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OPERATING INSTRUCTIONS
FOR PHONO PREAMPLIFIER
Vanguard II
Version 1, Jan2003
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Analogic
Even more than two decades ago, so the propagandists of the new medium Compact Disc
wanted it, the record had retired. The number of sold records removed from year to year,
those of the CD’s increased, until apparently now eternally of yesterday ones and the
nostalgic people at unexplainable expenditure maintained and supplemented their record
collections and had still no CD player. Yes, in addition maintained they their record player
makes more music... and harvested a pitiful smile.
But parallel to this development remarkable happens - and the smiled at record lover and
convinced analogue fan formulated not without sneers:
“The claiming already in the year 1980 perfect CD player is constantly improved and to the
yardstick of this striving the music rendition becomes similar good analogue record player but
not only this. At public demonstrations once CDs were thrown in the surprised public for the
demonstration of the insensitivity by Compact Discs then today the realization made itself
broad that they want to be treated just as carefully as records, even more, demagnetised,
frozen, painted or ground and with coatings provides to sound only correct to be supposed. A
similarity or an agreement with living disk washing machines, pucks, disk platelayers and
needle cleaners is purely coincidental and not intended.
If the first CD Player made music apparently still in each situation in life and on each
underground perfectly, then its descendants received beside constantly improved
digital/analogue transducers always more complex housings, damping and, a beggar who
thinks bad thereby, sub chassis drives or belt drives.
Almost exorbitantly expensive CD drive assemblies with separate digital/analogue
transducers recruit for itself with the statement, now, finally, in such a way to sound like the
best record players. But the uneasiness, which in-crept in things CD in the course of the
years, seems remained. New digital formats, like SACD and DVD, urge on the market and
are to now reach, what was already promised twenty years ago: “SACD has a transmission
range as large up to 64 times as the CD. Thus results a refinement of the signal, which
corresponds to analogue technique. (dpa/dwe, 14.11.2001)
We consider the evaluation of memory procedures, which work with data reduction, before
this background simply renounce able. Rational at this newest stage of the development of
digital music storage media, which increases not the transmission range, but the scanning
rate, is the insight that people had underestimated substantially the quantity and quality of
musical information from the record groove, once again the new wasn’t even the. In the age
of the permanent announcement of technical sensations and revolutions we form an analogy:
High End Audio won’t invent each month again. Persistent, consistent advancement and
innovation in smaller and larger steps, which is relevant before the introduction on the
market, define High End for us at the last state of things.
What now? Sell all CDs as once unfortunately, the record collection? Perhaps the view
continues to help that tone carriers and their artful packing are more than only technical,
exchangeable canned goods. The speech is about cultural properties and time documents,
which are not to be excluded straight from the individual Biography. In this regard the record
already furnished the proof of their, also technical, longevity as canned goods, that of the CD
isn’t done yet. There it is nevertheless reassuring that in the year 2001 the number of the
sold records doubled itself to more than in relation to the previous year. (dpa/dwe,
14.11.2001).
The latter makes at the same time hope for a further creative next to each other, which we,
apart from the conservative aspect, agree with. Because like the attempt of the CD to be
finally records heir had lead to ever better CD-players, without which already in view of the
existing software only few can to do and want seriously, then the competition of the new
medium has the similar record rendering again accelerated and on, at the gloss times of the
old tone carrier,
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a probably non-existing level elevated. Never before there were as good drive assemblies,
tone arms and pick-up systems as today. Oh, and phono amplifiers with which we would be
finite with the topic.
How little has to do the complex task of an equalizer pre amplifier with pure opinion, you’ll be
told in the next chapter. Who doesn’t want to know it so exactly first, may skip this chapter,
but only this, to find out, how the Vanguard II wants to be up and adjusted, attached, served
and treated, thereby it can helps to transform the high-quality, but sensitive phono signals of
your records in the best possible way into music and to thank you itself in our name for your
investment.
Little phono technology and technical description of the Vanguard II
With the
Vanguard II concerns it a phono pre amplifier for the equalization and reinforcement
of signal voltage coming from a record player.
Signal voltage coming from a pick-up system is unfortunately not as with CD-players or other
audio devices over the shown frequency range linear, but contained with 20 cycles per
second approx. 1000 time smaller signal than with 20 kHz. Without equalization the music
would therefore sound itself extremely full of high tones.
The task of the phono amplifier or better said the equalizer pre amplifier is it now to produce
a linear audio signal from this bent rendition characteristic, i.e. with all shown frequencies
equivalent loud.
Thus however not enough, the signals of the pick-up systems are also still very weak (or
quietly), so that a relatively high reinforcement is needed to raise the audio signal to the
level, which is usually available with all other audio sources (except microphones). With MC
pick-ups the task of the equalizer pre amplifier is more fastidious, because the output voltage
of these systems is usually lower even again around the factor 10 (i.e. 20dB) than with MM
pick-ups.
Furthermore the different pick-up systems need also another appropriate feed impedance,
which can be adapted individually for each pick-up, to be able to unfold their qualities
complete.
The demands, which are made against a phono amplifier, therefore are:
1. Exact equalization of the input signal
2. High, adjustable reinforcement
3. Individual adjustment of the feed impedance
The first task, exact equalization of the input signal, can be mastered only if you uses
highly exact construction units in the equalizer part of the phono amplifier. Therefore we
measure each construction unit for this stage with highly precise measuring instruments. The
values of the assigned construction units are selected here on a deviation from less than 1%!
Identical pairs of construction units are always formed for the two stereo channels, to exclude
channel inequalities. In this way the
Vanguard II produces an almost perfectly linear output
voltage.
The second task, high, adjustable reinforcement, represents a problem of completely
different kind. High reinforcement of the information signal means at the same time also high
reinforcement of spurious signals. The main spurious signal is thereby the noise. This
problem can be solved only satisfyingly with very efficient and at the same time low-noise
amplifier stages. In the
Vanguard II we use highly exact operation amplifiers, which besides
exhibit extremely small distortion values.
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The other spurious signal, which leads to problems in phono amplifiers again and again, is
the so-called humming. This humming has usually three causes: Stray effect through nearby
mains transformers, careless supply voltage and incorrect printed circuit board design.
Over to avoid the stray effects by the mains transformer the power pack of the Advance is
accommodated in a separate housing and so it can be set up in some distance to the set.
A special power pack circuit supplies the sensitive amplifier circuit with filtered direct current.
However in order to exclude net influences completely, we recommend to use the batterypower supply “TRIGON
Volcano II” with a lead gel accumulator, which is optional switchable,
with and without power pack support, to supply the
Vanguard II with (on principle) really
clean direct current.
The printed circuit board design is characterised among other things by a special star shaped
arrangement of the pig pus courses, so that humming signals cannot disturb the sensitive
amplifier stages.
The reinforcement can be adjusted individually in 16 stages by small mini switches, which
are attached on the lower surface of the set. With the help of that table indicated far down
you could make the correct attitude for the respective pick-up system there.
The third task, individual adjustment of the feed impedance, can be settled with the
Vanguard II by a mini switch on the lower surface of the set. Here are six different
adjustment resistances and this means 64 combinations are for the adjustment of one MC
pick-up and 2 capacities, so there are four combinations for the adjustment of a MM pick-up
at the disposal. Information about all combinations gives a table indicated far down.
You recognize already by the larger number of possibilities of adaptation of a MC pick-up
that the
Vanguard II treats MC pick-ups preferentially. The reason lies in the fact that the
majority of the offered High-end pick-up systems are nowadays of the type MC.
Because the
Vanguard II is a separate phono amplifier that is connected with the pre- rather
full amplifier via link cable, there are also placed high requirements to the output stages of
the amplifier. Here we have decided us for an output stage, which makes a sufficiently small
output resistance available, so that also cables of more than 2m lengths can be attached.
This makes it possible to set up the
Vanguard II in direct proximity of the record player and to
keep so the cable length between record players and
Vanguard II very small. This is of
importance, because short cables can minimize transducer losses and offer at the same time
external influences less attack region, so that the anyway very susceptible, low signal of the
pick-up is impaired as little as possible.
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The operation and wiring
In the picture down is shown the front and the back of the Vanguard II.
1. Operating key and control lamps
With the tracer (1) the Vanguard II can be switched on and/or off. The red indicator LED over
the key signals the operating status.
2. Line OUT
The output signal rests against these sockets. Connect this exit with a high level or a line
entrance of your pre and/or full amplifier. Prevalent are such entrances designated with AUX.
But generally you could use the CD- or TAPE-entrance of the pre and/or full amplifier, too.
3. Line IN
At these sockets the record player (pick-up) will be attached. With the mini switches at the
ground the feed impedance can be indicated adjusted, like shown in the table 1.
4. Power pack entrance socket
To this socket the ground power pack belonging to the scope of supply is attached. Make
first the connection between power pack and
Vanguard II, before you connect the
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power pack with the lighting system. Thus it is guaranteed that it comes to no inadvertent
short-circuits at the exit of the power pack.
5. Ground (ground terminal)
At this clamp the grounding- rather earth-cable, which is usually led out separately at record
players, is attached. In most cases is at these grounding electrodes a fork-putting shoe. To
be able to attach this fork, you untwist the knurled thumbscrew of the ground terminal a little
and wedge then the fork through closing the knurled thumbscrew.
Simple stripped cable ends can be also attached by solving, after that they were put into the
lateral drilling of the knurled thumbscrew and then likewise again with the knurled
thumbscrew clamped.
Subsequent is the view of the ground of the Vanguard II with the channel separated mini
switches for the reinforcement (6) and the feed impedance adjustment (7) illustrated.
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6
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6. Mini switch for the gain setting
With these switches for each channel the reinforcement is adjusted separately. For the
attitude you use the following table as guideline assistance.
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Table of the switching positions for the gain setting.
With the four-fold mini switch for each stereo channel on the lower surface of the Vanguard II
the reinforcement can be adjusted separated.
As this table shows, the reinforcement between 42 dB and 66.3 dB can be adjusted in 16
stages.
Reinforcement table for VANGUARD
S4 S3 S2 S1 Reinforcement
in dB
For systems with the
following output
voltages
0 0 0 0 42 4mV
0 0 0 1 47.5 2.2mV
0 0 1 0 51.3 1.4mV
0 0 1 1 53.6 1.1mV
0 1 0 0 55 0,89mV
0 1 0 1 56.5 0,75mV
0 1 1 0 58.1 0,63mV
0 1 1 1 59.2 0,55mV
1 0 0 0 62.2 0,39mV
1 0 0 1 63 0,36mV
1 0 1 0 63.8 0.33mV
1 0 1 1 64.3 0.31mV
1 1 0 0 64.8 0.29mV
1 1 0 1 65.3 0.27mV
1 1 1 0 65.8 0.26mV
1 1 1 1 66.3 0,24mV
A 1 means: Switch placed on position ON
A 0 means: Switch not switched
If you do not find the exact value of the output voltage of your pick-up in this table, you could
select the value, which comes next to your pick-up.
You reach in each case with the in the preceding table given attitudes a DIN-Output voltage
of 500 mV. It’s depended from the entrance sensitivity and reinforcement of your pre or full
amplifier you need often only a clearly smaller output voltage to achieve the desired hearing
volume. You should experiment in this regard because a lower reinforcement can be tonal
more favourable.
Louder systems (output voltage more largely 8 mV) can be naturally also attached, however
thereby the over-regulation reserve is reduced, i.e. it can come to the over-regulation of the
amplifier, which expresses itself by higher distortions.
Quieter pick-ups (output voltage of small 0.24 mV) can be operated accordingly problemfree.
Frequently, pick-up manufacturer indicates the output voltage of their systems in the e.g.
following way.
Output voltage = 1.2mV with 4.36 cm/s
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The standardized output voltage refers usually however to a reference fast of 5.6 cm/s. In our
case therefore the output voltage results to:
scm
scm
mV
ageOutputvolt /6.5
/
36.4
2.1
∗=
Thus results an output voltage of approx. 1.54 mV, i.e. the reinforcement you should set the
mini switch 2 to ON.
7. Mini switch for the feed impedance
These switches are adjusted separately for each channel the feed impedance. For the
attitude you use the following tables 1.1 and 1.2 as guideline assistance.
Table 1.1 of the switching positions for the entrance capacity
Adjustment capacities can be connected to magnetic systems by depressing the switches S1
and S2. S3 to S8 are switched off with MM systems, because MM systems are usually
operated at input impedance by 47KOhm.
S1 S2 S3 S4 S5 S6 S7 S8 Entrance capacity
Input impedance
in ohm
0 1 0 0 0 0 0 0 47pF 47000,0
1 0 0 0 0 0 0 0 100pF 47000,0
1 1 0 0 0 0 0 0 147pF 47000,0
A 1 means: Switch placed on position ON
A 0 means: Switch not switched
The entrance capacity without connected capacity amounts to approx. 60 - 100pF with the
Vanguard II.
Each capacity, which is connected, must be added to this entrance capacity. The cable
capacitance of the cable connections between record players and preamplifiers must be
added, too. Furthermore the cable capacitance of the cable in the tone arm pipe adds itself.
In this way do values of more than 200pF - 300pF often already come without auxiliary
capacities.
To be noted it should, however, that deviations by the pick-up manufacturer recommended of
the adjustment capacity, in the order of magnitude of 20 - 30 % are acceptable, since during
the production of pick-ups frequently similar tolerances develop.
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Table 1.2 of the switching positions for the input impedances
100pF 220pF 1800 1000 470 220 100 47
S1 S2 S3 S4 S5 S6 S7 S8
Input impedance
computed in ohms
0 0 0 0 0 0 0 0 47000,0
0 0 1 0 0 0 0 0 1733,6
0 0 0 1 0 0 0 0 979,2
0 0 1 1 0 0 0 0 634,2
0 0 0 0 1 0 0 0 465,3
0 0 1 0 1 0 0 0 369,8
0 0 0 1 1 0 0 0 317,6
0 0 1 1 1 0 0 0 269,9
0 0 0 0 0 1 0 0 219,0
0 0 1 0 0 1 0 0 195,2
0 0 0 1 0 1 0 0 179,6
0 0 1 1 0 1 0 0 163,3
0 0 0 0 1 1 0 0 149,4
0 0 1 0 1 1 0 0 137,9
0 0 0 1 1 1 0 0 130,0
0 0 1 1 1 1 0 0 121,2
0 0 0 0 0 0 1 0 99,8
0 0 1 0 0 0 1 0 94,5
0 0 0 1 0 0 1 0 90,7
0 0 1 1 0 0 1 0 86,4
0 0 0 0 1 0 1 0 82,3
0 0 1 0 1 0 1 0 78,7
0 0 0 1 1 0 1 0 76,1
0 0 1 1 1 0 1 0 73,0
0 0 0 0 0 1 1 0 68,6
0 0 1 0 0 1 1 0 66,1
0 0 0 1 0 1 1 0 64,2
0 0 1 1 0 1 1 0 62,0
0 0 0 0 1 1 1 0 59,9
0 0 1 0 1 1 1 0 58,0
0 0 0 1 1 1 1 0 56,5
0 0 1 1 1 1 1 0 54,8
0 0 0 0 0 0 0 1 47,0
0 0 1 0 0 0 0 1 45,8
0 0 0 1 0 0 0 1 44,8
0 0 1 1 0 0 0 1 43,8
0 0 0 0 1 0 0 1 42,7
0 0 1 0 1 0 0 1 41,7
0 0 0 1 1 0 0 1 40,9
0 0 1 1 1 0 0 1 40,0
0 0 0 0 0 1 0 1 38,7
0 0 1 0 0 1 0 1 37,9
0 0 0 1 0 1 0 1 37,3
0 0 1 1 0 1 0 1 36,5
0 0 0 0 1 1 0 1 35,8
0 0 1 0 1 1 0 1 35,1
0 0 0 1 1 1 0 1 34,5
0 0 1 1 1 1 0 1 33,9
0 0 0 0 0 0 1 1 32,0
0 0 1 0 0 0 1 1 31,4
0 0 0 1 0 0 1 1 31,0
0 0 1 1 0 0 1 1 30,4
0 0 0 0 1 0 1 1 29,9
0 0 1 0 1 0 1 1 29,4
0 0 0 1 1 0 1 1 29,0
0 0 1 1 1 0 1 1 28,6
0 0 0 0 0 1 1 1 27,9
0 0 1 0 0 1 1 1 27,5
0 0 0 1 0 1 1 1 27,1
0 0 1 1 0 1 1 1 26,7
0 0 0 0 1 1 1 1 26,3
0 0 1 0 1 1 1 1 26,0
0 0 0 1 1 1 1 1 25,7
0 0 1 1 1 1 1 1 25,3
A 1 means: Switch placed on position ON
A 0 means: Switch not switched
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Set-up recommendations
As well as almost all electronic devices the Vanguard II shouldn’t be exposed to the direct
sunlight, too. Because the set warms up a little when it is in operation, you should pay
attention to sufficient circulating air.
A phono amplifier is a device with high signal reinforcement. Unfortunately such devices
amplify also any spurious signals. One of these radiated spurious signals is the 50Hz-hum by
the transformers. To keep this humming as small as possible, we accommodated the power
transformer of the
Vanguard II in a separate housing, so that you can set up this power
transformer in some distance from the
Vanguard II. Of course our efforts are useless if the
Vanguard II is placed now on other sets with internal power transformers.
Therefore you mustn’t to place the
Vanguard II on other HiFi-sets. Pay attention to sufficient
distance (at least 50 cm) to other mains transformers.
Particularly transformers of halogen light systems and power-output stages have a strong
humming scattering field and should be therefore as far as possible from the
Vanguard II.
A rule is: The more largely the mains transformers the more largely should be laid out the
distance to phono amplifier.
Even mains cables or the net wiring in the wall are breakdown emitters. You receive the best
results by sufficient distance to these disturbers.
According to our experiences an installation close to the record player is the best solution. So
the critical cable connection between record players and
Vanguard II can be kept short and
spurious signals had only few chances to affect the low pick-up signal. At the same time
short signal paths means always-smaller transducer losses, too, in particular with sensitive
pick-up signals.
Care references
Never treat the set with a scrubbing means etc. Easy contamination such as dust and
finger marks can be wiped off with a fog-damp cloth or sponge. Water-dilute-cash
contamination (jam, fruit juices, etc.) could be eliminated with a liquid household cleaner,
especially with glass cleaners. Mineral oils as well as animal and vegetable fats are wiped off
with white spirits or Isoprophylalkohol. Always make sure that no cleaning fluid arrives in the
set inside.
The ground power pack you should be cleaned only with a fog-damp clothe or sponge and
somewhat with a liquid household cleaner. Please pull the mains plug from the wall socket
before cleaning the ground power pack. Make also sure that no cleaning fluid arrives in the
power pack inside.
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Technical data:
Reinforcement : 42 – 66 dB in 16 stages adjustable
input impedance : from 25 ohm to 1800 ohm in 31 stages (
see table)
: without connected resistances 47KOhm
capacity : Basic capacity = 60 – 100pF
: insert able capacity = 47pF, 100pF, 147pF
entrance : 1x Cinch
exit : 1x Cinch
Distance of weighted noise voltage : -72dB with 60dB reinforcement and
: -94dB with 36dB reinforcement
frequency response : + - 0,2 dB RIAA equalized
distortion factor THD + N : 0,06%
Crosstalk attenuation : -96.2 dBA with 10KHz
power input : < 3VA
Dimensions h x b x d : 55mm x 133mm x 182mm
Subject to change
Production and construction:
Trigon Elektronik GmbH
Korbacher Straße 185
D-34132 Kassel
Tel. +49 (0) 561/474462
Fax +49 (0) 561/474463
e-mail: trigon@trigon-audio.de
web: www.trigon-audio.de
Kassel, January 2003
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