Tube Technology SeM-02 Скачать руководство пользователя страница 26

large dynamic range of the audio signal; and
the other is that the loading is not always
resistive. It is under these (usually uninten-
tional) wrong conditions that differences may
show up.

Let us consider the over driving first. Owing
to continual improvements in recording and
playback technique, the possible dynamic
range of music signals- from either disc or
tape - is greater now than it used to be. As a
tentative estimate, it appears that the loadest
passage of a modern disc recording maybe
40dB above the average sound level. Now it
may be said that amplifiers in a high fidelity
system ought theoretically to be able to
reproduce the loudest of loud bursts without
distortion. However, to allow for 40dB above
50mW - not a very high listening level - a
power capability of 500W would be required;
and further developments may make the
figure even greater. One seems to hear a cry
of “where is it all going to end?” Anyway,
when setting up an amplifier system one
adjusts the gain to give the prefered average

sound level. One has no way in advance of
knowing in advance whether there is an
exceptionally loud passage coming that will
over drive the amplifier. Bursts in excess of
30dB above the average are quite rare.

If we accept, then, that occasional over
driving is virtually inevitable, how will the
amplifier behave? We now come to the first
possible reasons why tubes and semiconduc-
tors may “sound different”.

Presented with an over large signal, tubes
merely clip the peaks, delivering a flat-topped
waveform while the over driving is taking
place. The limiting may occur at the grid as
the circuit resistances are commonly such as
to prevent it from being driven more than
slightly positive, or it may be the results of
coalescence of characteristic curves at lower
voltages. The ear is surprisingly tolerant of
such clipping when it occurs only on these
occasional load bursts.

The semiconductors used in audio amplifiers
are virtually always bipolar transistors, either
discrete or integrated. They require base

Tube Renaissance 10 - 2

Содержание SeM-02

Страница 1: ...THE SEER PREAMPLIFIER BY TUBE TECHNOLOGY USER S MANUAL Applicable to PHONO LINE MODEL TT PART No SeM 02 Printed in England 1st Edition May 1994 i...

Страница 2: ...ding this manual please put it away in a safe place for future reference We have done our utmost in the design and build of the Seer to ensure you a low maintenance trouble free preamplifier that will...

Страница 3: ...udio Connection Rear Panel Connecting the Seer s Inputs Outputs Operating your System Front Panel Switching your Seer On Off Front Panel Functions Operational Notes Running In Burning in your Preampli...

Страница 4: ...hasis or a minor heading Italic Bold refers to a sub heading of a chapter This symbol refers to Notes containing important information set off from the text THIS SYMBOL REFERS TO CAUTION MESSAGES AND...

Страница 5: ...he following items are included in the packaging of the Seer 1 x Seer Preamplifier 1 x Reference Manual Registration Card 1 x IEC Mains Leads only on serial nos 6022 and up 1 x Allen Key Your pre ampl...

Страница 6: ...rear panel of the unit See diagram 1 Check that this voltage complies with your local supply When using a pre power combination it is essential to ensure that no earth loops occur this is when too man...

Страница 7: ...LOW E or EARTH or BLUE N or NEUTRAL or BLACK BROWN L or LIVE or RED If your mains plug has a fuse please fit a fuse with 5A rating IF YOUR SEER IS NOT SET CORRECTLY FOR THE LOCAL SUPPLY OR IF YOU INTE...

Страница 8: ...reamplifier should be allowed as this is where most of the heat is generated Dedicated racks are available for housing your tube equipment contact your dealer or Tube Technology Do not locate the prea...

Страница 9: ...Audio Connection 4 1 Audio Connection This chapter contains information on Connecting the Seer s Inputs Outputs Rear Panel Diagram 1...

Страница 10: ...eck The source to be recorded is selected by means of the input selector switch on the right hand side of the front panel See Diagram 2 This terminal is used to ground any inteconnecting leads which h...

Страница 11: ...e moving coil cartridges with outputs in the order of plus 0 5millivolts An external step up device is required for use with low output moving coil cartridges If you have a Line Seer this input is abs...

Страница 12: ...Operating your System 5 1 Operating your System This chapter contains information on Switching your preamplifier ON and OFF Front Panel Functions Operational Notes Front Panel Diagram 2...

Страница 13: ...lume Control Selects the source of the input signal PHONO Selection for listening to a Vinyl Recording from a Turntable Not functional in a Line Level Seer CD Selection for listening to a Compact Disc...

Страница 14: ...es peak performance levels 15 20 minutes after switch on Unless absolutely necessary it is not recommended that you leave your preamplifier permanently switched on this only wastes electricity and tub...

Страница 15: ...ss simply allows for new components like tubes capacitors and resistors to settle and sweeten enhancing the amplifiers sonic performance An estimated 40 hours of operation allows your Seer this runnin...

Страница 16: ...Anodised parts such as the front panel and top covers of the Seer painted parts such as the bottom cover are best cleaned with a damp cloth then buffed with a dry cloth DO NOT apply any kind of polish...

Страница 17: ...Diagram 3 Maintenance 7 2 WARNING ELECTRIC SHOCK HAZARD HIGH VOLTAGES EXIST WITHIN THE EQUIPMENT EVEN AFTER THE UNIT HAS BEEN DISCONNECTED FROM THE MAINS SUPPLY...

Страница 18: ...lifier 1 Ensure IEC plug on the mains lead is a snug fit into the IEC connector on the rear panel 2 Check the mains fuse located inside the fuse holder next to the switch Disconnect mains connector be...

Страница 19: ...oticeable if the tube has been fitted in the phono stage 2 Change the tube for another 1 This is caused by breakthrough on the selector switch it cannot be avoided unless complicated sound degrading c...

Страница 20: ...to 240V The primary of the mains transformer can be changed from 120V to 240V this is done by changing the taps on the transformer It is recommend that only an experienced technician carries out this...

Страница 21: ...tage Dimensions Weight ECC83 12AX7WB x 2 LINE x 4 PHONO 5V max 300mV in LINE 5Hz 120 KHz 1W 0 001dB PHONO 30 Hz 30KHz 3dB LINE 300 mV output 1V PHONO 0 50mV 150pF output 1V LINE 200 Ohms PHONO 47 KOhm...

Страница 22: ...d dealer under a consumer sale agreement at or near the recommended retail price The words consumer sale shall be construed in accordance with section 15 of the Supply of Goods Implied Terms act 1973...

Страница 23: ...stration To transfer this guarantee to subsequent purchasers the new owner must notify Tube Technology of their name address and serial numbers of the equipment This equipment should be packaged in th...

Страница 24: ...ault experienced In the event of equipment being returned which on test is found to comply with the published specifications the manufacturers reserve the right to charge a reasonable fee for testing...

Страница 25: ...ective differences to a listener between tubes and semiconductor am plifiers can they be explained technically One thing should be clearly understood it is possible to design either a tube or a semico...

Страница 26: ...y when setting up an amplifier system one adjusts the gain to give the prefered average sound level One has no way in advance of knowing in advance whether there is an exceptionally loud passage comin...

Страница 27: ...in a transistor that has been turned on hard in fact the larger the base current the longer will be the turn off time In audio transistors that have been over driven this time may be of the order of h...

Страница 28: ...y subjective effects that have been attributed to transistors Ways may be found of eliminating or obviating these effects in a transistor amplifier design but there is a simplicity about tube circuitr...

Страница 29: ...is something to be said for having an output transformer Perhaps enough has been said to suggest at least that the advantages are not entirely on the side of semiconductors and that points can be made...

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