Hammond cv with Leslie 21h --issue with distortion

[hammondcv]

what it that resistor that is discolored ? it may be the issue

[jimmywilliams]

NEver mind what I said about the power supply stage schematic - this one is different than the schematics I am used to looking at. They have the filter cap segments in different parts of the schematic.

[hammondcv]

pics of 21H Part kit. Im not sure if the relpacement resistor for the discolored one above is in the kit. Not sure what the blue resistor replace. Not sure about the 2 brown and white reisitor/fuse??? Please help break down what replaces what.


Thanks.
Part kit PICs #1

[jimmywilliams]

I see this unit has a tube rectifier - the diodes are only for the brake circuit. I'm taking some time to look at the schematic further. But you are better off relying on people who know more about this amp than I do!

[hammondcv]

21h parts kit #2

[hammondcv]

the can did come with the kit. its not in the picks. it appears that the burned resistor is tied to one of the 6v6 tube . your thoughts.

[hammondcv]

last pics for your review
as I forgot- sorry

If the burned resistor is not in the kit, where is teh best place to buy/order individual resistor of same value? It the white part a fuse or resistor?
Thanks

[hammondcv]

note the brown parts above have 2 different values

[hammondcv]

I didnt replace the can. I didnt replace anything from the kit yet

[jimmywilliams]

Johnny,
The large parts you make mention of in the kit are high power resistors. The ohms/watts markings are on them.
Please do not take this the wrong way, but since you do not seem comfortable identifying the parts and locating where they go, for your own safety I would strongly recommend that you please send the amp out to be professionally serviced.

[hammondcv]

I am very thankful for your advice. As I am a newbie, I want to learn I all I can, so that I dontget cheated, and can bless others along the way. Please continue to entertain the questions although I am a novice.

Thanks

[jimmywilliams]

Johnny,

I did get to look at this in greater detail. You have a 21H series 3 amp, and a later revision at that since it only has one tube rectifier instead of two (I can find no schematic with only one tube rectifier and that is one reason I was not certain what revision of the amp you really had - but based on the markings on your amp the original two tube rectifiers were replaced with a single heavier duty model). The burned resistor in question does not seem to be on the schematics I have read - unless I am not reading them correctly - based on Daniel's photos it looks to be a 15K resistor - and by the size it may be 2 or 3 watts. I am honestly not certain and do not feel comfortable giving any advice based on guesswork.

Another thing that bugged me about your amp is that it seems to be missing the mains fuse. Did you remove it for the photo, or was it never there? If it was always missing this would mean that it was bypassed somehow and this would make the amp an unquestionable safety hazard and it should never be operated this way - ever.

How have you done calculating the values of the resistors in your kit? You should at least be comfortable with that piece before proceeding any further. I trust you have also downloaded the appropriate schematic.

The blue resistor is to be read like any other resistor - the color code is the same. I cannot see the colors very clearly in the photo - they all just look "dark" to me but then again my vision isn't what it used to be...

I did not mean to "blow you off" earlier, but a Leslie speaker is not worth getting hurt or killed over. These old tube amps are very dangerous and a complete rebuild of one is not a novice project. There are other ways you can learn about this stuff and I encourage you do do as much reading, studying, and experiemnting as possible but on much lower voltage/amperage equipment first. If I seem a little "sensitive" about this it is because I unfortunately know first hand the tragic consequences of what can happen to someone who has suffered electrical burns (which I do not care to elaborate on any further as it is too emotionally painful - but suffice to say electricity can cause permanent and severe damage to the body even if it does not kill you then and there).

I still recommend you spend the money and send it in (perhaps along with the kit to the same place you purchased the kit from?) for professional repairs. Then you can even take a look at it when it comes back and see and understand what was done. There are also other things that the pros would be able to test/diagonse that you can not (for instance testing the vacuum tubes - unless you just happen to have a mutual conductance tube tester laying around and know how to use one). Something caused that resistor and filter can to go down and there is a chance that even if you replaced all the components successfully you would still have a problem. I don't think it is worth taking a chance over.

[hammondcv]

Its all Good - i totally understand
I have an update on my research

I did take the fuse out before i took the pics. I also ordered the kit from online (tonewheel hospital). Yesterday i took the amp to a local shop and the guy identified the burned resistor as a 15k 3 watt. he also showed me where it was on the schematic. unfortunately he did not have one in stock, he believes it was caused by bad tube or can. He matched up the ohms by putting (2) 3 watt 32k resistors together. He said this would work. your thoughts on this. I'm thinking, order the 15k 3 watt part online. Im also thinking at this point, just replace that resistor, can (from the kit), and 6v6 tubes as they are mismatched. If problems persist, take the unit into the shop. i believe a complete rebuild is $250-$300. I did start getting ohm readings on the other resistors in the kit and under the amp. As the new kit parts have a different look, i am understanding the importance in reading the ohm and watts. i will keep you updated.

[TheAdmiral]

What the tech did is OK. Replace it if it makes you feel better.

[jimmywilliams]

Yesterday i took the amp to a local shop and the guy identified the burned resistor as a 15k 3 watt. he also showed me where it was on the schematic. unfortunately he did not have one in stock, he believes it was caused by bad tube or can. He matched up the ohms by putting (2) 3 watt 32k resistors together. He said this would work. your thoughts on this. I'm thinking, order the 15k 3 watt part online. Im also thinking at this point, just replace that resistor, can (from the kit), and 6v6 tubes as they are mismatched.

Johnny, how do you know the tubes are mis-matched? Did you have them tested on a tube tester? Just being different brands does not automatically mean taht they are mis-matched. Also, what schematic are you reading? It is good that you have a local tech available. As Admiral said, putting the 2 replacement resistors in parallel should work fine (you will get 16K-ohms like that, but that is well within the tolerance of the original 15K resistor. It will also be able to handle 6 watts so this will be more robust and I don't think that will have any detrimental effect on that part of the circuit - Admiral will know better).

Admiral,
I read over the 21H type 3 schematic several times on the captain-foldback.com site, and just checked it again now. I still cannot find any mention of a 15K resistor ... except in the Tremolo Control Type II diagram. But I ignored this earlier becuase I thought that was a separate Lesie hookup box mounted in the organ. Am I wrong? Please let me know. Thanks.