[Trevor Wilson[_2_]]

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"Trevor Wilson" wrote in message
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In article ,
"Trevor Wilson" wrote:

"Drazen" wrote in message
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I would appreciate your experience!

My Revox B251 "gave up" and I would like to buy NAD pre- and power-
amplifier.

My requirements:
- Musical sound picture and details (i have also a 3020i and this
amplifier sounds really nice)
- can drive critical speakers (I have Dynaudio 3-ways system); I am
also thinking one day to buy Dynaudio Confidence 5
- good MC part for my Ortofon TMC 200 (low output MC)
- shall additionally to CD have also AUX input

How good are following NAD-s:
1155
1300
208 THX
218 THX
Are there better ones?

Remark: I am going to buy 2nd hand.

**Good. First off - Don't restrict yourself to one brand. Whilst NAD
have
built some good amps over the years, they've also built some
shockers.
Anything with the PE moniker, for instance. IMO, is a poor choice.
Another
excellent amplifier brand is Rotel. Well worth considering and,
depending on
your market, may be better value for money. There are other choices
too.

Trevor Wilson

Whats wrong with the PE monikered NAD amps?

**Where to start?
Let's start with:

* Sound quality - worse than competing products.
* Reliability - worse than competing products.
* The potential for serious damage to loudspeakers is ever-present.

That'll do. The PE stuff was a disaster.

Trevor Wilson



Not a NAD expert, really - but in my experience with NAD there is no
more
potential for damage to speakers than with any other amp with a
competently designed protection circuit.

**Incorrect. The disaster potential built into PE equipped NAD amps first
came to my notice when I was selling them. I sold a pair of KEF 104.2
speakers and a NAD 2200 amp to a client. He blew the tweeters in short
order. I was surprised, since the NADs used ferro-fluid cooled tweeters
and,
IME, were indestructible (up 'till that point). I had sold quite a few
pairs
of the things. Fortunately, the local distributor of the KEFs was also the
NAD distributor and I managed to squeak them though under warranty for my
client. Intrigued, I put the 2200 on my test bench to see what was going
on.
After 30 mins of testing, it became abundantly clear what the problem was.
It goes like this:

As you are no doubt aware, most people who listen loud, turn the volume
up,
'till the amp is just nudging clipping (slight harshness on loud notes).
Naturally, those with alcohol impaired hearing will tend to crank the
volume
up even further, but let's forget that, for the moment. Anyway, it would
be
safe to assume that less than 5% of the programme material is in the
clipping region and thus the harmonic structure is pretty much what it
should be. Not so, the the NAD PE stuff. When the high Voltage power
supply
is exhausted (which occurs after a period of time in all PE amps), the
clipping can be horrendous, amounting to easily 50% of programme material.
The skewed harmonic structure can easily destroy tweeters (and mids).


NAD was always a bit spotty on reliability, not limited to their PE
models. Long term heat damage to caps, resistors, etc for one thing; and
the Taiwanese origin of many of their products wasn't so great either,
from cheap electrolytic capacitors to somewhat shoddy physical
manufacture. I've seen one or two British-built NAD amps which did seem
MUCH nicer though.

**I've seen a Danish built NAD which was superbly built. That is not the
point. The vast majoriy of Asian sourced NAD stuff, with the PE moniker,
had
the extra unreliability associated with the PE circuits. That, combined
with
NAD's typical poor reliability, anyway, has led to other brands taking
over
their market spot.


I would say sound quality of the PE series was probably at least
average -
though I've never had one at home, and so my impressions having only
worked on them in the shop could be erroneous in this area...

**Sound quality was average. VERY average. The sudden application of a
massive extra supply rail is not conducive to proper operation of an
output
stage. I hasten to add that several other manufacturers have used the same
(or similar schemes) over the years.

Trevor Wilson

I think any competent listener will enjoy the extra headroom without
clipping
provided by the PE series. I had to fix a couple, so I have a little
reserve
as to why they failed. Im getting around to fixing that big NAD receiver i
have in my possession. I listened to a one of the smaller PE amps and I
just
thought it had a tremendous volume for what the basic power level was.

**I've serviced *a lot* of NAD PE amps. Far more than their immediate
competition. In the vast majority of cases, the PE circuitry was damaged,
along with at least one output stage. I've also listened to them. At low
levels, they're fine. At high(ish) levels (when the PE high Voltage power
supply cuts in), they just sound odd. The immediate competition (I rate
Rotel as the closest competitor) does not.

Trevor Wilson