MOSweb Online!
Knowledgebase
All About Vacuum Tubes
The following is from Wikipedia and is governed by their license. [wiki-embed url=’http://en.wikipedia.org/wiki/Vacuum_tube’ no-edit no-contents ]
Recommended Maintenance Schedule
Regular maintenance on Digital Pianos and Electronic Organs is essential to keep them in proper working order. While not all organs of a given make will need all these maintenance items performed (example, late model organ often CANNOT go out of tune) the following list will act as a guideline for how often a technician should be called to perform routine maintenance. Allen Analog Organs- Should be tuned and have their tab and key contacts cleaned every 2 to 4 years Allen Digital Organs- Consult your local Allen Dealer / Technician Baldwin Organs- Should be tuned and have their tab contacts and key contacts cleaned every 2 to 4 years. Conn Organs- Should be tuned and have their key contacts cleaned every 2 to 4 years Gulbransen Organs- Should be tuned and have their key contacts cleaned every 2 to 4 years Hammond Organs- Should have their drawbars cleaned every 2 years and most older models need their tone generators oiled every year. Ones built in the 70′s should have their board connectors cleaned every 6 to 8 years. Kimball Organs- Should be tuned and have their key contacts cleaned every 2 to 4 years. They should also have their…
Schematics and Diagrams
[gallery] Scanned 22H Schematic.pdf – Scanned 122 Schematic.pdf
Hookup Tutorial
There are many good references for the exact how-to for hooking up an organ to a Leslie, where the information isn’t available the complications are such that a tech is usually needed anyway. So I’ll simply offer this advice. Avoid “transformerless” or “capacitor coupled” connector kits at all costs, and don’t fall for the “hi-fi mumbo jumbo”. Is it cleaner, brighter, etc? Yes I think it would be, but that’s not the point. That’s not what you’ve been hearing for the most part. You might as well go all solid state and then marvel at how much it sounds like shit.
Leslie™ Pinout Data
INTRODUCTION This document covers the 5, 6, 9, and 11 pin STANDARD systems used by Leslie™. Pay special attention to the model’s listed in each section, as there are a number of Leslie™ models out there with “nonstandard” interfaces. FIVE PIN SYSTEM This system was originally designed by Hammond™ to: Connect Hammond™ tone cabinets to later model Hammond™ Organs which no longer needed the B+ supply from the cabinet. “Daisy-chain” older Hammond series (21H, 22H etc.) Leslie™ Cabinets. Connect Hammond™-type Leslie™ models to later Hammond™ Organs (-2 and -3 models among others) via 8000-type connector kits and five-pin sockets at the console. Despite all these applications, the 6 to 6 cable is far more common and is recommended for new work and as an upgrade to older instruments. In these cases the “extra” pin is simply left open and unconnected. Since a 5 pin plug to 6 pin socket cable is used in the above applications, I have provided the “6 pin” column below to illustrate the wiring of one of these “5 to 6″ cables. TABLE OF CONNECTIONS 5 PIN 6 PIN FUNCTION COLOR 1 1 1 of 2 Audio Black 2 3 1 of 2 Mains Gray 3 2 Ground Yellow 4…
Tone Cabinet Database
NOTICE: This database represents innumerable hours of work not only by myself but by many Leslie enthusiasts. YOU MAY NOT COPY THESE PAGES for any purpose with out first obtaining permission from me. CREDITS: Master Model List and Prototype Data – Harvey Olsen Technical Specifications – Original Service Manuals and advertising materials (where possible) Additional Tech Specs – World Wide Official Organ Blue Book – 1981-82 edition Published by Zeb Billings Music Publishing Company. PP L-1 thru L-5 PHOTO CREDITS: Black and White images are from service manuals and Hammond Suzuki ads. Color images with swirly back grounds are from CBS / Electro Music ads circa 1970s. Exceptions to the above are stated as follows: Model 30C – Dixson Rudolph Model 31A – Unknown Model 31H, 31W and 21H – Craig Browning Model 55C, 102, and 103 – Steve Cyr. Model 105 – Dan Nebenzal Model 212S – Gary Allsebrook. Model 215 and 215A – Udo Fischer of Berlin, Germany. Model 310 – Paul Strange of the UK. Model 312 – Unknown Model HL822 – Bob Larson Model 315, 415, 515, 615, HL722, 815, and 840 – from http://www.seipel.de/ Model 122N, 142N, 760N, and Euro variant of 760 from Stéphane…
PDF Library
Technical Glossary
BBD Modulator – BBD stands for “Bucket Brigade”, it is an analog chip that provides an amount of time delay based on the number of stages in it. BBD’s have been, and still are, used to create various analog effects such as chorus, flanging, phasing, and analog delay. In some Leslies this technology is used to create a simulated rotary effect for the low frequencies to save weight and mechanical parts. Compression Driver – High frequency speaker which produces sound via a diaphragm. By it’s self it is not able to project sound very well, it is therefore always attached to some sort of horn shaped resonator to project sound. In normal stationary speakers, such as PA speakers, the horn is mounted in a fixed position. In a Leslie cabinet this resonator is the upper rotor, referred to as the horn. See Horn. Drum – A rotating circular deflector which spins on the output side of a traditional speaker. Horn – A rotating horn shaped projector which is placed over the output side of a Compression Driver. (AKA Treble Rotor) Merc-O-Tac – A mercury filled rotary contact, see “Rotosonic Drum”. Multi Rank Effect – A simulation of the natural fullness…
Contact
Contact Form
About
This Site
MOS
MOS or Maryland Organ Service was a provider of service and maintenance for Pipe, Parlor, and Electronic Organs in the Baltimore / Washington area from 1972 to 2005. Maryland Organ Service began in 1972 as a “retirement plan” for James Henthorn. At that time, he, a lifelong church organist and physics graduate of Johns H
