Junilabs Juniline Five User manual

1 www.junilabs.com
Juniline Five
The Juniline five is the culmination of an idealist dream: to propose a high quality level
preamplifier at an attractive price. To reach this ambitious target, we integrate many inno
vations that you can only find in our realizations.
Line preamplifier

2 www.junilabs.com
Utilization
The Juniline five is a four inputs stereo line preamplifier. We think simplicity of usage and ro
bustness. Commands were simplified: input selector and control level. We can't do simpler; the
essential is inside...
Starting operation
The power ON button is on the rear panel, beside the power main cord. The preamplifier is
ready to go when the yellow LED is lit.
Power ON LED Input selector Output control level
Four inputs:
Tuner, CD, DVD, AUX
Output to one or two
amplifiers
Green Earth IEC plug 220V/115V, fuse,
switch ON/OFF

3 www.junilabs.com
Technical specifications
Inputs: 4 stereo RCA inputs
Outputs: 2 RCA stereo outputs
Gain: 6db
Input impedance: 25Kohm
Recommended output impedance: >10Kohm
Output impedance: <10 ohm
Maximum output level: 5V RMS
Maximum input level: 16V RMS
Main voltage: 220V or 110V.
Power: 11W
Dimensions: 44cm x 8cm x 22cm
Weight: 8k
Fuse for power supply 220/240V 4AT
Fuse for power supply 110/115V 8AT
Connecting
The Juniline five integrates 4 high level inputs allow connecting sources like CD, DAC, DVD,
Tuner... It integrates 2 outputs allow connecting two amplifiers in bi amplification mode. The fol
lowing schematic illustrate the connection.

4 www.junilabs.com
Mechanical
The aluminum chassis box uses hard and soft material to avoid sound degradations due to me
chanical vibrations. It sits on a massive Limba support (Limba, Afara (UK), Korina (US), African
wood. No feet, no spike). With its granite, it weights no less than 14Kg!
The PCB is fixed with mixed ma
terials (hard and soft); the trans
former is damped with sand and
absorbers.
This allows a high definition level
and comfortable bass.
Using of different materials for a better vibration
management.
Damped capacitors
Anti vibratory material fixed on the top chas
sis box.

5 www.junilabs.com
Technical solutions
To reach this ambitious target, we integrate many innovations that you can only find in our re
alizations.
Line stages works in class A, open loop (feedback free) configuration. The large powerful power
supplies use a 500VA transformer and many polypropylene or polypropylene film capacitors
(higher quality).
Into the Juniline five, we put an active shield toward positive ionic and an evolution of our
"shared current power supply". The regulators are powered with high tension, like valves circuits,
but with lower tension. The use of big electrolytic capacitors is reduced; we don't use any one in
the analog supply or stage! Only 20µF are used for filtering. This lower capacity allows using only
polypropylene capacitors for all stages. This gives a high quality and realistic tonal balance.
How to get the best from your preamplifier
Running-in period and heating
The preamplifier that you buy is new. To reach is optimal quality level, a 200 hours period is
necessary. During or after this period, your converter will give the best of itself when it is hot.
This heating period is reach at least after 24H00; we recommend a 48H00 or more heating pe
riod.
Analog cord
The quality of the analog cord is very important. Having a high quality analog cable is necessary
to reach high quality level.
ower cord and fuse
The quality of the power cord will act on audio rendering. The Juniline Five is provided with
standard power cord, it is recommended to change and replace it by a high quality cable.
The Juniline Five is provided with audio grade fuses. It is not necessary to replace it.

6 www.junilabs.com
Ground optimization
Green Earth
The Juniline Five’s chassis box is linked
to Earth via its IEC plug. To optimize
sound rendering, a second connector
named Green Earth is available in rear
panel. It is internally wired to audio
ground.
You can improve Juniline Five's audio rendering by linking the Green Earth to:
• A virtual ground, (see picture)
• A Main Earth via a big cable,
• Other audio equipment chassis box.
For any other questions, do not hesitate to contact us, or goes to our web site.
The Junilabs' team
[email protected]
www.junilabs.com
Here is an example of virtual ground where the
Green Earth can be connected. The link was
made by big cable (loudspeaker cable).