Hammond Organ Amp to Guitar Amp Conversion Project

[CaseyJones]

But more importantly all that wasn't my point. Many of us like the 44 key manuals and 12 pedals. If you want the chorus manual voiced differently it's not an impossible task to wire it differently. It's not a B, it's a full percussion tonewheel spinet that most ears can't tell from a B3, C3, or A100.

A100? Shhhh!! Just another low buck console. Don't give 'em any ideas.

You are a better man than I, Dan. My mind is still blown from all those little black wires. Guess they liked black, huh?

Anyone who bitches about a cap job on an amp should tackle a cap job on a B.

...someday I'm gonna go to a garage sale and find a B3 or one of it's equals with a 122/147 for $50. In Kansas maybe, or North Dakota. Maybe Detroit, where most folks would just shoot themselves if they could afford the bullets.

Waidaminnit. My head is still fried from all those little black wires. You live on a boat, right? B3 on a boat? In salt water?!

Kansas or North Dakota would be cool. If you really want to bag one think about Wisconsin.

Certain venues within certain demographics can be quite generous with their hand-me-downs. That's all I'm gonna say.

[skyboltone]

...someday I'm gonna go to a garage sale and find a B3 or one of it's equals with a 122/147 for $50. In Kansas maybe, or North Dakota. Maybe Detroit, where most folks would just shoot themselves if they could afford the bullets.

Waidaminnit. My head is still fried from all those little black wires. You live on a boat, right? B3 on a boat? In salt water?!

Kansas or North Dakota would be cool. If you really want to bag one think about Wisconsin.

We're on the five year plan to get off the water. I'm in accumulation mode while prices are down on certain items. I saw a Northfield Mod. 4 recently with a sliding table for $1200. Probably had less than 10,000 hours on it. Like new! Big roto converter and zoom. I just love to hear them start up. Scares the little kiddies.

[CaseyJones]

Waidaminnit. My head is still fried from all those little black wires. You live on a boat, right? B3 on a boat? In salt water?!

We're on the five year plan to get off the water. I'm in accumulation mode while prices are down on certain items. I saw a Northfield Mod. 4 recently with a sliding table for $1200. Probably had less than 10,000 hours on it. Like new! Big roto converter and zoom. I just love to hear them start up. Scares the little kiddies.

We got an 8 hp Northfield w/ the pattern maker's fence waitin' fer us to go pick it up. I never seen it. It's sittin' in a guy's workshop under a pile o' crap.

I think you had the right idea to begin with. Use the smallest setup you can live wif and make it take it. If you're shovin' white oak through it three shifts a day on Government contract, fine, go big or go home.

On the other hand no one wants three phase right now, not unless you're in Venezuela or Viet Nam. I wish the power company would let me use their nice three phase wifout those pesky demand charges. Hey... you're an electrician! Hook me up!

This economy is good new / bad news. All that stuff that was too expensive? It's cheap... for the moment. Rumor has it there are little towns in Nebraska the State will pay you to move to just so they don't dry up and blow away.

You can trailer that boat out, park it in the yard and use it to warehouse old tonewheels!

Plan "B": Trailer it out, wheel it into the barn. Some o' them barns 'r' the size o' Wall-Mart!

[Cygnus X1]

What could I build out of an AO-14?

7 octals, (1) 9 pin miniature.
I guess a bass amp is out of the question then without new iron.
I was thinking dual 5U4GB, dual 6550's or something.
And something really creative for octal preamps.

Would it have enough juice to build a single ended amp
like the SEL with an effects loop? Single power tube, probably 10-15 watts. Meh. Too much real estate, not enough power.

Ideas?

[CaseyJones]

What could I build out of an AO-14?

Ideas?

http://solorb.com/elect/musiccirc/hammonator1/

Tell 'em it wuz a PITA when you're done.

[skyboltone]

What could I build out of an AO-14?

Ideas?

http://solorb.com/elect/musiccirc/hammonator1/

Tell 'em it wuz a PITA when you're done.

They left the expression capacitor intact but a cursory look failed to find it on the sheme. Future re-conversion?

[Structo]

I got the Hammond amp yesterday afternoon.

For some reason I thought it had more 12ax7's but there is only one.
It's a Sylvania and the two 6V6's are Sylvania as well.
And the RCA 5U4 of course.
Oh and two 12au7's
This amp was made in 1958 according to the serial number the seller provided.

So far, all I think I got for my $98 is the trannys and 6 tubes....
This seller charged me $39 for shipping!

I may just see if I can scarf together a Deluxe in this chassis, just to see if it is feasible to dump any more money into it.

[Structo]

[IMG:800:600]http://i23.photobucket.com/albums/b392/ ... G_0303.jpg[/img]
[IMG:800:600]http://i23.photobucket.com/albums/b392/ ... G_0301.jpg[/img]
[IMG:800:600]http://i23.photobucket.com/albums/b392/ ... G_0305.jpg[/img]
[IMG:800:600]http://i23.photobucket.com/albums/b392/ ... G_0304.jpg[/img]

[skyboltone]

Did you already dump the Volume pedal variable capacitor?

[Cygnus X1]

Did you already dump the Volume pedal variable capacitor?

As for me...mine is totally gutted.
The capacitor sits humbly in a box.

[skyboltone]

Well, they are kinda interesting animals. The final pre stage is capacitively coupled to the PI rather than resistive coupling. Hammond didn't like scratchy pots. I wouldn't call it over engineered just perfectly engineered. They didn't put a pot in a swell pedal until the very very end with the LSI models that spelled the end of the company. I wouldn't mind having a spare.

[Structo]

Did you already dump the Volume pedal variable capacitor?

Heheheh, if you can tell me what it is I'll look.
I haven't thrown anything out yet.

Do you mean the Expression Control box? The box with the lever on it?

[skyboltone]

yes

[Structo]

Yes I do have it.

You want to trade something for it like a few sockets?

I found this one article that converted a Hammond to a guitar amp.
Here is a snippet:

The AC power input circuitry was modified from the original Hammond circuit. The power transformer is old enough that it was designed to run on 115V mains instead of the 120V mains found today. Running the stock amp on 120V produces higher filament and B+ voltages than desirable. This problem can be easily fixed by putting the 5V rectifier filament winding in series with the AC primary winding. The 5V phasing must be correct, the easy way to test this is to try both orientations and monitor the 6.3V filament winding, use the lower wiring that produces the lower voltage. When the tubes are connected, the filament voltage is very close to 6.3V.

So what do you think of that?
In that conversion they used solid state rectifiers.
I wanted to use the 5U4 if I could. How much is that going to bump up the heater voltage if I use the filament windings as is using a 120vac supply?

If I lift the filament center tap with higher resistors like 200R would that do anything to the heater voltage?

[Structo]

I see your Procol Harum and raise you one.

http://www.youtube.com/watch?v=_SbzE0dr ... re=related