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Simple SE with KT88's

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#121
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:

SSE_hookup_choke_triode_noCFB.jpg
 
#122
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
 
#123
nikolas812 said:

I installed the FREDS.

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

nikolas812 said:

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

nikolas812 said:

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.
Click to expand...
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.
 
#125
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
 
#126
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_0507.jpg
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IMG_0513.jpg
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#127
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
 
#128
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
 
#129
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
 
#132
True...

Should have thought about it (or looked at the schematic) a bit better. When you get the replacement rectifier, remove the FREDs. They did cause me problems.

Probably worth getting a two rectifiers. I reckon a second set of cheap output tubes is a good investment for troubleshooting too.

Enjoy!
 
#133
nikolas812 said:
Do I have a bad rectifier tube? ... 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..
Click to expand...

It may not look damaged, but what I have experienced with indirectly heated rectifiers is that the coating of the ceramic heater flakes off and causes a short. If you look at it carefully, you may be able to see something that resembles paint peeling off the heater element.

nikolas812 said:

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...
Click to expand...

Glad you got it working. Remember to drill some holes in the chassis for ventilation before you assemble the amp. I included a picture in a previous post.

ENjoy,
 
#134
The camera was haveing problems today so the pics aren't that great. When the amps completed I'll take it out side for nice beauty shots..



Primer

IMG_0516.jpg
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Sealer

IMG_0529.jpg
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Base

IMG_0532.jpg
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Clear

IMG_0536.jpg
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It will get wet sanded and buffed tomorrow. Then I'll start putting the amp together..


Thats Candy Apple Red by the way....

Cheers


Nick
 
#137
Good to see it is all working well! I just ordered a Simple SE today.... I did just build a K-8LS kit today, and am already hooked on the sound of tubes!
I spent an hour this morning desoldering an inadvertantly-upside-down-soldered 9 pin tube socket, so I do feel your pain!

Hope you continue to enjoy your amp!
 
#138
So I got the amp completly finished today. And decided to go ahead and wire it for UL. Well....I wired it up for UL and put it back together. Then turned it on. All the tubes looked good accept for the right power tube. It was glowing like I have never seen a tube glow before and no sound was coming from the right channel. I quickly turned it off. I swapped tubes and it did the same thing. I checked and rechecked my wiring and everyything looked good. So out of curiosity I wired it back up for triode to see if would work in triode mode. Well... It did the same thing only it took a little longer to start glowing..


Does anybody have any idea what has happned? Its obviously something I did because the amp worked before and now it doesn't.


Any help would be appriciated!


Heres a quick pic of the finished amp.




Nick
IMG_0549.jpg
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#139
Well.. Seems I figured it out. I pulled the pcb from the chassis and had a look on the other side. Sure enough a pad had came off.. Fixed it and the amp works fine now. But back in Triode mode. I guess UL wasn't meant to be for now. Oh well. I'm going to enjoy it for a little while before attempting the UL wiring again.




Nick
 
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