Cutter Head Impedance Matching Transformers

Impedance Matching Transformers for Cutter Heads Rated at 20 W, 20 Hz - 20 kHz, Impedance Range from 2 ohm to 600 ohm (please define impedance specification when placing your order). 

Price: GBP 120 

Other power ratings, wider frequency ranges and any impedance rating you can imagine can also be accommodated at additional cost. Please enquire for such requirements. 

We make custom transformers for matching disk recoding cutter heads of any usual or unusual impedance specification to cutting amplifiers of any make, shape and vintage. 

Why would I need an impedance matching transformer for cutting records?

If you happen upon a cutter head or amplifier, designed to work with unusual impedances, there is no need for costly modifications to your rare possession. All you need is a device that will transform the impedance of the cutterhead to a value that is convenient for the amplifier to drive. This is exactly what the impedance matching transformer does. 

Example: Let us assume you find an antique Presto cutter head in perfect condition, but specified as having a 500 ohm impedance. You already have a modern amplifier you would like to use it with, but this is designed to drive an 8 ohm load, since most modern loudspeakers are thusly rated. 

You should not attempt to drive a 500 ohm load from an amplifier expecting to work into 8 ohm loads, and likewise, you should not attempt to drive a 8 ohm load from an amplifier designed to work into a 500 ohm line. We have seen many cutter heads ruined as a result of people trying to rewind the coils to a different impedance, without the required tools or expertise. 

The safest and most cost effective solution is to contact us and tell us the impedances of your cutter head and amplifier, and we can supply you with a suitable transformer, to insert between the two. In the aforementioned example, we would make an 8 ohm to 500 ohm impedance matching transformer, so the amplifier would be working into an 8 ohm load, while the cutter head would be matched to the 500 ohm side of the transformer. Problem solved! 

High Quality Materials

We use high quality, audio grade transformer core laminations to assemble the core, and wind the coils using proprietary techniques, developed for critical high performance audio applications. The result is a very transparent device that will be gentle with your audio signal, for quality disk recording. 

More importantly, they can be made to any oddball impedance you can come up with. The usual values of cutter head impedances encountered are 4, 5, 8, 10, 12, 16, 32, 50, 500 or 600 ohm, but even if you manage to find a head specified as 437 ohm, we can make a transformer to match. 

Checking your cutter head impedance

If you do not know the impedance specification of your cutter head, just send it in or bring it in person and we will measure it for you for a nominal fee. Feel free to contact us to discuss any impedance difficulties you may be encountering.