Engineer's Thumb [Compressor] Product Details Engineer's Thumb [Compressor] ETPCB Weight: 15g Product Condition: New Units in Stock: 10 £4.00 inc. tax Product Description The best DIY guitar compressor money can buy! 54 x 62mm; will fit into a Hammond 1590 or equivalent.Note: On Iss.3.1 boards there is an extra R19 that shouldn't be there; it is next to R7. You do not need to fit anything in that R19 position.As of 2020 you will receive issue 4.1 boards or higher. Go to www.valvewizard.co.uk for the latest schematics and build guides.Components not included.Colour may vary. Facebook Google + Pinterest Twitter