Lowrey Organ Rumbling Pedal Notes

Check the loudspeakers.

Check the amplifier.

I Already checked all the known possibilities, but the rumbling is not mechanical, and being a former Hammond repairman, those mechanical tone wheels were sometimes a nuisance when they were not oiled properly. No, I believe the rumbling may be an electronic phenomena. It might be a condenser, or maybe even caused by those Neon lamps that Lowrey used in many of their early organs. I do not know much about the design of Lowrey electronic tone generating system's. Being a Hammond and Audio Tech, the Lowrey design has Me stumped. Maybe someone out there with Lowrey experience or a service manual for My model (LSL) or worked on older Lowrey's can help. The Amplifier is excellent, as I replaced the filter caps just a year ago when the rumbling had just started, but that did not help. Thanks for Your input. Chuck.

I'm obviously no help to you. Sorry for the elementary response.

One last thing, does the frequency of the hum/rumble change with pedal pressure?

There are some really sharp electrical types here, they probably can help you more than I.

Welcome.

Thanx Lyn! At least Your Honest. Nothing can be more frustrating then someone that wants to help someone out with a problem, then finding out that they are also not into the science of the problem being discussed. You are indeed a Friend. Thanks for trying to help. What is Your knowledge and interests? I'm personally into Broadcast electronics, Hammond organs, old Jukeboxes and other vintage electronics. Chuck.

I Can't believe it's those Neon bulbs. I think I have a few of those in My collection of old media lamps. Are those NE numbers specific?? Was this a common problem with Lowrey organs? I notice several of those Neon lamps used in the keyboard tone generator circuits of this instrument, as well as in the pedal circuits.. I'm going to have to delve more into the electronic tone circuits of Lowrey organs. I remember comments going on about Lowrey and their Neon bulb music when I was a Hammond in-home service agent. I always thought it was some kind of inside joke. Thanks for the Lowrey information. I'll try to find a service manual for this LSL model, then maybe I can do an overhaul on it. It does have a great sound. Worth fixing. Thanks again for the information. Chuck.

Hello Chuck,

I can't get too specific without seeing a schematic but if the problem is the neon bulbs, they are definitely specific to the part number, such as a NE-2 for example. These bulbs have a life span of a few thousand hours depending on the circuit parameters and when they get older, they start flickering, which gets worse with age. It does sound like you've got some neons in an relaxation circuit which are becoming near intermittant in their operation. I've seen this problem in null meters, it causes a lot of problems!

Some neons are still in production while others are obsolete. Mouser, Allied and Newark still stock some of the more common ones, if your type isn't listed, I may be able to locate some or a substitute for you, just send me an e-mail.

I have NOT gone through the links above, so forgive me if this is included in one or more of them.

If I recall correctly, the Leslie speakers rotate to produce tremolo. Is it possible that the bearings are worn/dirty/dry? They could be vibrating due to the bass vibration.

It's not the Leslie speaker that is built into the Organ. I have two 122r Leslie speaker systems attached to a large 1941 Hammond model E that came out of a Church, along with the twin Leslies, and am very familiar with them and worked on them at a Hammond Dealer. I am very familiar with Hammonds and Leslie systems. It's all the other brands I am not too familiar with. The outfit I worked with was also the local Leslie dealer. Seems that the problem is in the Pedal boards Tone generator, and another tech sent Me a trouble sheet from Lowrey explaining the rumble problem. I do thank You though for Your input. Cheers! Chuck

The pedals on my Lowrey TLOKS-25 have begun to rumble and is getting worse. I do have the service manual for it but I wanted to see what some others have experienced with pedal rumble. I am leaning towards checking out some of the transistors in the pedal circuits. I am new and perhaps I am off-topic. Just let me know.

Hi there Beasley.

This thread is 6-1/2 years old, it is unlikely to get much attention.

If you would start a new thread with your question, it will go to the top of the list and likely get some discussion.