VISTEK V1638 User Manual Download Page 3

VISTEK V1638 analogue audio  
distribution amplifier 

 

 

 

HU-V1638

 

 

 

       

3

 

 

 

1. 

DESCRIPTION  

 
The V1638 is a broadcast quality analog audio distribution amplifier which forms part of the Vistek V1600 
range of interface products.  It is a 3U high card which is fitted into either a V1601 or V1603 rack, from 
which it receives its power.  The V1638 is fully controllable by the DART remote control interface and either 
the V1605 remote control panel or the Vistek ViewFind PC-based host. .  A passive rear module with screw 
terminal connections, is required for all signal interconnections.  Rear assemblies with screw terminal 
connectors providing 8 outputs and rear modules with D-sub connectors providing 10 outputs are available. 
 
The unit accepts two differential mono audio inputs and distributes each of these signals to 5 differential 
mono outputs. The card can therefore be used as a stereo 1:5 distribution amplifier.   Modes whereby either 
input or the sum of both inputs is distributed to 10 outputs are provided and are selected by on-board DIL 
switches or the DART remote control interface. 
 
The V1638 has 2 population options: 
The base version has direct balanced  inputs and outputs intended for local distribution applications.  
The 

 

line version has  transformer coupling on both inputs. On either version input impedance may be set to 

600

Ω

 or  20k

Ω

 by means of on-board jumpers. 

 
INPUTS: 
 

Base version

:    2 x balanced analog channels, Z

in

 = 20k

Ω

 or 600

Ω

, max input 28dBu 

 

Line version

2 x transformer coupled  channels, Zin = 20k

Ω

 or 600

Ω

, max recommended input 

   

 

is +20dBu 

 
OUTPUTS

 

 

Monitoring: 

3.5mm Stereo jack socket  -18dBu into 600

Ω

  w.r.t. main outputs 

 

Main outputs: 

2x5 x balanced analog channels, Z

out

 

£

 50

Ω

, max output 28dBu into 10k

Ω

 

Resistor coupled expander panel: 

 

A rear panel expander is available which is fitted with a 96Way DIN 41612 connector and comes 
complete with a  locking, cable-mounted 96Way DIN41612 plug assembly with solder bucket 
terminations.  The expander has 4 resistor-coupled outputs for each of the 5 main outputs for 
channels A and B.  Using this expander panel, the V1638 can function as a 20+20 DA when driving 
high input impedances (

³

 10k

Ω

).  

 

 

 

The resistor coupled outputs of the expander panel should not be used to drive 600

W

 loads

 

 
 

A digitally controlled gain block allows independent user control of the gain of each input channel, over a 
range  -95.5  to  +31.5  dB.    The  gain  is  adjustable  by  front  panel  rotary  switches  (Local  mode)  or  via  the  
DART  control  interface  (Remote  mode).        Standard  version  offers  gain  resolution  of  0.5dB  from  both 
remote interface and panel, and hi-resolution version offers gain resolution of 0.25dB over remote interface 
and 0.5dB from panel controls. 
 
The input for each output group (Aout[1..5], Bout[1..5]) may be sourced from Ain, Bin or (Ain + Bin) and is 
selected by on-board DIL switches (Local mode) or via the DART control interface (Remote mode). 
 
The V1638 has an active first order lowpass filter on each input channel.  Rolloff point (-3dB) may be set to  
60 kHz or 120kHz by jumper option. LEDs for indication of clipping and low input for each channel are 
provided. 
 

Not more than two outputs per card may be used to drive 600

Ω

 loads at +20 dBu or more 

Summary of Contents for V1638

Page 1: ...1 VISTEK V1638 ANALOGUE AUDIO DISTRIBUTION AMPLIFIER USER GUIDE www pro bel com ...

Page 2: ... 2 INSTALLATION 4 2 1 Rear Panel Connections 4 Table 2 1 1 5 Figure 2 1 2 6 Table 2 1 2 6 2 2 Input Impedance 7 2 3 Input Mode 7 2 4 Lowpass Filter 8 Figure 2 4 1 8 3 OPERATION 9 3 1 Front Panel 9 3 2 LED Indications 9 3 3 Gain Adjustment 10 3 4 Monitoring Jack 11 3 5 Dart Interface 11 ...

Page 3: ...coupled channels Zin 20kΩ or 600Ω max recommended input is 20dBu OUTPUTS Monitoring 3 5mm Stereo jack socket 18dBu into 600Ω w r t main outputs Main outputs 2x5 x balanced analog channels Zout 50Ω max output 28dBu into 10kΩ Resistor coupled expander panel A rear panel expander is available which is fitted with a 96Way DIN 41612 connector and comes complete with a locking cable mounted 96Way DIN416...

Page 4: ...B rear panels are shown below 1U panels are similarly marked Table 2 1 1 details connections to these standard panels Figure 2 1 2 and Table 2 1 2 describe signals and connections to the DIN41612 cable mounted plug supplied with the resistor coupled expander panel Note that these pin numbers refer to those stamped on the back of the supplied cable mount connector with solder bucker terminals A IN ...

Page 5: ...rce Channel B differential input B In 7 Zin 20kΩ 600Ω max input 28dBu A1 out 14 V1638 Group A outputs A1 out 1 Zout 50Ω max output 28dBu A2 out 16 A2 out 3 A3 out 17 A3 out 4 A4 out 18 A4 out 5 A5 out 19 A5 output is not available on screw terminal A5 out 6 rear modules Only DSUB rear module has A5 GND 2 7 13 15 V1638 All screens from V1638 should be grounded 20 on the V1638 o p connector B1 out 2...

Page 6: ... out B51 out B11 out 2 A11 out B51 out B11 out 3 A12 out B52 out B12 out 4 A12 out B52 out B12 out 5 A13 out B53 out B13 out 6 A13 out B53 out B13 out 7 A14 out B54 out B14 out 8 A14 out B54 out B14 out 9 A21 out GND B21 out 10 A21 out GND B21 out 11 A22 out GND B22 out 12 A22 out GND B22 out A1 A2 A3 A4 A5 A11 A12 A13 A14 A21 A22 A23 A24 A31 A32 A33 A34 A41 A42 A43 A44 A51 A52 A53 A54 B1 B2 B3 B4...

Page 7: ...ould be used when the inputs are driven from any direct coupled sources electronically balanced or quasi balanced line drivers with low output impedance If the inputs are driven from a 600Ω balanced line the input impedance may be set to 600Ω by using the jumper settings shown below Note that the input impedance of the two channels may be set independently Figure 2 4 1 shows the location of the ju...

Page 8: ...by jumpers as per the table below Note that the filters of the two channels may be set independently Figure 2 4 1 shows the location of the jumpers 3dB rolloff point Jumpers Channel A f 3 60kHz LK3 CLOSED Channel B f 3 60kHz LK2 CLOSED Channel A f 3 120kHz LK3 OPEN Channel B f 3 120kHz LK2 OPEN The figure below shows the V1638 and the location of all the jumpers referred to in Section 2 2 4 Figure...

Page 9: ...have a fast attack and 0 8s retriggerable hold characteristic The output signal is monitored and the LEDs will trigger at 28dBu just before the onset of clipping The LED will be on continuously of sustained clipping occurs A yellow LO I P LED is provided for each channel These have a slow attack 0 8s and fast decay characteristic The input signal is monitored and the LEDs will trigger when the sig...

Page 10: ...96 mute 0 0 1 88 1 0 5 2 80 2 1 0 3 72 3 1 5 4 64 4 2 0 5 56 5 2 5 6 48 6 3 0 7 40 7 3 5 8 32 8 4 0 9 24 9 4 5 A 16 A 5 0 B 8 B 5 5 C 0 C 6 0 D 8 D 6 5 E 16 E 7 0 F 24 F 7 5 It can be seen from the table that the gain applied is the sum of the settings of the COARSE switch and the FINE switch Care should be taken when setting the gains in an application to allow sufficient headroom so that the V16...

Page 11: ...Bu level on the monitoring output which is designed to be used with professional quality headphones of 300 600Ω impedance eg Sennheiser HD520 3 5 Dart Interface The V1638 has a serial EEPROM for reading and writing card details through the DARTbus in the same manner as other V1600 range cards In addition the unit has several read and write registers which will be discussed Details of the DART inte...

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