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Version  1d: 01.99

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Mute-relay modification

A modification involving improving the
switch on/off threshold of the mute relay
was introduced shortly after production
commenced.

This involves the changing of resistor
R46, initially fitted as 100kR to 200k or
220kR. It is not practical or necessary to
remove the PCB, and the fitted resistor
can be cut out, and a substitute resistor
carefully soldered in it’s place.

Summary of Contents for Circle 5A

Page 1: ...ean sharp image where as the default around 60lpi may give a dark image to pictures WARNING DANGER OF ELECTRICAL SHOCK Opening mains operated equipment like the HHB Circle5A incurs a risk of electric...

Page 2: ...Version 1d 01 99 Page...

Page 3: ...ement notes on testing Page 4 Opening the Circle5A Page 5 Circuit diagram active filters Page 6 Circuit diagram power stage Page 7 Circuit diagram mains input Page 8 PCB silk screen top view Page 9 Pa...

Page 4: ...wo input connectors a master input an isolated XLR following the nor mal European wiring convention Pin 1 shield ground Pin 2 Live hot signal Pin 3 Cold return signal Also provided is a secondary inpu...

Page 5: ...cross head screwdriver of the Superscrew or Pozidrive NOT Phillips type The Superscrew type has 4 thin grooves into which the Superscrew screw driver securely locates If the Phillips type is used the...

Page 6: ...speaker is powered and awaiting a signal is the illuminated power on LED fixed in the tweeter face plate The power on LED is driven from the rectified unregulated transformer secondary and is a positi...

Page 7: ...Photograph of the amp module viewed from the inside Version 1d 01 99 Page 7...

Page 8: ...ld of the mute relay was introduced shortly after production commenced This involves the changing of resistor R46 initially fitted as 100kR to 200k or 220kR It is not practical or necessary to remove...

Page 9: ...he arms of the preset s X is pointing to 5 c clock fully clockwise Turning this arm anticlockwise until it points to 1 o clock i e nearly half way anti clock wise reduces the tweeter level by 1dB turn...

Page 10: ...Version 1d 01 99 Page 10...

Page 11: ...Connections to the Circuit board Version 1d 01 99 Page 11...

Page 12: ...Version 1d 01 99 Page 8...

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Page 14: ...Version 1d 01 99 Page...

Page 15: ...V Elko C20 68 pF Keramik C21 100 nF Folie C22 100 nF Folie C23 470 nF Folie C24 68 pF Keramik C25 47 uF 50V ELKO C26 47 uF 50V ELKO C27 47 uF 50V ELKO C28 100 nF Folie C29 68 pF Keramik C30 47 uF 50V...

Page 16: ...4 mm Cinchbuchse Monacor T 706G Kabelsatz Kaltger te Poti XLR Lackierung Platte K hlk B gel K hlk rper SK 81 300 AL Isolierfolie 25 x 50mm keraterm Trafo 120VA 2x25V Netzanschl 6762B Heil Sicherung 1...

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