Ok, Allen experts on here. Someone tell me the differnece between the ADC, MDC, MOS, etc. I am sure someone is brimming with info. Tell me about the electronic differnces, and the sound strengths/ weaknesses. I am sure someone is just waiting to pounce on this one-- perhaps a former or current Allen salesman with an axe to grind or just someone who wants to share some inside info..??
Ok then, someone tell me about the Rodgers models. I would really like to know what makes an ACD differnt from an MOS and MDC in terms of sound. Talk away. I will provide entertainig chat if you do...
I'm with you on the Princess pedalboard, Buzzy...</P>
I never could understand the reasoning behind it. Supposedly it was to save space, but the bench still needs to be back far enough for the player's hands and feet to be in a comfortable position. I'm not very tall (5'9"), but even with a standard pedalboard on my home and church organs, the bench is further back than the heel of the pedalboard, so where would a PP have saved any space? They make the organ look cheap, like a 'fun machine'. If it was so imprtant to save a few inches of space, it would have made more sense to keep the sharp caps the same size, and reduce the overall length of the naturals. </P>
The princess PB was designed to allow a narrower console and more compact footprint. I have one and it is no problem. I don't think AGO would improve my playing any. (hehe).</P>
MOS 1&2 were the first digital sampled sound production organs. They utilized technology developed by Robert Deutsch and sold to Allen. With reverb it's pretty good. No bad for something 35 years old. Of course I'm a bit biased as mine also runs 6 ranks of pipe. </P>
ADC was an improvement tonally whereas MDC was a lower cost unit.</P>
The real improvement is the MDS series. Of course it's not cheap, either.</P>
I KNEW Al would bite. Now if we can only get him to talk more. More details, etc. How do these differ from the Protege and such, if not the Quantum and Rennasiance models.
[quote user="buzzyreed"] Ok, Allen experts on here. Someone tell me the differnece between the ADC, MDC, MOS, etc. I am sure someone is brimming with info. Tell me about the electronic differnces, and the sound strengths/ weaknesses. I am sure someone is just waiting to pounce on this one-- perhaps a former or current Allen salesman with an axe to grind or just someone who wants to share some inside info..??
the buzzzzzzzzzzzzzzzzzzz
[/quote]</P>
</P>
So, bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz. Why do you want to know? So you can entertain yourself by slamming Allen organs? I have nothing to do with the company, but I have been curious about tech details over the years, so I know some things. Here is some info in a nutshell:</P>
</P>
MOS-1 and MOS-2:</P>
1) Single cycle waveforms, 8-bit DACs</P>
2) Single computer created 38, or so, stops. All stops created by a single computer were in perfect pitch and phase with each other, so many thought it sounded "sterile". Larger MOS organs featured multiple computers which dramatically increased the warmth and realism by having slight tuning and phase differences.</P>
3) Allen created the waveforms by analyzing the harmonic content of real pipes, then used a computer program to specify the strengths of the harmonics to re-create the waves. Not sampling ina strict sense.</P>
4) Each computer had two channels of audio: "Flute" and "Main", although some flute stops were on the main channel to try to give some phase separation. Some non-flute stops were on the "flute" channel for the same reason. Later models had stop-selectable sharp tuning for the Great manual to warm the sound a bit, when played with the Swell manual.</P>
5) While laughably primitive by today's standards, it was revolutionary in 1971. The only other digital product available the same year on the market was a four function Sharp calculator for $1000.</P>
Allen and Sharp won technical awards for their products and the first Allen digital organ is now in the Smithsonian.</P>
</P>
ADC:</P>
1) Single cycle waves with dramatically improved DAC's with many more sample points per wave.</P>
2) Much warmer sound due to separate voice boards that still had several stops per board. All stops on the same board were still locked in pitch and phase, but since several boards were used for even small organs, the sound was more "multi-rank" in nature.</P>
3) During this time, more advances were made on custom boards that featured a sort of wave-sequencing that re-created attack qualities of pipes. Also used multi sampling to do four samples per rank covering the length of the keyboard.</P>
4) Simple note-on and note-off MIDI became available during this era as did digital reverb.</P>
</P>
MDC:</P>
1) Sometimes confused with MDS.</P>
2) Appeared during the MOS era as a cheap digital replacement for the cheap transistor organs of the 1960's.</P>
3) The sound was even less realistic than MOS and featured a few basic waveforms that were filtered to produce different types of stops</P>
</P>
MDS:</P>
1) Truesampling used.</P>
2) More sophisticated MIDI standard on all models.</P>
3) Protege line introduced as lower cost version of more expensive MDS models.</P>
4) Not totally independent stops, but many more pitch clocks and output channels used for even better "multi-rank" sound.</P>
5) Samples were pretty short. Allen advertised the entire memory of the MDS organs in the megaBITS range, not megabytes.</P>
6) Had 16 bit resolution with a sampling rate higher than CD.</P>
</P>
Renaiisance:</P>
1) Totally independent stops (Can be voiced note by note, rank by rank)</P>
2) Much longer samples and more samples per rank.</P>
3) Uses flash memory so alternate samples can be loaded by CD-ROM over the original samples.</P>
4) Protege line eventually replaced MDS technology with Renaissance.</P>
5) Much more advanced digital reverb.</P>
</P>
Quantum:</P>
1) Extension of Renaiisance technology</P>
2) Protege line has started to feature Quantum technology</P>
3) Uses real-time convolution technology to sample the acoustics of different rooms.</P>
</P>
</P>
There you go, bzzzzzz. Let the lame jokes and criticisms begin.</P>
The MOS organ sample was a half cycle that wasprocessed before digitizing. It was not the harmonic structure. I have copies of the original patents by Deutsch. The biggest problem was getting the required processing speed to avoid digital aliasing. Aliasing is waveform errors (distortion) whigh results when any frequency being digitized approaches one half the sample rate(Nyquist limit). You get better sound today as a direct result of higher sample rates (44khz and higher). It is truly remarkable the results he was able to achieve with the micro development in its infancy. Later work was done for Yamaha utilizing Fourier analysis to store and reconstructthe sound harmonic structure yielding more efficient use of memory and reduced cost although requiring more CPU power. I don't know whether they are still utilizing those techniques.</P>
The only other toaster with this kind of longevityis the big "H"which will outlast us all.</P>
Why is everyone so darn cynical? I just wanted some info. Hmmph. Anyway.. I am looking at the deals on ebay for the earlier Allen compact digitals and was wondeirng how much worse the sound could be from my MOS 600 beast. I plan on moving around the country over the next 10 years or so until I finally finish grad school and get tenured at the right place and I can't imagine bringing that bad boy anywhere.
I am just wondering what limits I could stand in terms of the Atari effect. I would like to purchase an All in One unit like my TC-3, but digital and without the aesbestoes.
Lame jokes? Cricitism? Wow you ppl are just too cynical.
We're having a ball. I vented in another postabout having to releather a chest, then went downstairs, fired up the machine, had a Bud and worked on a very difficult but beautiful number. I have some beautiful arrangements but they are soo hard, especially for my fat fingers. I wish I had your playing skill but eventually I get the fingering right and it works with only a few mistakes. The Bud helps too. Don't be so serious. This is fun and you should enjoy it too. If you were out here I have a nice Allen 225 organ. Classical, AGO, Stoptab. Smaller than yours but a very nice sound. I had reverb and midi on it. </P>
The MOS organ sample was a half cycle that wasprocessed before digitizing. It was not the harmonic structure. I have copies of the original patents by Deutsch. The biggest problem was getting the required processing speed to avoid digital aliasing. Aliasing is waveform errors (distortion) whigh results when any frequency being digitized approaches one half the sample rate(Nyquist limit). You get better sound today as a direct result of higher sample rates (44khz and higher). It is truly remarkable the results he was able to achieve with the micro development in its infancy. Later work was done for Yamaha utilizing Fourier analysis to store and reconstructthe sound harmonic structure yielding more efficient use of memory and reduced cost although requiring more CPU power. I don't know whether they are still utilizing those techniques.</P>
The only other toaster with this kind of longevityis the big "H"which will outlast us all.</P>
Regards, Al</P>
</P>
</P>
[/quote]</P>
</P>
I guess I wasn't clear on my point on how the MOS waves were created. Allen indeed did analyze pipe sounds. They used a computer program that could allow the user to specify harmonic levels. The program then used that data to calculate the waveform. The result was a ROM wave with sixteen sample points. That corresponded to the positive half of the waveform. The MOS computer would read out the positive values, then reverse the process and read them out backwards as negative numbers to produce the negative half, or trough, of the waveform. Although you might think sixteen sample points isn't very much, it did a good job for the time. Later the ADC models used 32 points per half waveform.</P>
[quote user="buzzyreed"]Why is everyone so darn cynical? I just wanted some info. Hmmph. Anyway.. I am looking at the deals on ebay for the earlier Allen compact digitals and was wondeirng how much worse the sound could be from my MOS 600 beast. I plan on moving around the country over the next 10 years or so until I finally finish grad school and get tenured at the right place and I can't imagine bringing that bad boy anywhere.
I am just wondering what limits I could stand in terms of the Atari effect. I would like to purchase an All in One unit like my TC-3, but digital and without the aesbestoes.
Lame jokes? Cricitism? Wow you ppl are just too cynical.
Buzzzz
[/quote]</P>
Gee Buzzz, I must have gotten that way from reading your other posts here.</P>
The MOS organ sample was a half cycle that wasprocessed before digitizing. It was not the harmonic structure. I have copies of the original patents by Deutsch. The biggest problem was getting the required processing speed to avoid digital aliasing. Aliasing is waveform errors (distortion) whigh results when any frequency being digitized approaches one half the sample rate(Nyquist limit). You get better sound today as a direct result of higher sample rates (44khz and higher). It is truly remarkable the results he was able to achieve with the micro development in its infancy. Later work was done for Yamaha utilizing Fourier analysis to store and reconstructthe sound harmonic structure yielding more efficient use of memory and reduced cost although requiring more CPU power. I don't know whether they are still utilizing those techniques.</P>
The only other toaster with this kind of longevityis the big "H"which will outlast us all.</P>
Regards, Al</P>
</P>
</P>
[/quote]</P>
</P>
Of course there is also the issue of the three different card reader systems Allen used as well.</P>
We process personal data about users of our site, through the use of cookies and other technologies, to deliver our services, personalize advertising, and to analyze site activity. We may share certain information about our users with our advertising and analytics partners. For additional details, refer to our Privacy Policy.
By clicking "I AGREE" below, you agree to our Privacy Policy and our personal data processing and cookie practices as described therein. You also acknowledge that this forum may be hosted outside your country and you consent to the collection, storage, and processing of your data in the country where this forum is hosted.
Tweet
Comment