TAPE TOPICS - PRESSURE PADS.   

Heads Series 2 to 3

Heads Series 7

Logic 7

Studio 8

The design of any product is dependant on the technology of the day, which imposes certain criteria and restrictions on  designers.

Advances in technology were not as rapid when the first Ferrograph was designed and manufactured.  Designers were governed by the development of complimentary technologies.  Heads, motors, and crucially the tape on which the final recordings would be made. In those very early days, paper based tapes were still common, with standard play acetate tape becoming available in the mid 1950's.

These tapes were thick and inflexible.  They had to be strong enough to withstand the considerable tensions exerted on them by tape mechanisms, especially when stopping the tape after  wind and rewind. The pressure pad forced the tape into contact with the head as it passed over the head -gap.

So the initial design of the Wearite deck catered for the tapes available at the time of design. However, what Ferrograph continually failed to do was to review the design, taking into consideration the advances that had occurred in the quality and types of recording tapes available in the late 1960's. 

Even when the design change was drastic from a Series 6 to a Series 7, they persisted with pressure pads, at a time when their competitors had done away with them altogether,  Revox, Teac, Sony, Akai to name but a few. 

It was only with the advent of the Logic range that the penny dropped.

Pressure pads incorrectly adjusted or worn would cause excessive or uneven head wear, they also became hardened with use and could cause tape squeal.  This could be reduced by replacing the pressure pads, or if that wasn't possible, fluffing up the contact surface of the existing pad and rubbing in some "French Chalk" or "Graphite" from an HB pencil.

The pictures above show the development of the head design from the Series 2-3 onwards. 

Later developments that were available to the designers of the Logic and Studio 8, thinner more flexible based tapes, and the use of computer controlled sensors, which allowed accurate control of the amount of back tension required for proper head contact without excessive tension, and the resulting wow & flutter that could cause.