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Resistance

 

Normally, the ideal aim is to match the amplifiers input impedance to that of the cartridge, this will ensure maximum signal 
transfer, and minimise noise (hiss) —however, if you do not have this information (remember you can check the                    
manufacturer’s website), you can safely experiment with any of the possible values—again, tune by ear to get the most    
pleasing sound. 

 

Most MM cartridges are 47k, high output MC cartridges also tend to benefit from a high resistance setting, however low      
output MC cartridges are invariably low impedance, suggesting a low resistance setting. Please experiment with this setting,    
as the minor adjustments can make worthwhile improvement to the overall performance.

 

Capacitance

 

The effect of the capacitance setting is most obvious at high frequencies, but can be quite subtle. The values chosen are      
affected by the design of cartridge, but also but the connecting cables—so there is no absolutely correct setting, and            
experimentation is recommended until you find a setting that suits your set

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up and personal preference.

 

Low impedance designs tend to be largely unaffected by capacitance settings, but high impedance designs, and especially MM 
cartridges can be greatly affected. Start by okaying a selection of tracks you know well and adjust the setting until you find one 
where you feel the best balance of detail and musicality are achieved.

 

LINE INPUT

 

The Sigsum has Four line inputs: two Balanced and two Unbalanced— which you choose depends on your source equipment, 
but if you have the choice, we recommend using Balanced. These are referred to as Line Level inputs, and can be used to    
connect to any standard piece of audio equipment, such as CD, Media Streamer, or FM/DAB Tuner.

 

Unbalanced

 

The unbalanced inputs make use of the two pairs of RCA connectors immediately above the  three pin XLR sockets—these 
sockets are labelled RCA 1 and RCA 2.

 

Summary of Contents for SIGSUM

Page 1: ...SIGSUM High Performance Integrated Amplifier USER MANUAL ...

Page 2: ...nt 5 Connection Types 5 Phono Input 6 Line Input 7 Pre out 8 Loudspeaker Connections 9 Mains Power 10 Headphone Use 11 Mono Operation 11 Mute 11 Amplifier Protection 11 Troubleshooting 12 Specifications 13 Declaration of Conformity 14 Warranty 15 Table of Contents ...

Page 3: ...t the unit is switched off and unplugged from the mains before connecting or disconnecting any other equipment to your Sigsum This is to protect your speakers from any momentary high level signals which due to the high power capabilities of the Sigsum could cause damage There are no user serviceable parts inside please do not under any circumstances remove the cover of the Sigsum doing so would ex...

Page 4: ... the same high performance levels with regard to sensitivity and bandwidth with the balanced inputs inherently offering the best performance with regards to noise rejection The input sockets themselves have been chosen to offer the best in terms of audio performance and long term reliability High performance Phono stage with adjustable gain input resistance and capacitance Derived from our hugely ...

Page 5: ...orm of a shield in the case of coaxial cables The use of coaxial cables can improve susceptibility to noise however it can never be completely removed BALANCED CONNECTIONS A balanced connection is different in that there are two signal cables one with the positive phase of the signal and the other with the negative a mirror image of the positive signal if you like When the signal reaches the ampli...

Page 6: ...switches accessible through the apertures on the bottom towards the rear of the case Using a pen tip you can slide each arrow to either the ON of OFF position Moving Magnet A standard Moving Magnet cartridge is the easiest to configure simply ensure all the switches are set to OFF this is a starting Sensitivity There are three sensitivity levels available increasing from MM MC LOW and MC HIGH Chec...

Page 7: ...ted by the design of cartridge but also but the connecting cables so there is no absolutely correct setting and experimentation is recommended until you find a setting that suits your set up and personal preference Low impedance designs tend to be largely unaffected by capacitance settings but high impedance designs and especially MM cartridges can be greatly affected Start by okaying a selection ...

Page 8: ...lease make sure that the plugs are pushed in all the way and that these engage correctly you should hear a click when they engage PRE OUT The Sigsum is capable of outputting to an external amplifier should you require This signal is affected by the position of the volume control so your Sigsum takes the role of a high quality Pre Amplifier allowing you an upgrade path to the likes of the Celsus po...

Page 9: ...be kept as low as possible This can be achieved by keeping cable runs as short as necessary and using a cable with a large cross sectional area Correct Phase It is important to ensure that your loudspeakers are connected in phase This simply means that for both the left and right channels the positive output connections are connected to the positive terminals on the loudspeakers and similarly the ...

Page 10: ...e mains should be left as the last step Switching on Before switching the unit on ensure the volume control is turned to its minimum level fully anticlockwise Your Sigsum amplifier has a mains switch which is hidden on the bottom of the unit in the middle of the front panel There will be a few clicks from internal relays as the protection circuit is activated during the first few seconds There is ...

Page 11: ...the Mute button again its operation is indicated by a blue LED Press the button again to go back to normal operation Always check that the volume setting has not been inadvertently increased before unmuting the amplifier Amplifier protection In the event of a fault occurring the unit will protect itself this will happen when a DC offset or short circuit is detected or if the unit exceeds its maxim...

Page 12: ... that any headphones have been unplugged from the Sigsum 5 Check that the speakers cables are correctly connected at both ends Distorted sound 1 If the volume is excessively high turn the volume down 2 If you are listening to the Phono input reduce the sensitivity see PHONO INPUT Hum from Phono input 1 Ensure that the turntables earth cable has been attached to the earth post on the rear of the am...

Page 13: ... 0 5dB 5Hz 70KHz Neumann HF correction Noise A weighted MM 81dB MC 67dB high setting Channel separation 85dB 5Hz 20KHz Line RCA and XLR Nominal sensitivity 340mV Volume Full 100W XLR Input impedance 33 kΩ XLR 82 kΩ RCA Maximum input 11 Vrms XLR Frequency response 5Hz over 80kHz 1dB Signal noise ratio XLR Awtd 50 W ref 1V input 100 dB RCA Awtd 50 W ref 1V input 100 dB OUTPUTS Preamplifier output No...

Page 14: ...weight 34 5kg DECLARATION OF CONFORMITY EC Declaration of Conformity 06 December 2017 We declare that our Sigsum integrated amplifier conforms to directives and harmonized international standards EMC 89 36 EEC Electromagnetic conformity BS EN 60065 1994 Safety requirements for mains operated electronic and related apparatus for household and similar use CENELEC HD21 22 Flexible cables and cords EN...

Page 15: ...nsequential damages of any kind arising from the sale or use of its products The warranty applies to ex demonstration product using manufacture date as purchase date Where the product is sold under a consumer transaction as defined by the Sale of Goods Act 1979 the statutory rights of the purchaser are not affected by this warranty Products are sold on the basis of specifications applicable at the...

Page 16: ... Kimbolton Huntingdon Cambridgeshire PE28 0LW ENGLAND Tel 44 0 1480 869 900 Website www avidhifi com Email info avidhifi co uk Company Registered No 5435528 VAT Registration No GB 694 9858 48 Directors C Mas S J Mas Updated 9th October 2018 ...

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