR Dual Limiter (stereo)
* dbx 160XT (pair) with sequential serial numbers, mint
* dbx 160A (pair) with sequential serial numbers, excellent
* dbx 160X (pair) with output transformers, excellent
* dbx 163X (pair) modified, recapped, rebuilt power supply
* NTP 179-500 Limiters (pair) in NTP 1U rack
* Aphex Dominator cards (pair) for dbx rack, NOS (New Old Stock)
* Valley People Dynamite (stereo) original version in 1U rack, recapped, rebuilt PSU
* SPL Transient Designer (2-channel)
* SPL Transient Designer (4-channel) with XLRs

* UREI 546 Stereo Parametric Equaliser
* UREI 530 Stereo Graphic Equaliser, rebuilt, new slider pots
* UREI 535 Stereo Graphic Equaliser, rebuilt, new slider pots
* White 4100A Stereo 10-Band Equaliser, inductor EQ
* White 4000 Stereo 10-Band Equaliser, inductor EQ

 

 

Rhythm Roulette

 

My latest obsession: Rhythm Roulette. DJs & Producers take three records – or CDs – and chop them to make a beat. The level of talent is amazing – here 9th Wonder shows us how it’s done

Roland Boutique SE-02

Roland has partnered with Studio Electronics to produce an analogue synth with all the facilities of a modern digital synth. It sounds great in this clip

Shop Update June 2017

Incoming:

On sale now:

In the workshop:

Shop Update May 2017

New arrivals tested, modified, packed & ready to ship:

In the workshop:

Long-term projects

Shop Update March 2017

New arrivals tested, modified, packed & ready to ship:

In the workshop:

Long-term projects

Leon Theremin

Robert Moog, Roger Linn, Dave Smith, Don Buchla, Tom Oberheim, John Chowning, Leon Theremin, Olga Theremin

Robert Moog, Roger Linn, Dave Smith, Don Buchla, Tom Oberheim, John Chowning, Leon Theremin & Olga Theremin at Stanford University’s centennial celebration, September 1991

Leon Theremin was born on 15th August 1896. In this photo Theremin is surrounded by the most influential synthesiser designers & inventors of the last hundred years

 

Photo © Bob Moog Foundation Archive

OSCAR – Open Source Console for Analogue Recording

A recent idea inspired by the success of the 500-Series format and the continuing popularity of analogue consoles. OSCAR is a an open platform for building analogue consoles, based on buckets of eight channels with simple metalwork and – as far as possible – standard parts

One possible path is to size the bucket so that 500-Series modules can slot right in. They’re 1.5″ wide as standard. Other options include modules 2″ wide (actually 50.8 mm). This fits in with the Eurocard standard

Both 500-Series and Eurocard have a standard 3U (5.25″) module height, but Eurocard also allows for a 6U (10.5″) standard which is a far more usable size for a channel strip

I don’t see 500 modules as the perfect solution. A taller channel strip would allow greater flexibility and reduce cost and allow the format a wider appeal

Metalwork represents a sizeable proportion of the total cost of a console but it’s possibly the most difficult thing for DIY builders to create. Constructing a console out of standard parts, each built to close tolerances and with a good finish, would leave the DIY builder free to concentrate on electronics

There’s a thread running about the idea over on the Group DIY Forum

http://groupdiy.com/index.php?topic=63172.0

 

First sketch of OSCAR

modular_console_1

First sketch of metalwork ideas

modular_console_2

 

 

Links

http://groupdiy.com/index.php?topic=63172.0

http://www.radialeng.com/500series-standards.php

http://www.emusician.com/gear/1332/roundup–api-500-series-chassis/45767

http://51xaudio.com/alliance/index.html