Date: October 11, 1999 10:52 PM
Author: julian vereker
Subject: 300

Thanks Mike, and to Will - the 300 uses components that are also used
in the 250, but since it doesn't have regulated power supplies, it has
a lot fewer than the 250.

I suspect that if the NAB300 had been suitable for use at home, let
alone better than the 250 we should have made a great deal more than
11.

julian



Date: October 10, 1999 08:53 PM
Author: julian vereker

I haven't listened to a 300 in a hi-fi system for more than a decade,
but so far as I can remember it sounds a bit like a slightly bloated
140 that goes a bit louder.

I don't think that we actually sold* any of the NAB300s to retail
customers, most of them were lent to musicians, so our normal practice
of maintaining spares is not in place, but apart from a few unique
components, mainly the parts are shared with the 250. On the odd
occasions we have had to fix one, I don't recall any problems.

The forum clock is in the server, which resides in Palo Alto, CA

julian

* I'm sure somebody will correct me - I do remember selling one or two
but they got returned when they were found not to be anything like as
good as a 250.



Date: October 10, 1999 04:21 PM
Author: julian vereker
Subject: NAB300

Will

It might be worth remembering that these amplifiers are all over 20
years old and almost certainly would need a service.

Also I adjusted the power supply time constants to get a perceived
'hump' in the bass region to suit PA applications, you may not find
this appropriate at home.

julian



Date: June 05, 1999 01:15 PM
Author: julian vereker
Subject: NZ

There were several amps and pre-amps assembled in NZ in the late '70s
and early '80s. These were based on the NAC22, NAP120, NAC42 and
NAP110. We supplied the most of the critical parts, but unfortunately
there was usually an unseemly rush to get each batch assembled and
'out the door', and none of these (or maybe almost none) met our
performance standards. On several of the occasions that I visited to
check the local manufacture, I found everything from 'improved wiring
layout', 'better cable' and wrong thickness copper on the PCBs.

They are all marked Assembled in New Zealand, and any way none look
like the equivalent Naim numbered product.

The reason for licencing was the very high import duty on anything
without local content, or a quota system which was value based and so
was used to import Denon (or similar) by the 100 rather than half a
250.

The NAB 300 was designed as a studio monitoring or PA amp, but by the
time we made it, studios were into KW not W. I think that there are 10
or 11 of them. Fan cooled 150+150W into 4 Ohms.

julian



Date: July 08, 1998 05:05 PM
Author: julian vereker
Subject: transformers

Yes, we have not only tried but also used a variety of non toroids
over the years. But ultimately the toroid gives the lowest field and
the highest power to weight/(size) ratio of any type of construction.

So far as I can remember nobody else was using toroids in 1970 when I
designed the Naim power amp - I chose a toroid since it was the only
way to get the required VA rating in the case I had designed. After
Naim became better known, our transformer manufacturer used this info
to sell to the rest of the industry, and others found that size for
size the toroid offered better performance.

Except that transformers without an air gap are more susceptable to
odd harmonic distortion on the mains and the core can rattle under
certain circumstances.

The Naim NAB 300 power amp had a frame transformer, and in order to
get the VA rating, the case was twice as tall as a 250, and the
regulation was still not as good....

julian

PS when magazine people write and explain some 'wonder thing' is the
answer to better sound, I am always surprised that they don't go and
manufacture a product utilising the 'thing' and I find out if the
others agree in the market place.



Date: May 27, 1998 04:07 AM
Author: julian vereker
Subject: hdcd

Joel wished, "Put a manual defeat on the HDCD circuitry in the CD
players. HDCD is a menace, to these ears at any rate."

Sorry, but part of the agreement for using the excellent digital
filter is that if the cd being played is hdcd encoded, the hdcd decode
must be enabled. But the upside is that we found that if the cd was
encoded, it sounded better decoded than played 'straight', that is not
to say that using a better ADC wouldn't have sounded better still.

julian

PS some other things that come to mind:

It is very unlikely that there will be any changes to our tuner range
until the DAB situation becomes clearer - tuner development is very
expensive and the sales of expensive tuners is small.

The design of a 'perfect' remote is on the agenda.

We tried a half-ARO, the place where we could save on production costs
was the finish. The resultant product didn't pass potentional customer
acceptance tests.

I know of several customers who have replaced their 52s with new ones
each time there has been an improvement, so I assume there must be the
occasional second-hand market. (unless they just get relegated to the
children's room)

A big power amp has been on my agenda since the early 70s, but I
cannot bring myself to again (NAB300) make an amp which has more power
just for the sake of it and not actually sound better than the 135.
(but the idea has not gone away).

A 'simple' 52 would not save enough money to make the pain of adding
another product to our list worthwhile.

end of PS for the time being.

julian