noisy Leslie... not the motors!

[toasterDude]

Just wanted to share a tip, based on a "duh!" sort of moment I had today. I've been working with a Leslie 147 I picked up last week. When I had gone to see it &amp; check it out, about 30 seconds after I flipped the halfmoon to "Tremolo" the upper rotor started making an awful racket. "That's no big deal," I said confidently to the seller, "it just needs to be oiled." (I figured the motor bearings were just dry - the motor itself was buried under about 1/4" of dust and grime.)</P>


So I got it home and pulled the upper motor assembly, took it apart, cleaned it, and hit all the oiling points real good. Put it back together, reinstalled it, and... still really noisy. Damn. So I left it overnight, figuring maybe the oil still needed time to soak in through the pads, andmaybeit justhadn't reached the bearings yet. Fired it up again this morning, and... still really noisy, like the motor is just dry as a bone and about to freeze up completely. (?!?) So I'm standing there dumbfounded, thinking I'm going to have to do a complete servicing of the motors (disassembly, soak in solvent, re-oil etc.) -- I'm just kind of standing there staring at the horns, when it hits me: Hey, it doesn't sound like the squeal is actually coming from the motors... it sounds like it's coming more from the center of the cabinet. Again: [:^)]?!? I'm baffled. So then I think, well, I didn't oil the little bearing inside the pulley, on the idler... hmm... what the heck, it probably needs it anyway.So I take it out; sure enough it's pretty stiff. I oil it and work it around, spinning it a little to try to get the oil inside there where it belongs. And long story short: I put it back in and presto! Quiet as a church mouse!</P>


So don't forget that little bearing when you're trying to bring an old Leslie back up to speed. The service manual saysyou shouldput a drop of oil on there once in awhile, but I doubt many people ever really did. Thankfully I realized the problem before I got around to disassembling the fast motor completely.</P>


TD</P>
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[Hammond101]

Re: noisy Leslie... not the motors!



The upper rotor bearings not only get dry but they get gummy. I pull the treble driver, remove the horn and clean the bearing and thrust washer with solvent. The horn then typically gets cycled thrpugh the dishwasher on the upper rack with the "heated dry" turned off. They come out squeekly clean. I then coat the bushing and shaft with lightly with oil and re-install. Then one drop of oil down the oil hole to finish it off. You wouldn't believe the crap I have found in the drivers over the years. Look and clean in there too.</P>


H101</P>

[TheAdmiral]

Re: noisy Leslie... not the motors!



Ditto H101. </p>

It's amazing how much speed the upper horn will pick up by getting rid of gummy. To those of you whose horns seem to be too slow that is probably your problem. Clean the bushing and shaft well then oil.
</p>

[tonewheel1966]

Re: noisy Leslie... not the motors!



Thanks for that info just when I needed it guys! I have just started to get a squeak on Chorale.</P>


I started going through my '63 122R today. I rebuilt the amp using the kit from TWGH.</P>


Tomorrow I am going to do the lower rotor bearings and clean out the cab at the same time. I also have a new bearing from the same kit to do the upper idler and a new belt for the lower rotor.</P>


I have already rebuilt the lower motor but will do the upper as well.</P>


Just one query though, since rebuilding the amp I get a thump now when switching speeds..........any ideas?</P>


Rick at TWGH said that based on my serial number on this Leslie it is the 113th ever made, so well overdue for all of the above work!</P>


Cheers</P>


Dave</P>

[Brendon Wright]

Re: noisy Leslie... not the motors!



Dave, me old possum. </P>


Sherly you don't need me to tell you it mustthe capacitors on the switch/relay? I think from memory... 0.1uF? somewhere bridging the phase andneutral wire. It absorbs the spark when the switch is closing....the capsmust have come off, or something.</P>

[geoelectro]

Re: noisy Leslie... not the motors!

[quote user="tonewheel1966"]

Thanks for that info just when I needed it guys! I have just started to get a squeak on Chorale.</p>


I started going through my '63 122R today. I rebuilt the amp using the kit from TWGH.</p>


Tomorrow I am going to do the lower rotor bearings and clean out the cab at the same time. I also have a new bearing from the same kit to do the upper idler and a new belt for the lower rotor.</p>


I have already rebuilt the lower motor but will do the upper as well.</p>


Just one query though, since rebuilding the amp I get a thump now when switching speeds..........any ideas?</p>


Rick at TWGH said that based on my serial number on this Leslie it is the 113th ever made, so well overdue for all of the above work!</p>


Cheers</p>


Dave</p>

[/quote]</p>


The thump comes from the switching voltage. This switched DC voltage is felt on the input tube and under the right conditions, amplified and passed to the outputs. If the input caps and first tube are well balanced, the thump should be nulled out. You may want to try another 12AU7 for example.</p>

Also, the switching voltage may be too high. You should be able to switch your relay with +35Vdc coming from the Leslie kit. However, I have seen kits deliver as much as +100Vdc or more. The higher the voltage change when switching, the more likely the thump. Lastly, there is a small value cap in the kit that slows the voltage change from changing too fast. The faster the change, the more likely the thump.</p>

So, check your voltage, check the kit cap, and check the front end of the leslie amp for good balance. For example, measure both plates of the 12AU7 to see if they are fairly close in voltage.</p>

Geoelectro
</p>

</p>

[tonewheel1966]

Re: noisy Leslie... not the motors!



Cheers Geo</P>


I had put the wrong caps between volume and 12AU7 socket [:$]</P>


The kit has made one hell of a difference to bass and overall power! Just the crossover to do now.</P>


Thanks</P>


Dave</P>

[Subaru]

Re: noisy Leslie... not the motors!



I know this is a little old but what do you guys think about this? This is the newer age model a 771.</p>

</p>

skip to 0:35 I don't have another Leslie to compare but it's audible from like 15 ft away and more so when it has a mic behind it!</p>

</p>http://www.youtube.com/watch?v=ww3qgDJqE9U