Lowrey SS Lincolnwood

[KC9UDX]

I have acquired a service manual for an SS-25 because thus far I cannot find one for the SS. If anyone can source one for the SS, I'd buy it outright of course, or happily trade for the SS-25 manual.

[JQA]

You may be in luck. As part of my attempt to acquire and read all significant books on tube organs and other early electronic instruments, I recently found and scanned the Electronic Organ Handbook by H. Emerson Anderson, first published in 1960. It can be downloaded here: http://crasno.ca/articles/doc/EOH_HEAnderson_1960.pdf

So far, it is the only book I've found that gives a detailed description of any Lowrey tube organs (with the exception of the Organo attachment, which has very little in common with even their earliest standalone instruments). Specifically, it describes models S, SS, and DS, starting at page 100 of the PDF. Detailed schematics, circuit descriptions, and troubleshooting tips are provided. I hope it may be helpful; I imagine it will, since it even shows the schematic of the power supply section of the SS specifically, which I know you have been working on.

It is also quite interesting to me, especially the pedal circuit, which is virtually the same as used in my Lowrey LS from 1957 (for which I am also missing the proper service manual). This design is quite remarkable in the way it implements sustain. Each pedal switch has only a single pole consisting of a long flexible spring, and this pole is connected to a corresponding neon-lamp or tube-element keying circuit in the relevant generator section. The outputs of these keying circuits are added together, then routed to a string of dividers. When a pedal is pressed, its pole wraps around two contacts: first, a B+ contact that keys the relevant generator note (with a sustain capacitor, similar to the upper manual sustain), and second, a contact that turns on a massive relay when it is also connected to B+. This relay, when energized, both grounds all "off" contacts (thus quickly discharging the sustain capacitors of all unpressed pedals), and also keys the pedal control tube, which comes after the dividers. Note that the sustain time of the note is limited by the keying of the control tube (which has its own sustain capacitor), rather than by the sustain capacitors of the generator keying circuits. In fact, when the "off" contacts are not grounded, the notes going into the dividers are held on for many seconds, much longer than the audible sustain time.

One interesting consequence of this design is that when multiple pedals are played at once, the resulting tone is not simply the highest nor lowest of the selected pitches, nor a simple additive combination. Rather, it is usually a "rumbling" or "burbling" sound, since the pedal divider chain is fed multiple frequencies at once. This can be used to good effect by more adventurous organists. In fact, I've found that playing a perfect 5th interval results in an almost-constant octave above the lowest note being played, effectively extending the range of the normally constraining 12-note pedalboard!

Jesse

[KC9UDX]

Thank you! I'll have to print that and take a look. Hopefully I get time to work on this thing this year.

That burbling sound is a real bane. I never thought to try to make good use of it. But it really is obnoxious when accidentally pressing two adjacent pedals.

[KC9UDX]

Also I see that someone is selling this book on Amazon.

[JQA]

That burbling sound is a real bane. I never thought to try to make good use of it. But it really is obnoxious when accidentally pressing two adjacent pedals.

It does call for very careful pedal technique, especially when trying to play with both feet. I can see why Lowrey later changed to a more complex switch design (with 4 poles per pedal), in order to eliminate the relay and make it so that only one pitch may be sounded at a time. But I do consider it a "feature" of their early organs, since it is something that no other organ can do as far as I know, and it can sound pretty good when used carefully.

Also I see that someone is selling this book on Amazon.

I certainly prefer original print copies where possible, and they will only become harder to find as time goes on, so my suggestion is to go for it!

[Ordinary_Man]

One of the sellers on Amazon also has the book on thE Bay for a few bucks less. I already own this book and have no connection to any sellers. Just trying to promote "Thrift".

[KC9UDX]

One of the sellers on Amazon also has the book on thE Bay for a few bucks less. I already own this book and have no connection to any sellers. Just trying to promote "Thrift".

Thank you! I'll consider that. Not to save money, but I'm boycotting Amazon. Really I have *no* money at the moment so I probably won't buy it, but we'll see... I hate to pass it up.

[JQA]

It may not be needed now, but an original SS manual just came up on eBay (also with many others, including an LS manual which I snatched immediately): https://www.ebay.com/itm/Original-Lo....c100010.m2109