Autumn update – Dirty organ sounds?


Good Morning,

Welcome to the British summer, only a little rain today so that’s a WIN. Australia all out for 60 too!

So, let me bring you up to date with the Hammond Project. The C3 and 122 combination is working pretty reliably now and as far as this part of the project is concerned all that I need to do now is diagnose and fix the Percussion issue and then get someone who knows what they are doing electrically to give the whole thing the once over with a meter to make sure everything is reporting the right resistance and voltage in all the right places. I’m not much of an instrument electrician but I am learning about things fast!

With that running as a side project I have been impatient to get this C3 to sound like my inspiration’s Organ – Jon Lord. It was hearing Deep Purple in the early 80’s that inspired me to place my fingers on a keyboard in the first place and I have been chasing this sound and this combination of Organ and Leslie ever since, so now that I have one how do I make it sound like this:

Well, there is an exact answer to this but its a dead end unfortunately. Jon Lord used to crank his C3 up (and push it via the trim pot in the pre amp) and route it through a Gibson Maestro Ring Modulator and then through into the 122. The Ring Mod appeared mid 1972 gaffer taped onto the top of Jon’s organ and produced some really whacky sounds at the flick of a switch.

Seen here on top of the Hammond at the California Jam 1974:

And a further demonstration of the madness of the device from this guy (who can afford either a ring mod or a light but not both):

Anyway, back to the point. The Point is that this effect also supplied Jon with the overdrive as the input from the C3 was basically too high for the device to cope with and slowly broke over a period of years in a very pleasing way. The reason that this is a dead end is that the company went into administration years ago and in fact when Jon heard of this he bought the last 6 and was reported to still be on his first one in the 80’s with 5 others wrapped in cellophane in his loft. What I would give to have one of those! He did move away from this sound though and in the last performance I saw him in – his last live performance – at the Sunflower Jam 2012 ( I think it was) he had moved on to more ‘conventional’ overdrive methods.

So back to square one with just a C3 and a 122 (and a 145 actually, more on that later!).

Usual port of call is to ask the Guru Neil (ex of The UK Pink Floyd) how he would do it but, like me, he was also stumped. So we learn together. You google “how to overdrive a Hammond Organ” you do not get many results and certainly not many useful ones. You get people talking in general about adding amps and tweaking trip pots but you do not get a step by step guide, or a definitive way to get that classic sound. I guess there isn’t a definitive way, either that or once people have the sound they do not want to give their secrets away?

After you realise that you cannot get enough growl by simply pushing the Leslie to its limits (some may find this level acceptable but needed a little more that this method could give, plus there is another blogs worth of conversation around how long the top driver will be able to cope if you push it this hard for this long).

The idea then is simple enough, put something in line between the Organ output and the Leslie input that will help the overdrive process. This takes the strain off the Leslie and should help to keep it more reliable. Now, remembering that the 122 is not earthed and gains its power, speed switching , shielding and singnal from the same cable this is going to be tricky. So, I cheated, a bit. Putting the 122 to one side for a moment I wanted to check the principle and the chain out so I got my modified Leslie 145 out. This is a handy tool as it has been modified to have its own power and 1/4″ jack input and the 6 pin Leslie socket now only functions to switch Leslie speeds. By using this in the short term I am bypassing that fact that my 122 has a non-standard 8-pin locking connection on it and the whole earthing, powering, re-wiring and buzzing issues that my man Neil is working to overcome as we speak.

I like the tone of the 145 and it will do for the purposes of this test, inevitably the 122 will need to be modified to accept a device in the chain but I’ve not yet figured out if it needs a 1/4″ and power mod or the cable needs to break the signal element out and back in again to maintain the originality of the Leslie. Dunno. Anyway, I have dodged a bullet by wheeling out a Leslie that can accept a 1/4″ jack input.

The problem that I had was that the C3 output is high, really HIGH. Great really, right up until the point you want to put it through a line level effect pedal (typically -20bd) as it metaphorically blows it across the room. I’ve rigged up a cable with alligator clips on one side and a jack socket on the other that I can clip to the C3 pre-amp (tip to one of the “G” Tabs and sleeve to “GND”) so that I am now bypassing the Leslie cable altogether and taking my signal into 1’4″.

GND, G G Tabs
GND, G G Tabs

I am now at the point where I can plug things into the chain between the C3 and the 145 and see what happens. It’s pretty much what I expected initially the high input is making the effect unusable, I tried with a Boss Distortion pedal and an Aria OD-1 Overdrive pedal, Leslie pedal and NEO ventilator and the level of distortion was unusable. Choking the input down so that the pedal could cope produced an acceptable sound but lost all of the volume at the Leslie end. How to step it down and then up then…. Someone has wired an effect loop into my C3 and there is evidence of an after market reverb unit so maybe that was the opportunity I needed.

In my tireless googling sessions I found a few videos of people managing to get the right sound with certain equipment (non of whom explained how) so over the weeks I have bought all of these devices (and returned them all):

I bought the Behringer Vintage Tube Monster that same day


It had got my attention, although notable once the guy had gone 1/4″ he was going into a NEO Ventilator for the Leslie sound, so he didn’t have the problem I was going to have with stepping the sound back up.  I got the Tube Monster in line and it overdrove for England, Europe and The World and elsewhere. Unusable sadly…

I spoke to my man Malc at Hammond UK about the sound and he gave me a few tips on how to get the standard “light growl” (if you will) sound and most of this I had done, he also pointed out that the way the Leslie is recorded is a big factor in the overall tone that you want to achieve. After I had described what I was really after he suggested I track down a pedal that he saw to good use in Germany. Speaking to Hammond EU based outside of Munich in a lovely town called Ulm they were able to tell me what this product was and how much it would cost:

Now then, this is interesting and with the use of Google translate I was able to have a good conversation with Michael about the pedal and its use. Unfortunately however I still couldn’t glean how this was wired into the chain. If you are interested this product is stocked at best price by Thomann in Germany for £290 + delivery. I thought it may come to that, but it didn’t…. And I think this is the problem with us C3 idiots, we will spend a fortune on one and then try and find a cheap overdrive solution – my brother is always saying (more seriously than it may sound) that there are few problems that cannot be sorted by the injection of cash, the only question is “How much cash?”. And he’s got a point. So, I’ve got that in the bag, but lets keep looking on the cheap for a bit…

I was really interested in the “disable the Leslie amp and stick a Marshall master volume head in line” headline idea but its surprising how little is known about this over and above the headline. I know that Don Airey in Deep Purple currently does this and gets good results but when asking the right people about the setup its all quite vague, suffice to say there are many mods and chokes and this was done at the factory personally for him. I doubt I will ever find this one out. The theory being you “disable” the amp side of the 145/122 amp and retain the switching side, routing the signal through a Marshall head which in turn routes out to the speakers of the Leslie, pre-crossover. There are a couple of ways to “disable the amp” depending on the amp you have. The 145 can just have the power amp valves pulled (2 of, the 3rd one is for the speed switching) and that should do the trick (usual disclaimer* about any modification you make being at your own risk etc) but with the balanced 122 its a little more tricky. In a 122, one of the 12AU7s handles speed switching through a  relay. Unfortunately, simply pulling the other four tubes won’t work.   The speed switching 12AU7 shares cathode bias with the 6550s. Without  this bias, it will always switch to slow (This is why a 122 cycles from  fast to slow and back again when switched on with the switch in the trem  position. The 6550s take longer to warm up than the 12AU7, until they  do, there is no cathode bias.). Also, the speed switching 12AU7 is fed  with regulated HT voltage through the OC3. Without the OC3, the speed  switching will simply stick on fast. You could remove the other 12AU7  which would effectively disable the amp, but why not simply set the  volume to zero? In any case, you would be well advised to provide a  dummy load if the 6550s are still in place, just to be safe. Thanks for Chris Clifton for enlightening me on this one.

Then, as if by magic, my mate Spencer appeared. Spencer is a talented guitar player and sound engineer and has a LOT of equipment that he acquires and drops at a fair rate of knots. We were discussing this issue as a whole and he suggest maybe Valve Mic pre-amps as a solution – the idea being that they will be more used to the excessive gain and have more control stages. “I’ll lend you one” he said.

The next time we met I had a shiny old ART to take home and mess around with:


This is interesting as the theory went, stick it into this valve device and batter the valve until it starts to break down and listen to the results. This I have to say has been a great success, over engineered of course with it being dual channel and digital enabled but remember we are proving a point here. Converting my 1/4″ input back into XLR I rigged up the ART in line as before with the other pedals and had a listen. The overdrive was there, basically by turning the input gain know I could feed the overdrive in as it battered the tube harder and harder. The poor VU needle will get bend mind but it works and sounds like this:

Now, I’m only messing about here after a hard day and a couple of glasses of wine so don’t go thinking this is an audition tape because it is clearly floored but its here for you to get an idea of sound (and besides the leslie switch wasn’t connected to the Hammond so my “expression” was “clunky”!). I was able to move from slightly distorted “Might just take your life”, to Mega Overdrive “Perfect Strangers” to a nice blues growl, shiny “The Cat” style to overdriven “LAZY” and “Highway Star” Type sounds (yes I know there were recorded differently – more on that later).

I’m not sure what sound you are going for but if you are like me then this is pretty damn close.

This pre-amp is worth about £340 is dual channel and has a digital out. All more than I need so I immediately went out to look for something that would do the job more efficiently, cheaper and possible of a size that I could hide it away in the organ itself. To this end I spoke to the good people at ART who reckoned that their Studio V3 should do the trick at £60.


It came the next day thanks to a company called Juno on eBay and a helpful chap on their service desk called Jon. I couldn’t wait to get it in-line and tested. I particularly likes the “Valve Tone” concept, maybe I could warm it up just a little using this. Long story short, I’m afraid it does not act like its bigger brother at all. It pops and bangs, overloads and distorts pretty much like most of the others. I think although it has all the right knobs and buttons its either not made to the same specifications as its older brother or it is made with cheaper components. Either way, its a very nice device but not for me and the super helpful Jon and Juno said I could try it and send it back if it didn’t work. Which I did and have, today!

And now I am here today, with a C3 and a 145 modified to take 1/4″ and an ART MPA making pretty much the overdrive sound that I want. So what is next? Well, I can’t imagine this project will ever end until I am destitute but the list is getting shorter. Next instalments will and must really include:

  • The Modification of the 122 to work in line in the same way that the 145 is currently. The 122 is the one to have, a little taller, a little louder for it and a little sweeter in tone.
  • The alligator clips into 1/4″ cable needs to be swapped out for something more permanent and maybe switchable between 1/4″ and Leslie pin
  • Speaking of Leslie cable, I have a bizzare 8-pin lockable cable that someone must have upgraded to in the 70’s. Need to do a little work on Pin outs and spares for this
  • Get one drawbar repaired along with the faulty percussion unit
  • Install a reverb unit, maybe TrekII
  • Get it checked over by a qualified electrician
  • Get it on wheels!
  • Get a van!

I hope you have found this interesting, I can appreciate that to 99% of the world this is the most boring thing you could possibly have read but if, like me, you are struggling with the tone and sound of your organ an article like this would have saved me a lot of time. Give it a go, let me know how you get on, keep in touch, see me on tour in England with and come and say Hi!

Thanks for reading



*disclaimer, get an electrician to do stuff! Don’t come running to me if you kill yourself, treat this kit with the respect it deserves, switch things off at the plug each time you make a change or a mod and if in doubt seek out a qualified electrician. PLEASE!






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