with custom audio router · pdf fileultimate rockman setup with custom audio router _____

Ultimate Rockman Setup

with

Custom Audio Router

_____

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TABLE OF CONTENTS

THE PROJECT ....................................................................................................................................... 3

OBJECTIVES .......................................................................................................................................... 3

PROTOTYPE: THE OCTO-LOOPER ........................................................................................................... 3

DESIGN................................................................................................................................................... 6

UNITS SELECTION .................................................................................................................................. 6

MODULES MODIFICATIONS...................................................................................................................... 7

ROUTER PRINCIPLE................................................................................................................................ 8

PREAMPS SECTION ................................................................................................................................ 9

EFFECTS SECTION ............................................................................................................................... 11

CONNEXIONS....................................................................................................................................... 13

LED'S DISPLAY.................................................................................................................................... 14

THE MAKING........................................................................................................................................ 15

ENCLOSURE AND LIGHTING SYSTEM...................................................................................................... 15

POWER SUPPLIES ................................................................................................................................ 16

AUDIO CARDS ...................................................................................................................................... 17

LOGICS CARD ...................................................................................................................................... 18

LED'S INDICATORS .............................................................................................................................. 18

INTEGRATION IN THE ENCLOSURE ......................................................................................................... 19

AUDIO CORDS, SWITCHING CORDS, MAINS AND MIDI CONNEXIONS........................................................... 20

THE RESULT ........................................................................................................................................ 22

OPERATING THE RIG.......................................................................................................................... 23

PRESETS MANAGEMENT ....................................................................................................................... 23

SMART GATE AND MUTE ...................................................................................................................... 23

STANDALONE UNIT............................................................................................................................... 24

INSERT A MONO EFFECT ....................................................................................................................... 25

COMBINED WITH ANOTHER RACK .......................................................................................................... 25

COMBINED WITH A COMBO.................................................................................................................... 27


THE PROJECT

Objectives

� The setup is based on a series of Rockman Modules, controlled by a Midi Octopus, and on a PGE2 that replaces the classic Instrument EQ's found in every Rockman rig.

� The global control unit - called Custom Audio Router - is a 19' 1U rack unit that has three main functions:

- Optimize the control and routing of the Rockmodules - Allow using the PGE2 with several modules configurations - Combine the Rockman setup and an external 2-channels combo

Prototype: the Octo-Looper

� Before building this complex unit, I had built 3 years ago a first control device called "Octo-Looper". I had no PGE2 by the time, and its primary function was to interface my series of Rockmodules with my Boogie Combo.

� Note that there was no Sustainor in this rig: my first approach was really to see each module as an effect added to the Boogie. The concept was to connect all the units in series, and to control each of them from the Octopus. Each channel of the Octopus opened or closed a true-bypass loop, based on a relay (the 8

th octopus switch being dedicated to the channel control of the combo).

Principle of the Octo-Looper


The board of the Octo-Looper

The Mini-Rack with its Octo-Looper (under the Midi-Octopus)


� Such a simple device has clear limits, the most critical being the useless Octopus combinations that a series looper cannot correct: connecting the preamps in series obliges to bypass one when the other is on, and assigning one Octopus channel per preamp makes some combinations useless.

Replace the external combo in the above diagram by a Sustainor. You can use the GC in CLN2 mode, the DG for the DIST-like sounds, and the Sustainor for the CLN and EDGE modes. Now, check the situation from the Octopus point of view:

A

GC

B

DG

C

Sustainor

D

Channel

Result

Off Off Off Off Nothing: useless

Off Off Off On Nothing: useless

Off Off On Off CLN

Off Off On On EDGE

Off On Off Off DIST

Off On Off On DIST: useless

Off On On Off DG+SP: useless

Off On On On DG+SP: useless

On Off Off Off CLN2

On Off Off On CLN2: useless

On Off On Off GC+SP: useless

On Off On On GC+SP: useless

On On Off Off GC+DG: useless

On On Off On GC+DG: useless

On On On Off GC+DG+SP: Useless

On On On On GC+DG+SP: Useless

Out of 16 possible switches configurations, only 4 of them are used! With this system, all the channels are used to turn the modules on and off, and there is no channel left for the options footswitches.

� This critical issue is the main reason why I have decided to build a new device that would not only switch the modules on or off, but also route the signal in an optimal manner and control the options footswitches of the Rockmodules.


DESIGN

Units selection

� Apart from the PGE2, I have kept 8 modules, selected between the 71 modules I have purchased. I could live with less, and don't really need more!

- 1 Sustainor 200 (original Double-IC) - 1 Stereo Chorus - 1 Stereo Echo - 1 Stereo Chorus/Delay - 1 Distortion Generator (one of the last units made by SR&D) - 1 Guitar Compressor - 1 Smart Gate - 1 Midi-Octopus (a rare late blue-faced type)

� A few comments can be useful:

- The PGE2 makes the classic EQ's useless. It's only a matter of connexion and signal routing, as developed below.

- Keeping a Chorus/Delay is interesting to add other sounds to the non-programmable Stereo Chorus, and for its reverb capability.

- The DG has more balls than the Sustainor, and is a cool addition for mighty distortion sounds

- The Guitar Compressor is probably the less useful unit when you have a Sustainor, but in case you want to use the Semi-CLN feature of the Sustainor, the GC can be used for the straight CLN sound. Of course, the GC is cool when you also use a tube combo beside the Rockman rack.


Modules modifications

� The first modification I made on my gear was adding an pre-distortion loop to my DG: the three bands built-in EQ is really poor compared to a real 12 or 14 bands EQ. I have later added a built-in Smart-Gate module, cloned from the Sustainor's circuit. This mod requires and additional board installed inside the DG:

The additional board includes a bypass for the built-in compressor of the DG. I don't use this feature in the present rack.

� The second important modification was to add a footswitch to the Sustainor, so that the 4 channels can be used without manual switching. This mod is based on an additional 4053 JFET switches chip:


Router principle

� The router must basically control a series of switches that will send the audio signal through the proper path: the series path of the first looper had to be replaced by a combination of parallel and series routing, with the proper A/B switches and bypass loops.

The router must also control a number of modules footswitches corresponding to sound options (Sustainor channel, Long Chorus, Sweep Stop, etc…).

� Doing that with series connections and by connecting directly several Midi Octopus to the 7 modules, plus the external preamp, would have taken 19 Octopus channels, i.e. three Midi Octopus with a lot of lost combinations.

The router includes therefore a logic card that converts the 8 Octopus switches position (0 or 1) into switching control signals used to turn the 19 control points of both audio cards and modules footswitches. One Octopus only is necessary, and all the combinations are used.


Preamps section

� The first section of the rig corresponds to the preamps: Sustainor, DG, GC and External. The global structure combines parallel and series connexions:

This structure was then developed as follows:


A few comments about this preamps section:

1 - The Sustainor and the DG are seen as two halves each (pre and post distortion) 2 - The Sustainor has two switches that allow selecting one of its four modes (not shown here) 3 - The two halves of the PGE2 are connected to the proper sends and returns, depending on which branch of the structure is active 4 - A Tuner/Mute relay is added just after the main input. This relay is controlled by a manual front switch, not by the Octopus.

Note that instead of relay hard-switches, the Sustainor and the DG's are selected by J-FET electronic switches. Their inputs are not switched, and an input buffer is installed to prevent impedance issues. This option was selected for a perfectly silent switching, knowing that true-bypass was not necessary here.

On the other hand, since the external loop is designed for an all-tubes combo, it was necessary to have relay-based true-bypass switches in the GC+Ext. branch.

� The preamps section has thus 5 control points. With the two footswitches (Channel and Alt) that control the Sustainor's modes, the preamps section allows 8 different configurations:

- Sustainor (CLN2, CLN, EDGE and DIST) - DG - GC - GC + External - External

� The objective is to select one of these 8 combinations with 3 Octopus channels only. The truth table to implement is the following (note that when an Octopus channel's LED is lit, the switch is closed: that's a logical "0", not a "1"):

Sus. CLN2 Sus. CLN Sus. EDGE Sus. DIST DG GC GC+Ext Ext

A 1 1 1 1 0 0 0 0

B 1 1 0 0 1 1 0 0

C 1 0 1 0 1 0 1 0

R2-R4 0 0 0 0 0 1 1 1

J1 1 1 1 1 0 0 0 0

R3 0 1 1 0 0 1 1 0

R5 0 0 1 1 0 0 1 1

R6 1 1 1 1 1 0 1 0

Channel 1 1 0 0 1 1 0 0

Alt 1 0 1 0 1 0 1 0


The grey cells are whatever they want. Their values were selected to optimize the logical circuit as follows:

� The channel D is dedicated to the Rhythm/Lead switching. It is connected to 4 switches:

- Sustainor's Rhythm volume - DG's Lead Boost - GC's Lead Leveller - External preamp's channel

Effects section

� The effects section starts with the Smart Gate, and is made of the Stereo Chorus followed by a Chorus/Delay and a Stereo Echo.

� The Stereo Chorus and the Stereo Chorus/Delay both have one input and two outputs. The only way to use them together is to use only the processed channel of the C/D, in series with the processed channel of the SC. The non-processed channel can thus be picked-up from the SC:

� Since these effects can be used in the FX Loop of the external all-tubes combo, some relay-based true-bypasses were necessary:

- The Smart-Gate is placed in a loop, controlled manually by a front-switch - The two chorus units are placed in the same stereo loop: when none of them is used, the loop is closed. - The Stereo Echo has its own stereo true-bypass loop

� The question with the chorus units was then to determine which combinations were useful. There were 3 Octopus channels left, knowing that the Stereo Echo uses one and that the preamps section uses 4 of them. 3 channels make 8 possibilities, the first one being of course "no effect".


� I have therefore decided no to the use the Alt-Mix switches of the CD and SC, and have thus selected the 8 following possibilities (Dry sound + 7 chorus sounds):

Dry SC Normal SC Long SC Normal + Delay SC Long + Delay CD Chorus SC Sweep Stop CD Delay

E 1 1 1 1 0 0 0 0

F 1 1 0 0 1 1 0 0

G 1 0 1 0 1 0 1 0

Chorus 0 1 1 1 1 1 1 1

SC Bypass 1 1 1 1 1 0 1 0

SC Long 0 1 0 1 0 1 0 1

Sweep Stop 1 1 1 1 1 1 0 0

CD Bypass 1 0 0 1 1 1 0 1

CD Delay 0 1 1 0 0 1 1 0

The corresponding logical circuit looks as follows:


Connexions

� The rack must have a guitar input, and two stereo outputs.

� I have added a tuner output jack: there is a manual frontswitch that both mutes the rack and sends the input guitar signal to this tuner output (the audio switching being provided by a relay).

� The external combo requires a send and return pair of jacks (connected to its guitar input and send jack), plus a channel footswitch jack. A fourth jack is necessary for the return jack (that corresponds to the input of its power amp). I have therefore added an active mixer that generates a mono output from the two stereo outputs of the Rockmodules.

� The router has also a basic FX Loop set between the preamps section and the effects section. It didn't cost much (2 jacks), and allows connecting any mono external device (a wah, a phaser, etc…). This loop is not controlled by the Router, it's only an insert connexion.

� Since the rack enclosure was large enough, I have decided to install an Ebtech Line Shifter, connected to a pair of XLR sockets. I can thus use either the unbalanced outputs directly connected to the Rockmodules, either the balanced outputs of the Ebtech Line Shifter.


LED's display

� The Octopus has LED's connected to each of its 8 channel. Yet, it is not really convenient, when you're on stage, to remember that A=On, B = Off and C = On corresponds the GC while A=Off, B=On and C=Off corresponds the Sustainor in Edge mode!

� I have thus added a LED's display unit, based on 74138 decoders, that clearly indicates which mode is active. The LED's are organized in 2 blocks:

- The left block has 8 LED's (A to H), each LED corresponding to one of the preamps mode - The right block has 8 LED's too, the 7 first LED's corresponding each to a chorus mode and the 8

th indicating that the Stereo Echo is on.

16 holes in the frontplate for the LED's indicators


THE MAKING

Enclosure and lighting system

� The 1U rack enclosure I have used comes from a Furman PL8 power conditioner (it was too deep for the rack I had originally purchased it for). This power conditioner was equipped with a cool LED's lighting system that I have kept.

All I had to do was to replace the original front panel by a new one, and to cover the rear side by an additional rear plate. I had these done by Schaeffer AG (www.schaeffer-ag.de):

The new front panel and the original Furman panel.

� For the final touch, I have used some sticker-letters provided by Vince from RMC when he sent me my 6U rack.


Power supplies

� The power supply section is in fact made of:

- A HF filter placed between the mains plug and the transformers - A 3W, 5VDC power supply for the logic circuits - A separated 5W, 5VDC power supply for the relays - A balanced +8V/-8V power supply for the audio switches and the buffers - A 12VAC transformer for the Furman lighting system

� The 230VAC comes through a first IEC socket. I have added a second socket before the main switch: I can thus connect another unit (rack or combo) without a power strip.

� The modules are powered by an IEC cord and a home-made 12 outlets power strip.


Audio cards

� The preamps audio switches is the biggest unit of the router. It has 6 jacks, 7 relays, a 4053 JFET switches IC plus a TL072 used for the Sustainor and DG's input buffer and the active stereo to mono mixer.

� The effects audio bypass is smaller: 5 relays and 4 jacks only.


Logics card

� Like all the logics cards, a few IC's, no discrete components and a lot of very thin tracks on the PCB:

LED's indicators

� This unit is made of two boards: the LED's themselves, and the decoders and inverters that drive them on a second PCB. I have superglued the two PCB's to get a compact assembly:


Integration in the enclosure

� A complete 1U rack was necessary to host all these cards. No major issue during the wiring: only patience. These two pictures were shot before and after the wiring operations


Audio cords, switching cords, mains and midi connexions

� There's a total of 33 audio cords, 10 switching cords, 8 Octopus channels cords, 2 midi cords and one power cord between the router and the Rockmodules. All these cords go through the bottom plate of the enclosure: it saves space, and there is no need for costly connectors.

� I have soldered the audio cords and the switching cords directly on the boards inside the router, and cut rectangular holes in the bottom plate of the enclosure to let them fall towards the modules:


� The same technique was used for the mains cord, the two midi connectors, and the eight-jacks spider that brings the Octopus switching signals to the logic card:

� It was necessary to identify all these cords one way or another. I have used colour-coded rings:


The result

� The rig is housed in a 6U rack made by Vince from RMC ( www.rackmountconcepts.com ). Here's the rear side, without and with the rear panel:


OPERATING THE RIG

Presets management

� The Octopus and the PGE2 can store 99 presets.

The Midi connexions of the two devices are linked, so that the Midi pedalboard (Rockman Midipedal or any similar floorboard) can send the same Program Changes orders to both (provided the Midi channels are correctly set).

� Defining a preset corresponds to:

1 - Selecting a preamp configuration

Mode (Front LED’s)

Octopus A

Octopus B

Octopus C

Rhythm/Lead (Octopus D)

A Sustainor CLN2 0 0 0 Rhythm Volume

B Sustainor CLN 0 0 1 Rhythm Volume

C Sustainor EDGE 0 1 0 Rhythm Volume

D Sustainor DIST 0 1 1 Rhythm Volume

E Distortion Generator

1 0 0 Lead Boost

F Guitar Compressor

1 0 1 N/A

G GC + Ext 1 1 0 Lead Leveller + Ext Channel

H Ext 1 1 1 Ext. Channel

2 - Tweaking the pre and post EQ’ing on the PGE2

- Modes A and B: the second half of the PGE2 is on, the first half being off

- Modes C and D: the first half of the PGE2 is in the Sustainor’s pre-distortion loop, the second half being the post-distortion EQ

- Mode E: the first half of the PGE2 is in the DG’s pre-distortion loop, the second half being the post-distortion EQ

- Mode F: the first half of the PGE2 is combined with the GC for any clean-type sound and volume. The second half is bypassed

- Mode G: the first half of the PGE2 is placed between the GC and the external preamp, as a pre-distortion EQ, the second half being the post-distortion EQ

- Mode H: the PGE2 is bypassed

3 - Selecting a chorus, delay and echo configuration

Mode (Front LED’s) Octopus

E Octopus

F Octopus

G

0 Dry 0 0 0

1 SC Normal 0 0 1

2 SC Long 0 1 0

3 SC Normal + CD Delay 0 1 1

4 SC Long + CD Delay 1 0 0

5 CD Chorus 1 0 1

6 SC Sweep Stop 1 1 0

7 CD Delay 1 1 1

The CD Chorus can be set in fast mode. The last switch of the Octopus (H) controls the Stereo Echo.

Smart Gate and Mute

� A manual switch on the front panel both mutes the rack and sends the signal to a Tuner output.

� The Smart Gate is turned off or on by a front switch. This feature is based on a true-bypass loop.


Standalone unit

� The rack can be connected to a mixer either with the jack outputs (for shorter cords, e.g. in a homestudio), either with the XLR balanced outputs (for longer cords, e.g. on stage).


Insert a mono effect

� The rack has a basic mono insert loop, placed between the PGE2’s output and the Smart Gate’s input. It can be used to insert a wah, a phaser, or basically any stompbox or external effect.

� This loop is not midi-controlled: if the external effect has no midi input, it cannot be controlled from the midi pedalboard.

Combined with another rack

� My additional rack is a 3U unit that has:

- A midi programmable PSA 1.1 from Tech 21 - A midi programmable Xpression from Rocktron - A Samson VHF wireless receiver

� The connections of this rack can be used in several configurations, thus providing a total flexibility:

- It can be used with or without the wireless system: pluging a jack in one of its inputs disconnects the Samson system. - The wireless system can be used either with the pair PSA+Xpression, either separately with the main Rockman rack. - The Xpression has a dedicated input jack that allows using this unit for an acoustic guitar. - The rack can be used as a standalone unit or as an extension of the main Rockman rack.

� The two racks (Rockman 6U and additional 3U rack) can be combined, allowing endless programmable combinations between the Rockman sounds, the flexibility of the PSA (analog simulation of any type of amp) and all the effects of the Xpression (chorus, flanger, phaser, tremolo, autopan, delay, reverb).


The connexions of the 3U rack are not made directly, as represented on this simplified diagram: they are in fact centralized in a custom switching unit that organizes the connexions to match the actual configuration. All in all, combining the two racks is equivalent to the following representation:

� The PSA can be used straight (Mode H of the router) or combined with the GC and the PGE2 (pre and post-EQ’s). It can be used with the Rockman chorus units and/or Stereo Echo, as well as with the effects of the Xpression. On the other hand, the Rockman preamps can be used with the effects of the Xpression.

The PSA and the Xpression being fully programmable and Midi controlled, the setup has a total flexibility and endless possibilities.

� Note that when the PSA and the Xpression only are used, the Rockman units are true-bypassed by their relay loops: the set-up is really equivalent to a PSA and an Xpression only, i.e. to the 3U rack alone.


Combined with a combo

� The mono output allows connecting the rack to my Boogie combo with 4 short jack cords. The setup is then self-amplified, but loses its stereo features.

� The preamps modes that are based on the combo’s preamp are modes G and H:

Mode G: GC + PGE2 pre-EQ + Combo + PGE2 post-EQ Mode H : Straight Combo preamp (no compression, no EQ)

� The channel D of the Octopus controls the channel of the combo. In Mode G, the same switch activates the Lead Leveller of the GC when the combo is in lead mode.

� When the basis sound is set, one can add some chorus and/or delay and echo to the all-tubes sound of the Boogie.

� Note that the GC, the PGE2 are controlled by true-bypass loops, like the Smart Gate, the two chorus units and the Stereo Echo. When none of these devices are used, the sound of combo is really straight, all the add-ons being true-bypassed: this is important with an all-tubes combo.

with custom audio router · pdf fileultimate rockman setup with custom audio router _____

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