Leslie 145 Distortion

[Polkahero]

I just picked up a Leslie 145 and the Jensen V21 upper driver is distorted even at lower volume levels. Unplugged it and the bass driver sounds fine. Several years ago I used a company out of Texas called Freeman Tuell and they reconed one of these for me. Any idea if they're still in business? I'd prefer to get the original repaired vs. going with an Atlas replacement if possible.

 

Also, what load resistor setting should I be using on the amp if I'm using a Trek II UC-1A universal preamp pedal? "Open" had the most volume.

[mate stubb]

I have changed many a diaphragm in a V21. Still the sweetest sounding driver and worth keeping running if you don't require high power.

 

The driver could be rattling from loose frame parts or the diaphragm could be buzzing due to being off center in the gap slightly, but it is probably a blown or partly blown diaphragm.

 

If you want to change it out, you can still get replacement diaphragms from Tonewheel General: https://ssl.tonewheelgeneral.com/build_page.php?category=Speakers&subcat=Drivers

 

When you install the new one, you center it so that it doesn't buzz by putting a low level steady tone through it as you tighten things up.

[Polkahero]

I have changed many a diaphragm in a V21. Still the sweetest sounding driver and worth keeping running if you don't require high power.

 

The driver could be rattling from loose frame parts or the diaphragm could be buzzing due to being off center in the gap slightly, but it is probably a blown or partly blown diaphragm.

 

If you want to change it out, you can still get replacement diaphragms from Tonewheel General: https://ssl.tonewheelgeneral.com/build_page.php?category=Speakers&subcat=Drivers

 

When you install the new one, you center it so that it doesn't buzz by putting a low level steady tone through it as you tighten things up.

 

I'm aware of the replacement diaphragms but I'm not comfortable replacing one of them myself. I know it takes certain skill to get it right and I don't want to screw the original Jensen up more than it already is.

[rod76]

I personally had more trouble with keeping the gaskets put than anything else.

[Jim Alfredson]

The diaphragm might be fine and it just has debris rattling around in there. Most of my buzzing V21s were just dirty.

[U.Honey]

I have somewhat similar question as Polkahero. I recently acquired a Leslie 45 cabinet from craigslist and 47 amp from eBay. I then modified it for two speeds, added a tube preamp & 1/4 input jack and so now I have what"s essentially a 145. I can report that it sounds gorgeous! And, I can plug my clonewheel directly to it and with the preamp I can dial in as much crunch as I need.

 

My plan is to take it out to gigs (post Covid-19) but I remember reading that it"s easy to blow up the V21 driver if you play it loud and especially if you overdrive the amp. Well, that"s exactly what I"m looking to do :-)

 

I"m thinking of replacing the original V21 with Atlas PD-5VH Driver. Has anyone experience with that? In particular, can it handle an overdriven amp with high volume levels? And, is there a difference in sound compared to V21?

[mate stubb]

That Atlas is the go to replacement when you need more reliability at higher volume. It can be just a little harsher than the old Jensen but the drivers that come in new stock leslies are very similar tone wise.

[bjosko]

It might be a good idea to replace the crossover caps inside there, if it still are the originals in use. Otherwise you might sending most of the sound to the horn and overload it.

I started out with a cheap kit from an obscure online so-called Hammond expert, later changed to this capacitors below. Huge difference. But it are easy to measure out your existing crossover. If it still are the original old big flat grey combi - condenser, my guess are that it are way off.

Also worth to check that the bolts on the large backplate on the cabinet are tight, if loose, it might give some nasty rattling on certain volumes and frequencies.

 

https://ssl.tonewheelgeneral.com/build_page.php?item_no=XO-CAPS

[bourniplus]

+1 on re-capping the crossover.

 

Also, have you removed the driver to make sure nothing is in there? I once had a buzzy V21 because of a dead fly.

[Polkahero]

The diaphragm might be fine and it just has debris rattling around in there. Most of my buzzing V21s were just dirty.

 

Noted. I'll remove it and blow it out with some compressed air, hopefully it's something that simple.

[Polkahero]

It might be a good idea to replace the crossover caps inside there, if it still are the originals in use. Otherwise you might sending most of the sound to the horn and overload it.

I started out with a cheap kit from an obscure online so-called Hammond expert, later changed to this capacitors below. Huge difference. But it are easy to measure out your existing crossover. If it still are the original old big flat grey combi - condenser, my guess are that it are way off.

Also worth to check that the bolts on the large backplate on the cabinet are tight, if loose, it might give some nasty rattling on certain volumes and frequencies.

 

https://ssl.tonewheelgeneral.com/build_page.php?item_no=XO-CAPS

 

Thanks for that info, I'm sure all the components are original and the cabinet dates back to 1964. Got a link where to measure the capacitor values? I'm good with a soldering iron but I've always shied away from working on my Hammonds, scared of the high voltage caps inside!

[dfcas]

The resistance setting should be "open" for the preamp pedal. The 8 and 16 ohm settimg are for tube and solid state small power amps.

[bjosko]

 

Thanks for that info, I'm sure all the components are original and the cabinet dates back to 1964. Got a link where to measure the capacitor values? I'm good with a soldering iron but I've always shied away from working on my Hammonds, scared of the high voltage caps inside!

 

You will need a multimeter with a function to measure capacity.

I am using a Fluke 179, but many cheaper multimeters can do the job.

First you need to locate the crossover. It is a square box behind the bass speaker in the larger room between the upper and lower speaker.

If you disconnect your leslie cable first, there shouldn"t be any risk for current up here.

The crossover are bolted down with two screws.

Unplug the cable going into it from your amp, and then the two plugs from upper and lower speaker, and you can take it out off the Leslie for easier access.

 

Here is a video showing the measurements, you can find more by searching at Youtube for crossover leslie.

[video:youtube]

[Polkahero]

Well, it's definitely the driver. Plugged the bottom speaker directly into the amp to bypass the crossover and it sounds fine. Plugged it back into the crossover and then ran two extension wires for the upper driver to a different Leslie speaker and it sounds fine. Just removed the Jensen V21 and it's got a bunch of bugs/debris in it so will blow that out with compressed air next, maybe I'll get lucky!

[Polkahero]

The resistance setting should be "open" for the preamp pedal. The 8 and 16 ohm settimg are for tube and solid state small power amps.

 

Thanks, that's what I figured. Guess they made these to be more "universal" with other makes of organs, never seen that on one of these amps before.

[Jim Alfredson]

The diaphragm might be fine and it just has debris rattling around in there. Most of my buzzing V21s were just dirty.

 

Noted. I'll remove it and blow it out with some compressed air, hopefully it's something that simple.

 

When you re-install, the method I use is to make an extension cable so I can put the driver on my workbench. Hold a key down with some tape, somewhere in the upper part of the keyboard, maybe third drawbar, decent volume. Use earplugs 'cos it's gonna be loud. Re-install the diaphragm, tighten to screws very lightly, and check for buzzes. When you hear one, loosen the screws just barely, move a tiny bit while the note is held, and get it so it doesn't buzz. Very gentle process.

[Polkahero]

No luck, blew out a bunch of rice grains (mice?!) from the speaker but it's still distorted. Going to call Minnesota Organ Service tomorrow to send it in for repairs.

[The Real MC]

That Atlas is the go to replacement when you need more reliability at higher volume. It can be just a little harsher than the old Jensen but the drivers that come in new stock leslies are very similar tone wise.

 

A month ago I bought a 760 for the rehearsal room in excellent condition. Opened it up to give it a lube and immediately spotted the non-stock upper driver. Discovered it is a Universal Sound ID-60 driver. Next to the Atlas, the ID-60 were a common replacement for the V21 in the early 70s. EV later acquired US. Can handle 60 watts, weatherproof, I'll never come close to blowing it. I switched that driver to my gigging 760 which already had an EVM-15B for lower driver. Did A/B comparison with stock next to hot rodded 760, very little difference.

[Gary75]

Made me smile as a misaligned diaphragm is a feature on the overdrive on my C3.

 

 

 

[jpgxk3]

Ok Gary, I"ll ask, where did you get that drive unit and who makes it if still available? I"m sure it covers the o/d and looks cool. Nice find. Joe

[Delaware Dave]

Ok Gary, I"ll ask, where did you get that drive unit and who makes it if still available? I"m sure it covers the o/d and looks cool. Nice find. Joe

 

https://www.ebay.com/itm/Profkon-ZD-1-Mark-II-and-CWOD-Overdrive-for-Hammond-and-Clones-Synths-Plugins-/303652493110

[Doerfler]

Ok Gary, I"ll ask, where did you get that drive unit and who makes it if still available? I"m sure it covers the o/d and looks cool. Nice find. Joe

 

Hey Joe, I remember looking at these about 8-10 years ago. IIRC, they are made in Australia. I never got one.

[jpgxk3]

Thanks Dave and Dave.