What the heck is wrong with my Leslie 145?

[Juan]

I'm still not convinced that this noise is a resonating frequency. It is very loud and gets more crazy loud with more volume. I can check the 6550 by replacing them. I have a bunch of them. I have three Leslies plus two extra tube sets to draw from. I am starting to wonder if the problem is actually in the organ. I am going look at the signal path and see if anything is amiss. My Hammond tech is comming over next week (after he gets through the Easter holiday). Eventually I will get this figured out.
Perhaps I will haul the Leslie over to his shop and test it out on his "house" A-100.

[Juan]

The Saga continues... I swapped out the Valve Art 6550's (only about a year old) with a very old, dirty set of Tung Sols. The TSols sounded fabulous and the mystery noise did not occur. To verify that the problem was indeed a failing 6550, I put the Valve Art tubes back in and retested expecting to hear the weird noise again. The noise did NOT return. However,... I noticed that when the Valve Art tubes were in, the overall sound of the Leslie was slightly distorted. I put the old, dirty TSols back in to verify how they sounded. Fabulous again.
This leads to believe that I might be having the same problem Hanman had - a failing 6550. With the help of my Hammond Tech, I will try to verify this with a volt meter.

[bossbandbob]

Well, I just isolated the cause of my Leslie rattle. I had installed a wooden rotor in my Frankenleslie 130. When I push the rotor up from underneath on one side a slight bit while it's on stop the rattle goes away. I need to take the upper back cover and woofer off next to see what's causing this as I'm thinking its related to the mounting hardware. It is not any of the counterbalance screws on the rotor itself. Juan, did you check your rotor?

[Hamman]

Juan thats exactly what I did as well.....tried a different set of 6550's and my issue went away....then tried the original pair of 6550's again just to double check and like your situation I couldn't get volume and it was distorting. So I put back the fresh 6550's and the Leslie has sounded great since! I only found the issue with my 6550's by having my wife hold a chord on the organ why I hunted around down at the amp to "duplicate" the problem. I lightly tapped on each tube as well as wiggled them in their seat until I came across one of the 6550's that just went awry. I haven't had 1 issue since changing them out. Hopefully your situation is good to go now. Still has me wondering, on my situation, if there is something else upstream that could of caused the tube to go bad in the first place....hmmm

[bossbandbob]

Well, I just isolated the cause of my Leslie rattle. I had installed a wooden rotor in my Frankenleslie 130. When I push the rotor up from underneath on one side a slight bit while it's on stop the rattle goes away. I need to take the upper back cover and woofer off next to see what's causing this as I'm thinking its related to the mounting hardware. It is not any of the counterbalance screws on the rotor itself. Juan, did you check your rotor?

Mounting Hardware is all good. before I remove it does anyone know what else could be causing the wood rotor to rattle? It does this only on certain notes as well. it is slight. it is really strange as at times it seems to be emanating not from my Leslie but from the studio walls.....,but when I push on the rotor it stops!

[Juan]

Juan thats exactly what I did as well.....tried a different set of 6550's and my issue went away....then tried the original pair of 6550's again just to double check and like your situation I couldn't get volume and it was distorting. So I put back the fresh 6550's and the Leslie has sounded great since! I only found the issue with my 6550's by having my wife hold a chord on the organ why I hunted around down at the amp to "duplicate" the problem. I lightly tapped on each tube as well as wiggled them in their seat until I came across one of the 6550's that just went awry. I haven't had 1 issue since changing them out. Hopefully your situation is good to go now. Still has me wondering, on my situation, if there is something else upstream that could of caused the tube to go bad in the first place....hmmm

I asked my Hammond tech about the upstream concern. I'm not very good with the technical stuff so he tries to keep his answers simple for me. If I understand his answer..., there is little upstream that would cause the 6550 tubes to fail except for the power transformer. He thought it was most likely a faulty tube. This kind of irritates me because the darn tubes were expensive and have had very little use. It's sad that a new set of expensive matched tubes would fail after less than 5 hours of use but all three of my 40+ year old tube sets work great.

[johnny b3]

most retailers have a 30-day money back or swap initiative in the event of a tube that fails so quickly. There is a thought that the longer a tube is in service, the more it proves itself (obviously in high-stress situations the tube will eventually begin to have weaker emissions). A defect in the tube usually shows up fairly early in the tube's life.

[Juan]

I'm afraid I am out of the warranty period. These tubes are over a year old. The reason the tubes have such low use time is because I had my organ ( M3 ) torn apart for most of that time.
I also have an A-101 that I normally use with my 251. However, I took the 251 apart over the winter because I am repairing and refinishing the cabinet. While I complete my 251 repair, I decided to set up the A-101 for use with the 145. This is when I discoverd the odd buzz noise.
Now that I think about it, my M3 also sounded distorted. I thought the problem was with the organ. It appears the problem was actually with the Leslie. Tracking down these problems is making me crazy. The learning curve on Hammond and Leslie repair is steep. If I don't poke my own eyes out, I will eventually become an expert. Although, a very reluctant expert.

[jhelm_waterw]

The Saga continues... I swapped out the Valve Art 6550's (only about a year old) with a very old, dirty set of Tung Sols. The TSols sounded fabulous and the mystery noise did not occur. To verify that the problem was indeed a failing 6550, I put the Valve Art tubes back in and retested expecting to hear the weird noise again. The noise did NOT return.

Sometimes, just the act of removing and re-inserting a tube can make a difference.
Mind you, this is much more common with preamp tubes than output tubes but, it happens.
My old fender super occasionally starts with a staticky sound... wiggle a 12AX7 and it goes away.
You should give the pins and sockets a shot of de-oxit while you're there (pre and power). Can't hurt.

[geoelectro]

I buy 6550's 6 pair at a time. It's not unusual to discover bad tubes right out of the box or within a week of use. We send them back for replacements.

Geo

[TheAdmiral]

I buy 6550's 6 pair at a time. It's not unusual to discover bad tubes right out of the box or within a week of use. We send them back for replacements.

Geo

What brand do you use?

[geoelectro]

Winged c or 6550ASTR.

Geo

[Tim_at_Jonas]

I am reminded that I had to use the superglue trick on a drum that rattled. Also had a 122A styrofoam drum that rattled.

[bossbandbob]

I am reminded that I had to use the superglue trick on a drum that rattled. Also had a 122A styrofoam drum that rattled.

I think I solved it by putting a thin washer under one side of the top mount bar. It may have gotten a hair off balance but seems to be spinning relatively quietly now. Where did you have to apply the super glue?