Obsolescence Notice

AEM issued its initial obsolescence notification letter for the Legacy PA amplifiers (PA110, PA220, PA250, PA700 products) to aircraft OEMs and to our distribution network in the summer of 2019. This webpage is intended to provide an update on the situation as well as guidance information on replacement and upgrade options/cautions associated with AEM’s next generation of speaker amplifiers and speakers (LSA and LS series products).

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PA220 Series Power Amplifier
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PA250 Amplifier with VR33 Power Conversion Device
PA700 Series Power Amplifier
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PA250 with VR33-001 Cropped.png

PA Obsolescence FAQ

What products are affected by this obsolescence notice?

AEM has issued obsolescence notifications for the PA110-xxx, PA220-xxx, PA250-xxx, PA700-001. At this time the Controllers (AA22-xxx and AA21-xxx) and Speakers (TS100WR, TW200WR, TS9x) typically configured with the amplifiers are not facing obsolescence but there are implications to be considered for continued system integration and usage.

When will AEM stop selling and servicing the products that are facing obsolescence?

Final orders for the PA110-xxx, PA220-xxx, PA250-xxx and PA700-xxx amplifiers will be accepted up until June 30, 2021 for delivery by December 31, 2021. Product repairs and support will be available until December 31, 2031.

What does AEM recommend as replacements for the obsolete products?

For new installations and refits, AEM recommends the use of select LSA/TSxxx series OR LSA/LSxxx series product combinations for optimal performance. Please download the AEM Legacy PA Systems and LSS Replacement Guide here.  

Upgrading PAxxx Series Amplifier without Upgrading TS9x-0xxx Speaker Series 

AEM recognizes the cost and complexity faced by the aircraft OEM and/or installing agency regarding legacy speaker installations (still the current product on many new generation aircraft). Although replacing the full system provides optimal performance, it could represent significant engineering and certification costs and delays. However, using the new generation amplifiers (LSAxxx) with the legacy speakers (TS9x) is limited to certain speaker configurations and has some inherent risks.

What risk would this pose to legacy equipment?

The issue that represents the biggest concern between the two generations of loudspeaker systems is the amplifier. Each generation of amplifier was designed to drive a specific impedance/load (intrinsic to the amplifier design, cannot be changed):

  • PA250/700; 1.75/1.4 ohms
  • LSA400/800; 3.00 ohms

Driving a lower impedance load can cause the new generation amplifier to deliver too much power to the speakers, which could result in the failure of the legacy speaker drivers and/or the amplifier moving to one of its protective states. The following considerations must be assessed and understood:

  1. Speaker damage possible
  2. Speaker warranty void
  3. Amplifier damage possible
  4. Amplifier warranty void if repeated activation of and/or failure of protective circuits 
What measures can be taken to optimize performance and mitigate risk?

To optimize performance and mitigate risk to existing legacy equipment, reduce low level audio input to amplifier (siren audio most critical). Using AEM loudspeaker controllers:

  1. LSC22 requirement; various audio adjustment options on the LSC22 may allow the system to be optimized for best performance of the ‘hybrid’ system. Will be dependent on the amplifier/speaker combination.
  2. AA21 requirement; various audio adjustment options on the AA21 may allow the system to be optimized for best performance of the ‘hybrid’ system. Will be dependent on the amplifier/speaker combination.
  3. AA22 requirement; not recommended due to the older technology and limited adjustments in the AA22, and performance of the audio circuits.
Can I use the existing wire harness?

No, a new wiring harness is required. Please contact us for more information. 

Product Details Request Form 

If you have a capability requirement that isn’t met by an existing system, AEM is open to new opportunities that meet the demands of both fixed- and rotary-wing aircraft. We work with flight crew, integrators, and OEMs to deliver solutions for today’s avionics market.

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