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View Full Version : Lansing Iconic repro field supply project



Steve Schell
05-27-2007, 09:04 PM
Two friends and I had a great time on Saturday. We had talked about building some new field supplies for our Lansing Iconic two way speakers (or parts thereof) for years, and finally got around to studying the project seriously about three months ago.

I didn't have enough F-820 field supplies to power the Iconics on hand, and my friends have been more or less in the same boat. We decided to build a dozen new ones, to meet our current (sorry) and future needs. I also had three original supplies in bum shape, so I ordered enough parts to bring them back up to spec.

To start the project I disassembled one original supply. The transformer and choke went to Jack Elliano at Electra Print Audio in Las Vegas so that he could quote on new iron built to original specs. The bare chassis went to a metal shop. New sockets, capacitors, wire and other miscellaneous bits were obtained here and there. Jack shipped us a dozen new transformers and chokes that are just beautiful, typical of his work. The lamination sizes are just a bit larger than the originals, as those sizes are now obsolete. The new chassis were designed to reflect the slightly different iron dimensions, and we were relieved when the new trannies dropped right into place. One friend mixed up some enamel that beautifully matches the original Lansing dark blue color and sprayed the chassis and transformers.

On Saturday we built up two new supplies and made needed repairs to two original ones. The new ones tested fine under load, delivering just a few volts lower than the original supplies. This seems to be a good result, as line voltage is probably higher now on average than in the 1940s.

Upon completing the rest of the new supplies, the next phase will be to build new wiring harnesses. All Iconics except the earliest ones supplied 330VDC to the field coils of the 801B high frequency driver and 815 woofer in a series string. The harness connects to the drivers using Amphenol four pin and five pin connectors. These are thankfully still manufactured, as is cloth covered wire that closely matches the original harness wiring. The harness also incorporates signal leads from the dividing network to the drivers.

The pictures show one of our new supplies as well as an original, a circa 1945 Altec era piece. By that time they had shifted to a dark gray finish, though all earlier ones were Lansing blue.

mikebake
05-27-2007, 09:13 PM
Wow. Great stuff as always, Steve.

glen
05-29-2007, 11:06 AM
Very Cool Steve!
Now all you need are reproduction decals like they make for classic cars!
Very sweet looking!

Is Jack Elliano at Electra Print Audio making these custom transformers available to all comers?

And most importantly...
Have you set up your Lansing Iconic 5.1 theater surround sound system yet?
You being the only one in the world likely to pull that off!

Congrats on the beautiful reconstruction!:applaud:

Steve Schell
05-30-2007, 12:27 AM
Thanks, Mike and Glen. No, the 5.1 Iconic setup is not in place yet, but it won't be long once I get the wiring harnesses built. The Lansing Monitor 500A ("History Found" LH article) should make a nice center channel.

I am sure that Jack would be happy to supply more of these transformers and chokes. I asked him to hang onto the specs for them in case we need to order more in the future.

allen mueller
05-31-2007, 05:58 PM
Very nice work.

Steve Schell
06-01-2007, 11:05 AM
Thank you, Allen.

We had big fun in Lansing Land yesterday. I built two new Iconic wiring harnesses, to get two Iconics up and running with the new field supplies. I had two tattered original harnesses to work from. The Amphenol connectors are still manufactured, and I used new cloth covered wire for an authentic look. After moving two Iconics to the living room and hooking up the supplies, I conducted a long search for a second 5Z3 rectifier. Once found, I was able to listen to Iconics in stereo for the first time.

They are really something. The performance of the 801 small format driver on the H-808 tar filled horn is very good. Sharp transients like finger squeaks on a guitar fretboard and plucked notes are lifelike with excellent dynamics, and the sound is clean with nary a trace of tizzyness. The 815 15" woofer in the 812 reflex box has a fair amount of boom and a slightly muddy upper register (I'm used to listening to bass compression drivers), but there is plenty of impact and liveliness in the woofer's performance and surprising floor-shaking bottom end when things get loud. Once I had made a few adjustments and swapped out a dividing network the systems imaged quite well.

My friend Robert Grunberg was here last evening, as was my friend and Cogent partner Rich Drysdale. We shared a bottle of wine and listened to the Iconics for a couple of hours; it was one of those memorable listening experiences.

In the Iconic a four pin connector brings DC to the field coil of the compression driver as well as the audio signal from the dividing network. A five pin plug accomplishes the same for the woofer. The two field coils are connected in series with the 330VDC supply.

rs237
06-01-2007, 11:52 AM
Hello Steve,

outstanding work. I envy you for these moments. I would gladly have participated. I would have bring along also some 5Z3 (grr .. is this correctly translated? ) .:)

regards

juergen

Steve Schell
06-02-2007, 12:04 AM
Juergen, I wish you could have been here. You are welcome to visit anytime you can make it out to California.

JBLnsince1959
06-02-2007, 06:13 AM
fantastic as always:applaud:..great work..I really love the very old stuff.