News
Getting wound up about; Neve transformers
19 April 2011
We've recently been contacted about the history and detail surrounding the transformers used in Neve classic modules (and other units too), which help to deliver the unique Neve sound. Some of the questions and statements we received were partially correct and some of them were incorrect. 'Urban legend' surrounding this matter becomes more and more distorted as time goes by. While it is not only the transformers that create the amazing Neve sonic footprint that is globally revered, they do play a very important part in the audio path. With this in mind;
This information details the facts relating to Neve transformer designs. Engineers who worked alongside those directly involved in these designs have validated the following information.
LO 1166 – Gapped Output Transformer
Rupert Neve designed and produced the first LO 1166 transformers; they were hand wound by Rupert during the period when he had just one other employee. Early transformers were wax impregnated; these were used in the first black front panel channel modules such as the 1053, circa 1965/6 for the Philips Studio mixer. Circa 1966, Marinair Radar of Harlow started to produce the LO 1166 and changed to varnish impregnation. There is no official EM____ specification for the LO 1166 as its design pre-dated any documentation system. There is however a Research and Development Technical Report, TR-188 dated 5 August 1977, approving samples of a transformer type LO 1166 manufactured by St. Ives Windings Ltd. Rupert Neve has confirmed that St. Ives Windings was one of the suppliers of this transformer to the Neve Company.
There was at least one other manufacturer of this transformer, in addition to Marinair and St. Ives who supplied Neve with this transformer.
As far as records show, the LO1166 was likely last used in Neve standard production 31102 Channel amplifiers used in the 8058/68 standard consoles. The records show console #A7983, an 8068 MkII being produced late 1980 or early 1981 for Rupert Neve Inc. - this would be around the last time Neve Electronics Laboratories purchased this transformer.
When AMS-Neve decided to re-start manufacturing the Neve 1073 classic module back in 2003, an evaluation was made of a gapped output transformer which Carnhill (who had taken over St. Ives Windings in 1994) had been manufacturing for others since the 80’s. The conclusion of this evaluation was that the performance of the transformer did not meet the original specification. So senior design engineers at Neve and Carnhill designed and produced a transformer which met all of the original performance criteria of the original 1965/66 design. This transformer is as close to the original as anyone can produce. This is the transformer which AMS Neve purchases from Carnhill today. The tag-board dimensions may have been reduced and the bobbin dimensions may have been tightened up, but the electrical design and performance is exactly the same.
Contrary to many recent statements made, AMS Neve has confirmation from Carnhill that this design is exclusive to and only supplied to AMS-Neve, as originally stated in the December 2004 review of the 1073 Classic module by EQ Magazine (see section "Clones and Transformers")
LO 2567 – Output Transformer
This transformer is to the same winding and core specification as the LO1166 but for use in situations not requiring DC current flow in the primary i.e. it has no gap. Originally it was for use in distribution amplifiers etc, used as the output transformer with the early BA340 output amps such as in the 1081.
10468 - Input Transformer
A senior R&D engineer at Neve and a design engineer from Marinair designed this transformer in late 1968. This was to replace the larger round octal base Gardners transformer MU7524, used for Microphone inputs and mix amplifiers. They managed to design a smaller transformer with excellent performance; initially in a round can with the 11-pin base but also the square can version, which would fit better inside the 45mm wide modules.
AMS Neve holds the copies of the original notebook pages showing the performance results achieved. Marinair initially produced this transformer. When Marinair couldn’t keep up with the demand from Neve, St.Ives Windings was asked to produce this transformer as well as Marinair. Both Marinair and St. Ives produced variations of this transformer for Neve - all designated 10468 - but having different part numbers. Technical report TR-187 dated July 1975 evaluated a modified version of this transformer from St. Ives, comparing it to a non modified one.
When AMS neve began re-starting the manufacture of the original Neve 1073 classic module back in 2003, Neve's senior design engineer evaluated the VT26670 which Carnhill were producing and concluded that this was as close to the original as it could possibly be. This is the transformer supplied to AMS-Neve exclusively in the Green can and to the rest of the world in the Blue can.
31267 - Input Transformer
A senior R&D engineer at Neve and a design engineer from Marinair designed this transformer in 1967. This was to replace the larger round octal base Gardners transformer MU7526, used for Line inputs and bridging input line amplifiers. Again they managed to design a much smaller transformer with excellent performance, initially in a round can with the octal base but also the square can version which would fit better into the 45mm modules and the 2253/4 which he was designing. AMS Neve also holds the copies of the original notebook pages showing the performance results achieved.
Marinair initially produced this transformer and when they again could not keep up with the demand from Neve, St.Ives were asked to produce this transformer as well as Marinair. Both Marinair and St. Ives produced variations of this transformer for Neve again - all designated 31267 - but having different stores code numbers. Technical report TR-186 dated July 1975 evaluated a modified version of this transformer from St. Ives, comparing it to a non modified one.
When AMS neve began re-starting the manufacture of the original Neve 1073 classic module back in 2003, Neve's senior design engineer evaluated the VT22671 which Carnhill were producing and concluded that this was as close to the original as it could possibly be. This is the transformer supplied to AMS-Neve exclusively in the Green can and to the rest of the world in the Blue can.
