CurvyMama is a special preamp that will give flesh, curves and grain to harps or guitars …
It can fatten and overdrive tight sounding amps.
In that aim, it features an original tone control and a germanium output preamp.
CurvyMama, Harp version
• Adjustable gain to adapt the grain of overdrive to the mike.
• Original tone circuit, improving the nuances
in the low medium and at the medium-treble junction..
• Midcut and phase invert switches.
• Output stage with germanium NOS transistors,
producing a mild and organic overdrive.
• High level low impedance output.
1. Choose the version.
2. Specify a tone option.
3. Specify the shipping zone.
4. Click <Add to cart>.
5. Click ‘Cart’ on main menu, or keep on visiting.
Price down : 169 €
Preamp-corrector for harp,
as described on this page.
• 5 basic controls :
drive, bottom, biting, contour, volume.
• 2 switches : invert phase ; less mids
• 200kΩ high impedance (who can do more can do less)…
• Ajustable level using gain control.
The input can be used with all usual microphones for harp.
• Antique piezo or ceramic “bullet” microphones (JT30, Green Bullet) …
• Old high impedance dynamic microphones (Shure Control Magnetic, 545, 588) …
• Modern dynamic microphones, low level low impedance (SM57) …
• Invert Phase Switch : phase inversion in order to minimize the risks of Larsen.
• Less Mids Switch : 1,5kHz attenuator in case of a bullet mike too generous in mediums.
• Bandwidth and tone settings have been studied specifically for the harmonica.
• 3 controls : Bottom, Biting, Contour…
Bottom : the belly of the harp sound, at the junction of bass and low medium.
Biting : The global roundness or sharpness of the sound, according to the played styles.
Contour : Carves symmetrically mediums and presence …
• The output preamp uses two NOS germanium transistors.
• The diagram is an adaptation of a classic circuit from the sisties.
• The overdrive is adjustable using the Gain control, from a clear sound to a fuzzy grain.
• In between, overdrive is progressive and organic, like coming from the heart of sound.
•The tone controls are placed upstream and define the texture without washing it out.
CurvyMama is powered by a 9V battery or an external 7 to 12V supply.
• Sound is typical with 9V, more dynamic with 12V, dirty and compressed with 7V.
• An internal electronic filtering eliminates common supply noises:
Hissing of switching power supplies, humming from transformer power supplies.
• Typical consumption with 9V: 8mA.
Like any germanium circuit, Curvymama gives its best sound after 5 to 10 minutes under power, when its internal temperatures have stabilized.
PCB of the 2018 prototype.
To know more…