Forum Top Banner Ad

Collapse

Ebay Classic organs

Collapse

Announcement

Collapse
No announcement yet.

I got to play a beautiful Baldwin church organ.

Collapse
This topic is closed.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • I got to play a beautiful Baldwin church organ.

    I guess I should never judge an organ by its brand. When I think "Baldwin", I automatically think of rocker tabs and cartoon-like flute sounds. For Easter Sunday, I got to play a beautiful Baldwin that in many ways seems light years ahead of my regular Rodgers T787. I have no idea as to the age (although the former organist told me it's at least 40 years old). There are transposer buttons which look a little clunky but have more character to them than a more modern console's digital readout. Lots and lots of couplers (something the T787 is sorely lacking) make the sound even more interesting and varied than what would otherwise be possible. There's a funny little feature called "celestial vibrato." In my mind, it's more appropriate for a haunted house than a sanctuary but it did get some chuckles from the music director. It has a very nice harp and chimes sound. One of my favorite features was that I could either play through the console or antiphonal speakers and/or both. But yes, there are some negatives Given that there's no computer action, I couldn't set the pistons to my own specification so it was a little bit wearisome having to always change my registration via the tabs. The antiphonal speakers are located "around the corner from the organ so I was in a dead spot (people could hear me but I couldn't hear myself).

    But all in all, a lovely service complemented by a surprisingly very nice organ.

    I'm curious as to the model and anybody else's opinion of it.
    Attached Files

  • #2
    I believe it is a model 625 from the early 1980's. I happened to be on a business trip to Cincinnati and had a little time on my own--stopped by at Baldwin headquarters with no appointment, and their VP of marketing graciously showed me this organ. The sound was very impressive for an analog, frequency divider organ. I appreciate that on this and later Baldwin organs they included complete sub and super octave couplers, even on the Great.

    Comment


    • #3
      Might be a 632, which I think has all the features shown here -- the flip tabs and external speakers, four presets. Definitely a member of the series that includes the 632 along with the 626, 625, 635, 636, 645, 520, 540, and the somewhat older and larger 640. The models in this series differ in tab type and stop control system -- some have flip tabs, some have mechanical rocker tabs, others have "silent-touch" tabs that spring down and up to turn a stop on or off but always return to center. These silent touch models have a CPU that runs the stop selection and capture action, and they have settable pistons and some have a crescendo pedal as well. The old 640 was probably the last moving knob organ Baldwin tried to offer and was plagued with a quirky capture system, but it was the first of these multi-generator IC driven organs, and the models that followed it were quite good.

      As I recall, the preset pistons on some models can actually be changed if you know how to do it. Take off the back of the organ, and a board right in the middle has a bunch of DIP switches on it. You can add or remove any stop to any piston. Like a setterboard, but in a very inaccessible place!

      They sound so good in part because of an unusual "rate-scaling" circuit developed by Baldwin. This system makes possible a flexible 6-up and 6-down transposer, and also a truly wonderful and unique one-generator organ that sounds like it has a lot more oscillators. While there is a single master oscillator that drives the primary top-octave-frequency-generator chip and its related divider network, there are some slave generators that get fed a slightly altered control frequency, created by throwing in some specific frequencies off the primary TOFG/divider set along with the master oscillator itself. Running through a complicated bit of Rube Goldberg circuitry, this mishmash comes out as individual master frequencies slightly offset in pitch. Looks like voodoo in the service manual, but it does indeed output several distinctly different tuning references that drive separate TOFG chips and divider networks, the pitches of which go to some of the stops or octaves of some stops that give the organ an unmistakable "ensemble" sound as if there are numerous ranks of oscillators like a big Rodgers or Allen analog. One of the ranks is even tuned 10 or 12 cents sharp to serve as a true celeste source.

      The system also sounds good because of the large number of diode gates incorporated into big circuit boards that stand up on the motherboards. These diode gates are greatly miniaturized compared to the discrete gate boards of the big old Baldwins from the 60's but they provide very well controlled attack and decay characteristics for the individual stops and pitches. These gates also turn the square waves of the divider outputs into various pulse or other wave shapes that make more realistic string, diapason, and reed stops than the simple square waves that are filtered and combined to make different voices in the older and less interesting Baldwin organs. (Techies may have a better explanation of how this works. I just know that it sounds good!)

      The outputs of these sophisticated gates are collected by a group of op-amp boards, then sent on to filter boards where each octave of each stop has its own voice shaping circuits. (It's not as grand as it might seem, because a close look at the schematic reveals that there are actually only a handful of truly separate stops going into these voice boards. The numerous tab voices are created by unification and borrowing, using identical stops at different volume levels, etc. But the effect is pretty darn good.)

      Baldwin also wisely divided these stops into several output audio channels, more on the larger instruments of course, and included a very effective bass crossover network that sends the lower frequencies of all stops into the dedicated bass channel which is normally played through a pretty hefty subwoofer.

      The huge downfall of these organs is in the details, unfortunately. The grand design depends on the proper operation of all these gate boards and other components which are interconnected through the large motherboards into which they are plugged, and also by a spaghetti-like mass of wires that plug onto the edges of the boards. The motherboards are prone to developing bad solder joints where the big socket pins are soldered on, and the connectors on the edges are prone to developing loose crimps in the wiring pins.

      Just recently we spent a very long day trying to chase down all the loose connections in one of these organs, and by the end of the day it was working very reliably. Problem is, we can't say how long it will be before more cracks open up in the solder or more crimped connectors get wobbly.

      Personally, I think they are quite amazing and I'd love to have one if had room for a private collection of interesting organs!
      John
      ----------
      *** Please post your questions about technical service or repair matters ON THE FORUM. Do not send your questions to me or another member by private message. Information shared is for the benefit of the entire organ community, but other folks will not be helped by information we exchange in private messages!

      https://www.facebook.com/pages/Birds...97551893588434

      Comment

      Working...
      X