CurvyMama + SimSym

CurvyMama is initially a preamp designed to process the flesh and grit of harmonicas sound. In this aim, It features a special tone circuit and a germanium overdrive stage.

This version + SimSym also features a boost stage.
Above all, it has an active speaker simulator, and a balanced output to the PA console.

CurvyMama SimSym Output, logo

CurvyMama SimSym Output, préampli spécial harmo avec simulateur de HP et sortie symétrique pour liaison directe avec la sono

The first CurvyMama SimSym, a custom order – March 2020.

Main Features

The CurvyMama preamp was designed from the start for the harmonica …
The Drive Boost pusher expands its use in concert.
The SimSym system completes the set, and increases the autonomy of the musician.

CurvyMama SimSym Output, préampli spécial harmo avec simulateur de HP et sortie symétrique pour liaison directe avec la sono - diagramme fonctionnel

From left to right: Microphone input – Power socket – Amplifier output – PA output.

CurvyMama preamp

Universal input.
Original tone circuit, managing the nuances
in the lower medium and at the medium-treble join.
Germanium final stage, producing a smooth overdrive.
Phase reverse switch to minimize feedback.
Boost pusher.

Two output SimSym system

  Output for stage amplifier or amplified monitor
(6.35 jack, unbalanced, guitar level -15dB)

  Output to the PA system, preceded by a speaker simulator.
(XLR3, balanced, mike level -30dB)


Downloadable leaflet

Hear samples from the amp output

Hear samples from the XLR3 output to PA (to come)

Bandeau medium rouge - L15To order

1. Specify your options
2. Specify the shipping area.
3. Click <add to order>.
4. Click <Cart> on the main menu to finalize.

CurvyMama SimSym Output, préampli spécial harmo avec simulateur de HP et sortie symétrique pour liaison directe avec la sono - intérieurCurvyMama
+ SimSym
239 €

Preamp specialy designed for harp
• Universal input. Controls :  Gain, bottom, biting, contour, volume.
Phase reverse switch.
1.5kHz switch to round off antique bullets mikes (free option).
Drive boost stompswitch and control.

SimSym output stage :
• Standard output for scene amp.
• Celestion or Jensen type speaker simulator of your choice.
• Balanced output to PA (after speaker simulation).

CurvyMama SimSym

Shipping costs (French post)
France: 12 € — CE + Switzerland: 24 € — Other countries: 32 €

Bandeau medium rouge - L15

Technical datas

Input level

• 500kΩ high impedance input.
• Nominal level: 10mV to 500mV, adjustable by the Gain pot.

Standard gain settings

The settings below apply to a microphone without potentiometer, held with closed hands.
They fix the input preamp at the junction between clean rendering and a bit of overdrive.

Antique bullet mikes, piezo ou ceramic
(JT30, Green Bullet…)
• Nominal level : 200 to 500mV, high impedance.
• Standard gain setting: minimum to 9:00 a.m.  Optional 1.5kHz filter recommended.

Antique or neo-vintage dynamic mikes
(Shure Control Magnetic, Shure 515, 588 switched on HiZ,… Bottle O Blues, Silverfish…)
• Nominal level: 100 to 500 mV, mid pr high impedance.
• Standard gain setting: minimum to 10h00, to precise according to the mike.

Mosern dynamic mikes
(Shure 55SH « skull », 565D, SM57, SM58…)
• Nominal level : 10 to 30mV, low impedance.
• Standard gain setting: about12h00…

Output level

Volume potentiometer
• Standard setting : about 13.00, to modulate according desired level.

Drive Boost potentiometer
• No effect at minimum… At first very gradual, then more powerful above 12.00.
• Moderately increases the volume, and especially the fat of the overdrive.

Stage amplifier jack output:  “guitar” level, low impedance. (150mV or -15dB).
Balanced XLR3 output: “Mike” level, low impedance (25mV or -30dB).

Tone controls

Three knobs that works on critical frequencies for the sound of the harmonica.

Bottom: the bottom of the harp sound, which is located at the junction of bass and lower midrange, at about 180Hz.
Biting: The general roundness or the bite of the sound, between 500 and 2kHz.
Contour: carves symmetrically the mids around 600Hz and the presence around 3kHz …

Special functions

Phase reverse Switch :
By selecting a routage in phase or not, the acoustic relationship between the instrument and the amplification system is modified. Generally, one of the two positions minimizes the risk of feedback. This switching also affects listening comfort on stage.

Drive Boost push button and potentiometer:
They push the gain of the overdrive stage and add grain to the general setting.
As a reminder: a moderate boost is obtained for the Drive Boost potentiometer at 12:00.

Ground / Lift Switch:
It establishes or interrupts the active mass link between the pedal and the sound system.
• Ground position: The masses are coupled. Ordinary position for small installations.
• Lift position: The masses are decoupled. Preferable on large installations.

Speaker simulator

It colors the signal sent to the PA system in order to simulate a stage amplifier.

In small places, an HP simulator eliminates the need for a stage amplifier. So you may be connected with confidence directly to the sound system.

It is made up of active filters preceding the output stage.
It limits the extreme bass and treble, to avoid cheap BoomBox effect.
It carves the transmission curve, to simulate the typical response of the loudspeakers.

Two options are available, to be selected when ordering.
• “Celestion” : clean and square rendering, slight high mids boost. The most universal.
• “Jensen” : American rendering, with “à la fender” dents and hollows…


CurvyMama Sim + Sym uses a 9V battery or an external 9 to 12V power supply.
The sound has all its qualities with 9V, with a little more dynamic in 12V.
Internal active filtering eliminates common hum and hiss.

Typical consumption: 20mA at 9V.
Autonomy: about 10-20h on alkaline battery.

Like all germanium circuits, Curvymama produces its best sound after 5 to 10 minutes under power, when its parts have stabilized their internal temperature.

Bandeau medium rouge - L15

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