
June 9th 04, 02:04 AM
posted to uk.rec.audio
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Anyone Got a Cheap Valve Power Amp or Integrated Amp For Sale?
"Wally" wrote in message
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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
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June 9th 04, 02:44 AM
posted to uk.rec.audio
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Anyone Got a Cheap Valve Power Amp or Integrated Amp For Sale?
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.
Why should someone who elects to take a different approach from what you
advocate *deserve* problems?
**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.
Thanks.
www.artbywally.com
www.wally.myby.co.uk
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June 9th 04, 03:18 AM
posted to uk.rec.audio
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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.
Why should someone who elects to take a different approach from what you
advocate *deserve* problems?
**They only deserve problems, AFTER ignoring good, logical, sensible advice
(like listening/examining first). Kinda like those guys who buy the 'white
van' speakers, even after having been warned about them. Still, the 'white
van' speaker buyers, usually think they're buying stolen goods, so maybe
they do deserve what they get. :-)
**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.
Thanks.
**My pleasure. I learned about such things many years ago. I serviced an
amplifier whose output transformer had gone belly-up. I took it to the
rewinder. He called me a few days later, uttering many profanities. It had
15 interleaves and cost a small fortune to rebuild.
--
Trevor Wilson
www.rageaudio.com.au
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June 9th 04, 08:08 AM
posted to uk.rec.audio
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Anyone Got a Cheap Valve Power Amp or Integrated Amp For Sale?
**They only deserve problems, AFTER ignoring good, logical, sensible advice
(like listening/examining first). Kinda like those guys who buy the 'white
van' speakers, even after having been warned about them. Still, the 'white
van' speaker buyers, usually think they're buying stolen goods, so maybe
they do deserve what they get. :-)
Trevor,
You are a fool.
I have stated that I was curious to see how the amp will sound. If I
don't like it I'll flog it on.
Why is this so hard for you to understand?
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June 9th 04, 09:47 AM
posted to uk.rec.audio
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Anyone Got a Cheap Valve Power Amp or Integrated Amp For Sale?
This has been an interesting thread, with a useful mix of opinions and
information. As with most hifi matters, things eventually resolves,
usually with a purchase, or an abrupt refusal from the bank to extend
credit :-).
Martin please keep us posted on how you get on--what you get within your
budget, whether it meets your current needs, etc. Note, this does not
mean "top quality hifi"; just "good enough to give you enjoyable results
for your money".
If the valve revival is to continue, there surely need to be products
available in the mid-fi price range. Having said that, IMHO Trevor is
right about the link between transformer cost and quality, so there are
constraints. Another possible solution is the hybrid route.
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June 9th 04, 09:53 AM
posted to uk.rec.audio
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Anyone Got a Cheap Valve Power Amp or Integrated Amp For Sale?
"Keith G" wrote in message
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"Wally" wrote in message
...
Keith G wrote:
... and who has just bought a 'scope ...
What did you get?
This one (eBay No.) 3819029867
I don't suppose it's much cop as scopes go, but as you can see it's the
whole beeswax - scope, signal generator, probes and books. A 'learning
kit'
in one go!
It was a lot cheaper than most and I'm assured it's in good working order
by
a nice old boy who's bringing it here to straight-swap it for some of my
'spare vinyl'!!
;-)
Good deal Keith - we'll look forward to seeing interesting unusual scope
traces via the website :-)
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June 9th 04, 10:52 AM
posted to uk.rec.audio
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Anyone Got a Cheap Valve Power Amp or Integrated Amp For Sale?
Trevor Wilson wrote:
Why should someone who elects to take a different approach from what
you advocate *deserve* problems?
**They only deserve problems, AFTER ignoring good, logical, sensible
advice (like listening/examining first).
You haven't answered my question - why do they DESERVE problems?
**My pleasure. I learned about such things many years ago. I serviced
an amplifier whose output transformer had gone belly-up. I took it to
the rewinder. He called me a few days later, uttering many
profanities. It had 15 interleaves and cost a small fortune to
rebuild.
Are these things made by rotating the former and drawing the wire onto it,
or is there some 'arm' thingy that moves around a static former? (I'm trying
to visualise how the sucessive interleaves connect to each other.)
--
Wally
www.artbywally.com
www.wally.myby.co.uk
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June 9th 04, 02:17 PM
posted to uk.rec.audio
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Anyone Got a Cheap Valve Power Amp or Integrated Amp For Sale?
Wally wrote:
Trevor Wilson wrote:
Why should someone who elects to take a different approach from what
you advocate *deserve* problems?
**They only deserve problems, AFTER ignoring good, logical, sensible
advice (like listening/examining first).
You haven't answered my question - why do they DESERVE problems?
**My pleasure. I learned about such things many years ago. I serviced
an amplifier whose output transformer had gone belly-up. I took it to
the rewinder. He called me a few days later, uttering many
profanities. It had 15 interleaves and cost a small fortune to
rebuild.
Are these things made by rotating the former and drawing the wire onto it,
or is there some 'arm' thingy that moves around a static former? (I'm trying
to visualise how the sucessive interleaves connect to each other.)
If you want a real challenge, think about how they wind torriods.
--
Nick
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June 9th 04, 07:38 PM
posted to uk.rec.audio
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Anyone Got a Cheap Valve Power Amp or Integrated Amp For Sale?
"Fleetie" wrote in message
...
**They only deserve problems, AFTER ignoring good, logical, sensible
advice
(like listening/examining first). Kinda like those guys who buy the
'white
van' speakers, even after having been warned about them. Still, the
'white
van' speaker buyers, usually think they're buying stolen goods, so maybe
they do deserve what they get. :-)
Trevor,
You are a fool.
**A fool? What do you base this opinion on? Please enlighten me.
I have stated that I was curious to see how the amp will sound. If I
don't like it I'll flog it on.
Why is this so hard for you to understand?
**Tain't hard for me to understand at all. What is hard for me to understand
is how a computer programmer cannot respond to logic and reason, without
resorting to insults.
--
Trevor Wilson
www.rageaudio.com.au
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June 9th 04, 08:05 PM
posted to uk.rec.audio
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Anyone Got a Cheap Valve Power Amp or Integrated Amp For Sale?
"Wally" wrote in message
...
Trevor Wilson wrote:
Why should someone who elects to take a different approach from what
you advocate *deserve* problems?
**They only deserve problems, AFTER ignoring good, logical, sensible
advice (like listening/examining first).
You haven't answered my question - why do they DESERVE problems?
**It is the only way some people learn.
**My pleasure. I learned about such things many years ago. I serviced
an amplifier whose output transformer had gone belly-up. I took it to
the rewinder. He called me a few days later, uttering many
profanities. It had 15 interleaves and cost a small fortune to
rebuild.
Are these things made by rotating the former and drawing the wire onto it,
or is there some 'arm' thingy that moves around a static former? (I'm
trying
to visualise how the sucessive interleaves connect to each other.)
**To be honest, I haven't watched a rewinder ply his craft. However, the
usual method is to rotate the former. With a power transformer (and cheap,
crappy valve amp output transformers), it is a two step operation.
1) Wind primary.
2) Wind secondary.
With a quality, interleaved output transformer, it goes kinda like this:
1) Wind some primary.
2) Terminate.
3) Wind some secondary.
4) Terminate.
5) - N) Repeat for the required number of interleaves.
--
Trevor Wilson
www.rageaudio.com.au
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