Group A. Economy range, where the price/quality relationship is carefully calculated to ensure audio quality in a compact package. The quality criteria for group A are 20Hz to 20KHz -1 to -1.5dB, they are IE cored with silicon steel laminations and are supplied with frames and solder tags, which will allow good audio quality at the cost. The main cost saving being the use of a smaller core, specified to the exact power level required, rather than overspecifying by 50 or 100%, as we do on Group B, the winding quality and copper wire is the same.

Group B. Mid-price range, these are typically 20Hz to 40KHz minus 1.5dB, IE cored with high quality silicon steel laminations, wound with oxygen-free copper wire and supplied with either bell-ends or frames always with flying leads. Andy Grove is designing a small range of push-pull transformers over the next 3 month to compliment those listed. I shall announce these as they become available.

Group C. The higher categories offer a choice of either copper primary and secondary, copper primary with Audio Note™ pure silver secondary or fully Audio Note™ silver wired bobbins with a choice of different core materials, all the transformers are wound in-house and can be fitted with any type of core listed below, no push-pull outputs will be offered, unless demand requires it and even then I think it is a waste of time.

Other info.
All primary impedances are calculated for Class A operation, with the main consideration given to maximum dynamic power transfer ability and minimum distortion, rather than meaningless steady state sine- or squarewave conditions.
All Audio Note™ single-ended output transformers are airgapped.
All are tested to insulation levels of minimum 3,000 volts, all 211/845 outputs are insulated to 5Kv flash, every transformer is tested to this level of insulation.
We generally overspecify our transformers by 50% power in Push-Pull (which means that a transformer stated as 25 watts will not saturate at stated power but will allow about 35-38 watt peaks, our single-ended outputs are generally over specified by 100%, which means that they will instantaneously allow peaks of double the given maximum power through undistorted, this is necessary due to the better clipping behaviour of the single-ended stage.

table info.
PP = Push-Pull. PPP = Parallel Push-Pull. SE = Single-ended. PSE = Single-ended Parallel. UL signifies 43% ultralinear taps, as a general rule we do not condone the use of UL-taps, as we consider these detriment to sound quality. ** Dynaco replacement. Sizes are given as Width/Height/Depth, where depth is the depth of the coil itself and width is the length of the core.




Group A - Single Ended Types