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Old June 9th 04, 02:04 AM posted to uk.rec.audio
Trevor Wilson
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Posts: 242
Default Anyone Got a Cheap Valve Power Amp or Integrated Amp For Sale?


"Wally" wrote in message
...
Trevor Wilson wrote:

* People who buy audio equipment, without first evaluating the
product/s deserve all the problems they are likely to encounter.


Why?


**I'd have thought that the answer was obvious.



The problem associated with cheap valve amplifiers, is well known.
Output transformers. Output transformers completely dominate the
sound of valve amps. A quality output transformer will typically run
to around 200-500 Squid. And you need two of them.


What is it that makes the good ones cost so much?


**A good audio transformer is constructed using 'interleaving'. That is: A
portion of primary is overlaid with a portion of secondary, then more
primary, then more secondary and so on. Interleaves upwards of 13 are not
uncommon in high grade audio transformers. Such a process is extremely time
consuming and difficult to get right. Power transformers (which many low end
valve amp manufacturers use as output transformers) are much cheaper to
produce. One winding is typically bunged on top of the other. End of story.
They also perform poorly.

Good audio transformers also use high grade, 'grain oriented' silicon steel.
This costs more money than the non grain-oriented stuff.


--
Trevor Wilson
www.rageaudio.com.au