You are here

Drawmer 1961

Dual-channel Vacuum Tube Equaliser By Paul White
Published May 1994

Drawmer's new dual‑channel tube equaliser combines traditional parametric EQ with Drawmer's own high and low‑pass filters to create a highly flexible, classic‑sounding EQ. Paul White takes it into the studio.

Vintage tube equalisers and compressors are much sought after at the moment, and change hands for large amounts of money. Of course, there are manufacturers building brand new, all‑tube equipment, but this carries a hefty price tag. In building the 1961, Drawmer have taken the same approach as in their highly acclaimed 1960 compressor — valves are used in those parts of the circuitry where they contribute to the tonal character of the unit, and modern, low‑noise op amps are used in areas where clean, controllable gain is all that's wanted. This results in a more affordable design that runs at a lower temperature, with less circuit noise than a comparable all‑valve design.

Apparently the original plan for the 1961 included classic LC filters, but it was discovered that a modified gyrator circuit could reproduce the same characteristics using no inductors, resulting in more consistent performance and a far greater immunity to magnetic interference.

The Circuit

The main signal ins and outs are on balanced XLR connectors, and an Insert linking jack (stereo) is fitted, which allows the 1961 to be used in conjunction with the Drawmer 1960 tube compressor/preamplifier, either in the side‑chain or in the main signal path. To connect the 1961 into the side‑chain of the 1960 requires just one standard stereo jack lead per channel.

Each channel of the 1961 comprises, in addition to an Input Level control, four parametric filter sections, a high‑pass, 12dB per octave variable frequency filter and a low‑pass, 12dB per octave variable frequency filter. Each of these has its own Bypass switch and red status LED, while a further Master Bypass switch brings the whole channel in and out of circuit.

There are six dual‑stage (ECC82) valves in the 1961 circuit, one stage in each equaliser section and two in the output section. All the valves run off a full 200V supply, and may be driven into soft clipping if desired by means of the Input Level control, which provides up to 20dB of gain. An LED input meter shows the signal level pre‑EQ.

The input stages, built around 5532 low noise op amps, are balanced and may be individually switched on the rear panel to accept either ‑10dBV or +4dBU signals. The high‑ and low‑pass filters are similar in design to those used in the DS201 gate side‑chain, and are also built using 5532s to minimise noise. A simple output metering circuit is included, which lights a yellow LED when musically useful distortion is being added and a red LED when clipping is imminent.

The Equaliser

Like the 1960, the 1961 is a 2U processor finished in the familiar Drawmer livery: black with white legend and yellow trim. The two channels of equalisation are located one above the other. Unlike most solid‑state equalisers, which are built around a variation of the textbook state‑variable filter topology, this gyrator design employs switched frequency ranges, with six ranges per section. As the switch is turned, a different pair of capacitors is switched into the filter circuit. Each EQ section overlaps with the next, and the filter frequencies are staggered, which means that having only six switchable positions per band isn't as restrictive as it might at first appear. Furthermore, the filter frequencies appear to have been carefully chosen so as to encompass all the musically important areas of the audio spectrum.

Up to 18dB of cut or boost may be applied in each band, and the bandwidth control is calibrated in musical octaves to make it more musician‑friendly. The high and low‑pass shelving filters work in tandem with the parametric sections, providing a precise means of controlling the upper and lower cutoff frequencies of the signal passing through the unit.

In Use

This equaliser works equally well on individual tracks or on complete mixes, the wider octave settings producing a particularly warm, sweet sound. Driving up the gain so as to make the yellow LEDs flash produces a subtle coloration as the output valves add harmonic distortion. Though on paper this level of distortion would make a hi‑fi enthusiast cringe, the subjective result is a very slight thickening of the bass end and a subtle lifting of high‑frequency detail. This may be used to good effect both on whole mixes and on individual parts such as vocal tracks, where a conventional mic can be endowed with some of the tonal attributes of a tube model. It must have been tempting for the designers to go over the top and hype up the valve distortion, but I think they've made the right decision in keeping it natural and fairly subtle.

Initially, I thought I might find the switched filter frequencies rather restricting, but in practice, the correct choice of bandwidth or Octave seemed to be more important than being able to pinpoint the exact frequency to operate upon. As stated earlier, the filter frequencies seem well chosen; at the low end, for example, there's a setting at 50Hz to address mains hum problems and a setting at 80Hz to beef up kick drums.

The usefulness of the high‑ and low‑pass filters shouldn't be underestimated; I've used the side‑chain filters in my Drawmer DS201 for many years to provide me with additional EQ. The high‑pass filter is wonderful for thinning out acoustic guitars or backing vocals to make them sit in a mix, while the low‑pass filter is a powerful tool for skimming the noise off dirty guitar or noisy synth tracks. It's also quite convincing when used to take the rough edge off a digital synth to emulate analogue warmth. This, in conjunction with the available valve coloration, adds up to a powerful creative tool.


Like all Drawmer's analogue products, the 1961 is very easy to use and very predictable. The parametric equaliser sounds very nice indeed, and whether or not it exactly emulates the characteristics of the all‑tube, all‑inductor classics isn't really an issue. The ability to control the amount of tube distortion rather than simply taking what you get is welcome, and the inclusion of the high and low‑pass filters means the 1961 can take on both creative and corrective work with ease.

There are very few complaints that can be levelled at this product, though I know some users prefer continuously variable filter frequencies. The frequency knobs (rotary wafter switches) were also a trifle stiff on the review model, but as this was part of a pre‑production run, this may well be straightened out before they start coming off the line in earnest.

On balance, the 1961 is a very desirable equaliser that compares favourably with its all‑tube counterparts, yet costs rather less. It makes the ideal partner for the 1960 in audio sweetening and post production applications, yet also stands in its own right as a serious and powerful piece of studio equipment. Once again, Drawmer have proved that the era of analogue excellence has not yet drawn to a close, and the 1961 looks set to take its place alongside the 1960 as a modern classic.


    The Input Gain control has a range of ‑20 to +20 dB. A 5‑segment LED meter shows the input level over the range ‑10 to +10dB.
    Continually variable 12dB per octave shelving, high‑pass filter with a range of 15Hz to 500Hz.
    Continually variable 12dB per octave shelving, low‑pass filter with a range of 2kHz to 56kHz.
    Each equaliser is capable of providing up to 18dB of cut or boost. The bandwidth is determined by the Octave control, which is continuously variable from 0.3 to 3.0 octaves.
    20Hz, 32Hz, 50Hz, 80Hz, 125Hz and 200Hz.
    100Hz, 160Hz, 250Hz, 400Hz, 650Hz and 1kHz.
    0.5kHz, 0.8kHz, 1.2kHz, 2kHz, 3.2kHz and 5kHz.
    Frequency selector switch. Available frequencies are: 2.5kHz, 4kHz, 6kHz, 10kHz, 15kHz and 25kHz.


  • Easy and intuitive to operate.
  • Warm, musical sound.
  • Includes Drawmer's versatile high‑ and low‑pass filters.


  • Switched filter frequencies are not to everyone's taste.


A great sounding, flexible equaliser that combines valve tonality with solid‑state reliability and noise performance.