From james_eaton@btopenworld.com Thu Feb 18 14:28:13 2010
Subject:Re: Roland VK-7 Opinions Sought - Am I Going to Like It?

Not sure I agree Goff747. The VK-7 was designed to work with current/modern 11-pin Leslies, hence the picture and pin out of an 11-pin Leslie on P116. 11-pin Leslies that implement brake through the standard cable by turning both sets of motors off have been around since the early 1980s (eg 122XB).

In the 11-pin world "brake" or stopped is implemented differently from the 6-pin 147/122 (see standard Leslie pin-outs below). This was an evolution of the 9 pin system used on the Leslie 760 which also used two pins to control speed in the same way.

Leslie 11-pin interface
1 - Audio (Rotary Channel)
2 - Audio (Stationary Channel)
3 - Audio (Aux Channel #1)
4 - Ground
5 - Control Supply Common (Short to pin 6 to turn Leslie on)
6 - Control Circuit Common
7 - Fast (Short to ground to activate)
8 - Slow (Short to ground to activate)
9 - Ext. Speed Adjust (Only w/ tachometer motors, unused)
10 - Audio (Aux Channel #2)
11 - White w/ Black Tracer +29 v dc (Powers CPA)

Leslie 9-pin interface
1 - Ground
2 - Audio
3 - NO CONNECTION
4 - Audio (Stationary Channel)
5 - +28 v dc (Powers CPAII)
6 - Fast (Ground to activate)
7 - Slow (Ground to activate)
8 - 1 of 2 Mains
9 - 2 of 2 Mains

To achieve stopped on an 11-pin Leslie, you leave pins 7 and 8 floating relative to ground.

Roland could have implemented brake on the VK7 quite easily but chose not to. I found this surprising given the attention to detail in other areas so I suspect it was out of ignorance. Perhaps they were using the Hammond-Suzuki XB-2 as a template which also didn't implement brake despite using the 11-pin interface.

The VK-7 11-pin has two speed modes - pin 7 grounded and pin 8 floating (tremolo)/pin 7 floating (chorale) and pin 8 grounded.

From what you are saying it seems like H-S just chose not to implement brake on their 11-6 pin adaptors it makes, but there is nothing to stop a tech building a working interface implements brake provided the instrument puts out the right control signals so again strange that Roland didn't implement it.

I've built 11-6 pin interfaces for my Leslies that implement brake but as there is no common standard for the connections and many people use SS relays the HS adaptor would have to deal with many standards and I guess they couldn't be bothered as they want people to buy shiny new 11-pin Leslies rather than keep vintage ones going from which they don't make any money.

As an aside, even if Roland had implemented it, the buttons on the VK-7 work funny: When you press fast it cancels the brake rather than leaving it on so that when you go back you are in chorale mode rather than braked So had brake been implemented on the connector they would have received a flood of calls saying they got the button logic wrong and would need to revise the firmware again. Again this behaviour suggests Roland didn't really get how the brake was supposed to work.

Regards
James