Hammond cv with Leslie 21h --issue with distortion

[TheAdmiral]

Jim,
IIRC and off the top of my head I think the schematic shows 22k but the amps actually have 15K in them. I looked at one of mine at home when this first came up (I'm at work as I write this). I'll look up that schematic again to make sure and report back. Leslie did some tweaking like that. It pays to have a pile of amps to actually go look at!

OK. Just checked schematic. It's the 22K (15K) going to the relay coil. It's part of the circuitry inside the amp. Don't ya just love it when the factory amps don't match the official schematics! That's when the many years of experience pays off.

[hammondcv]

Jim-
When I reffered to the Mismatched 6v6 tubes, I was speaking of all 4 being different name brands. I got the information about the 15k from the schematic on the side of the amp. The guy also took a reading on the one burned and it read right at 13ohms.It does lead to the relay coil.Thanks for the information about the resistors, I will proceed and report back.

Thanks

johnny

[hammondcv]

Progress UPDATE: Last night I took the burned reistor out and replaced it with the piggy back resistors. I also installed the can from the kit. It was pretty easy. After I put the amp back in the leslie and and started the CV. the Leslie would only run fast. When i hit the kick switch button, It would not go to stop. i did get sound. I could not tell if the distortion was there or not. i can say that it did not solve my low bass volume. i failed to mention that the cable hooking the leslie appears to have a bad connector going to the leslie. I plna to replace the end. Could that cause the speed not to switch to stop. I'm also incline to believe that i may have tubes that need to be replaced. or and maybe the leslie switch. Your thoughts are greatly appreciated. i will mention that prior to me changing the resistor the speed did switch back and forth.

[DanielP]

When the orange drop capacitor that is soldered between the motors up at the front of the amp on mine failed I had the same issue where my 21H would only run on fast. Looking at my amp photo I noticed that the cap is soldered to the first and third motor and the first is jumpered to the middle motor whereas on yours the cap is soldered to the third motor and the middle and then the middle is jumpered to the first...I'm still learning about wiring, maybe it doesn't make a difference but I thought I would point that out.





If you have doubts about whether your cable is working or not it would be a very good idea to check that. It is not difficult to pull back the metal or plastic covering and see if the wires are wired correctly and firmly. They are color coded and each performs a specific function. Color codes and their functions for the cable are easily found on captain foldback, do a google search for "leslie pinout captain foldback" and the page will show up.

[hammondcv]

Update: I changed the cap ends on my 6pin leslie cord, replaced the 15k resistor, replaced the orange capacitors, replaced the fuse, replaced just about all of the resistors, I replaced all of the tubes and CAN capacitor. I also cleaned the contacts on the cv I can tell that the sound is better, but I still have the slight distortion when I press multiple notes at the same time and an uneveness when I press the bass notes the manuals volume is greater than the bass. I also oiled the cv and leslie. I'm thinking that it could be the organ. i looked at the back of the organ when I was cleaning the contacts. i saw some resistors piggy backed and jumpered in serval areas. I will post pics as maybe someone was trying to modify to get a more raspy tone. Please check out the pics and give me your opinion. Thanks

[hammondcv]

under the hood of my cv pt1

see if everything looks good to you

[hammondcv]

more pics to check out py2

[hammondcv]

part 3

[hammondcv]

pt 4 -trying to see if current config can yield distortion,raspy tones& low bass

[hammondcv]

UPDATE-- I've have the local tech to look at the leslie and he said that there was definitely a problem wiht my Jensen v-20 upper Driver. He suggested that I replace it. He also suggested that I replace my 15'' woofer. The woofer inside was not stock and very questionable. As im now in the market for driver and 15''. I would really like some advice and information on the various ones out there. I keep running across the atlas pd60a driver. Is that the best sounding (for Gospel music?) I also see that there are screw on and bolt on drivers out there. Whats the difference. Whats the difference between the v20 adn v-21? the replacements I see are usually in reference to v21 replacements. In referernce to the 15'' I am interested in a deep low bass sound.

Thanks,

[DanielP]

Hey hammondcv,
Can't help you with any info on the CV jus isn't my area of expertise. What woofer are you using? The 21H amp is designed to use a field coil speaker, 16ohms with a field coil resistance of 2650 if I remember correctly. Unless your amp has been modified or a large wattage resistor has been added to account for the field coil resistance that the amp is looking for you are going to have more problems! You can check both of these values with a multimeter on the proper terminals on your woofer, look into it.

As far as treble drivers go I've tried a few, here is a snippet from a different post listing some of the differences I found in the drivers (it is a bit lengthy but maybe it will help you):

...I've found big tonal differences in the treble drivers I've experimented with. The original V21 which was in my 21H was quite subtle and sweet, the highs folded in to the sound in a really unobtrusive manner, gave the 21 a more midrangy sound...At that point I wanted more trebles so I swapped that out with an Atlas PD60 which was the polar opposite, it was aggressive, loud but in my opinion overpowered the jensen woofer and was too extreme. Then I found an EV 1829 60watt driver on ebay for super cheap and tried that out, it ended up being the winner in the 21H, it was between the V21 and the Atlas but more sweet like the V21.

My old 31H has one of the original Jensen Hypex drivers and it is probably my favorite of all, but it can't really be compared to the others though because the 31 top shelf is so much bigger than the 21. And then it is also being driven by a different amp, different crossover (same caps in both xovers both recently recapped). The 31 top shelf just adds a different tonal character to the trebles than the regular 122, 142 size cabs.

My other 31h has an original jensen V20. I didn't even know there was a V20 and it just screams, its a lot like the Atlas actually, aggressive and trebly. Although I tamed it a bit by recapping the xover and taking out some nasty Shuguang 6L6 tubes I was trying out which were brightening it's already xtremely bright natural sound. Put in some old coke bottle 6L6s and it is sounding real real good, different than my earlier model 31. I wanted to try out the EV 1829 in this speaker but because of its shape and the way the treble drivers fit in the 31 it won't fit and I'm not going mod it just to try a different treble driver. I may pop in my old V21 to hear that at some point, because it will fit without mods.

Keep in mind these tests were done on guitar, so the results may be slightly different than with an organ. Point is though, it may be the treble driver you are using. If you can, swap it out with another maybe brighter one. Oh, and I don't use the back panel on the treble shelf of the 31, or the 21. Was doing that with the 21 but am now liking it better sans back....

[DanielP]

I was thinking too, if you think the treble driver is the problem a way to test it would be to just plug the woofer directly into the amplifier (where the crossover plugs in). That would bypass the treble driver and then if the distortion goes away that would be a pretty clear indication that it was the driver. Just a thought.

Did you get a chance to find out about your woofer? The problem could really be that, especially if it is not a field coil speaker or if it is the wrong FC resistance, etc. Not only would that probably sound bad but it could also be putting extra strain on your amplifier. Measuring the speaker load and FC resistance (if it even is a field coil speaker) is easy with multimeter, I'd really make that a priority if I were you. Look it up online or let me know and I can explain if you can't figure it out.

[hammondcv]

The woofer looks like an off brand jenson P15LL, but there is no tag on the maggnet/bell. someone did place marking on it that says 16ohms. It is grey with a nice size metal bell/ magnet on the back. I will get a reading on it. With the V-20, i did notice the scream and over powering of the horn over the woofer. I ordered an Atlas pd-5vh horn and adaptor plate. Your thoughts? If I'm not mistaken, the woofer is not a field coil speaker, right? Given that is the case, What might be a great replacement. I did notice that one site recommended a Delta 15-b ($94.00). I'm really looking for a well balanced (treble/bass) sound with great powerful bass lows. Right now, if I pull out all the db's the Treble is overpowering the bass.

johnny

[hammondcv]

BTW The Atlas PD-5vh is also 16ohms---

[DanielP]

I've never heard the Atlas pd-5vh, but 16ohms is correct. The pd-5vh is 40 watts too so that is pretty good, I think some people prefer the extra headroom (60 watts) with the PD60 but you should be all right.

Can you take a photo of your woofer? Does it have 4 wires coming from the top of it (2 from the voice coil and two from somewhere under the bell)?. Field coil speakers have 4 wires, 2 for the voice coil and 2 for the field coil. I don't know what type of output signal you get when you plug a regular speaker into an amp designed for a field coil, it is possible that also is why your driver sounded so much louder than your woofer.

If it is not a field coil speaker and you want to replace it with a FC speaker (Jensen F15LL or a vintage Magnavox with a FC of 2650). FC speakers get pricey, the Jensen F15LL fetches ridiculous prices and the Magnavox is cheaper but they don't come on the market as often. The Magnavox was used in early 31H speakers. They both sound very nice.

Other option is that you can use a permanent magnet speaker, the one you have may even be fine, but you'll need to add a large resistor if it has not already been added to account for the fact that the amp is looking for FC resistance. Otherwise you will damage your amp and it may sound bad, I've never heard a PM speaker through a FC amp without adding the resistor. If the resistor has been added it is probably easy to spot, maybe mounted somewhere in the cabinet off to the side of the woofer or near the amp. It would probably be too big to put under the amp and it would also get quite hot so most likely it wouldn't be in there. Look for it, even post a pic if you want and I'll see if I can spot it. If it isn't there maybe someone else can chime in on the exact wattage specs etc. you would need and the best place to mount it. I know it has come up in other threads.