Volume Control Comparison
A REVIEW OF A RANDOM SELECTION OF WELL KNOWN LINE VOLUME CONTROLS READILY AVAILABLE IN THE UK COMMERCIAL AUDIO MARKET

INTRODUCTION

Since 100V line volume controls became 'popular' around 30+ years ago they have been a target for importers wanting to offer cheaply made, high profit margined, versions.

The initiative of John Woodgate F.inst. S.C.E. in the ISCE Engineering Note No6suggesting Standards of test (and comparison!) was appropriate though we do not agree that his tests identify all failings; we test more deeply.

The Standards do not highlight mechanical and aesthetic problems; these affect the amount of time taken to install, their vulnerability to 'public' abuse once installed, the appearance of the final installation, including compatibility with other switches or wallplates.

Five years ago we made the following observations to our Industry:

Many (100V line volume controls) products sourced from the Far East and on the European market, fall short of expectations typically for the following reasons:

a) volume control switch contacts do not take the maximum rated power of the volume control, so they can fail.

b) cheap transformer laminations, or not enough of them, cause the control at low frequencies to absorb up to 10 times the rated load, so they use a great deal of amplifier power, often making its protection circuit intermittently operate, shutting down the system.

c) control knobs can be pulled off - even by the innocent (but always curious)public!

d) some products have to be partially dismantled before they can be installed; that costs time and money too.

e) they don't fit standard UK backboxes, so the electrician who pre-wired the system might not have had access to the one they should have fitted. Anyone got a chisel? Where's the plasterer?

f) there is no facility for fitting matching decor/lightswitch front panels; most architects and interior designers hate this omission, even if they don't use it, so why compromise the possibility of getting an Order?

For a the full review please download the PDF