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Old 26th February 2009, 02:02 AM   #121
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Nick,

Put it down, let it rest. Come back and look at it with a fresh pair of eyes tomorrow.

I believe this is the configuration you have:

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Old 26th February 2009, 02:11 AM   #122
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Yes that is the one.




OK. Heres wher I am at now.


I installed the FREDS.

The powers up and runs fine with the FREDS. No fuses blow.


But I don't have any sound.

I am still getting around 450 volts on the T1 RED

But I am only getting about 5 volts on the T1 Yellow

And I am not getting anythign on my B+ voltage at all.


Nick
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Old 26th February 2009, 02:16 AM   #123
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Quote:
Originally posted by nikolas812

I installed the FREDS.

The powers up and runs fine with the FREDS. No fuses blow.
I assume you mean that the tube filaments glow.

Quote:
Originally posted by nikolas812

But I am only getting about 5 volts on the T1 Yellow
That's OK. The yellow are the heater for the rectifier tube which is not used in this case.

Quote:
Originally posted by nikolas812

But I don't have any sound.

I am still getting around 450 volts on the T1 RED

And I am not getting anythign on my B+ voltage at all.
No B+, no sound. That is because the FREDs are not connected to anything. You have to jumper the SW1 pads in order to provide the B+ from the diodes to the rest of the circuit.

One last thing to check is for solder bridges (shorts) under the electrolytic caps - unfortunately, you would have to desolder them and remove them to check....

I suggest you leave the troubleshooting until tomorrow.
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Old 26th February 2009, 02:21 AM   #124
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OK


Sounds good to me.




See ya tomorrow..



Nick
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Old 26th February 2009, 02:38 AM   #125
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Ok



I couldn't help myself.


I jumped the SW1 pads


I now have voltage on everything

T1 red - 405v
T1 Yellow - 524v
C1 524v
C2 494v


I'm not sure about the B+ voltage. When I put the probe on the red wire at 03 on T3 pri pins it says 1103v??



I can also hear music but is very very faint.


The tubes also look good.


Nick
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Old 26th February 2009, 02:53 AM   #126
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I think I might have teh volume pot wired wrong. Hence the reason for the very low volume.


My ALPs volume pot has not yet arrived from Germany. So I had to rob one out of another tube amp. It just so happened to be a 100k unit also. But it was wired funny.


I think I might try wiring it another way.


Heres a couple pics of how it was wired in the other amp and the way I have it wired.


Nick

[IMG]Click the image to open in full size.[/IMG]
[IMG]Click the image to open in full size.[/IMG]
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Old 26th February 2009, 03:13 AM   #127
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YES!!!!!!!!!!!!!!!!


I have a working amp!!!!!!!



I was too close to stop...


I re wired the volume pot and it works like a charm.







I was SOOOOOOOO depressed earlier. I thought I might have ruined the borad or just done soemthing horribly wrong down the path of the build...



So.


What does this mean?



Do I have a bad rectifier tube? Because the amp works fine in SS mode.


I didn't mention it but I dropped the rectifier tube on the floor the other day. But it didn't hit hard so I didn't think it was worth mentioning..


What do you guys think? Should I go ahead and order a new Rec tube?



Oh man. I am listening to right now and it sounds oh so sweet...



I think htis is a great stopping point for the night.



See you guys later and THANKS a Million for all the help. I'm sure I'll need a little more to get everything fine tuned...



CHEERS!


Nick
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Old 26th February 2009, 03:15 AM   #128
chrish is offline chrish  Australia
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I do not have a volume control on my amp at all. Can you wire as a power amp with no volume pot? Then you can use an iPod, walkman, portable CD player, computer, or just about anything with a volume control and a line/headphone output.

Before doing that I would still check for shorts in the amp. There was a problem that blew your rectifier, and that problem has not been found. Are you getting the correct B+ at the output transformer. If there is short somewhere here, it may mean low volume, and it may also have caused the load on the rectifier to be too high, causing its failure.

To measure B+ at the output transformer, put the probes on the terminal block where the blue and the red wires attach in the diagram shown previously.

Chris
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Old 26th February 2009, 03:19 AM   #129
chrish is offline chrish  Australia
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See you posted while I was writing... Glad it is working!

Still check the voltage at the output transformer, just to be sure...

Yes, there was a problem with the rectifier, but we did not want to just swap it out, as if there was another problem, it could get expensive swapping rectifiers and fuses!

Yes I would order a new rectifier and then take the jumper out for the FREDs. Leave them there just for emergency use, as I and others have had problems with them in the past.

Good luck with the rest of the build!

Chris
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Old 26th February 2009, 03:20 AM   #130
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486 at the b+ voltage.







Nick
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