Fisher X-1000 restore hold my hand
- Thread starter Kingbleu
- Start date
Often times, it is on the back side of the front panel.
Dave
Dave
Kingbleu
Well-Known Member
The schematic I am using shows C45 and C46 rated at .1uf, 400v
what is actually inside the Fisher is C45 and C46 rated at .1uf, 250v
I ordered caps based on the schematic. Would it be ok to replace these caps with whats on the schematic. Or should I replace the caps with whats inside the Fisher? I know the schematic I have is for later Fisher models and up until now I haven't seen any differences.
what is actually inside the Fisher is C45 and C46 rated at .1uf, 250v
I ordered caps based on the schematic. Would it be ok to replace these caps with whats on the schematic. Or should I replace the caps with whats inside the Fisher? I know the schematic I have is for later Fisher models and up until now I haven't seen any differences.
Fisher no doubt used the 250 volt rated part due to space considerations relative to its size, and because it will work acceptably. However, the 400 volt rated part would be much preferable to use in that location, and is likely no bigger than the original 250 volt part installed if that. Go for it.
Dave
Dave
Kingbleu
Well-Known Member
When I ordered my parts the .1uf, 400v caps were replaced with .1uf, 630v
so I actually will be replacing .1uf, 250v with .1uf, 630v
Size is not an issue I just wanted to make sure the voltage rating isnt to high. One thing I did notice about the new caps is that the caps rated 400v are much bigger than the caps rated 630v both are Cornell Dubiler (DME6P1K-F) (225P10494XD3)
so I actually will be replacing .1uf, 250v with .1uf, 630v
Size is not an issue I just wanted to make sure the voltage rating isnt to high. One thing I did notice about the new caps is that the caps rated 400v are much bigger than the caps rated 630v both are Cornell Dubiler (DME6P1K-F) (225P10494XD3)
Kingbleu
Well-Known Member
I finished all the caps last night. Said a prayer and turned it on. Let it warm up and tested the output tube bias. The lowest I can get is channel A 1.14v channel B 1.43v The specs call for 0.86v so not sure where to go from here.
Next I hooked up some crappy computer speakers. Ok got sound. Finnaly I hooked up to my main speakers Pioneer HPM-100. Jaw drop this amp is banging super power but I still wish I could get the output tube bias within specs.
I also need to put in the current limiter (which I have no idea how to do). And I also need to install some resistors across the tubes that Dave told me to order. (also have no idea what to do here).
Here's some pics some are better than others.
Before
Getting Closer
Have to drill out clamp so new can will fit
Whoops new can to big wont clear chasis
All caps are done
Next I hooked up some crappy computer speakers. Ok got sound. Finnaly I hooked up to my main speakers Pioneer HPM-100. Jaw drop this amp is banging super power but I still wish I could get the output tube bias within specs.
I also need to put in the current limiter (which I have no idea how to do). And I also need to install some resistors across the tubes that Dave told me to order. (also have no idea what to do here).
Here's some pics some are better than others.
Before
Getting Closer
Have to drill out clamp so new can will fit
Whoops new can to big wont clear chasis
All caps are done
You can pop the top off the Hayseed can cap. If there is a fair amount of room you can "CAREFULLY" dremel the extra off the length and re-install the top. Chances are there isn't a lot of room. OR call TOM and ask him if he can make one with a shorter length and take back the long one. That can cap with those values is a fairly common one for FISHER's.
Larry
Larry
Kingbleu
Well-Known Member
Larry,
Thanks yes Tom already sent me a new can and its installed. Now I want to install the current limiter and add the resistors to the tubes. Just waiting on instructions from Dave or anyone else who chimes in. After that I would like to find out how to get the tube bias to specs. I wonder if new tubes would help any? Then its just some good cleaning and cosmetics.
Thanks yes Tom already sent me a new can and its installed. Now I want to install the current limiter and add the resistors to the tubes. Just waiting on instructions from Dave or anyone else who chimes in. After that I would like to find out how to get the tube bias to specs. I wonder if new tubes would help any? Then its just some good cleaning and cosmetics.
The current limiter gets installed between the power cord and it's attachment. I disconnect the side that the switch is on (which means more hand over hand tracing of wiring) and install between the power cord and where the cord attached to, usually the end of the fuse holder. If the switch is on the other leg, see if there are two lugs on a terminal strip in the immediate area and attach the current limiter there along with the power cord lead and the switch lead. If no terminal strip you can install one. Best NOT to have "flying" or "airborne" leads hanging around.
I'll leave the bias to Dave or one of the guys who have one.
I'll leave the bias to Dave or one of the guys who have one.
King -- What does the negative bias voltage measure at the output of the bias rectifier? And, what does the B+ voltage measure going to the CT of the OPTs?
Dave
Dave
Kingbleu
Well-Known Member
Remember the title of this post HOLD MY HAND
How do I measure negative bias voltage at the output of the bias rectifier? One probe to ground and one probe to ? Do I do this with the speakers connected?
I took a picture of the rectifier and have it marked number 1 number 2 am I even in the ballpark here.
My next question is how to do this And, what does the B+ voltage measure going to the CT of the OPTs?
How do I measure negative bias voltage at the output of the bias rectifier? One probe to ground and one probe to ? Do I do this with the speakers connected?
I took a picture of the rectifier and have it marked number 1 number 2 am I even in the ballpark here.
My next question is how to do this And, what does the B+ voltage measure going to the CT of the OPTs?
In your pic, the bias rectifier is at the very bottom right hand corner of the pic, mounted on the side wall of the chassis. The output is the yellow wired coming from that rectifier, you can measure it at either end of the wire. Black probe to chassis, red probe to the yellow wire. DVM set to measure 200 vdc.
To measure the main B+ voltage, follow the two red leads coming from the output transformers (one lead per transformer) to where they tie together in the power supply. There will be over 400 volts at this point, so BE Careful!! As before, black probe to chassis, red probe to where the two red wires meet.
Dave
To measure the main B+ voltage, follow the two red leads coming from the output transformers (one lead per transformer) to where they tie together in the power supply. There will be over 400 volts at this point, so BE Careful!! As before, black probe to chassis, red probe to where the two red wires meet.
Dave
Those are dead on the money. Next, check the values of R133 and R134, which are supposed to be 10 ohm resistors, but their accuracy is important.
Dave
Dave
Kingbleu
Well-Known Member
Dave AKA Tube master
You are the man.
I have found a kink (bad solder joint) in the right leg of R133 as seen in the pic. When I measure above the kink I get 10.2 ohm but below the kink where the leg connects to the tube socket the values are off the charts.
Whats the best way to repair this should I just cut a leg off a big resistor in my parts bin and solder it in or is there a certain type of wire that should be used.
You are the man.
I have found a kink (bad solder joint) in the right leg of R133 as seen in the pic. When I measure above the kink I get 10.2 ohm but below the kink where the leg connects to the tube socket the values are off the charts.
Whats the best way to repair this should I just cut a leg off a big resistor in my parts bin and solder it in or is there a certain type of wire that should be used.
That would certainly do it for that channel, but first make sure that your probe was making a good connection when measuring at the tube socket terminal. With the amount of resin residue present, it can sometimes make getting a good contact with your probe difficult. No specific wire is required other than it being generally of a similar size so you can work with it in the space provided.
At some point, I would consider replacing both resistors with tight tolerance 10 ohm 1 watt resistors. The 5 watt rating of the original components is serious overkill, while a 1 watt rating will still allow full power to be developed in each channel on a continuous basis, but also act as a semi-fuse should a tube decide to become socially unacceptable. A 1 watt component would also easily fit into the space allowed much better as well.
Congrats on finding the bad connection!
Dave
At some point, I would consider replacing both resistors with tight tolerance 10 ohm 1 watt resistors. The 5 watt rating of the original components is serious overkill, while a 1 watt rating will still allow full power to be developed in each channel on a continuous basis, but also act as a semi-fuse should a tube decide to become socially unacceptable. A 1 watt component would also easily fit into the space allowed much better as well.
Congrats on finding the bad connection!
Dave
Kingbleu
Well-Known Member
After fixing the bad solder connection I tested the output tube bias and nothing changed the readings are still channel A 1.14v channel B 1.43v
Dave you must have been right maybe I just wasnt getting a good connection with the probe.
What else could be causing the output tube bias not to adjust within specs?
Dave you must have been right maybe I just wasnt getting a good connection with the probe.
What else could be causing the output tube bias not to adjust within specs?
King -- If your 10 ohm cathode resistors are in reading 10.2 ohms, that is only a 2% error, causing your bias voltage readings to be 2% high, which is not nearly off enough to cause the readings you are getting.
OK. Two things:
1. To make sure you are adjusting the controls correctly, turn both Bias controls all the way in whichever direction produces the lowest reading in each channel, and then adjust the DC Balance control for a minimum reading as well. What are the minimum readings you are getting when adjusting the controls this way? Also, without disturbing the adjustments --
2. What is the negative voltage reading on pin #5 of each output tube?
Let us know!
Dave
OK. Two things:
1. To make sure you are adjusting the controls correctly, turn both Bias controls all the way in whichever direction produces the lowest reading in each channel, and then adjust the DC Balance control for a minimum reading as well. What are the minimum readings you are getting when adjusting the controls this way? Also, without disturbing the adjustments --
2. What is the negative voltage reading on pin #5 of each output tube?
Let us know!
Dave
Kingbleu
Well-Known Member
Minimum readings with all controls turned down
.77
1.11
Tube #1 -28
Tube #2 -20.6 going down gradually
Tube #3 -25 rappidly going down then +4 then SPARKS and SMOKE
Now when I power on after about 1-2 minutes one of the 750ohm 5watt resistors either R10 or R11 starts smoking
Im positive the probe was on pin 5 and the probe has little grabbers so I'm positive it didn't slip off. When I was turning the controls down maybe I turned them the wrong way and juiced it up before I turned them back down.
.77
1.11
Tube #1 -28
Tube #2 -20.6 going down gradually
Tube #3 -25 rappidly going down then +4 then SPARKS and SMOKE
Now when I power on after about 1-2 minutes one of the 750ohm 5watt resistors either R10 or R11 starts smoking
Im positive the probe was on pin 5 and the probe has little grabbers so I'm positive it didn't slip off. When I was turning the controls down maybe I turned them the wrong way and juiced it up before I turned them back down.
Kingbleu
Well-Known Member
c62 and c63 are both rated 18uf
without taking them out I'm getting 60uf and 114uf
I probably have to take them out to get a proper reading but they both look pretty crispy
Not sure where I went wrong I was playing music loud, for hours, with no problems up untill I took those last readings
without taking them out I'm getting 60uf and 114uf
I probably have to take them out to get a proper reading but they both look pretty crispy
Not sure where I went wrong I was playing music loud, for hours, with no problems up untill I took those last readings
