Arcam Troubleshooting Faults in Your A85 Stereo Amplifier

Page 9

Fault Diagnostics

Fault

Action

No power

Check fuses

 

Check power supply rails

Unit functions ok but no audio

Check preamp fuses

 

Check RL100A (volume control mute relay)

 

Check +5V supply rail

 

Check mute signal line

Volume control locks up

Check software version is 2.0 or higher

DC offset

Check equipment connected to amp for DC on the audio leads

 

Check alterations as per ECO 01_1101 have been fitted

Unit fails to respond to commands

Check ribbon cable from display to main board

 

Check ribbon cable from display to preamp board

Unit gets very hot

Check power stage IQ settings

Hints & Tips

!To check software version press PHONO, TUNER, DVD buttons on the front panel simultaneously.

!On issue 2 phono boards only, fit Kapton insulation tape to the phono stage PCB (rear panel end) to prevent track shorting to chassis.

!Check all fuses are the correct rating.

!Check DC offset alterations are fitted as per ECO 01_1101

!To isolate a fault between the pre or power amp section press the PRE/PWR button on the rear panel to separate the two sections.

!Check R100 on amp/psu board is not shorting to the track underneath (through plated via).

Image 9
Contents A85 Contents List Pre-amplifier circuit description Amplifier & PSU Circuit Description L882 Circuit Sheet PSU Ground naming convention is as follows A85, P85, P85/3 Service Guide Fault Diagnostics A85 amplifier and PSU top sheet Circuit Diagram A85 amplifier power supply and microcontroller interface A85 amplifier power output stage left A85 amplifier power output stage right DVD Display PCB USE Exclude NF When Using Runout Sheet Program Integrated amplifier preamp main signal path Integrated amplifier preamp power supply A85 Display PCB Circuit Diagram A85 Phono Stage TOP Level A85 Phono Stage Left Channel A85 Phono Stage Right Channel AP85 third channel top level 23425 P85 microcontroller and switch Page Page Page Page Page Page Page Arcam 220NF Class X2 CAP 275VRMS IC Vreg POS Wima FKP2 Ppro Obsolete, absent, redundant, or incorrect issue in PDM Part Qty Iss Description Designators Phono SKT 4-WAY EMC Gold SK2 SK3 SK4 SK5 WAF MN12818A VFD Itron DISP1 Title A85 Phono PCB Title RES SM Phono SKT 2-WAY EMC Gold Title P85 Switch Board Tact Switch 2-PIN LOW Prof SW1 SW2 A85 General Assembly Parts List Silver Black Description Where Used QTY P85 General Assembly A85P Transformer P85/3 General Assembly Clamp E912MC to E804HK ST=L
Related manuals
Manual 14 pages 30.61 Kb

A85 specifications

The Arcam P85 and A85 amplifiers are a testament to Arcam's commitment to high-quality audio performance. These components are well-known in the audiophile community for their unique blend of state-of-the-art technology and superior sound quality, catering to discerning listeners who value fidelity and craftsmanship.

The Arcam A85 is a high-performance integrated amplifier that features a robust design and advanced circuitry. It offers a powerful 85 watts per channel output, which is more than sufficient to drive a wide range of speakers with clarity and precision. The A85 incorporates a dual mono design with separate power supplies for the left and right channels, ensuring low crosstalk and high channel separation. This design choice also enhances the amplifier’s dynamic response, allowing it to handle complex musical passages with ease.

One of the standout features of the A85 is its use of high-quality components, including low-noise transistors and capacitors that are specifically chosen to minimize distortion. The amplifier exhibits an impressive signal-to-noise ratio, contributing to a clean audio signal that preserves the nuances of the music.

On the other hand, the Arcam P85 is a powerful, dedicated power amplifier that pairs perfectly with the A85. It utilizes a Class G amplification technology, which provides significant power efficiency. This means that the P85 can deliver peak power output without generating excessive heat, making it an ideal choice for long listening sessions.

The P85 offers 85 watts per channel into 8 ohms but can also deliver 140 watts into 4 ohms, allowing it to drive even the most demanding loudspeakers with authority. Its balanced XLR inputs, alongside standard RCA inputs, ensure compatibility with various audio sources, while the sturdy construction ensures durability and performance.

Both the A85 and P85 feature a simple yet elegant design, characterized by a sleek chassis that minimizes resonances and maximizes aesthetic appeal. They also come equipped with a variety of connection options, including multiple line-level inputs and outputs, making integration into an existing audio system straightforward.

In summary, the Arcam P85 and A85 amplifiers represent a harmonious fusion of innovative technology, impeccable sound quality, and user-friendly design. Their powerful performance, combined with high efficiency and low distortion, makes them a prized possession for any audiophile seeking to enhance their listening experience. Whether used in a stereo setup or as part of a more extensive home theater system, the A85 and P85 deliver exceptional audio performance that stands the test of time.