Audio Developments AD 245 Скачать руководство пользователя страница 2

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Time was when it became necessary to update the ubiquitous AD145 PICO mixer.
Our survey showed two main requirements: as well as Audio Developments' build
and audio qualities, narrower and shorter modules were required, and the simple but
effective equaliser from PICO had to be retained.

By this time, 4-track recording

equipment had begun to trickle into the marketplace (Nagra D etc), so we decided to
give the new mixer four outputs.

Because of the lower noise-floor of modern digital

recorders, the level of input signals may be reduced.

We have taken advantage of

this fact and lowered the slope ratio of the limiters to 7:1.

By so doing, not only is

signal distortion greatly reduced, but also the artefacts associated with limiters
become much less noticeable or objectionable.

Also, sixty years after the event,

sound engineers have come to realise the potential of Blumlein's M-S techniques; to
this end,

facilities

have

been

incorporated

to

take

advantage

of

these

techniques. The result is AD146 - a four-output mixer.

This was followed by AD148 - edit mixer.

Based on AD146, two comprehensive left

and right monitor modules have been added for editing purposes.

If a mic/line

module is included for commentary or voice-over purposes, its input-gain switch can
be changed to a potentiometer, and its gain structure changed to ensure consistent
level matching with a fixed, mechanical point of reference.

Unfortunately, this way of

working does reduce headroom and also compromises a mixer's noise performance.

After AD146/AD148 it was back to the drawing board.

Our customers were still

demanding a two-output mixer - as a true replacement for the PICO, and with the
PICO's simplicity.

Despite past assurances to the contrary, T powering is still

required.

And could we incorporate auxiliaries?

And could we possibly bring it to

market at 'entry level'? We have, and we have and that's MERCURY (AD147).

AD149 completes the 140 series of mixers, and has a repertoire of party tricks not to
be found in any other mixer - not even for 'ready money'.

The design team took, as

its starting point, our list of all the ideas and suggestions presented to us over the past
few years.

Many of these requests came from film-sound recordists - a sub-set of

recordists we have unintentionally neglected in the past.

Since the days of R & D for AD146, channel insert points suddenly became de
rigueur.

It transpires that many sound engineers have experienced the power of

FLEX-EQ, our industrial-strength equaliser, and wish to be able to use it when making
original recordings.

Содержание AD 245

Страница 1: ...ETY INSTRUCTIONS 5 POWERING 6 TECHNICAL SPECIFICATION 8 EQUALISATION CURVES 11 BLOCK DIAGRAM 12 CONNECTOR PANEL 13 CONNECTIONS 14 INPUT MODULE 16 OUTPUT MODULE 18 ADJUSTMENTS AND CALIBRATIONS 21 AD100...

Страница 2: ...c line module is included for commentary or voice over purposes its input gain switch can be changed to a potentiometer and its gain structure changed to ensure consistent level matching with a fixed...

Страница 3: ...te the 140 series We d reckoned however without the persistence nay insistence of our customers for a mains operated version of the AD146 with four auxiliaries we ve called it AD144 Radical change and...

Страница 4: ...Temperature check the meter glasses for condensation If the package has been in transit during cold weather leave the mixer for at least 12 hours to allow it to return to normal room temperature Any m...

Страница 5: ...ected to the module Module fix screws Hexagon head screws are used to fix the modules and back cover The size being 1 5mm HEX A F with a 2 5M thread If it becomes necessary to remove modules or back c...

Страница 6: ...ly unit that is connected to the mains supply to drive the mixer it must be CONNECTED TO EARTH In certain types of malfunction or breakdown earthing provides a path of least resistance for electric cu...

Страница 7: ...rnal power source PIN 1 is the 0v connection and a voltage in the range 12v to 15v DC should be supplied to PIN 4 The power source should be capable of delivering approximately 400mA allowing some cap...

Страница 8: ...7 THIS PAGE IS BLANK...

Страница 9: ...DER MAX OUTPUT 23dBm L R TRANSFORMER BAL 600R LOAD MONO TRANSFORMER BAL 18dBm H PHONE MONITOR UNBAL 600R LOAD TB SEND UNBAL OUTPUT IMPEDANCE 60R L R MONO 20R MONITOR 20R TB SEND FREQUENCY RESPONSE 0 1...

Страница 10: ...TRANSFORMER 12dB OCTAVE 3dB 150Hz 3dB 90Hz OUTPUT LIMITER THRESHOLD 8dB RATIO 7 1 ATTACK 2 SETTINGS INTERNALLY SWITCHABLE 1 4mS 2 0 8mS RELEASE 2 SETTINGS INTERNALLY SWITCHABLE 1 250mS 2 80mS FACTORY...

Страница 11: ...AL SPECIFICATION MECHANICAL SIZE 6 I P 8 I P 10 I P 12 I P A 320 381 442 503 B 295 356 417 478 ALL DIMENSIONS IN MILLIMETRES WEIGHT 6 I P 8 I P 10 I P 12 I P 6 7 8 9 ALL WEIGHTS IN KILOGRAMS EQUALISAT...

Страница 12: ...11 AD 245 HIGH AND LOW EQ 20 15 10 5 0 5 10 15 20 10 100 1000 10000 100000 FREQUENCY dB AD 245 MID EQ AND HPF 20 15 10 5 0 5 10 15 20 10 100 1000 10000 100000 FREQUENCY dB...

Страница 13: ...12 BLOCK DIAGRAM...

Страница 14: ...o output XLRs L R 3 Mic Line input XLRs 4 Headphone monitor jack 5 External DC power input 6 Off On switch internal and external 7 Stereo return jacks L R and calibration preset 8 Subsidiary connector...

Страница 15: ...O UNBALANCED JACK Tip Signal Tip Left signal Ring Signal Ring Right signal Sleeve Shield Sleeve Shield The 6 pin XLR connector SUB 8 carries all signals to and from an outstation Reverse talkback leve...

Страница 16: ...ts either internal batteries or an external DC source Power to the mixer is confirmed by the MIX ON LED on the output module The LED flashes when the internal voltage falls below the safe operating le...

Страница 17: ...e input 3 Input gain control 4 Phase change 5 High pass filter 6 EQ Selector 7 Panoramic potentiometer 8 Pre fade listen 9 PFL indicator LED 10 Overload indicator 11 High frequency control 12 Mid freq...

Страница 18: ...r The input gain of the microphone amplifier is set by the 6 position switch 3 The range of this control is 50dB in 10dB steps For line level signals an input attenuator is inserted via switch 2 Follo...

Страница 19: ...R or MON to meters 8 Line up tone 9 1kHz or 10kHz line up tone 10 Limiter link 11 Limiter LEDs 12 Output limiters 13 Direct or Return to HP 14 Left only 15 Right only 16 Monitor output level 17 Mono o...

Страница 20: ...tput Battery status is read on the upper meter by BATT 5 and the meters may be illuminated by ILL 6 overuse of this function will rapidly drain the batteries When the internal voltage drops below a sa...

Страница 21: ...output is in the L R domain the matrix will enable mono compatibility to be assessed on the left earpiece and out of phase components to be checked on the right earpiece When working entirely in the M...

Страница 22: ...volts is at 0VU On a PPM meter it is indicated by a separate marking yellow on a BBC scale and red on an N10 and SDR scale VU meter there is one preset on the VU meter PCB for meter adjustment Set an...

Страница 23: ...r reading at 18 Repeat this procedure to obtain an accurate reading at each of these three points Now check the calibration of all meter points SDR scale with a main output signal level of 6dBu adjust...

Страница 24: ...t signal to just greater than 8dBu with the limiter deselected Introduce the limiter and adjust VR4 until the output signal falls to 8dBu This is the THRESHOLD setting If a different threshold setting...

Страница 25: ...tted in an AD140 series mixer they may be recharged in situ from AD100 09 power supply whether the mixer is in use or not Maximum current is set at 250mA in addition to the 500mA of current supplying...

Страница 26: ...25 TECHNICAL LIBRARY...

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