John East MMSR 1-Pickup 4-Knob 3-Band Vol - Treb - Bass - Mid/Mid Stack



The BTB-MMSR 4 Knob, including Mid Sweep, has been designed with characteristics very similar to the original MM Stingray 2 Band EQ, but is not an exact copy of the original circuit.

$230.00 - $245.00
$230.00 - $245.00

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Control Configuration

  1. Volume
  2. Treble
  3. Bass
  4. Mid Stack
  5. Available in Black, Chrome, or Gold Finish


The BTB-MMSR 4 Knob, including Mid Sweep, has been designed with characteristics very similar to the original MM Stingray? 2 Band EQ, but is not a copy of the original circuit. The original used a single op-amp chip (single amplifier stage in the form of a chip) for both bass and treble circuits, whereas this unit utilises a more modern dual op-amp chip (two amplifiers stages in a chip). The bass and treble are stacked which allows inclusion of a mid sweep, along with original MM style bass and treble, on a 4 knob plate. When the mid boost/cut is centred, its effect is neutral and the EQ is purely late 70s MM style.

This unit is supplied fully wired, including 3 single pots, 1 stacked pot, knobs, jack and battery clip, which may be spliced into an existing battery box, as would be available, in most cases.

The design of the 2 band EQ in the early Stingray basses is unusual in that it does not follow the types of topologies around which the majority of equalisers are designed. It would seem that Leo Fender designed it to create a particular sound rather than follow any conventions, such as symmetrical EQ curves. Consequently the figures shown may appear unusual to those familiar with such specifications. In fact it's not easy to portray what this EQ does with a few numbers, but in any case some figures, based around a flat response input signal, are quoted as reference points

Note: Like the original Bass/Treble EQ, this circuit does not have a flat response when the controls are set midway. This unit is not designed as a clinical tool, where what goes in, comes out at some reference setting. However, the Mid Sweep circuit does have a neutral setting in order to preserve the original feel of the Bass & Treble EQ.

Technical Specifications:

  • Volume:Sets the level from the bass and treble section of the preamp feeding the mid section.

  • This means that the pickup feeds the preamp directly, allowing the best possible transfer of signal, and full interraction of the pickup with the preamp. Since the mid section is after the volume control, it feeds the jack directly with a low impedance output.

  • Treble:(+20dB / -16dB @ 10 kHz)

  • There is more boost than cut, giving rise the characteristic 'sizzle' associated with the Stingray style of EQ.

  • Bass: (+14dB / -7dB @ 40Hz)

  • The bass control has a little more boost than the original. The boost curve continues to rise towards the lower frequencies, without flattening out at any frequency within the normal bass guitar range. Conversely the cut characteristic is shelving, having an essentially flat response from 30 - 100Hz, when fully cut.

  • Mid Level Boost/Cut: (+/-12dB)

  • The upper knob sets the amount of Mid boost or cut at frequencies according to the setting of the Frequency knob. The midway indent is the 'flat' setting.

  • Mid Frequency:(100Hz - 1kHz or 200Hz - 2kHz)

  • The lower outer ring sets the continuously variable Mid frequencies for boost or cut. DIL switches on the circuit board allow low or high ranges to be set. Both switch sections should be set to ON for the Low Range and both set to OFF for the High Range.

Question: Where Can I Buy a John East MMSR 1-Pickup 4-Knob 3-Band Vol - Treb - Bass - Mid/Mid Stack?

Answer: You can buy this from Best Bass Gear by Calling 877-839-3531 or Emailing us at or chatting with our Bass Techs


Rate and Review this item
Verified Buyer
Great sound and build quality
I put the John east MMSR 4-knob setup in my 5-string Ibanez ATK, and it turned it into an amazingly great sounding bass. The factory pickup in that bass is not very Musicman-like, and has a slightly lower output with lots of detail in the midrange. The progressive bass boost/shelving cut is a perfect match for the slightly reduced low end output of the configuration, and the treble has that peaked "zing" that everyone talks about. If I had to find something to compare it to, I might say it sounds like a Stingray with an EMG pickup, but with the vintage factory preamp and a sweepable mid control.

The sweepable mid control is a great product in its own right and recommended, but I find I don't really need it as the stock pickup has "all the frequencies".

Installation is done entirely with screw terminals, although there is some soldering if you need to connect to an existing output jack. There's something almost disappointing about not "getting to solder" but the connections were really easy to make and no mess.

The knobs are nice, and the pots have that heavy-oil damped feel. All in all I love it.

(Why the factory preamp sounded so bad is a mystery as they are rumored to sound great; the short story is that something must have been wrong with the factory preamp, because it did indeed sound terrible, all midrange with no bass or treble.)
Verified Buyer
You can't beat this preamp for your Stingray
By John Tompson
I think anyone who owns a 3-band Ernie Ball Musicman Stingray should put one of these in their bass. I put this in my EBMM fretless Stingray and it came to life! I did have one particular challenge installing this -- the control plate was not grounded with the stock wiring setup and I had to solder a ground wire from the supplied output jack to the base of the bass control pot to ground everything. John East was answering my emails on Christmas eve in the UK!
Verified Buyer
By Antonio Solorio Gonzalez
I am a tone freak; stock MM preamp was not bad but lacked versatility to my taste so I tried first with a Bartolini preamp but did not count with the tight space you have in the control cavity. Then I found this John East:MMSR and gave it a try. It fits easily in the cavity and the tone is genuine Stingray sound, add to this a stacked Mid Sweep control and you are set for any scenario. The quality is superb and assembly flawless; John East preamps are a great option to expand your sound.