Akai AM-2600 Amplifier Review

The Akai AM-2600 amplifier, which does not have an excess of knobs, has practical controls which function in a proper manner. In addition to two tape inputs which can be used for either tape monitoring or dubbing from one recorder to the other, the amplifier has switch selection of either of two phono inputs, a tuner input and an auxiliary input. In all cases, the sensitivities and impedances are sensible, and one phono input has rear panel switch selection of impedance from 32k to 47k to 86k ohms. However this switch was not well shielded and could be a source of hum pickup. With the exception of the DIN tape connector all connections are through phono sockets.

On the output end, there is provision for headphones and two sets of loudspeakers, with switch selection of speakers ‘off’ or either or both sets on. Whilst the amplifier can drive quite a lot of power into 2 ohms, it is felt inadvisable to use two sets of 4 ohm loudspeakers in parallel.

Switchable high pass and low pass filters are provided, each with two turnover frequencies, and as is to be seen from the plot these filters have well chosen frequencies which do not produce excessive effects. The same applies to the tone controls which are smooth in operation and do not introduce significant unbalance between the channels.

It should however be noted that the phono inputs suffer from a frequency sensitive unbalance and a deviation from the ideal RIAA equalization of about 1dB which is worse than any other input.

Subjective testing showed that the Akai AM-2600 sounded clean and had good transient performance with the front panel level meters having fast response which can be useful. It is, however, hard to see the point of the meter sensitivity switch which allows full scale meter deflection of either 3W or the normal 80W. The worst case noise with volume control setting was subjectively irritating, particularly when listening with headphones, and as it occurred at about the 3 pm setting of the volume control (with another bad point lower down) it could not necessarily be avoided by use of the ‘mute’ switch which introduced either 15dB or 30dB extra attenuation.

The volume control itself was of the stepped type with adequately small steps and a large easy-to-handle knob concentric with the balance control, the latter being of the full range type whereby either channel could be completely faded out.

As with many cheaper amplifiers the stepped volume and tone controls are in fact potentiometers with detent mechanisms, but in the case of the Akai AM-2600 amplifier the potentiometer law was such that the steps between detents are well graduated.

On the input noise front, this amplifier was unusually quiet on the high level inputs, but the poor noise performance of the volume control could lose this advantage and also spoil the good performance of the phono input which is about average.

Whilst the external appearance of the amplifier is neat and tidy, the internal standards leave something to be desired with rather untidy wiring and ordinary printed circuit boards. Unfortunately, these do not identify the components which would make servicing that much easier.

For those who like loudness controls, the one on this amplifier really bangs out the bass with an enormous boost of 8dB at 100Hz associated with a mere 4dB boost at 10kHz.

Read all