OUTPUT TRANSFORMERS >>
The designs are specified according to their reflected primary impedance, maximum recommended dc standing current and maximum power. Frequency response is typically within 1dB from 20Hz to 40KHz and 4 and 8 ohm secondary taps are provided. The power rating of the OPT should be twice the maximum power output of the stage. Open frame, fully shrouded or drop through can be supplied as required.
single ended output transformers
These transformers all have multi wound primary sections for enhanced performance and bandwidth
Single ended output transformers
All can have ultra linear taps at no extra cost, all can be supplied fully shrouded, open frame or drop through as required. Please enquire about any requirements not listed here.
Transformer Size Chart
All dimensions are in mm
MAINS TRANSFORMERS >>
Our mains transformers are all designed using the latest CAD technology to provide good regulation (usually <5%) and optimum performance together with cool running for increased service life.
All transformers are varnish impregnated using a UL approved clear Solventless varnish which not only seals the windings against moisture ingress but also gives extremely low audible noise.
Open frame, fully shrouded or drop through types are available as requested.
Pricing for mains transformers is based upon having 3 secondary windings and the VA rating of all the secondaries added together.
INTERSTAGE COUPLING TRANSFORMERS >>
The 1:1 ratio transformers have a very wide, flat, frequency response and excellent sonic characteristics. The 1:1.5 designs are more compromised, but still extend beyond 40KHz. The initial designs have been based around using the following valve types for drivers: 5687, E182CC, 417A, parallel 6SN7, parallel ECC82. Designed around a 15mA-20mA primary current, approx. 3K5 anode impedance, or below. Other drivers such as 3A/167M and ML4 have been used successfully. They can be used with a large range of output valves, including 211, 845, 300B, 6080, 2A3 etc.
POWER SUPPLY INDUCTORS >>
Inductor smoothing is becoming popular factors, and better voltaagain as more people realise it was abandoned for reasons of cost, not quality. Inductors afford higher smoothing ge regulation, giving quieter operation and better dynamics. Using chokes enables lower values of smoothing capacitance to be used, allowing higher quality types to be specified.
The ch109 has been specially developed for use in high current, high voltage, choke input filter power supplies. Its primary use is for choke input supplies for stereo 300B amps where you may be looking at 450Vdc rails at up to 200mA. It is available only as an open frame construction, but has been built to be quieter than normal chokes in a similar supply.
300B CIRCUIT INFO & DIAGRAMS>>