This is truly a classic distortion pedal. 

It produces a distortion sound with a hard edge and is known to have a very low noise level compared to other distortion pedals. 

Many people swear that the older Japan made pedals sounds better than the newer ones made in Taiwan. 

The DS-1 has over the years been used by a lot of great guitar players. 

Steve Vai and Joe Satriani are just two of the players who has voiced their praise over this pedal. 

The DS-1 is also a favorite among modifiers. Keeley, Analogman and Stinkfoot all provide their own versions of this icon among distortion makers.

Version differences 

The design of the DS-1 has changed little throughout its lifetime but the opamp the circuit is based around has changed several times. 

From 1978, the DS-1 was using the Toshiba TA7136AP opamp. 

This remained unchanged for about 16 years but in 1994 it was replaced by the Rohm BA728N. 

In 2000 the op-amp was again changed. 

This time the Mitsubishi M5223AL was used. 

The last change came 2006 when the New Japan Radio NJM2904L op-amp was introduced.

The DS-1 went through a few cosmetically changes in the early years of production. 

The first version had a clear switch, silver thumb screw and the D in DS-1 placed directly underneath the t in Distortion. 

This is usually referred to as the long dash version. 

The clear switch disappeared around serial number 8700, the silver thumb screw at serial number 0500.

While the D in DS-1 ended up under the i in Distortion around serial number 14xx00 (short dash version). 

Since early 1982 the only changes has been to the bottom label. 

It changed when the production moved from Japan to Taiwan i 1988 and a silver label was introduced when the circuit was modified to accept the PSA adapter 1994.

Specifications

Controls: Tone, Level, Dist

Connectors: Input, Output, AC Adaptor

Current Draw: 4 mA (DC 9V)

Weight: 400 g (15 oz.)

Nominal Input Level: -20dBu

Input Impedance: 470kOhm

Nominal Output Level: -20dBu

Output Impedance: 1kohm