YBA Signature Preamplifier MKII Owner’s Manual

June 3, 2024
YBA

Signature Pre Amplifier MKII
Owner’s Manual

Warnings and Precautions

CAUTION: To reduce the risk of electric shock, do not try to open the device. No user serviceable parts inside. Refer servicing to qualified service personnel only.

The lightning flash with an arrowhead symbol within an equilateral triangle is intended to alert the user to the presence of un-insulated dangerous voltage within the product’s enclosure which may be of sufficient magnitude to constitute a risk of electric shock.
The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in the literature accompanying the product.

This product is designed and manufactured to meet strict quality and safety standards.
the safety and operating instructions before using the product. Retain the manual for future reference and adhere to all warnings in the manual or on the product.
You should read all
WARNING: To reduce the risk of fire or electric shock, do not expose this product to rain or moisture. The presence of electricity near water can be dangerous. Do not use the product outdoors or near any source of water for example next to a bathtub, washbowl, kitchen sink, in a wet basement or near a swimming pool, etc. Take care that objects do not fall and liquids are not spilled into the enclosure through any openings.
Do not place this product on a bed, sofa, rug or similar soft surface, or in an enclosed bookcase or cabinet, where ventilation may be impeded. We recommend a minimum distance of 100 mm (4 inches) around all sides and top of the product to provide adequate ventilation. Be sure that the ventilation holes below and on the top cover of your product are neither covered nor obscured by any object or dust.
Locate the product away from naked flames or heat producing equipment such as radiators, stoves or other appliances (including other electronic devices) that produce heat. The amplifier has been designed for use in moderate climates.
You should never attempt to service the product beyond that described in this manual. All other servicing should be referred to qualified service personnel. The only fuse used in this device is on the AC socket.
Always use exactly the same fuse as the one provided with your unit.
If an abnormal smell or smoke is detected from the product, turn the power off at once and unplug the unit from the wall outlet. Contact your dealer immediately.

The product should be referred to qualified service personnel when:
The power supply cord or plug is damaged
The product has been dropped or the enclosure has been damaged
Objects have fallen, or liquid has been spilled, into the product
The product has been exposed to moisture
The product does not appear to function normally or exhibits a marked change in performance

We thank you for your purchase of our YBA Signature product. We with many years of listening pleasure.
are confident that it will provide you YBA Signature products have been manufactured with the same pride and attention to detail as every other product made since our creation in 1981. Your new product will give you the very best audio quality.
This user manual has been designed to give you all the information you need to install, connect, setup and use your product. For your own safety and to ensure that no damage occurs, we strongly recommend that you read the safety guidelines carefully before installation.
It is our recommendation that you use a rack or stand that is recommended for use with audio equipment.
If your equipment is on a portable rack it should be moved with great care, to avoid any accident.
It is always advisable to unplug the unit from the mains supply before cleaning. The casework should normally only require a wipe with a soft, damp, lint-free cloth. Do not use paint thinners or other chemical solvents for cleaning or furniture cleaning sprays or polishes as they can cause indelible white marks.
Only connect the product to a power supply of the type described in the operating instructions or as marked on the rear panel. Be sure to check the noted voltage. Power supply cords should be routed so that they are not likely to be walked on or pinched by items placed upon or against them. Only use the power supply cord supplied with your product.
Unplug the power cord or switch it off if left unused for a long period of time.

This product has been designed to meet the IEC 60065 international electrical safety standard as well as CE and RoHs regulations. The pictorial “crossed- bin” means the equipment must not be thrown with ordinary wastes but must be collected for reuse, recycling and other forms of recovery. If no longer required it must therefore be deposited in an appropriate collection point.
YBA is a registered trademark of YBA SAS and is restricted for use by YBA, its subsidiaries and authorized agents. All other brands and product names quoted in this manual are registered trademarks and the property of their respective owners.
Disclaimer: All the information contained in this manual was correct at the time of publication. However, as our engineers are always updating and striving to improve our products, your amplifier may have slightly different appearance, performance, or modified functionality than presented in this manual.

YBA Warranty Policy Information

YBA warrants this product to be free from defects in materials and workmanship subject to the following: The warranty period may vary from country to country and according to local regulations. Consult your dealer or distributor to confirm the warranty duration in your country.
YBA will repair or replace this product (at YBA’s sole option) or any defective parts in this product within the terms of the warranty.
YBA warranty applies to the original purchaser only. Always ensure that you retain a valid proof of purchase.
YBA shall not be liable for any incidental or consequential damages for breach of any express or implied warranty in this product.
Except to the extent prohibited by law, this warranty is exclusive and in lieu of all other express and implied warranties.
YBA warranty does not affect your statutory rights.
Warranty Procedure
To obtain warranty service, please contact the YBA authorized dealer from whom you purchased this product. Your dealer will deliver the product to the registered YBA service centre.
Shipping to the service centre is at your cost and your amplifier must be packed in either its original carton or packaging affording an equal degree of protection.
Proof of purchase in the form of a bill of sale or receipted invoice, which is evidence that this product is within the warranty period, must be presented to obtain warranty service.
This warranty is invalid if
(a) the factory-applied serial number has been modified, altered or removed from this product
(b) this product was not purchased from a YBA authorized dealer
(c) the product shows any evidence of repair or attempt to repair not performed by a YBA authorized service centre.
Warranty Exclusions
Maintenance and service or replacement of parts due to normal wear and tear
Problems arising from the misuse of the product or use of this product for non-domestic use
Damage to the outer chassis due to normal or abnormal wear and tear
Faults caused by extreme situations (such as damage due to lightning, floods, moisture, fire…)
Faults caused as a result of a short-circuit on the loudspeaker outputs
Faults caused by shock or the result of the product being dropped
Damage or defects caused by the use of inadequate packing during return to an authorized service centre
Faults caused by other devices or accessories such as power cords, power filters, loudspeakers
Damages due to repairs, modifications or cleaning by non-approved technicians or due to the use of nonYBA parts
Faults due to unauthorised opening or tampering with the unit
Any complete or partial loss of data/files

UNDERSTANDING YOUR YBA AMPLIFIER

Every unit is personally listened by M. Yves-Bernard ANDRE himself and all components are handmade in France, included solder, wires, transformers, etc….
An important design goal for Yves-Bernard ANDRE is the control of parasitic vibrations. These mechanical vibrations in the air have a negative effect on the purity of sound. The impact of these vibrations depends on the size of the amplifier, the internal components and the rigidity of the construction.
The solutions chosen for the YBA Signature amplifier include The mechanism is designed to be as compact and as rigid as possible. The amplifier has only three feet which is ideal for draining vibrations. The transformers are suspended to reduce the transmission of their vibrations to the rest of the circuitry.
For YBA Signature, input stages are housed in enclosures full of damping materials and calibrated synthetic diamonds.
The choice of materials is also an important part of the design of YBA amplifiers : The chassis of the Signature line items are all made from a block of alurninum rnilled in the rnass. Besides absolute rigidity, it also allows you to have different internal boundaries free from electro-magnetic interference. This mechanical structure allows mounting on 2 levels of components that are fixed on either side of the central portion! The transistors are mounted on a solid aluminium block with special mica wafers, which improves heat dissipation to avoid thermal distortions.
All of the materials used to manufacture for YBA electronics are non-magnetic.
The selections and tests of the components are more precise to avoid any unbalanced effect and increase reliability. YBA Signature transistors are specially selected in order to be perfectly matched.
YBA Signature Amplifiers are class Alpha amplifiers. This means that the power supply works as a class A one, although the power stage follows the power requirements. So, there are class A advantages (linear characteristics As diodes, ability to deliver current peaks needs) without the inconveniences (high temperature). So, the YBA amplifiers are always cool to increase the reliability and avoid the mechanism growth due to heat and the parasitic vibrations due to it.

DESCRIPTION OF THE CIRCUIT
The circuit used for your YBA amplifier is completely symmetrical; this cancels any defects introduced it the power source, minimizes parasitic ground currents and avoids any need for passive components in the signal path.
The number of components has been minimized; the signal traverses only transistors. No passive components alter the original purity of the musical signal.
The input stage is of the complementary double differential type; it is followed by a pre-driver stage, which allows the adaptation of the impedance and initial amplification of voltage.
The pre-driver stage is followed by a third stage, which completes the amplification of voltage ; it distributes the current and voltage necessary to the output stage, which is directly coupled to the speakers.

The bandwidth of these four stages is so constructed that it decreases from input to output, thereby assuring the minimum distortion from transient modulation.
The output stage has no feedback ; the overall feedback is very low (< 20 dB), which is essential to good listening quality. In fact, feedback can only correct defaults that already exist. Including strong feedback would overload the input of the stage, hide detail and produce an “electronic” sound.
The geometry of the circuit has been optimized to reduce the distances between components and the connecting wires to the absolute minimum: only a few centimeters at the input and output of the amplifier. The transformers are suspended in order to reduce the transmission of their vibrations to the rest of the amplifier.
Grain orientated double Ctransformers While most manufacturers have chosen toroidal transformers, YBA amplifiers are the only solid state amplifiers to use double C transformers. Yves Bernard ANDRE noticed the huge influence these components have to the musicality of the unit.However, double C transformers cost 3 to 5 times more than the toroidal variety. The following technical points explain why they make YBA amplifiers sound better:
– Primary and secondary windings are separated to avoid the negative effects of AC power on the power supply of the circuit.
– The isolation between primary and secondary windings is high enough to create an AC line filter.
-The wires in the windings is grain oriented iron which is selected to maximize conductivity.
– The metal is impregnated with a special varnish. This eliminates air pockets and thereby helps make the transformer be as quiet as possible.
– The voltage of a double C transformer drops off slowly like a vacuum tube amplifier, unlike a toroidal design which has sharp cutoff point. This attribute of a double C transformer becomes a source of energy to feed the amplifier’s current needs. They are less sensitive to variations of reactive energy on the secondary side.
Warm Up
For best results, the amplifier should initially be broken in with 30 hours of play. A warm up of 2 hours is best whenever the unit has been switched off. It is preferable to leave your YBA amplifier permanently on. The power consumption is low and the sonic benefits are high. YBA DIAMOND interconnects and speaker cables will give the best sonic results.

Cleaning
To clean the cabinet, panel and controls use a soft cloth lightly moistened with a mild detergent solution. Do not use any type of abrasive pad, scouring powder or solvent such as nail polish remover.
Fuse
The YBA Signature amplifier has only one fuse : it is found in the AC socket. It is a special handmade YBA fuse. If it blows, you should contact your dealer to determine if the equipment is faulty. To change the fuse, disconnect the amplifier from the AC supply. Replace only with an identical fuse. A substitution will degrade the sonic quality. Use a 5 Aslow-blow. The fuse must be supplied by your dealer.

Using your YBA Remote Control

Note: PRESS means a short press on a key while HOLD means to keep the key pressed for more than 3 seconds. Always point the remote towards the IR window of your Signature PRE MKII.

Select the device you want to control between AMP, CD and AUX. To control the Signature PRE MKII, you need to select AMP button.
Press AMP to turn on your pre-amplifier.
Hold (> 3 seconds) AMP button to turn off your pre-amplifier.
Note: AMP will remain the active function until you press another device.
SOURCE+/SOURCE-: Press SOURCE+/SOURCE- to skip to the desired source.
VOLUME+/VOLUME-: Press VOLUME+ to increase the volume or
VOLUME- to decrease the volume. This is a universal control and does not require specific source selection.
VIEW: Hold (>3 seconds) to switch ON/OFF the display (dimmer).
FCT: Hold (>3 seconds) to hold the current volume level.
AUDIO: Press to resume the stored volume level.
MUTE: Press to mute. Press again to exit mute.
phase from this button. Hold (>3 seconds) for PHASE switching. When the PHASE LED is on (amber) the pre-amplifier generates a 180 degree phase shift between the input and output signals. When the LED is off, this does not occur.
You can also control the

CAUTION Before connecting any input or output…..
Always make sure your Signature PRE MKII is in the OFF position. If you have any doubt, unplug the AC power cable from the wall.
Make sure any components connected to your Signature PRE MKII are off.
Neatly arrange and organize wiring to and from your Signature PRE MKII and to and from all your components.
Separate AC wires from audio cables to prevent hum or other unwanted noise from being introduced into the system.

Discovering your Signature PRE MKII: Front view

  1. Input Selector: Selects between 10 different inputs.
  2. Standby touch switch: Touch YBA for 1 second, this turns your Signature PRE MKII on is Standby.
  3. IR Sensor: Point remote towards this sensor for control of your Signature PRE MKII from a distance.
  4. Display: Indicates selected input together with music signal level.
  5. Phase: When the PHASE LED is on (amber) the pre-amplifier generates a 180 phase shift between the input and output signals. When the LED is off, this does not occur.
  6. Mute: Press once to mute the signal. Press again to exit mute.
  7. Volume: As the volume control in your Signature PRE MKII uses a rotary encoder, it can be turned indefinitely in either direction – left to decrease volume and right to increase volume.

Discovering your Signature PRE MKII: Back view

Discovering your Signature PRE MKII: Rear view continued

0. Should you wish, you can disconnect power to the digital section of your Signature PRE MKII when using an analogue source. Remember to re-engage this switch when using any digital input.
1. RCA Audio inputs: Connect the RCA outputs of your source to the RCA inputs of your Signature PRE MKII. Be sure to connect the RIGHT output of your source to the R input of your Signature PRE MKII and the LEFT output to the L input of your Signature PRE MKII.
Note: IN5 input has a Bypass feature. When selecting the IN5 input, if you press <, >, OK buttons on the remote in sequence, the pre-amp will enter into the Bypass status. Repeating this process restores the Signature PRE MKII to Input 5 status.
2 & 5. Balanced Audio input / : This is a higher quality input that can reject noise and interference in output the cable when used with equipment with balanced outputs. XLR connectors should be wired: Pin 1 – Ground; Pin 2 – Hot (in-phase); Pin 3 – Cold (phase-inverted).
3. Digital Input: The Signature PRE MKII is equipped with one S/PDIF (75 Ohm) COAXIAL digital input, Toslink and USB (PCM32/768KHz, DSD512) to receive digital signals from separate digital components.

Your Signature PRE MKII can be used with your PC as a source.
In order to accomplish this, it is necessary to download a driver to your PC. This is only necessary for use with Windows – no download is required if using a MAC.
The file can be downloaded from the YBA website – www.ybahifi.com/downloads.html
When you have completed the download and you connect your Signature PRE MKII, the Windows ‘Found new hardware’ bubble will appear. The description of the Signature PRE MKII will be Eddict Audio Device.
After a few seconds you will receive a message ‘Your new hardware is installed and ready to use’. Your PC’s previous audio output device should be temporarily disabled and the Signature PRE MKII will become the default audio device automatically. This can be checked in the Control Panel. Select Sounds and Audio Devices. In the volume tab check Eddict Audio Device.
If you wish to disconnect your Signature PRE MKII and return to your soundcard, simply disconnect or switch off the power on the front panel. If for some reason your PC fails to disable the Signature PRE MKII, you can manually do this in the Hardware Device Manager.
4. RCA output: Connect the RCA outputs of your Signature PRE MKII to the RCA inputs of your power amplifier (SIGNATURE AMP).
6. Power inlet: Connect provided mains cable. Be sure your Signature PRE MKII switch is in OFF position before plugging or unplugging the mains cable.
7. ON/OFF switch: Use this button to switch ON or switch OFF your Signature PRE MKII.
Before making any connections always make sure your Signature PRE MKII is in the OFF position. If you have any doubt, unplug the AC cable from the power inlet. Make sure all components connected to your amplifier are set to off.
Neatly arrange and organize wiring to and from your Signature PRE MKII and to and from all your components. Separate AC wires from audio cables to prevent hum or other unwanted noise from being introduced into the system.

www.ybahifi.com
info@ybahifi.com

References

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