External Power Supplies

History

Few subjects arouse as much excitement as a nice hearty discussion of Rane's use of external power supplies. We have done this long enough that it is a good time to review why.

The idea began with the realization that it was unbelievably wasteful and totally unnecessary for every product to have separate AC line transformers...and diodes...and capacitors...and regulators. The alternative was what the instrumentation guys did: use one power supply for an entire rack of equipment. Our vision was that no one would build power supplies into signal processing units; alternatively, the pro-audio industry would have specific manufacturers that only built power supplies: big ones, little ones, fat ones, skinny ones, rack-mount, desk-top, stand-alone ones, etc. (but no wall-warts-wall-warts bite.)

In our vision, one power supply would give you a system power switch, it would sequence your equipment on and back off; and it would provide all the safety, isolation, balanced AC power, audio-friendly grounding, ground-fault protection, monitoring lights and meters you need. But our vision was not to be.

We tried. From April, 1988 until October, 1989, Rane worked through the AES trying to establish a remote power supply standard, but to no avail.

So we modified the vision, called it RAP for Remote AC Power and made a successful go of it alone. Since that time we have discovered many more reasons for using external power supplies:

Reasons To Use External Power Supplies

• Better Audio Performance. Removes the hum source, i.e. the AC line transformer and all primary circuits resulting in quieter noise performance, without the usual (and annoying) 50/60 Hz and 150/180 Hz hum components.
• Increased Safety. Remove the AC primary circuits from the unit and you remove the shock hazard. Remove the shock hazard and you remove the requirement for safety agency compliance. All RAP units qualify worldwide as Safety Extra Low Voltage (SELV) units, i.e., no shock hazard.
• Agency Compliance Exemption. By using remote power supplies and sizing them correctly all products powered by them become as exempt as possible from safety agency compliance - only the power supply itself must comply with each safety agency.
• Quicker Product Development Time. Eliminates the (considerable) time required to develop a separate power supply for each new product. Getting a transformer correctly sized and located is much more of an art form than a science. Each solution is unique and requires much trial and error - a very time consuming task. Making a product work is much easier than making it work without hum in the noise floor. A tedious thankless job. Rane could not have developed as many products as it has without external power supplies.
• Faster Product Manufacturing. Eliminates the time spent on issuing, prepping, installing and testing transformers, line cords, grommets, brackets, hardware, fuses, holders, insulation, hum barriers and shields for each product built. Rane could not build all the units it does each month without external supplies.

Reasons Not To Use External Power Supplies

• Customers hate them. Realize the life-long benefits instead of apologizing for the one-time inconvenience.
• Salespersons hate them. See the above.

Note: Products shipped with the RS 2 will operate just fine with an RS 1.

Note: All new Rane products have been redesigned with internal power supplies that will operate anywhere 100-240 VAC is available, so the RS 1 was only used with legacy products.

The Rane RS 1 Remote Power Supply Is No Longer Available

Due to new power efficiency regulations our supplier is no longer able to manufacture RS 1 power supplies. Meeting the new regulatory requirements would require a prohibitively expensive redesign for an obsolete part. Rane stopped manufacturing products requiring RS 1 power supplies in 2009. Since that time, for over five years, we have been able to supply replacement units; unfortunately that is no longer possible. We sincerely regret this unavoidable action and the difficulties it makes for our customers.

Product Literature

• RS 1 Data Sheet (100k)
• RS 3 Data Sheet (80k)