let's crank up our hammond M3's - help with the mods!

themagicmanmdt

another idea, and I'm examining schematics for this one:

we've all got m3's hanging around. they sound great!

one problem: they don't get any grit on them!

now, there's an amplifier with 12ax7's and 6v6 output tubes back in there. looks fender deluxe-ish to me!

how can we get more gain and volume out of our m3's?

is there something 'limiting' how loud the power amp gets?

looking at the m3 schematics here:

http://www.captain-foldback.com/Hammond_sub/hammond_schematics.htm

my guess would be resistor R37, which appears to lie right after the volume (expression) control, bleeding off signal to ground before it hits the second side of V4.

second guess: R29, which is right before V4a's grid input.

anyone else think what i'm thinking?
_________________
tell me why
(tell me why!)
i wanna know
(i wanna know!)
because the best part of breakin' up
(oooooooo)
is when we're making up!

http://www.stereophonicstudios.com

daniel ramirez · ass engineer Joined: 30 Nov 2008 Posts: 42

There is a small screw on the back of the volume pedal. turning it changes your output power. Have someone play a big chord while you adjust the screw.

Or plug it into a leslie or guitar amp. Even a100s are pretty weak through their own speakers, but they scream when hooked up to an external speaker.

Harry

I just want to wire in an FX loop in mine. That would be the shit!

PeterSawatzky

Check this out: If you don't have a Leslie, you may find the chorus/vibrato settings rather useless. However, I discovered that setting the C/V tab to Vibrato and the Small/Normal tab (I think that's what it's called) halfway in between settings, you can get a rather interesting Leslie-like chop.

themagicmanmdt

Overt Clam

Overt Clam

An FX loop would seriously be amazing! Please let us know if you find anything out. This is a great thread, M3's are awesome. I got mine about a month ago for free! It's a 1958 in perfect condition, it even came with a set of RCA Blackplate 6v6's that I totally snatched and put in my Deluxe Reverb....Sweeeeeeeet!

themagicmanmdt

update on what i've found:

1) adjustable preamp volume!

on the back of your organ, follow the metal lever system that comes from the volume pedal. it's connected to a metal box that sits on top of the amplifier. on the front of that box, facing you, is a small plug that's covering an adjustable screw. the screw is 'preset' to not have any audible distortion when the volume is all the way up.

i put something heavy over all the lower manual keys, and fiddled around.

grit! distortion!

not overwhelming - but it's growl - and it's cool!

this is also awesome for:

2) aux input!

on that SAME box, there's a RCA jack that's wired and designed for people to plug in music to, so they can 'play along' with their favorite record! it's a line level input, so -

use it as an aux input for a guitar! reamp something through a 12w tube amp!

3) the effects loop, and/or line out

here's the link that tells you how to do it.

http://www.dairiki.org/HammondWiki/GettingALineOutFromThePhonoJack

here's what they don't go into detail with on that page: for an effects loop, the idea is to drill another hole. Leave the phono jack hooked up as is (or change it to a 1/4 instead) as the 'return' of the effects loop or aux input. install another 1/4 jack hooked up as described on the site as the 'effects send', or line output.

so, it looks like:

organ tonewheel/preamp -----> 'line out' ----> (patch through effect of choice or use as a DI) -----> 'aux in'/phono jack

ta-da!

i'll be doing this mod this week! i've already done #1, and #2 is true to exist. there was a 'dead' RCA plug stuck into the side of mine.

-mt
_________________
tell me why
(tell me why!)
i wanna know
(i wanna know!)
because the best part of breakin' up
(oooooooo)
is when we're making up!

http://www.stereophonicstudios.com

Overt Clam

Awesome, this is going to make my musical world a bit more interesting! Thanks for digging up this info.

Harry

Nice!!
Let us know how it goes for you.

Is there any good places to pick up a used Leslie in the Chicago area?

Mine has all the hookups/half moon switches and everything.

I really need to get around to getting this thing up to speed.

themagicmanmdt

I just tried to get a Leslie. Went for about $500.

Keep in mind - when I say Leslie, I mean the model with both the bottom rotor and the upper horn, with the different speakers and the crossover.

They make leslies that are just one full range speaker - they're not the same - close, but not the same.

The going price for Leslies in and within a few hours drive of Chicago seems to be $300 (needs work) to $700 (great shape).

For that price, maybe later...
_________________
tell me why
(tell me why!)
i wanna know
(i wanna know!)
because the best part of breakin' up
(oooooooo)
is when we're making up!

http://www.stereophonicstudios.com

fazeka · pushin' record Joined: 07 May 2003 Posts: 284

Foldback is a great, if not somewhat tedious mod:

http://www.sympac.com.au/~retrojet/foldback.htm

I have two foldback kits I am looking to sell shortly... enough for one M-3 or two M-3s if doing only the upper manual.

daniel ramirez · ass engineer Joined: 30 Nov 2008 Posts: 42

supafuzz · Posted: Sun Feb 08, 2009 1:46 am Post subject: foldback

I read about this after I got my m3 [$125 and a van trip to NJ in the rain]

So when you do the foldback mod does it sound more like a B3 on the upper keys? They seem to thin out sonically in the upper register/

It looks like an insane job where I could ruin the organ....

I'm interested in a line out mod....

and how do you hook this up to a leslie?

I've been micing the speaker and running it thru a guitar head into a couple of rotating speakers
I have [one is a rotating horn assembly] with great results except for feedback
If I turn it up too loud
_________________
Vintage modern recording and mixing now in glorious HD2!
www.zerovillerecording.com

hogfish · takin' a dinner break Joined: 15 Dec 2003 Posts: 167

You cant ruin the organ, but is is possible to screw it up so bad that you need to hire a good Hammond tech to fix it. About 2 years ago I did this mod on an M3 I purchased off of Ebay. Generator recap,(not hard, recommended) line box recap (also easy,and recommended) and a complete cleaning of the scanner system(which is a bit more difficult, but if you stay organized and use your digital camera to take alot of pictures, it is not so hard).I then Moved on to doing the foldback mod on the top keyboard only,only because the degree of difficulty and tedious labor involved is very high. There is a site on the interweb that details 1 guys completion of this job, but the only thing I got from the site was the chart that maps out which keys and bussbar contacts need to be wired up to the output terminal. The way he did it seemed half assed to me, by lifting out the chassis and doing it with the chassis still attached to the organ. To me it seemed impossible to do it that way, so i went in and tore the whole organ down (there were Hammond parts all over the house for 2 weeks) and took lots of pictures. If you go slow and double check every connection against the chart, you will be hard pressed to screw it up. It is very time consuming. When you put the keyboard chassis back together, lube the bussbar system while you have it apart. also check the condition of the bussbars to see if there are any deep wear points.If there are replace them,
but it is going to be difficult to find M3 bussbars. I got mind from a parts organ I had laying around. Also, get a copy of the organs manual, down load it or get it from Goff. This will give you a lot of info as far as taking the organ apart, and schematics for doing other modifications.........