Kit’s Secret Guitar, Gear, and Music Page
Guitar stuff, gear stuff, soundclips, videos, Gilmour/Pink Floyd stuff, photos and other goodies.
Contact: nasnandos@kitrae.net
Copyright Kit Rae.

VISIT MY SWORDS, KNIVES and FANTASY ART WEBSITE www.kitrae.net

 

READING VINTAGE BIG MUFF POT DATE CODES

..

All vintage USA Big Muffs have source-date codes stamped on the underside of the potentiometer cans, or “pots”. The pots are what the knobs are mounted to, essentally manually adjustable resisitors that control the voltage across a circuit. The codes were created by the Electronic Industries Association (EIA) in 1920s to identify the product source and date of manufacture. The first string of numbers is usually the part number, or sometimes the pot value. In the second string of numbers, the first three numbers are a code identifying the manufacturer - CTS (Chicago Telephone Supply) brand is #137, and Stackpole is #304. The next two numbers are the year, and the last two numbers are the week of the year the pots were made. So a pot stamped 1377833 is a CTS pot made in the 33rd week of 1978.

Note that this does not mean a Muff with a 1978 pot was actually made in 1978, it just means it was not made much earlier than 1978. The Muff could have been made months or even years after the pots were purchased as it is known that Electro-Harmonix bought the pots in bulk, as did Fender, and other companies at the time. Stackpole and CTS made the pots in large runs also, so they may have shipped pots dated earlier than the year Electro-Harmonix ordered them. This just gives you a ball-park age for the Muff. Some Triangle Muff pot codes are dated 1966, two years earlier than the founding of Electro-Harmonix! Even buying new CTS pots today does not give you an accurate age because they are dated several months in advance of actual manufacture. The pots on the newer USA made E-H Muffs after 1999 do not have date codes. The Russian made Big Muff pots also lack date codes.

Website and contents ©2007 and ©2010 Kit Rae. All rights reserved. Linking to this website is allowed, but copying the text content is strictly prohibited without prior authorization. No part of this work may be reproduced, stored in a retrieval system, or transmitted in any other form, or by any means, electronic, mechanical, photocopying, recording, computer networking, or otherwise without prior permission in writing from the copyright holder(s).