From what I have seen the output transformers in the Larger 275 watt amps are completely different to the smaller series and need to be to cope with the extra output devices. Not only do they have a different turns ratio to account for the additional output devices but they also use a large gauge wire on the winding's to account for the increased load. Both of these qualities will extend the bandwidth and damping factor of the larger amplifiers beyond that of the smaller series. The big CJ’s all use these ‘special custom high bandwidth’ transformers and is why a smaller cj amp will never sound better than a larger one in the same system.
The smaller stereo and mono amps generally share the same transformers which is why they are practically doubles of each other----(the mono version being a double of the stereo version). With the smaller Mono blocks you instantly receive a doubling of power supply but not the larger ‘custom full bandwidth ’ transformers.
Through the years CJ have used a very similar recipe for their amps – P12 is ‘basically’ two P11’s – Lp140 is basically two LP70’s and so forth – The basic output circuits are for all intents the same -- it makes perfect sense to refine an excellent base product, after all the basics of tube amplification have not changed in 60 years—it has just been gradually refined.
Conrad Johnson probably has one of, if not the best and most expensive commercially viable parts bins in the business and they need to make the best use of it and do---this is why we can see many of the same parts being used throughout the range for nearly 20 years .
Changing coupling capacitors with like for like values is no different from changing interconnects…..at this point you are playing with the flavour of the amplifier. Teflon capacitors came in for one reason – CJ could no longer reliably source any more polystyrene and would not sacrifice on quality. The next stop as we all know was Teflon ----- but it is by no means the end of the road and other options are available but may not be commercially viable. Imagine the retail cost of the GAT if all the Teflon caps were replaced for something costing twice as much and marginally ‘better’ . Number one you would sell less pre amps number two they would cost more to make – in the end it is not viable but this does not mean that there are no other options out there. There is always scope for improvement –be that cars-boats- computers you name it ….hifi is no different---especially when the products are a few years old.
|