The car I am selling has a great sounding Nakamichi 14 X 4 watts per
channel with only 0.008% total harmonic distortion. Does anyone make
such a high quality low powered amp these days ??

Roger In Mass

wrote in message
...
The car I am selling has a great sounding Nakamichi 14 X 4 watts per
channel with only 0.008% total harmonic distortion. Does anyone make
such a high quality low powered amp these days ??

Roger In Mass


Not likely, as most aftermarket CD players are capable of that these days..

Yeah but most aftermaket CD Players today don't have the 0.008% Total
Harmonic Distortion Level. I mean they may be even rated at 20 watts
pers channel but whats the distortion ? you turn them up and all you
get is distortion.

why not just take the one out of your car that you're selling and replace it
with road gear or some cheaper brand?
wrote in message
...
Yeah but most aftermaket CD Players today don't have the 0.008% Total
Harmonic Distortion Level. I mean they may be even rated at 20 watts
pers channel but whats the distortion ? you turn them up and all you
get is distortion.

wrote in message
...
Yeah but most aftermaket CD Players today don't have the 0.008% Total
Harmonic Distortion Level. I mean they may be even rated at 20 watts
pers channel but whats the distortion ? you turn them up and all you
get is distortion.

There is 20 watts and then there is 20 watts. Some of the better head units
these days put out a good 20 watts (although anything claimed much over that
and I'd be highly skeptical, since it's almost impossible given the small
space they have to put the amplifier in.) Why can't you just move your old
amp? And why are you looking specifically for a low powered amp? What's
the point? Just buy a good 40w amp or something.

Yeah but most aftermaket CD Players today don't have the 0.008% Total
Harmonic Distortion Level. I mean they may be even rated at 20 watts
pers channel but whats the distortion ? you turn them up and all you
get is distortion.

That's because when you're putting out 20 watts with those units you're
driving them into clipping. Very very few head units can actually deliver
20 watts per channel, despite their bogus claims. When you bench them, you
find that most HUs tend to reach about 12-15 watts prior to the onset of
clipping, but the distortion content before that point tends to be quite
low.

The car I am selling has a great sounding Nakamichi 14 X 4 watts per
channel with only 0.008% total harmonic distortion. Does anyone make
such a high quality low powered amp these days ??

As Jeffc pointed out, you'd probably be better off just getting a slightly
higher-powered amplifier. Then you'd be assured of low distortion all the
time, since you'd be less likely to drive the amplifier into clipping.

Many amps these days spec out around .008% at some point along the THD vs.
power output curve. Regardless, the distortion level would be well below
audible threshold prior to the onset of clipping. So even if you could
trust the manufacturer's claims (which you can't), it doesn't matter anyway.
First of all, total harmonic distortion doesn't tell the whole story. The
spectral content of the distortion is more important - in simple terms, how
the distortion is spread out over the audible bandwidth. Also, the THD%
varies with power output - some amplifiers actually have the highest
distortion percentage at low power levels, which wouldn't register in the
".008% at 14x4 watts" type of spec.

Here are a couple examples off the carsound.com reviews website to
illustrate my point.

They benched a Jensen amplifier, a brand which many consider to be "low
quality", and found that the THD% into a 4 ohm reactive load bridged was
under .1% prior to the onset of clipping:

http://www.carsound.com/review_archi...s50rxchts.html

When they benched a Zapco amp, a brand which most people would consider to
be one of the best available, they found its THD% into the same load at
lower also reached about .1% prior to the onset of clipping. But at lower
power levels, it was about .5% or so:

http://www.carsound.com/review_archi...g1000chts.html

wrote in message
...
Yeah but most aftermaket CD Players today don't have the 0.008% Total
Harmonic Distortion Level. I mean they may be even rated at 20 watts
pers channel but whats the distortion ? you turn them up and all you
get is distortion.

When you max out any amplifier you get distortion.. if the gain was cranked
on your nak and voltage was sufficent, the same would occur..
The key is to have an amplifier powerful enough that you're not maxing it
out into clipping to get a satisfactory volume.
A modern head unit may well provide these results for you, if the speakers
are sensitive enough and you don't need to overpower them.

Getting a good distortion-free volume range from an amp is why we have gain
knobs..

Roger,

First, forget the THD figure... anything below about 1% is simply not
likely to be audible, particularly in a car environment. The market is
loaded with amps that will run circles around your Nakamichi. I have
forgotten the model # (PA56? Something like that) but installed a number
of those back in the mid-1980's and they are nothing special. Only real
advantage was they produced a little more power than powered radios did
(at the time, not any more) and were small enough to stuff in the
dashboard.

Second, don't be scared about using a little larger amp - which can be
found for stupid low prices these days - due to your previous
experiences. ALL amps can be set up to give good range of output level
simply by adjusting the input gains correctly. I use three amps in my
car currently, total about 1600 watts as configured, and I assure you I
can listen to it at any level from very quiet to louder than concert
levels and anywhere in between simply by turning the HU volume control
up and down. It's just a question of adjustment.

JD

wrote:

The car I am selling has a great sounding Nakamichi 14 X 4 watts per
channel with only 0.008% total harmonic distortion. Does anyone make
such a high quality low powered amp these days ??

Roger In Mass

He's hung up on the ridiculously low THD spec Nakamichi put on that
little bugger.

Which is meaningless for a couple of reasons. First, we know that you're
not going to hear any audible difference between 0.008% and 0.8% anyway.
The Japanese were real busy selling audio gear based on stupid low THD
back in the mid-80's when his amp was sold. It wasn only later that the
audiophile community woke up and realized that the ability to deliver
current to the load and IMD were a lot more important than THD.

Second, that 0.008% is measured before the onset of clipping, and at
4x14W he's going to end up clipping the crap out of it trying to achieve
a reasonable output level in a car even with 90dB+ efficient speakers.
This little booster (has a mirrored 12VDC power supply in it, not a
DC-DC switcher) will distort pretty quickly as you push it past the 14W
rating.

I've used the piece he's talking about many times, and I will say it had
more balls and clipped fairly gracefully when overdriven, but it's no
match for any competent 4x35 (RMS, continuous) amp... which you can buy
for peanuts any more.

JD

jeffc wrote:

wrote in message
...


Yeah but most aftermaket CD Players today don't have the 0.008% Total
Harmonic Distortion Level. I mean they may be even rated at 20 watts
pers channel but whats the distortion ? you turn them up and all you
get is distortion.



There is 20 watts and then there is 20 watts. Some of the better head units
these days put out a good 20 watts (although anything claimed much over that
and I'd be highly skeptical, since it's almost impossible given the small
space they have to put the amplifier in.) Why can't you just move your old
amp? And why are you looking specifically for a low powered amp? What's
the point? Just buy a good 40w amp or something.

OK, I see (sorry for the top posting, but you're apparently posting some HTML crap.) Understandably, car amps are more difficult to audition than home amps. If you can't hear the difference, don't pay for it, I say. But if you have to look at specs, I agree that THD spec is not very useful (assuming a reasonably low number.)
"John Durbin" wrote in message ...
He's hung up on the ridiculously low THD spec Nakamichi put on that little bugger.

Your answers have all been great a real education !!! But still no one
can tell me what to use to replace this amp ?? I think I will pull the
Nakamichi and put in another decent low priced amp to replace it to sell
this car. I am only powering two Boston Acoustic 6 X 9 's so what
would be a replacement that would not cost much and might deliver the
same results ??

Roger In Mass

Thanks Again For All Your Time Spent !!!!!!!!!!!

If you want to stick with that brand, there are a couple of great deals
on ebay currently:

This one is a 70W x 2 PA300, which dates from the same time period as
your small amp (maybe a year or two older, but a very solid amp:

http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

Or here's a slightly smaller but new Nak amp:

http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

Some small Alpines:

http://cgi.ebay.com/ws/eBayISAPI.dll...0488 485&rd=1

http://cgi.ebay.com/ws/eBayISAPI.dll...0502 030&rd=1

Or some of our nice, older a/d/s/ models:

http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

http://cgi.ebay.com/ws/eBayISAPI.dll...10963 11&rd=1

http://cgi.ebay.com/ws/eBayISAPI.dll...1767 261&rd=1

(these PS5 were a very nice, small amp - good for 2x40 or 2x45 depending
on series)

It's a big world of decent amps out there...

JD


wrote:

Your answers have all been great a real education !!! But still no one
can tell me what to use to replace this amp ?? I think I will pull the
Nakamichi and put in another decent low priced amp to replace it to sell
this car. I am only powering two Boston Acoustic 6 X 9 's so what
would be a replacement that would not cost much and might deliver the
same results ??

Roger In Mass

Thanks Again For All Your Time Spent !!!!!!!!!!!

IMO
the best low RMS amps are

HIGH RMS AMPS which are not played very loud...


ha ha ha

Eddie