NAD 3020 Upgrades & Repairs

We all love the old NAD 3020 and over the years owned several examples. Currently we have two versions of the 3020 in use around our home. One is an original 3020 “series 20” from 1979 in perfect original condition and the other is a version of the 3020B without tone controls called the 3120. This is my favorite version of all 3020’s of which the 1st one owned was a brand new item from my father’s warehouse back in 1985.

3020 amplifiers respond extremely well to selected modifications. The design is of such engineering that replacing the original parts with higher specification ones yield great returns in the sound quality department. We have done exhaustive testing over the years with various types of substitutions we fitted and listened to. We have preference for a selected few with which we felt the amplifier preserved most of its original character while gaining in areas where previously it could have been stronger.

This stage yields the greatest return and is also our most popular modification. It centers on optimizing the power amplifier circuits by restoring and improving upon power delivery and control. We replace the old output and driver transistors with improved versions of higher specification and speed to greatly improve detail retrieval. We also replace the main reservoir capacitors with higher capacity ones to mainly aid in tightening up the amplifier’s bass response. Together these two elements form the basis of the modification. We use specific transistor / capacitor pairings to achieve the overall balance we prefer. Some other less substantial replacements include key capacitors, resistors and diodes within the circuit and signal path.

Here we take a serious look at the preamplifier section to aid in supplying the improved power amp with the detail it deserves. Our focus is primarily on optimizing the signal paths for better transparency. We however also improve key aspects within the regulator section of the preamp power supply to clean-up the direct current supplying it of energy.

This stage is primarily for the vinyl brigade. It is specifically focused on the phono stage within the amplifier. All NAD 3020 models were released with phono stages on board, so it makes this amplifier a sure bet for those interested in getting into the vivid sensation of vinyl. As with the preamplifier, we similarly optimize the phono’s signal paths for greatly improved transparency and signal to noise ratio. We can however perform variants of these modifications to many other NAD models.

NAD 3020 Series 20
NAD 3020B
NAD 3120
NAD 3020 Absolute Sound Review 2004

Leave a Comment