Allen MOS 1105 stop list variants?

[organman95]

Saw this 1105 on eBay, http://m.ebay.com/itm/182113696696

And noticed something I found peculiar to me. The stop list (and the number of stops) is slightly different than my 1105. I know stops lists are subject to change, but number of stops would change in a given model?

For comparison, my 1105 has 64 stops (vs the 59), three reeds on the Great, two mixtures on the Swell, 16' Quintaden on the Swell in place of 16' Flute Counique, 2' Flute a bec on Pedal, etc.

I was under the impression that a difference in number of stops would either be a new model, or be considered "custom"

Mine also has 12 channels across 26 speakers, and (I think) 6 antiphonal speakers

[jbird604]

The 1105, standard configuration, is 8 channels -- two DAC outputs per computer. Custom versions with additional stops and more than 8 outputs were built up with "SDDS" add-on boards. If yours has 64 stops and 12 discrete channels, you may have some SDDS stops.

As you note, the number of stops is invariable, as the MOS-II computer system has a set number of slots. Each board has two EPROM sockets, and these could be used to customize the stoplist in various ways. There were numerous options for the 16' and 32' stops, mixtures, types of chiff, etc, available via EPROMs. One can also easily create "new" stops by using diodes on the tone strip to cause a single knob to call forth more than one of the on-board waves. Of course these aren't truly new stops, just re-mixes.

There is just SO much that can be done with an 1105, it boggles the mind. During the years we had one here locally that my business partner presided over, we discovered tons of "undocumented features" in that system. He had installed tabs that converted it into a very convincing theater organ with massive tremulants, and without the need for any trem generator units. The capabilities are all built into the system, but were never fully exploited by Allen, since the MOS-II era was so brief.

I'd love to get my hands on one of those again. The price quoted here is of course a "pipe dream."

[djseverus1]

FF strikes again. Where is he getting these?

[organman95]

I wish the Choir had both an 8' Erzahler and 8' Erzähler Celeste. Or at the least had a Celeste Tuning rocker for the Choir to pair with the 8' Viole....

[myorgan]

I wish the Choir had both an 8' Erzahler and 8' Erzähler Celeste. Or at the least had a Celeste Tuning rocker for the Choir to pair with the 8' Viole....

Amen! I totally agree.

John, sometime I'd be very interested in knowing how to make those specific changes. Perhaps when you come and visit the Northeast?;-) Just be sure to make it February or March because we have so much snow the rest of the year.

Michael

P.S. Djseverus1--I suspect he's getting these from organists who move to FL and retire, then the estates are sold. Perhaps also from local churches as they "convert" to alternate styles of music. Most don't realize FL can be considered part of the Bible Belt--even though many of the churches are Catholic instead of Protestant.

[jbird604]

Would be nice if the choir on the 1105 had celestes, but alas all choir stops come from a single computer, so the tuning is locked. That is why it's only the doubled divisions that have celeste tuning. HOWEVER ...

There IS a provision built into the MOS-II hardware for increasing the "frequency separation" (i.e., tuning spread) between the two DAC channels of a single computer. That spread might be sufficient to sound like a celeste. Somewhere on one of the boards it is possible to move a jumper to accomplish this. It would require soldering on some wires and running them to a switch, perhaps a blank knob or rocker. Then, drawing any two stops on the choir that are in opposite channels you could have a decent celeste!

I happen to believe that Allen was planning to use this feature to create REAL celeste stops on single-computer MOS-II organs, but they never got around to doing it, as the ADC models came along with real celestes on even the smallest models. This feature on the MOS-II system is very much like the chorus/celeste-tuning effect on all ADC models.

I'd have to dig through my MOS-II service manual to find the location of the jumpers in question. I seem to recall that they are hard-wired with a splash of solder, but it should be possible to replace the solder bridge with a pair of wires.

[organman95]

At what point did Allen start adding sub & super couplers? Did MOS ever have them?

[MarkS]

At what point did Allen start adding sub & super couplers? Did MOS ever have them?

In custom organs:

http://www.nycago.org/Organs/NYC/htm...ist.html#Allen

[jbird604]

I imagine that the sub and super couplers on a custom MOS were done the same way they were done on a few MDS models -- the coupled stops were in fact totally separate stops. Otherwise the system would have been limited to only six keys down with one coupler engaged, or only FOUR keys down with both couplers on!

The need for two or three copies of each stop is met by the additional MOS computers (this one had 11). The copy-cat stops were not doubled like the unison stops, and some stops were not even affected by the couplers, such as very high or very low-pitched stops. Making those extra copies play 8va or 8vb was the job of a board called the "universal coupler board" installed in series between the keyboards and the KBA.

[organman95]

Interesting. I knew there was a key limit, but I didn't think it was that bad!

[radagast]

I imagine that the sub and super couplers on a custom MOS were done the same way they were done on a few MDS models -- the coupled stops were in fact totally separate stops. Otherwise the system would have been limited to only six keys down with one coupler engaged, or only FOUR keys down with both couplers on!

The need for two or three copies of each stop is met by the additional MOS computers (this one had 11). The copy-cat stops were not doubled like the unison stops, and some stops were not even affected by the couplers, such as very high or very low-pitched stops. Making those extra copies play 8va or 8vb was the job of a board called the "universal coupler board" installed in series between the keyboards and the KBA.

I used to have literature on the entire MOS lineup. I'm pretty sure at one time it went up to a series 1800 model. The differences in the stop list to the 1500 and 1200 were slight except that there were super and sub couplers on one division on the 1500 and super and subs on 2 divisions on the 1800, meaning that the extra computers were mainly providing the extra voice channels for the couplers.

[michaelhoddy]

In custom organs:

http://www.nycago.org/Organs/NYC/htm...ist.html#Allen

Random aside, one of my college organ professors, Paul Liljestrand, presided over the replacement of the Welte-Trippe/Moller pipe organ with the custom Allen MOS at Calvary. That pipe organ was not inconsequential, and the church would have been able to pony up the funds to fix it, so either it sounded really bad, or the Allen sounded really good. I always wished I had asked him about that.

I played the Wicks/Walker that's in there now a few years back, and it sounds quite nice. It's hard to tell where the pipes end and the Walker begins. Now, back to your regularly-scheduled topic!

[beel m]

I used to have literature on the entire MOS lineup. I'm pretty sure at one time it went up to a series 1800 model. The differences in the stop list to the 1500 and 1200 were slight except that there were super and sub couplers on one division on the 1500 and super and subs on 2 divisions on the 1800, meaning that the extra computers were mainly providing the extra voice channels for the couplers.

Just a small correction- the 1500 was a 1200 (4 computers) with a Swell-to-everything (even Pedal) 16' coupler, plus a 32' Reed which the 1200 didn't have. To get a Swell Super, you had to add yet another computer- thus the 1800. The two big Allens (Calvary NYC and St Thomas Houston) had 11 computers, so they could have sub/super Choir couplers, a Great super, etc etc. All this sub/super coupler wizardry was done by halving or doubling the clock frequency... that's also how a 1500 got the 32 Reed from what would normally have been a 16 Pedal Reed.
Reason for all that- the 12-note MOS-1 limitation.

R, Bill

- - - Updated - - -

Random aside, one of my college organ professors, Paul Liljestrand, presided over the replacement of the Welte-Trippe/Moller pipe organ with the custom Allen MOS at Calvary. That pipe organ was not inconsequential, and the church would have been able to pony up the funds to fix it, so either it sounded really bad, or the Allen sounded really good. I always wished I had asked him about that.

I played the Wicks/Walker that's in there now a few years back, and it sounds quite nice. It's hard to tell where the pipes end and the Walker begins. Now, back to your regularly-scheduled topic!

Michael, my teacher played their Welte organ in the (IIRC) late 1930's, and years later after Moller redid it. He later recorded the Allen (which cost 75K in 1972 dollars). He told me that their pipe organ needed tonal updating as well as rebuilding. And, the church saw the Allen as a way to "fire the organ tuner." (their reasoning, not his or Paul's)
He also told me that ",,," (Allen's sales manager) didn't want him to say it, but he felt the big analog Allen at his church (26 generators) was much finer musically. Tenth cost $65K in 1969, so their prices were comparable...

R, Bill

[michaelhoddy]

Michael, my teacher played their Welte organ in the (IIRC) late 1930's, and years later after Moller redid it. He later recorded the Allen (which cost 75K in 1972 dollars). He told me that their pipe organ needed tonal updating as well as rebuilding. And, the church saw the Allen as a way to "fire the organ tuner." (their reasoning, not his or Paul's)
He also told me that ",,," (Allen's sales manager) didn't want him to say it, but he felt the big analog Allen at his church (26 generators) was much finer musically. Tenth cost $65K in 1969, so their prices were comparable...

R, Bill

That's the part I really wonder about- the Moller/Welte was tonally somewhat out of vogue, as the '58 rebuild added some period-specific reeds and the ubiquitous neo-baroque Positiv, but the rest of the organ was 30's Whitelegg symphonic. Lots of foundations, lots of celestes, two real 32's. The Allen had to have sounded VERY different than all that- perhaps the thin bright tonality of the MOS I organs was on par with what was in vogue tonally at that point so that to 1972 ears it sounded "good?" And if the Welte was failing mechanically (although only 14 years out of its last rebuild), that's another factor to consider.

Paul liked Allen. That I know- he did several organ dedications for them over the years and spoke well of them as late as 1999, but he was also a pipe organ guy with a strong classical and academic pedigree.

I also agree that the big analog Allen customs probably sounded much nicer, and with far fewer workarounds required in a bigger spec.

[beel m]

That's the part I really wonder about- the Moller/Welte was tonally somewhat out of vogue, as the '58 rebuild added some period-specific reeds and the ubiquitous neo-baroque Positiv, but the rest of the organ was 30's Whitelegg symphonic. Lots of foundations, lots of celestes, two real 32's. The Allen had to have sounded VERY different than all that- perhaps the thin bright tonality of the MOS I organs was on par with what was in vogue tonally at that point so that to 1972 ears it sounded "good?" And if the Welte was failing mechanically (although only 14 years out of its last rebuild), that's another factor to consider.

Paul liked Allen. That I know- he did several organ dedications for them over the years and spoke well of them as late as 1999, but he was also a pipe organ guy with a strong classical and academic pedigree.

I also agree that the big analog Allen customs probably sounded much nicer, and with far fewer workarounds required in a bigger spec.

Fascinating! You cleared up one thing I always was curious about- Paul L's ability. The Allen write-ups at the time called him a "noted concert pianist"... knowing nothing about him, I always wondered if 1; he was decent at organ, but really a pianist- perhaps they had him for 'prestige' reasons- or 2; he was a superb organist but Allen downplayed that because they chose Robert Elmore to record the organ and didn't want to ruffle RE's feathers.
Thanks for setting me straight.
R, Bill