Hammond B3/C3 & Leslie. Motor Speed control. by Dan.Vigin

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1 Hammond B3/C3 & Leslie Motor Speed control by Dan.Vigin Hammond and Leslie are registered trademarks of Suzuki Musical Instrument Manufacturing Co. Ltd. Binche / Belgium Oct. 013 Page 1 Oct.013

2 Hammond B3/C3 & Leslie Motor Speed control Purpose of this project. The idea behind this project is to take benefit of the various DC voltages that are now available from the newly installed PSU of AO-8 B3/C3 preamp equipped with a toroidal transformer. Refer to 'Hum & Noise reduction' chapter for details. Motor Speed Control PCB. Personally, I dislike the original speed control system provided with Leslie kits. There are several ways to control the motor speeds of Leslie cabinets: - either the +300Vdc is coming from Leslie PSU itself (Pin #) and via a basic network of resistors, the relay can be activated. - or another Leslie kit is collecting the B+ voltage from the AO-8 through one 7-pin adapter on the 6X4 rectifier tube to activate or not the relay. In both cases, it creates problems on a long term basis. - If the 10KΩ/7W resistor in the Leslie amp becomes opened, speed of motors will go to '' at once and you have no other alternative than to remove the motor plugs from the Leslie chassis. - with the 7-pin adaptor on 6X4 socket, you can expect poor contacts and other troubles. In my case, only Hamptone SSR-1B solid state relays are used and installed in my Leslie's. SSR-1B PCB's only require either 0 Vdc () or + 9Vdc () to change the speed of the motors. Hamptone SSR-1B board. ( see website : ). Also, no more audible 'clanky noise' of relay when speed of motor is changed. Page Oct.013

3 Since +9Vdc is now available with this newly installed PSU board, the initial Leslie kits have been abandoned. Inevitably, some precautions have to be taken and a small PCB has been designed with a few components (see schematic diagram) to assure safe liaison between the organ and the Leslie cabinet. Protection PCB (installed in B3/C3) There are some advantages in doing so: - the Leslie isolation transformer is no more needed - no more audible 'Pop' noise when switching from to or reversely. - no more bad contacts - more reliable setup However, such connecting setup (B3/C3 Leslie) is no more standardized. This means that the organ must be connected with its companion Leslie cabinets and not with any other one. Important! Nevertheless, it has to be mentioned that the original wiring at Leslie side can be restored quite easily in a few minutes whenever needed. From AO-8 Preamp Unit + 9 Vdc From PSU Board 0 Vdc Kick Switch (*) 1N4007 * installed on swell pedal 1. K 1N4007 D3 ZY 16 1AF F +8.3 Vdc ( Speed) 0 Vdc ( Speed) Motor Speed control Modified 6-Pins Leslie Socket at Pin# (not standard) RY 30 Vac IMPORTANT Pin # is now used to control the speed of motors. High voltage available from Leslie cabinet must be removed. Wiring diagram inside the B3/C3 organ. Page 3 Oct.013

4 Motor Speed control at Leslie side. Solid State Relay SSR1B (from Hamptone USA / Bill Brown) Static switching via triacs S N F P 6,3Vac Yellow Motors 11Vac Orange Neutral Pin #4 of P1 White Motors 11Vac Dark Red Speed Control Voltage from organ (Pin # of 6-Pins Leslie inlet) +8.3Vdc = 0 Vdc = Red Black Pin #4 Pin #9 (filament) 6,3Vac V1 socket Solid State Relay Leslie 1 30V version Type : SSR-1B Hamptone/USA File: SSR1_wiring.vsd Issued by: Dan.Vigin Date: 06/0/007 Wiring diagram inside the Leslie cabinet. The installation of SSR-1B inside the Leslie chassis is quite simple. The relay REL.I has to be unwired and removed. The tube V1 (1AU7A) has to be removed and is no more used. The remaining wiring is self-explanatory, see above wiring diagram. The switching of speed is provided by a basic toggle switch installed on the left hand side of the swell pedal. Shielded cable is used up to the Motor Speed control board. As a reminder, a 'Customization Diagram' of both B3/C3 and Leslie schematics is shown on the next page. Page 4 Oct.013

5 Oct.013 Page +9 Vdc AO-8 PREAMP AO-8 PREAMP Shielded cable Foot Switch (*) D3 1N4007 * installed on swell pedal D4 1N4007 Leslie TR 48-47K / 1W 1. K Foot Switch (*) R / 1K + - Original wiring inside Hammond B3/C3 10 µf 40V 1AF F ZY 16 D Motor Speed control 68K /1W BRN 30 Vac B+ (+7 Vdc) available from Leslie cabinet 116 Vdc () 0 Vdc () Customized wiring inside Hammond B3/C3 Customized 6-Pins Leslie outlet (not standard wiring at Pin #) +8.3 Vdc ( Speed) 0 Vdc ( Speed) RY Standard 6-Pins Leslie outlet 30 Vac IMPORTANT Pin # is now used to control the speed of motors. High voltage available from Leslie cabinet must be removed. 10K/7W R18 30 Vac Standard 6-Pins Leslie inlet Original wiring inside Leslie 1 R4 Not standard wiring at Pin #! 30 Vac Customized wiring of 6-Pins Leslie inlet +310 Vdc 1 nf/630v R1 R R1 R R 100 K C6 1 nf C7 1 nf 630V 1 REL K C8 1 nf/630v C6 1 nf C7 1 nf 630V 3 V1 ½ 1AU7A R 1.K R6 R16 1K/W SLOW/FAST R7 R 1.K R6 R7 + Vdc Customized wiring inside Leslie 1 R C Vdc / 0 Vdc To Point P of Solid State Relay SSR-1B (Hamptone) Customization Hammond B3/C3 with Leslie V 1AU7A Vdc 1 V 1AU7A 6 Issued by: Dan.Vigin File: Motor_Contr.L1_01.vsd Date: 1/1/009

6 Conclusions. The Solid State Relay SSR-1B from Hamptone is highly recommended, provides excellent results and is very reliable. Installation is rather simple. Trust having been of some interest, Dan.Vigin Page 6 Oct.013

Hammond X-66. Connecting Leslie cabinet to Hammond X-66 Console

Hammond X-66. Connecting Leslie cabinet to Hammond X-66 Console Hammond X-66 Connecting Leslie cabinet to Hammond X-66 Console by Dan.Vigin Hammond and Leslie are registered trademarks of Suzuki Musical Instrument Manufacturing Co. Ltd. Binche / Belgium Dec.2011 Page