HAO SP-1 Sole Pressure Fat Boost/Drive Effects Pedal (Japanese, VERY RARE)

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  • Regular price £160.00
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Originally designed as a low frequency booster, the HAO SP-1 Sole Pressure Fat Boost/Drive is an ideal pedal for those who want to add more lows and warmth to thin-sounding guitars and generates the fattest tones imaginable.

When the ‘Drive’ knob is cranked, the SP-1 Sole Pressure is reminiscent of overdriven 6V6 tubes in the vintage tweed amps of the 50’s. And with ‘Drive’ and ‘Level’ controls (and a 3-position mini switch, which lets you select from Normal, Bright, and Warm EQ curves), your tonal options are infinite!

The HAO SP-1 Sole Pressure was designed to recreate the classic sounds of one of the most desirable guitar amps in history – in this case, the legendary ’59 Tweed Bassman 4×10 combo. It contains carefully selected components that allow the user to dial in the smooth, creamy overdrive of this classic amp, right down to the characteristic low-end sag unique to the combo version.

Dual knobs control Output and Drive levels while three switchable EQ curves offer plentiful tonal options without compromising your guitar sound. This dual control configuration also allows to the Sole Pressure to act as a semi-clean booster to coax more character out of your amp.

This pedal is crying out to be played through a clean amp as, if you also engage the drive channel of your amp, the sound can become too coloured and muddy. That said, if you want to teeter up to the border between drive and distortion, then crank it up and enjoy!

If you’re looking for the classic Fender amp tone that defined a generation, the HAO Sole Pressure will let you achieve it with any guitar and amp in any playing situation, without the hassles that sometimes come with owning vintage gear.

It is worth noting that these are very rare pedals, made by one of the best boutique makers in Japan. They rarely come up for sale outside of Japan (and sometimes the US).

It is in great used condition with only a few cosmetic signs of wear and use.

Finally, it’s worth commenting on the beautiful mottled combination of metals – a brass/copper looking enclosure with a aluminium base. Sure to stand out on any pedalboard and have other players asking what it is, what it does and where it came from!


  • Input Impedance: Approx. 1M-ohm
  • Output Impedance: Approx. 10K-ohm
  • Controls: Drive, Level, 3-Position mini EQ Switch (Normal, Bright, Warm), DC9V Adaptor Jack (Negative Tip), True Bypass ON/OFF Footswitch with LED
  • Weight: Approx. 260g (including a 9V battery, not included).


This item is available from our store in Exeter or by post (at an additional cost of £10 due to weight and levels of required insurance).

If postage is selected, it will be packed very carefully and sent via Royal Mail 2nd Class Signed For.

If you have any questions, please contact us before purchasing either by email or phone.