In defense of Cordovox amplifiers and speaker cabinets

[AloneInTheDarkRecords]

Hey guys! I'm new on here, and am a Midwesterner so forgive me for typing through my nose (anyone else from around here will get that!). After reading some articles on a few of the underrated vintage gear I own and love I decided I had to get on, and particularly set a few misconceptions straight. This particular little diddly is about the now-becoming-harder-to-find cordovox gear; particularly their amplifiers but with a little company background on the side. I've been seeing a peek of interest, and a lack of appreciation for these little beauties over the year since I've gotten my first cordovox Leslie unit, the CL-20 is my model if not mistaken. Well, yesterday I managed to find a really cool guy on Craigslist who sold me the cordovox amp and tone generator; so finally I got a taste of what these little beasts can do when in combination. Yes, I was using them for guitar and not accordian, and yes I know accordians can be annoying; but forget about the sound you attribute to an accordian. Cordovox turned accordians into portable Hammond-esque organs. I believe, actually, they may be able to be considered the first "combo"organs if you really want to get into technicalities. The man who sold me the Leslie cordovox actually described the first time he saw one as "I was at a polka concert for a wedding and all I could think was, man this is gonna be a bore. Then the band gets up and plays and I hear what my ears could only discern to be a Hammond b-3 with a Leslie speaker somewhere in the room. After looking the stage over and seeing no organ player, then scanning the entire room just to find myself equally puzzled, it finally dawned on me; it was the accordian player! I finally asked him after the show how he had done it and lo and behold; a cordovox Cl-20!" Albeit I may have paraphrased a bit, but the man summed up what everyone online doesn't seem to get, these were made to have amazing tone and to be an alternative to carrying around a massive, bulky organ to shows (some of you may remember these days!!). At any rate, I promised a little tid bit of company history and this is it; THESE WERE NOT MADE IN JAPAN!!!! They were manufactured probably 3/4 in the United States, and 1/4 (mostly the accordian components) in Italy. There were 3 companies that partnered together to make cordovox: Lowery organs, Chicago musical instruments, and the predecessor of Farfisa. That's quite a credential list if you ask me, considering that at the same time Chicago musical instruments was making those famous now-vintage gibsons. Of course this doesn't include the 4th company that didn't own part of cordovox but produced and patented rotary speaker cabinets for them; Leslie. Now that I got that out, back to talking tone. So, my Leslie cordovox unit is an earlier one which has a wood rotating driver, not the foam ones that notoriously corrode over time. This may be part of why these units get a bad rap. Now I know what you're saying "isn't it just a cheaper rip off of a fender vibratone (isn't that what they're called?). The answer is sweet and simple, you have it bass ackwards my friend. Cordovox Leslie units predate fenders copy of them. The first guitarists to use a Leslie for guitar probably did so with these early cabinets which were made to be an alternative to the bulky big Leslie units we have all scene in church's and onstage at deep purple shows. I will say, they are not going to sound as amazing as a 147(another gem I've the fortune of having in my studio, acquired cheap from a cool cat!), but the rub fenders nose in the dirt and make those cheesy cordovox knock-offs sound like someone playing guitar into a tin can with a string and having someone listen to the other can a room away. At least in my humble opinion. Another neat deal with them is the jack that they had wired in pulls signal in and then spits it back out into your amp; thus spreading the sound of that Doppler effect into your amp and speaker cab for an all around mind warbling vibrato that will really make you say "...like...what..?" This may be why a lot of people haven't enjoyed these cabs. They were not made to be a main speaker cabinet, have one tiny little speaker, and often the speakers they were stocked with seemed to be subpar (especially compared to the Amps, which I'm about to get into). But, these little bad boys were not meant to be main cabs. They were tone cabinets, for cordovox amplifiers, which would take the Leslie sound and feed it right back into the main speakers. What are those main speakers, you may be asking? How many of you have fender deluxe amps, the old school ones, and wish you could find a replacement for that one Jensen 14" out of the four but don't want to hack your arm off to pay for it? Well, you may be surprised to find one in a cordovox amp, and tone generator cabinet. That's right you fender only guitarists, cordovox isn't so sub par is it? And considering the circuitry and tubes used in the amplifier closely resemble early ampegs, you can imagine that the tone on these little bad boys is not at all sub par. The only thing I did was swapped the ge 12ax7 with a 1950's west Germany telefunken, which made a world of difference. This, of course, isn't talking about the overly confusing wall of tubes in the back of one cab in the pair that everyone is so so afraid of. Rest assured guitarists, if you use the microphone jack you won't have any need to ever do anything but watch these little puppies glow. This is the accordian's "organ" tone generator, and is only accessible by a special plug made to fit only cordovox accordians. There may be one or two tubes that are used as a rectifier for the Jensens in that cab or as a pre for the pots, but the rest are each for a specific key on the accordian. Yes, it is complicated, yes retubing would have been a nightmare (except the fact that back then tubes were much cheaper), but can you imagine the tone those accordians would have had??? It's unreal to me how so many people are turned off by this piece, because it is seriously fascinating to me. Eventually I would like to find a combo organ with the same adaptor, if they exist, because I bet it would give a Hammond a true run for its money. So, how does this mysterious accordian amplifier sound for guitar? My one word to sum this up is, A-M-A-Z-I-N-G. Extremely extremely clean, very very warm, extremely broad tone (remember accordians have a wide octave range), and with reverb, it sparkles like the morning dew. It sounds equally great with my 12 string Martin as it does with a PRS electric; and with my rat rodded Gibson skylark which is more of a fender champ after someone decided they hated Gibson ( I'll save that story for another time) as an over drive unit, it takes to distortion really well. It also sounds great with my memory man, again sparkly, like the stars at night, mix that with the Leslie vibrato unit and mmmmmmm damn girl. And, did I mention that they come with an expression pedal??? Did I also mention that with out the expression pedal my unit would not power on? This may be why so many are sold as is because they won't "power on". So! This is my rant of the cordovox amplifier/Leslie combo. If there is enough interest I may record some samples to share because man, you should never knock it until you hear it!! Next time I post I'll get into why the Gibson Thor amps (the tube ones not the solid state door stoppers) are also extremely underrated; as that's another baby of mine that is tired of being downtrodden by the snobbiness of gear forums. Hope it was a decent enough read and please forgive me if its a grammatical mess, I had to use my phone because the anklebiter wanted to watch Dino trux on my laptop! 👌😘

[WRGKMC]

Two things in your statement. There's no such thing as 14" speakers. Even by the 60's most instrument amps used standard sizes. Your cab uses a 15" and you can buy speaker for it. Jensen has been Alnico making reissues for many years.

 

Second, rectifiers are for producing your DC voltages to make the tubes work. The power tubes and output transformer drive your speakers, not the rectifier tube(s)

 

The tone generator is what many early organs used. They are tube oscillators (analog synth tone generators) and the unit used 60 tubes for producing the chord tones of an accordion. The accordion used a heavy multi pinned connector for a switching matrix (much like an electronic keyboard in an organ). The tone generator uses 6X8 tubes. They work well as oscillators but are completely useless for guitar. There's no actual sound passing through that multi pinned connector from the accordion, at least for the chord side. It's designed to turn different tubes on an off and produce the organ tones. You could do all that with a single chip these days but the unit pre dates solid state.

 

The amp itself has a strange setup. The preamp is built into the tone generator chassis and it connects to the power amp which is in a separate cab. Unless you play accordion and have the matching accordion for the unit, the tone circuit is just dead weight. It would be best to extract the preamp and have it placed in the power amp, thus eliminating the cable which connects the two. That's a pretty heavy mod because the preamp and 60 tone tubes likely share the same power supply but a good tech can likely pull it off.

 

Given the age, recapping the amp would be an important thing to do. Power cord should be replaced with a 3 way grounded plug too.

 

This article describes the unit in detail. I don't advise following this guys advice on modding anything electronic however. He's obviously an amateur who hasn't got a friggin clue to what he's doing. He rewires the speakers to series which is stupid. Old amps like that often had 2 or 4 ohm transformer like the old fenders did. he wires 4 speakers in series which gives him either 16 or 32 ohms. He'll fry those tubes and the output transformer in no time. The amp is supposed to run at a low impedance with the speakers in parallel.

 

The first half of this article is informative. The second half I'd ignore. http://www.chosenfool.com/?p=146

[AloneInTheDarkRecords]

Thanks for the info, like I said I'm using the Internet on a phone so some info is me trying to remember what I had read a few nights before posting. The tone generator is in a sense "dead weight", but I'll probably wind up just keeping it original other than probably grounding it when my soldering iron is fixed and having the caps checked next time I visit a tech.

All I'm trying to get across is that these aren't terrible amps. Are they designed for guitar? No, they certainly aren't. but they have a nice tone, and for someone who is trying to have a good tone from an early 60's tube amp, but can't afford a thousand dollar amp, and doesn't know how to convert old PA's or build a tube amp from scratch, it's a nice affordable option. And there are 5 12ax7 tubes total, 4 of them are on the tone generator. I just assumed that since the preamp is built into the generator that that they may have current going in from the mic jack. Either way, it's pretty freaking neat seeing all those tubes lit up. A novelty in and of itself.

But like I said, this set will probably remain modless. The whole reason I have this post is because every article I've read is just people butchering these amps to save space when they are already playable. It's kind of like people chopping a Leslie to save a foot of space; well they don't make them anymore, or at least not the way they used to.

I'm a generally broke guy with a family to take care of who still tries to play as much as time and money permits so to me these things are an awesome find and I'm very grateful for them. Definitely going to put a 3 prong grounded power chord, definitely going to have the caps checked and what I had in mind was eventually finding a busted set or lone cabinet and to just make an extension speaker cab that matches with the identical speakers.

cheers!

[AloneInTheDarkRecords]

Actually, seems my hunch about the 12ax7's in the tone generator was correct. There are two and they were the other two I changed (3 including one on the amp itself). sometimes you get lucky 😎

Edit: I meant to say they were the preamp tubes for the mic channels. Sorry like I said, my phone likes to trick me and swap words around!

[WRGKMC]

Yes, that was in that article about the mic channel. It allowed the accordion player to sing along with his accordion playing

 

Apparently the accordion had a series of controls. In the first photo the plugs are on the right. Above is the volume, treble and bass. Not sure what the knobs on the left control. The buttons in the middle look to control the different reeds. This side of the accordion looks to be acoustic and is miked from inside.

 

 

 

 

 

 

 

 

 

 

The round red element looks to be a mic for the reeds. The boards connect to a harness that goes to the other side of the unit.

 

 

 

The harness connect to these buttons which turn the tone generator tubes on and off much like a standard electronic tube organ.

 

 

 

The amp itself is likely voiced like most organ amps were. Hammond for example made great tube amps which could easily be converted into guitar amps. The voicing isn't that far off from guitar, though they may have richer lows then needed. Accordions simply aren't a very popular instrument so the gear gets passed around allot. The Tejano bands and Cajun music here in the south uses accordion music allot. Most of its based in Polka style music with modern influences. The players make good money playing these monsters.

[AloneInTheDarkRecords]

Yeah I saw one when I bought it! the guy had the accordion and was selling it to someone else else for only 75 dollars, regretfully I only had the 220 I offered him for the amp. :/

It would have been really sweet to have the full set, it even came with original manuals and paper work, but alas, sometimes having to juggle my love of music with taking care of a household just doesn't permit. That's the reason I bought this in the first place.

One interesting thing I read about the tone generator in the same article is that it is basically an analog synth in and of itself; and that someone had made an adaptor for it to be used as such. I have a scrapped Hammond (long story short I spent months getting the motor to start and getting the oil to set to get the tone generator to run; only to realize that it was shot), and am curious if the components of that could someone be meshed with the tone generator of the cordovox to make a small tube combo organ. It's far out of my jurisdiction of knowledge on circuitry and design but it almost makes me wonder.

One thing about this amp, and I don't know if it's a common problem or not, is that the sound of all of the tones on the tone generator come through with the hum of the tubes. Very subtly but when I stop playing through it and it's quiet it's easy to notice and actually sounds really really neat. Picture every note at once on an organ going through a 60+ tubes and being spit out through a subtle and warm hum. Definitely going to see if something needs to be replaced but also definitely going to record it to use on a track

Thanks again for the info man, and like I said, I may have come up a bit edgy in my original post but I just really don't get why these guys get such a bad rap other than specifically the tone generator; which to me is just a freaking neat piece of history and more possibilities for future projects as I learn more about designing analog technology. I know some things but not enough to mess around yet. Don't wanna fry my own circuits, ya know? 😁

[AloneInTheDarkRecords]

Also I can agree and disagree on the lows, it's pretty crazy the way the tone is on these. It's kind of like the bass of what you are playing and the treble are two different instruments. Reminds me of if you took a bassman and then added the entire circuitry and speaker of a smaller amp like a fender champ and smushed them togather in a way that is really clean and resonant. Don't know if that makes much sense but it's the best way I can describe it. And Jesus this amp gets loud once you crank it past the halfway point. Not a full stack by any means, I can still hear when I'm done playing, but definitely rattles the room. I'm heavily considering making this my small venues set up once I get the kinks worked out. Had a partial retube so far, grounded power, and I'm going to have a friend check the caps to make sure that's all good. A few wires function but the skin is coming off and is held together by electrical tape; obviously that's not going to fly haha

[Axisplayer]

You know, the bottom line is that it doesn't matter what anyone says if the amp makes YOU happy. I can't comment because I have never heard one, but it wouldn't matter anyway. Another thing, you can hand the same gear to two different players, and they won't sound the same. A significant amount of tone is in your fingers and touch. What works you might not work for anyone else, but it might be exactly what you need. More important than any of this is that you like to play, find the time, and do it even with the limitations you have to work with. Brother that sounds good to me. Forget about what other people think of your gear. All it has to sound like is the tone you hear in your head. Play on!

[AloneInTheDarkRecords]

Very true man very true! I'm the kind of person who doesn't really need much, music is my way of coping with the past, having a release and some fun in the moment, and trying to communicate some love and hope and occasionally a little rage for the future and who knows, maybe making a ripple one mind at a time. I'd say and not even bat an eye that if it weren't for me taking up music, writing and composing, I'd probably be dead one way or another by now.

But hey, sometimes life shines a miracle on you and the miracles in my life are my family and music

[WRGKMC]

As far as adapting the tone generator to the Hammond Keyboard it may be possible. Figuring out the wiring matrix would require a detailed schematic and someone with a whole lot of wisdom and electronic skills. I deal with digital matrix signals in digital equipment quite a bit, even used to teach it to students but I wouldn't want to tackle a job like that. Way too much work for far too little payback. For the cost of the labor involved you could buy a half dozen used tube organs in working operation. Better yet I can buy dozens of portable keyboards with midi capability, have hundreds of different instruments available and strap it on my back like a guitar.

 

The hum is likely your power supply power caps that are in desperate need of replacement. You likely need to change many of your coupling caps too. Caps are good for 10 years, 20 tops if you run the amp allot. If you let it sit they die very quickly. Newer caps don't even last that long either. The EPA has made the manufacturers use non cancerous compounds so they don't last nearly as long as the older components did.

 

That amp is around 50 years old now. As the caps get old the dielectric barriers break down and they begin to short out (that's why you're hearing hum, the insulator layer in the caps is broken down leaking AC into the DC supply) They can no longer hold a charge and smooth the ripple. They're like batteries that wont charge and begin leaking acids.

 

Not to alarm you, but the next step is the insulation barrier gets a pin hole in it, shorts out and your amp and takes out your power transformer. Given the uniqueness of the amp, the currents needed to run so many tubes, the limited number of those amps made, the chances of finding a replacement transformer is as close to zero as you are going to get. Caps are only a couple of bucks a piece and relatively simple to change. I'd make that your first priority over anything else you do with the amp. If you have a tech do it, don't let him just change the power caps that are leaking either. Make sure he changes them all as a set cause when one goes, the others overwork.

 

[markanthonydiamond]

Thanks for the thread guys! I made a few bucks playing one back in the late '60s, wish I had kept it! Thinking of buying one (more of a memorabilia kind of thing.) Any advice as what to watch out for?

 

Thanks again!