Manufacturer Module API • 505-DI Direct Input • 512c Mic Preamp • 512v Mic Preamp • 525 Compressor • 527 Compressor/Limiter • 529 Stereo Compressor • 535-LA Line Amplifier • 550A Equalizer • 550b Equalizer • 560 Equalizer • 565 Filter Bank JDK • V10 Single Channel Mic Pre • V12 Single Channel Compressor • V14 4 Band Equalizer A Designs • EM-PEQ • EM Blue Mic Preamp • EM Gold Mic Preamp • EM Red Mic Preamp • EM Silver Mic Preamp • P1-500 Mic Preamp AEA • RPQ 500, Single channel mic pre Analog Allstars • EQP-1S5 Passive Equalizer Aphex • A Pre 500 mic pre • COMP 500 optical compressor • EQF 500 three band semi-parametric EQ • EX•BB 500 Aural Exciter and Optical Big Bottom • J Pre 500 mic pre Audified • Synergy R1 Audio Maintenance Limited • 5003d Mic Preamp Avedis Audio Electronics • E27 3 Band Equalizer BoZo Electronics • MPA3 Mic Preamp Buzz Audio • Elixer Mic Preamp* DACS • MicAmp 500 Daking Audio • 500 Compressor • EQ 500 • Mic Pre 500 Danfield • MX20 Mic Preamp dbx • dbx 510 • dbx 520 • dbx 530 • dbx 560A • dbx 580 Electrodyne • 501 Mic Preamp • 511 2 Band Equalizer elysia GmbH • karacter 500, Class-A Stereo Saturator • mpressor 500, Discrete Class-A Compressor • Nvelope, Discrete Class A Stereo Impulse Shaper • skulpter 500, Discrete Class-A Preamp • xfilter 500, Stereo EQ • xpressor 500, Discrete Class-A Stereo Compressor Empirical Labs • DerrEsser Model EL-DS FiveFish Audio • Janus Active DI/Shift EQ • MX5-mk500 Mic Preamp • PEQ-503 Equalizer • SC-501 Mic Preamp • X-12mk500 Mic Preamp • X-72mk500 Mic Preamp Forsell Technologies • SMP-500 Grace Design • M501 Mic Preamp Great River Electronics • Harrison 32EQ • MP-500NV Mic Preamp Heritage Audio • 1073/500 Channel Amplifier Inward Connections • EQ2P JCF Audio • Levr Summing Amplifier J-Lab Studio Electronics • JLA3 Transformer Balanced Optical Leveling Amplifier Kush Audio • Electra 500 - Electrified Transient Equalizer LaChapell Audio • 583s Mic Preamp Maag Audio • EQ4 Equalizer • PREQ4 Mic Preamp Mooktronics Research • PDI 500 Nixer, Ltd. • London Mic Amp NIX00205 • Broadway Mic Amp NIX00220 • Vanguard Mic Amp NIX00230 Pete's Place • BAC-500 Compressor Phoenix Audio LLC • DRS-EQ/500 Mono 4 band EQ Rascal Audio • Two-V, dual-channel microphone amplifier Roll Music Systems, Inc. • Tubule RMS5A7, Microphone Preamp Safe Sound Audio • P501 Audio Processor Shadow Hills Industries • Dual Vandergraph Stereo Compressor Skibbe Electronics • 736-5 Mic Preamp SMG Productions, Inc. • Channel Strip 500 CS-D S&M Audio • EQSM1 Speck Electronics • ASC-V Equalizer True Systems • pT2-500 Precision Mic Preamp XQP • 531A Optical De-esser • 535 Program EQ • 541 Optical Compressor • 545 Optical Disrupter • 570 Mic Preamp • Lima 704 Program EQ * Maximum 2 units recommended per lunchbox

API Audio's VPR Alliance is a program of standardization and consistency guidelines for approved manufacturers wishing to design products for API's 500-series rack format. The program provides complete design specifications for manufacturers interested in producing third-party modules that physically fit and electronically conform to API's rack specifications.

The creation of the VPR Alliance was encouraged by the overwhelming popularity of API's 500-series racks, including the 10-space 500V and the six-space lunchbox®, which led to a proliferation of third party modules that fit the API format. Typically installed into API racks, these third party modules had raised issues of warranty and interaction with API-manufactured modules in the same rack.

Because of the variables related to those third party modules, API had previously been forced to declare that inserting any third-party modules into a 500V or lunchbox voided the warranty on that rack. Through the VPR Alliance, API is now able to eliminate confusion as to which third-party products definitively do and do not void the API warranty. The VPR Alliance is a straightforward resolution that saves the company time and money while promoting goodwill to API customers.

Our customers benefit from the VPR Alliance with the knowledge of exactly which products are approved for placement in API racks; customers have a wider range of module choices for their racks that have been tested by API staff for specification compliance.

VPR-approved manufacturers benefit by earning the right to sell API racks and power supplies at dealer pricing to support sales of their products. Alliance membership additionally eliminates third-party research and development costs and production expenses associated with creating an alternate rack solution.

Members can further benefit from the exposure API generates by promoting the VPR Alliance through the strength of the company's various advertising, marketing and public relations channels, including the listing of all members on API's website. Members are encouraged to reciprocate by displaying the VPR Alliance logo on product information, public relations materials and websites.

Manufacturers wishing to join the VPR Alliance should contact API's managing director, Gordon Smart (gordon@apiaudio.com) for a program application. If approved, API will send the manufacturer copies of the 500 Module Series Specifications and instructions on the review process. Additionally, members will receive recommendations regarding competitive issues and pricing guidelines.