LESLIE Model 16... Stuck on HIGH Speed

[Pastortom]

I've just finished cleaning and restoring a nice Leslie 16 like Stevie Ray used to use.........

I've cleaned everything, checked every contact and solder joint, replaced the power switch, and just generally put it back in pristeen appearance and workability...........Problem is that it's stuck in high speed........I can't get it to run slow........ :shocked:

When I switch it ON, the motor starts at high speed, even without the switching cables plugged into the control box.  When I plug in the cables, it doesn't make any difference, nor does the foot switch........I've checked and rechecked, and all the joints seem original, as do the caps and such.....doesn't look tampered with........checked for shorts, and found none......

Any of you'se guys have any experience with these things?  I can't use it unless I can switch from high to low speed and back. 

Doc           

[Pastortom]

I ran a limited diagnostic on the motors and came up with a partial conclusion, BUT need help on this......

The large motor and the small motor are working flawlessly.......BUT, the small motor will NOT turn "On".....in order for it to be on (which runs the slow speed), the electro magnetic coil switch inside the control box must be activated....when it gets it's signal, the coil/magnet pulls the points-switch to the opposite side, turning the small motor on.  If this point/switch is not activated, the large motor runs the drum at fast speed only.

As I stated, even if I unplug the cable assemblies from the control box, the large motor is ON and running the drum at fast speed.  This makes no sense to me, as other Leslies I've worked with always run at slow speed unless switching is activated.  If this is the norm, then the electro magnetic point/switch is not operating AT ALL, whether or not the foot switch is used.

IS THERE A SUPPLIER FOR THE SWITCH I NEED ?? (If that's the prognosis...?)

[sluckey]

Here's the manual... http://www.schematicheaven.com/fenderamps/vibratone_manual.pdf

The relay may be defective. However, it could also be something in the coil circuit that is preventing the relay from energizing. T1 and SW2 are the only components used to energize the relay coil.

I'd first manually operate the relay by pushing on the actuator with an insulated stick. If doing this causes the slow motor to run then the relay contacts are OK.

Next unplug P1 and measure the relay coil resistance. I don't know what the reading should be but it should not be infinity.

Next check the resistance between S2 pins 2 and 4. It should be zero ohms with SW2 closed and it should be infinity with SW2 open.

Finally, check the secondary voltage of T1. It's probably 24VAC or maybe 12VAC. Look for writing on the transformer or the relay for clues as to what the voltage should be.

T1, SW2, and REL 1 are the only components used to 'turn on' the slow motor. If the motor is good and there are no broken wires or bad connections in the harnesses and plugs, it should be easy to find the culprit. BTW, according to this schematic, the fast speed is the default mode.

If the transformer or relay are bad, you should be able to find either one at a good electronics supplier. Just make sure the replacement will physically fit the chassis.

[Pastortom]

OK.......

First, the points are cleaned, and OK...operates the motor fine when closed manually.

Second, the coil does have resistance.

But THIRDLY, socket-2  pins 2 and 4 have NO interaction.....For some reason, it is pin 2 and pin 5 that operate from the footswitch, NOT pin 4 which is definitely directly inline with the relay.

Strange thing is that not a single one of the solder joints looks as if it's been tampered with in any way.

Apart from any further advice or revelations, I'd need to rewire the plug and see if it works with 2 and 4.

[sluckey]

Before rewiring anything, just put a jumper between pins 2 and 4 on P1. If the relay energizes then the transformer and relay are OK.

Here's a question. Does P1 actually connect to S2?

[Pastortom]

Yes, P1 actually connects to S2......that's the only way the cables can attach.....they're both 5 pins......the top of the control box is for the speaker controls which is a different harness altogether.

I jumped pins 2 and 4 on the control box (P1) and the relay kicked right in.....SO, the transformer and relay are both flawless.

My problem lies in the cable wiring......regardless of how "nice" those joints are, they've been tampered with for some reason.  I guess it's a matter of being sure it's exactly like the schematic displays it.......

I'm tellin' ya, I am so glad the original electronic parts are still all good   .........This is the BEST example of an early Model 16 I've ever seen......Pristeen original grille's and tolex, shiny hardware, clean interior, AND all original cables/crossover assembly and footswitch.....Just gotta get her put back the way it was on that plug and switch.

[sluckey]

Open up the footswitch. I think someone may have replaced the switches and got something crossed up. It's less likely that someone actually rewired one of the plugs or sockets. At least now you know it's just a wiring boo boo.

[Pastortom]

I've had the footswitch open all this time to check the continuity........

Just finished the job....desoldered and resoldered the plug with pin 4 to the switch like it should have been, and it's operating 100%........I have absolutely no idea why those wires were screwed up...someone at some point was trying to troubleshoot and crossed it I guess.......at any rate, she's a workin' girl agin' !!

THANKS guys.     Doc :blob1:

[sluckey]

That's great. While you still have it apart, energize the relay and measure the AC voltage across the relay coil. Then write it down inside the chassis for future reference. However, if the transformer lists the secondary voltage or the relay voltage is stamped on the relay already, just never mind.

[Geezer]

I have absolutely no idea why those wires were screwed up...

It's quite possible it came like that from the factory & NEVER worked correctly.....human error.
Maybe the folks who originally bought it never used the slow speed??

I've heard of amps wired incorrectly from the factory & guys finding the error many (40-50) years later.....

[TubeGeek]

Pastortom,

I just came across your project and I am hoping you can help me out.  I have a Model 16 in good condition only I do not have the foot switch assembly.  I have looked at the schematic and have thought about making my own foot switch but haven't made it a priority.  Would you be willing to take some pictures of the assembly so I can study how it was built? 

TG

[sluckey]

I think the hardest thing about building the footswitch would be finding the plugs for it. The plugs could be hardwired if you can't find them. You'll need one SPST push on/off switch and one SPDT push on/off switch. I'd just get one of those cheap dual footswitches from ebay.

[TubeGeek]

I have the male and female plugs.

I do need to place an order for the switches.

It'd be nice to see a pic of how it was done so I could reference it.

[sluckey]

Does this help? I didn't see an internal pic of the footswitch, but it's only 2 switckes and one cap. Layout isn't critical.

[sluckey]

Here's another pic that may be helpful...

[TubeGeek]

Sorry to hijack this thread...it's related and is inspiring me to finally get this project going.  I've had this leslie for near two years now and I still have yet to even plug it in a listen to it connected to my twin reverb "verbolo" amp.

I have opened it up and taken pics...http://www.glacieramps.com/Glacier_Amplification/Pics/Pages/Fender-Leslie_Model_16.html

Next I need to go over each assembly and get a parts order together.

What I do not have is the male barrel connector in the pic posted.  I'm going to have a few more questions to ask, things are busy for me so I'll try to get a few hours or so in over this weekend and get something going.

[sluckey]

What I do not have is the male barrel connector in the pic posted.

That's the crossover network (cap and inductor). You will likely have to build that yourself. While googling "leslie 16 footswitch" I ran across plenty of useful info, including using an audio transformer to replace the inductor. Even had a Mouser part number.

That crossover network is not entirely necessary but gives a good sound.

Don't be concerned about hijacking this thread. It's pretty much dead except for your new interests.

[TubeGeek]

I finally got around to building the footswitch assembly for the leslie.  I used a 1.0mH inductor with a 2.2µF cap in parallel.  Sounds pretty good.


The "from amp output" and "to speaker" are simply 1/4" jacks so I can use speaker cable's there.  The leslie cable is leftover mogami quad mic cable I had.