Ultimate Hammond Conversions thread

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donzoid
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Re: Ultimate Hammond Conversions thread

Post by donzoid »

Here's a live clip, both the Express clone, and the 1/2 power Rocket are stacked but you are hearing only the Rocket. Taken with one of those "sports cams"... not the greatest recording, but I've had way worse.

http://youtu.be/rnqQLGGJ2yQ
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darefugee
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Re: Ultimate Hammond Conversions thread

Post by darefugee »

Last weekend I picked up an inoperative Hammond M143 for free and scrapped it, it had an AO-29 and an AO-44 in it plus the reverb tank and some decent speakers. So now I actually have a small stock of spare iron and tubes for 6V6 and EL84, with no active projects. I already have a Plexi6V6, a 5E3 clone and an AC15 clone all built with Hammond iron. Anyone care to suggest a follow-on project?

This coming Friday I'm supposed to pick up an inoperative A100 for free. I'm a bit torn about scrapping it though, unless it turns out to be a real basket case. The A100 represents the Hammond "holy grail" to me - electronically a B3, in a smaller cabinet. Although I don't play keyboards, I'm thinking owning my own A100 would be a really good reason to take lessons. Plus I don't need the iron for any projects...
Last edited by darefugee on Wed Dec 17, 2014 9:21 pm, edited 1 time in total.
Thanks,

Roger
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donzoid
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Re: Ultimate Hammond Conversions thread

Post by donzoid »

Well I'm not sure how "much" different it would be from your vox15, but I sure am pleased with the 18watt 2-hole Rocket I built from the AO-43. Its like a Vox that goes to 11...

Based on what I measured for the OT in my ao-29, (new to that but pretty sure I got it calculated right) the turns ratio is 36.7:1 so in an 8 ohm load that makes about 10K8 - which should work for pairs of either 6v6 or el84 builds. Or, 6L6 at half the ohmage.

Yeah, I have an M3 here that's in such nice shape, I can't bear to tear it apart. So I gave it a spot in my studio "in case" some of my keyboard playing friends want to play on it. If I get an A series, I would probably also try to see if I could get that running! Good luck.
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drew
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Re: Ultimate Hammond Conversions thread

Post by drew »

darefugee wrote: This coming Friday I'm supposed to pick up an inoperative A100 for free. I'm a bit torn about scrapping it though, unless it turns out to be a real basket case. The A100 represents the Hammond "holy grail" to me - electronically a B3, in a smaller cabinet. Although I don't play keyboards, I'm thinking owning my own A100 would be a really good reason to take lessons. Plus I don't need the iron for any projects...
Hell, yeah, keep it, or pass it along to someone who can play and/or fix it. Please don't even consider scrapping it.
Tubelube
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Hammond AO-35 AO-39 Organ to Guitar power amp conversion

Post by Tubelube »

I have two Hammond AO-39 and two AO-35 organ power amps that I am looking into converting into guitar power amps with pre and post volume controls. Any rack mount guitar preamp could be used with them. This shouldn't be hard as they are organ power amps to begin with; I'm not trying to convert them into full guitar amps. Do you have any thoughts as to where I could obtain the needed info? Best Regards! Gary DiCenso :D
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Re: Ultimate Hammond Conversions thread

Post by darefugee »

drew wrote:Hell, yeah, keep it, or pass it along to someone who can play and/or fix it. Please don't even consider scrapping it.
yeah, I did keep the A100, and fixed it. Found a place for it right next to my Leslie (imagine that). I'm having a blast learning how to play keyboards now.

Been playing guitar over 40 years. In just one week of teaching myself keyboard, I learned why 1-4-5 progressions are called 1-4-5. Plus learned to play a Bob Seger tune. Life is good.
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Thanks,

Roger
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lord preset
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Re: Ultimate Hammond Conversions thread

Post by lord preset »

I came across another AO-39 chassis a while ago. This time I'm trying the normal channel of a Trinity TC-15 which is in turn a 15 watt version of a Matchless DC30. This requires two additional preamp tubes but I have reports that the PT filament winding can support this. Rather than try to deal with the existing tube layout and figure out a PTP version of the TC15 I decided to do major surgery on the chassis to accommodate a more conventional layout. After plasma cutting, welding and punching the zinc plating was toast, hence the paint and lacquer to prevent rust. This is for a friend in Florida, which is not a welcoming environment for raw steel.

Some progress pics:
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sluckey
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Re: Ultimate Hammond Conversions thread

Post by sluckey »

Ha. Must be the season for AO-39s. I'm currently redoing mine. The first conversion was an 18 Watt IIB. Then I replaced the Marshall preamp with a Vox AC-15 pentode preamp. I like the Vox better but I also missed the Marshall. So, now I'll have both preamps, kinda a Dual Lite. I'm using a new blank 12.5 x 6.5 x 2.5 chassis. The board is done and all the chassis work is done. Tomorrow I'll start on the actual wiring.

This AO-39 is really a nice little platform for simple 15W amps.

I like what you are doing with yours. Be sure to post some more pics as you progress.
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lord preset
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Re: Ultimate Hammond Conversions thread

Post by lord preset »

Heaters and transformers wired. Boards made. This is as far as I can go with on-hand parts. Now I wait for AES to send me the missing bits.
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sparrott
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A044 Conversion...

Post by sparrott »

Pretty much a stock A044 reverb amp with the FET input stage removed and a seven pin pentode stage. Built it for my brother in law who is a pedal junkie and just a bare-bones amps. Speaker is a Peavey Sheffield. Great sounding 8 watt amp but the price for A044 amps is climbing.

[IMG:800:600]http://i5.photobucket.com/albums/y182/sparrott/reverb%20amp_zpsobgufyxw.jpg[/img]
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lord preset
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Re: Ultimate Hammond Conversions thread

Post by lord preset »

All amps should have at least two knobs. It's OK if the 2nd knob doesn't do anything.
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donzoid
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Re: Ultimate Hammond Conversions thread

Post by donzoid »

I've got one too, but won't build it for a while...cool ideas for when I do!

Not to worry Preset, I'll have at least three knobs ... but I like the looks of that cane grille and head cab...nice work for your brother, Sparrot.

I have collected a ton of chassis and iron from these and others. I would bet I can build ten amps out what's in the shop, and yeah I plan to use, give away or otherwise repurpose (up-purpose?) 'em all.
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sluckey
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Re: Ultimate Hammond Conversions thread

Post by sluckey »

I just finished my AO-39 project. Not sure it still qualifies as a conversion since the only thing I reused this time was the iron. Anyhow, it's a Dual Lite, Vox AC-15 pentode preamp and Marshall 18W IIB preamp into a typical 18W power amp. I've got both my lites back.
Baddog01
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Re: Ultimate Hammond Conversions thread

Post by Baddog01 »

I only look for Hammond L100 organs because the come with AO-43 amps. I've converted three of them to guitar amps . Carmen Ghia, 18watt clone and a Matchless Spifire. Great little chassis

Keith
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Re: Ultimate Hammond Conversions thread

Post by Baddog01 »

I think I've parted out about 20 organs or more in the last 10 years. I believe the L100 is the best one for an amp conversion. I have found some other ones that have great iron but the L100 has a good size chassis for an amplifier build. I have another chassis sitting in my basement that has a nice Power and transformer setup. The problem with most organ amplifiers is the voltage they put out. The V-Dump thing that Weber Speakers offers is a great solution though I've never tried one personally.

I would have read through the whole post but I hate reading unless there's pictures of naked pictures of naked chicks on the same page....:)

By the way the tubes amplifiers aren't to only cool thing in the organs. Soe really nice speakers can be had too.

Keith
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