ขายรีซีฟเวอร์ NAD 7020 แอมป์เสียงดีหายาก ราคาประหยัดที่รวม 3020 รุ่นดังกับวิทยุไว้ด้วยกัน
ขายรีซีฟเวอร์ NAD 7020 แอมป์เสียงดีหายาก ราคาประหยัดที่รวม 3020 รุ่นดังกับวิทยุไว้ด้วยกัน
ไปอ่านเสปค-รีวิวร์จากต่างประเทศก่อนครับ...
NAD, or New Acoustic Dimension, was formed in 1972 by Martin Borish and others.
Bjorn Erik Edvardsen did most of the engineering. NAD’s initial concept was to build audio
components that rivaled the performance of separates but that were affordable to younger
buyers or audiophiles without large budgets. This NAD 7020 receiver fits that description perfectly.
It’s basically similar to NAD’s famous 3020 amplifier but with an integrated tuner. The NAD 3020
is one of the best selling amplifiers of all time and it’s performance-to-cost ratio caused other
audio manufacturers to scramble in order to compete with NAD. The 7020 came out in 1979,
a little after the 3020, and packed a big performance punch that didn’t hurt the wallet.
You might think the NAD 7020 receiver (not to be confused with the later 7020e) is under
powered at 20 watts per channel but the way the amp circuit is engineered gives it a huge
amount of headroom. 3 dB in fact. That means it can supply up to 40 wpc transients into 8 ohms,
58 wpc into 4 ohms and 72 wpc into 2 ohms when required. Obviously the 7020 can handle
very demanding speaker impedance.
The bass and treble controls on the 7020 are designed for an effective response in the low
and high frequencies but not much in the mid range which results in a more musical response overall.
How does the 7020 perform? Excellently. The FM tuning section has a junction FET front end,
three ceramic I.F. filters and a phase locked loop (PLL) multiplex decoder. These features give
the 7020’s tuner high sensitivity, sharp selectivity and clean separation in the FM frequency range.
The phono stage on the 7020 is very good. It has a 6 transistor pre-amp stage that is quiet and
has extremely low distortion. It can handle both MM and MC cartridges and it has a 107 dB
dynamic range which is beneficial if you’re listening to CD’s or digitally remastered recordings.
As I mentioned above, the 20 wpc 7020 acts more like a 40 wpc receiver due to it’s wide dynamic
range. NAD also uses a proprietary Soft Clipping circuit that limits waveform voltage to make sure
the output transistors are never over driven.
The NAD 7020 has a pretty large transformer with shielding and a strangely large tuning flywheel
as well. The amp board is standing directly in the middle of the unit. The FM and Phono boards
are on the right. There are a couple versions of the 7020. The above is the rev 2 version with
multiple circuit boards. You can see rev 1 below which is a single large circuit board and power
supply board.
Some have stated that the rev 1 version of the 7020 has a less than stellar build quality.
The circuit boards are allegedly flimsy and the traces on the boards are thin and tend to crack.
The capacitors aren’t the highest quality either. Rev 2 supposedly remedied these deficiencies.
Keep in mind that NAD was trying to minimize costs to keep the equipment affordable.
Unfortunately that requires some trade offs. Forty years later a lot of those trade offs come
back to haunt whoever owns the unit now. The rev 2 version starts at serial number 7218469.
For a great look at a 7020 refurb check out the page HERE.
One of the drawbacks of the NAD 7020 is that is does not have many inputs. This is probably
due to trying to fit the 3020 amp circuitry and tuner circuits into a fairly small case. Some features
needed to be sacrificed in the name of space.
You can use the preamp-out and power-amp-in jacks on the rear panel for an EQ or time delay
unit, or just use the 7020 as a preamp itself.
The NAD 7020 is a good receiver and, when working properly, sounds fantastic. It does have a
few build flaws but its musicality and dynamic headroom make up for those deficiencies. If you
don’t want to go the route of separates and get the NAD 3020 amp and a separate tuner,
then the 7020 receiver is a great no-frills choice. The later 7020e (1988), which is all digital,
is also a good choice.