Neil McCauley
14-07-2008, 10:24
Recently I have been measuring the input voltage in the listening room of customers. This has varied between 216v (the customer got the electricity supplier to correct this) to 258v. Moreover this has varied during the course of the installation. THD has been typically 2.5% (strangely consistent across every installation of mine in SE England) and occasionally as high as 3.8%.
Years back, one of the reasons that so many of the US valve power amps I had for blowing up was that the suppliers had fitted 220v transformers. I might be wrong about this but my guess was that they were unaware of a European-wide agreement to settle on 230v.
Anyway, recently I have noticed that some valve amps (which I don’t sell) have been performing sonically unpredictably and not necessarily as well as the owner or indeed myself would have hoped. I’ve been looking for patterns to this.
The sample set is very small and thus any ‘pattern’ is open to inaccuracy. However what seems to be emerging is this.
1. All and any US made valve amps seem more susceptible to UK mains variations than UK ones.
2. Conrad Johnson seems more susceptible to this than ARC
3. This problem is more acute in rural areas than city ones.
4. I have never, not even once, encountered this problem with US solid state gear. The occasional poor sound of US sourced SS gear was usually down to inappropriate speaker matching, or the all too frequent application of MOM (marketing-over-mediocrity) techniques.
I'm not technical. However people who are have indicated to me that it is possible and indeed probable that the power supply transformers on some US equipment (220v rating, 230v rating? might be being saturated by 240v and certainly by 258v – the maximum I have encountered so far on site.
Any observations, comments or thoughts on this? These would be most welcome. Thanks. H
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Years back, one of the reasons that so many of the US valve power amps I had for blowing up was that the suppliers had fitted 220v transformers. I might be wrong about this but my guess was that they were unaware of a European-wide agreement to settle on 230v.
Anyway, recently I have noticed that some valve amps (which I don’t sell) have been performing sonically unpredictably and not necessarily as well as the owner or indeed myself would have hoped. I’ve been looking for patterns to this.
The sample set is very small and thus any ‘pattern’ is open to inaccuracy. However what seems to be emerging is this.
1. All and any US made valve amps seem more susceptible to UK mains variations than UK ones.
2. Conrad Johnson seems more susceptible to this than ARC
3. This problem is more acute in rural areas than city ones.
4. I have never, not even once, encountered this problem with US solid state gear. The occasional poor sound of US sourced SS gear was usually down to inappropriate speaker matching, or the all too frequent application of MOM (marketing-over-mediocrity) techniques.
I'm not technical. However people who are have indicated to me that it is possible and indeed probable that the power supply transformers on some US equipment (220v rating, 230v rating? might be being saturated by 240v and certainly by 258v – the maximum I have encountered so far on site.
Any observations, comments or thoughts on this? These would be most welcome. Thanks. H
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