Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: MrPotatoSalad on September 02, 2014, 09:35:29 AM
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Finished building the Crack and Speedball but had to remove the Speedball. Here are my issues:
1) There is a slight white noise with the Crack (stock). It is not loud, but enough to be easily noticed as soon as the headphones are plugged in. It does not change with the volume knob (even when all the way down). I unplugged the RCA jacks and tried wiggling the 12AU7 and still the same in both ears. Is it a cold solder, bad tube, or something else? Replacing 12AU7 tube solved the problem
2) My 5W 270 ohm transistors got really hot since I forgot the plastic sheet between the transistors and heat sink. I don't know if this made one of the resistors crack directly or if it simply made an already damaged transistor more damaged, but one of them cracked so I need a replacement. Will this work: http://www.amazon.com/gp/product/B009PIQUDE/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 (http://www.amazon.com/gp/product/B009PIQUDE/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1). Solved
3) Finally, the Speedball originally lite up all LEDs both before and after I put the plastic sheets in. However, I was not getting any voltage readings on the first 6 terminals because I had the ground on terminal 13 instead of 12. :P While I was voltage testing, there was a spark on terminal 7. I don't know if it shorted to terminal 6 or not, but all the LEDs went out except the bottom main board (which glowed strong), and the LED at A8 to center pin. I tested all the transistors and resistors and the only bad one I found was the bottom TIP50, which gave a low resistance from red collector to black base. The PC board did not have any shorts or disconnections so my best guess is that the transistor is shorting out the power at the bottom board not allowing the electricity to travel any farther. Any guesses as to what it is? Solved
Cheers
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1) There is a slight white noise with the Crack (stock). It is not loud, but enough to be easily noticed as soon as the headphones are plugged in.
What's the nature of the noise? Is it a rustling noise, hum, or something else?
2) My 5W 270 ohm transistors got really hot since I forgot the plastic sheet between the transistors and heat sink.
A voltage check will address any issues that cropped up from this damage.
3) Finally, the Speedball originally lite up all LEDs both before and after I put the plastic sheets in. However, I was not getting any voltage readings on the first 6 terminals because I had the ground on terminal 13 instead of 12. :P While I was voltage testing, there was a spark on terminal 7.
I would start over with a fresh Speedball once you know your Crack is working. (Like we recommend)
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What's the nature of the noise? Is it a rustling noise, hum, or something else?
Like this, except quieter: https://www.youtube.com/watch?v=iMrjYpU3YD4 (https://www.youtube.com/watch?v=iMrjYpU3YD4). Try turning the volume bar down to as low as possible on the video. it is about that loud if not a little quieter (starting from a "normal" listening level).
A voltage check will address any issues that cropped up from this damage.
The voltages are withing the 10-15% range. The problem is it is cracked ceramic, so I would like to put a new resistor in since they are dirt cheap anyways. I only want to know if the linked resistor is the right specs. It seems like it is.
I would start over with a fresh Speedball once you know your Crack is working. (Like we recommend)
What do you mean? The Speedball is out right now. I tested the components when they where detached from the Crack. No problem with Crack except noise and resistor. The top plate gets a bit hot, ~115F, but that is expected as far as I know.
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Yeah, it wouldn't hurt to replace the cracked resistor first, just to be sure you have solid parts upon which to form a solid opinion.
As far as the Speedball goes, putting the TIP50's in without the mounting pads generally destroys the large PC board, but you can (briefly) try it on a working Crack to see if it is still functional.
-PB
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Reheated all the 12AU7 terminals and no luck. I doubt the transistor will do anything. The only thing I can think of is a bad tube.
As far as the Speedball goes, putting the TIP50's in without the mounting pads generally destroys the large PC board, but you can (briefly) try it on a working Crack to see if it is still functional.
Is there any way to test if the PC beard is bad now? I don't have any shorts or disconnects so how would it be destroyed? All the lights were on without the pads. The spark is what shut the LEDs off.
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Listen to CB. The two TIP50 if installed without isolators will have been cooked because the matching heatsinks are grounded. You can use split half troubleshooting which was recommended to me when my large speedball board was suspect.
You can take out the large speedball board and restore the two original 3K Cathode resistors from the original crack configuration. This is advantageous in a couple different ways. If it isolates the issue you get to use your amp while you figure out what you want to do. You can either try replacing just the TIP50s, or the whole board. You can test the individual components easily enough with a multimeter. Just youtube search on testing transistors. I grabbed a bunch of backup parts including 10 TIP50s from mouser and the biggest expense was shipping.
Here was my experience: http://bottlehead.com/smf/index.php?topic=6368.0
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I'm getting a few TIP50s by next Monday. All three boards have been removed. The Crack is stock. The white noise is from the stock Crack. No Speedball is attached in any way.
Am I able to attach the two smaller PC boards and just leave the large PC board out, keeping the 3K resistors in for now, with no problems in sound assuming the two smaller boards are fine?
I tested everything and the only problem was the lower TIP50, where the LEDs where glowing strong.
I am looking to replace the tubes as well since I cannot find a solution to the noise.
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I'm getting a few TIP50s by next Monday.
The 2N2222's should be replaced also.
Am I able to attach the two smaller PC boards and just leave the large PC board out, keeping the 3K resistors in for now, with no problems in sound assuming the two smaller boards are fine?
Yes, but you should sort out the noise first.
I tested everything and the only problem was the lower TIP50, where the LEDs where glowing strong.
Better safe than sorry, I would also replace the 2N2222's.
I am looking to replace the tubes as well since I cannot find a solution to the noise.
Did you already replace the resistor in the power supply?
It wouldn't hurt to get a 2nd 6080. When you put the TIP50's on without the insulator, you basically allow the 6080 to draw all the high voltage current that the power supply can deliver until something breaks. A 6080 is a tough tube, but that's a pretty brutal operating condition.
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I'll replace the one resistor and then add the two smaller boards in to see if they work. Already placed my order for the TIP50s so unless I can find a 2N2222 on Amazon prime, I'll just wait and see if the TIP50 fixes it.
Any suggestions as to what the noise could be from? I know tubes are a bit noisier than SS, but is it supposed to be easily noticeable when the HP is plugged in?
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You could think of the cracked 270 Ohm resistor as a wounded part that may be too injured to properly perform what would be its primary task. (It could also be internally shorted a bit, which would bring up the noise floor)
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Noise did not go away with replacement. However, I have some discrepancies in voltage now. I measured before and after the resistor replacement and they both gave the same voltages:
5: 124V
9: 132V
A1: 124V
B4: 124V
B6: 132V
Also, if I put in the 2 small PC boards, should I removed the resistors at 1/2 and 4/5 first?
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Is only one half of your 12AU7 glowing now?
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No, both sides are glowing. Like I said, this was something that must have happened between the last voltage check a few days ago and today.
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Do T4 and T5 have the same voltage?
I'm guessing one of the LED's on the 9 pin socket isn't glowing also.
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Do T4 and T5 have the same voltage?
I'm guessing one of the LED's on the 9 pin socket isn't glowing also.
Both LEDs are lighting up. If you mean terminal 4 and 5 (the ones with U and L designations), then no. T4 is at 170V and T5 is at 128V.
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On a side note: there is a metal particle that will freely move inside the 6080 tube. This has been there ever since I remember flipping the tube upside down. I will get new tubes anyways since I would rather have the curvy look on the 6080 and get a quieter 12AU7.
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Carefully measure the voltage at A7 and A8.
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A7: 0V
A8: 1.6V
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On the up side, the white noise is now only in the left ear piece.
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How about A2/A3?
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A2: 0
A3: 1.5
I measured all of them. The ones I stated were the ones that were over the 10% difference from reference. The rest measured OK.
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Odd, if you have 0V at A2 and 1.5V at A3, your A1 voltage should be nice and low.
It's possible that you have a flaky 12AU7. Based on the nature of the way this thread has unraveled, can you confirm that you still have the 22K plate load resistors in? You might try retouching your solder joints around T4/T5.
-PB
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Yup, everything is stock Crack right now. I guess screw the tubes. Wasn't planning on having to roll them right away, but so be it.
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Nope, no luck with resolder.
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One last check - yank the 6080 and run the amp with just the 12AU7, then recheck T4 and T5. T4 will pop up, but maybe T5 will move down to where it should be.
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One last check - yank the 6080 and run the amp with just the 12AU7, then recheck T4 and T5. T4 will pop up, but maybe T5 will move down to where it should be.
T4: 240
T5: 139
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Can you compare those to T1/T2 with the 6080 out of the amp?
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Can you compare those to T1/T2 with the 6080 out of the amp?
T1:107
T2:240
T4:240
T5:139
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With 6080 in:
T1:88
T2:172
T4:172
T5:118
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I realize I should probably outline my thought process a little bit, as you're probably getting annoyed with my constant requests for voltages.
If we just consider the 12AU7 on its own with no 6080, we know you have 1.5V of cathode bias on both channels (which is good), 0V on the grids (which is also good), and then we can look at the voltage drop across the 22K plate load resistors for each half of the 12AU7.
1
On the T1/T2 side, you have 172V-88V=84V, this 84V is dropped across 22.1K, so Ohm's law says there's 3.8mA of current rolling through there. This is all OK.
On the T4/T5 side, you have 172V-118V=54V, across 22.1K, this is 2.4mA of current, which isn't particularly stellar.
Since this happens with the 6080 out of the tube socket, we can rule out tons and tons of random miswires, tube weirdness, and other issues that could take a few days of troubleshooting, and we can basically focus just on the 9 pin socket, and what might be happening there.
The last test, which should be nice and conclusive, would be to pop the red wires of T1 and T5, and wire them to the opposite terminals. These wires might not be long enough to reach, but you can temporarily tack in a jumper to make the connection, then see if the flaky voltage moves over to T1. If it does, the 12AU7 is just behaving a little weakly, and you can continue using it or send it in for an exchange. If the flaky voltage remains on T5, then there's likely a cold joint on that front 5-lug strip.
-PB
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With T1/5 switch:
T1:132
T2:170
T4:170
T5:96
If I exchange the 12AU7, do I just pay for shipping and do I have to send my tube in before I get the new tube?
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Yeah, just pop it in the mail, first class post is inexpensive and should get here quickly. We will take care of the outbound postage.
-PB
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Put in a new transistor on the lower large PC board and still all the LEDs are out except the two lower LEDs on the large PC board glow bright and the LED on A8 is lit.
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I suppose I should say I put in the SB again if that wasn't clear.
Should I try replacing the other TIP50, or is there something else wrong?
Can I keep the small PC boards in and just replace the large PC board with the two 10W 3K resistors?
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Removed the large board and replaced with the 3K resistors. All LEDs went on and I still have same bad voltages as before. However, now the sound in the left ear piece has cut out so it is very quiet now. No problems with distortion, just low volume in left ear.
All resistances OK.
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I would wait until you can exchange the 12AU7's before doing much more.
Also, you really ought to replace both the TIP50 and 2N2222 in the offending channel.
-PB
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I agree. LEDS that won't light are often fine but the corresponding 2n2222 is blown.
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The LEDs are not dead. They all light up slightly when I do a resistence check on them. They just will not light up when they are in the Crack.
I'll just get new transistors for all the boards.
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I'll suggest only replacing the transistor at the point where you are seeing the problem. They are a hassle to change out and if the rest are working OK it would probably the cleanest and least risky to just replace the bad one.
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I'll suggest only replacing the transistor at the point where you are seeing the problem. They are a hassle to change out and if the rest are working OK it would probably the cleanest and least risky to just replace the bad one.
Thanks, I'll keep the others as replacements just in case. Had to order $10 anyways to avoid $5 charge.
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Got an RCA Cleartop and voltages are good and noise is gone. Volume control is improved as well. Simply beautiful. I'll send my weak tube in for replacement tomorrow.
Thanks a lot PB. ;D
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Got an RCA Cleartop and voltages are good and noise is gone. Volume control is improved as well. Simply beautiful. I'll send my weak tube in for replacement tomorrow.
Thanks a lot PB. ;D
Did you replace the transistor AND the tube OR just the tube?
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Did you replace the transistor AND the tube OR just the tube?
Just the tube for now. The Speedball is out until tomorrow when I get my transistors.
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Switched out the lower TIP50 and 2N2222A transistors and I am still getting bright glowing LEDs on lower main board as well as the LED at A8 lighting up but normally.
The spark that caused this to happen originally was at T7, so would that affect the lower, upper, or whole main board. Should I try replacing upper transistors?
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What are your current voltages?
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Didn't measure them since I didn't want to leave it on in fear of damage. Is it safe to measure them?
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OK, after the test, the 5W capacitors were quite hot.
1:57
2:70
3:0
4:67
5:16
6:0
7:66
8:0
9:16
10:0
11:0
12:0
13:67
14:0
15:138
19:0
20:195
A1:18
A2:0
A3:1.4
A4:0
A5:0
A6:74
A7:0
A8:1.6
A9:0
B1:74
B2:67
B3:75
B4:19
B5:67
B6:17
B7:0
B8:0
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You still have a short somewhere drawing down the power supply. If you run it long enough, you will blow out the 270 Ohm resistors again.
Are you triple sure that the TIP-50 transistors aren't touching the heatsinks in any way?
-PB
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You still have a short somewhere drawing down the power supply. If you run it long enough, you will blow out the 270 Ohm resistors again.
Are you triple sure that the TIP-50 transistors aren't touching the heatsinks in any way?
-PB
I have 49 more 270K 270 ohm resistors so no worries there. Don't want to ruin a capacitor though.
And yes, the plastic fully surrounds the 4 edges of the TIP50s and carbon washers are between the screw and TIP50.
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I'm getting a 60K ohm reading on the collector to base on the new TIP50, which is on the bottom of the board.
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Just to clarify it's the 270 ohm 5W resistor PB is talking about, not a 270K ohm resistor.
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Just to clarify it's the 270 ohm 5W resistor PB is talking about, not a 270K ohm resistor.
Oops, I did mean the 270 ohm 5W resistor.
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So my TIP50 is attached to the heatsink by screw head>fibre washer>TIP50 plate>thermal pad>heatsink>flat washer>lock washer>bolt. Could it be possible that the screw is touching the TIP50's metal plate as it passes through the plates's hole, which would give it connection to the heatsink via the flat washer?
Also, even if the TIP50 is shorting, the LEDs should still light up. The LEDs light up when I first powered it up even though there were no thermal pads. The spark is what caused the LEDs to go out, so whatever the spark did is still not fixed.
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When I attach the black probe to the heatsink and red probe to either the collector, emitter, or TIP50 plate I get a resistance of 400M ohm for both TIP50s. The screw to heatsink and screw to TIP50 plate show no connection.
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At this juncture, the best bet is photos, and lots of them.
I would unscrew the big PC board and tip it to the side, then take a shot of the bottom. Also, the general wiring around the octal socket would be helpful.
-PB
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Hopefully this works.
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And if you thought that was the end...
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I thought of an easy test.
Pull the mounting kits off both TIP50 transistors and bend them away from the heatsinks.
Run the amp for ~30 seconds (not much more), then measure the power supply voltage at B2/B5.
If it stays up around ~160V, we have confirmed that you have a short between TIP50 and heatsink. In this case, maybe fresh mounting kits would be the way to go.
If it still pulls way down, I'll keep pouring over the photos.
-PB
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B2/B5: 67V
The problem has to be the SB since the stock crack ran fine on its own, so you could probably ignore half the photos.
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OK, let's do some process of elimination stuff here.
Go ahead and remount the TIP50's to the heatsinks with the kits.
There's a red jumper that goes from B+ to B+ on the big Speedball board. Yank that, then remeasure B2/B5.
-PB
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There's a red jumper that goes from B+ to B+ on the big Speedball board. Yank that, then remeasure B2/B5.
Same LEDs still lit. Voltage B2/B5: 71V
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Should I replace the remaining two transistors on the top main board or do you have any other tests?
I've checked over every circuit on the boards and everything is in place. The only issue is that there has to be a bad part that needs to be replaced.
I could also try removing the smaller or larger boards and replacing them with their corresponding resistors if that would help eliminate extra variables.
What is the next step?
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Running the amp without the 6080 and just the 12AU7 will allow you to test the functionality of the front two boards. Seeing 150+V at T2/T4 and something around 70-90V on T1 and T5 means that your small boards are good.
-PB
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6080 out gives:
1:80
2:230
4:229
5:77
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Yeah, this is indicative of a short on the large Speedball board.
You can put the 6080 back in, then try removing one of the "O" wires and running the amp.
Then try putting that "O" wire back and removing the other.
Let me know what you find.
-PB
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Top O out:
1:68
2:70
4:70
5:21
LEDs same
Bottom O out:
1:83
2:204
4:204
5:78
All LEDs on except the bottom main board LEDs are out and top LEDs are bright.
Also, both LEDs on the 12AU7 socket went on with the 6080 out. All board LEDs were out.
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Top O out:
1:68
2:70
4:70
5:21
LEDs same
That's the problem area.
Bottom O out:
1:83
2:204
4:204
5:78
All LEDs on except the bottom main board LEDs are out and top LEDs are bright.
That side is good.
Also, both LEDs on the 12AU7 socket went on with the 6080 out. All board LEDs were out.
The LED's on the small PC boards should've been lit up pretty brightly with the 6080 out. The LED's on the socket couldn't light unless this was the case.
-PB
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The LED's on the small PC boards should've been lit up pretty brightly with the 6080 out. The LED's on the socket couldn't light unless this was the case.
You are correct, they just weren't noticeable with my lights.
Should I replace both transistors on top then?
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I would go over that big board with a fine toothed comb. You have one side that is doing what it should, and one side that isn't. The most probable cause at this point is that two legs of a transistor on that side of the big PCB are soldered together.
-PB
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I would go over that big board with a fine toothed comb. You have one side that is doing what it should, and one side that isn't. The most probable cause at this point is that two legs of a transistor on that side of the big PCB are soldered together.
-PB
No visible connection or measured connecection with any of the transistor legs. Perhaps the TIP50 or 2N2222 is bad?
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Yeah, I suppose swapping them both out won't hurt anything.
-PB
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Replaced the top transistors and started it up. All LEDs were lit except the one at terminal 3. The bottom main board was strong. The top was very faint along with the small boards. The top may have been lighting the whole time, but it was so dim that I never noticed (had to turn off all lights. Started voltage check and it was in the 68V area for the first 2 terminals so I turned it off.
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Resistance check on bottom TIP50 (black/red probe):
E/C:15M
E/B:15M
C/B:81K
Top TIP50:
E/C:infinite
E/B:15M
C/B:13M decreasing to 4M and now rising
Brand new TIP50 out of circuit:
E/C:infinite
E/B:16M
C/B:13M
When I removed the lower TIP50 because I was going to replace everything (but only did the top instead) the lower TIP50 measured then same as the new, so I didn't replace it. It seems that something in the board is causing a short.
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Yeah, a less fuzzy photo of the bottom of the board might reveal something.
-PB
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I can't do any better. Only have a camera phone and a webcam. Webcam will do even worse.
I checked over all the joints. Everything matched the pictures in the instructions. The only thing noteworthy is that I initially installed the TIP50/heatsinks on the wrong side. When I took them out, the heatsink on the bottom of the board's inner joint (the one more towards the center) had the metal ring inside the hole come out. I scraped off the surface to get to the metal path and then soldered the heatsinks on the correct side. When I test for connectivity between the heatsink metal lugs, each one has connectivity to the other 3.
(You can kind of thee the bottom left heatsink joint extends on the board a bit to connect to the path.)
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Also, is it of any concern if I had the large board out and replaced it with the 10W resistors but sill had the smaller boards in and got hardly any power in the left ear. If the small boards are fine, should they work as replacements for the stock resistors on T1/2 and T4/5?
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Small boards out gives:
1:61
2:70
4:72
5:20
All lights on at first (of course bottom board strong), but then the light on A3 goes out after a few seconds of glowing. Issue is definitely the main board as you said.
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Large board out gives:
1:80
2:178
3:178
4:79
All LEDs on. Rest of voltages check OK for the Speedball manual. Some are a bit higher, but only 10% or so.
Sound is also OK. No distortions or noticeable issues vs the stock Crack.
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Yeah, with the big board out and the 3K/10W resistors in, the amp should work.
Beyond a problem on the big PC board, can you triple check the wiring hookup of the board itself? Depending on how your amp is wired, wiring one of the "O" pads to 6 or 10 accidentally could also cause your problem.
-PB
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Checked the four wires going into the large board and they are all in the correct place. Only thing I can think of is that one of the capacitors or wires is shorting T6/7 or T9/10, but then there should be some obvious voltage differences with the 3K/10W in, right?
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If one of the capacitors was shorted, the corresponding 2.49K resistor on the headphone jack would explode.
With the 3K/10W resistors in, your power supply voltage should pop back up, and you should have ~100V at 7 and 9.
-PB
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If one of the capacitors was shorted, the corresponding 2.49K resistor on the headphone jack would explode.
Good to know ;D
Yes, my voltages were around 108V for T7/9, so the issue is the large board. Could there be anything wrong with the large PC board itself? Like I said, I am getting different resistances when I compare the same points on the top versus bottom. All resistors check out, so there must be a short in the path.
And what I did with the heatsink lug is fine, correct? All lugs should have connectivity to each other.
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Yeah, the heatsink lugs isn't too much of an issue.
Yes, there is a short in there somewhere, and we have narrowed it down to one half.
You can measure between pairs of transistor legs on that half to see if you can identify a shorted transistor in the path.
Beyond that, replacing the big PC board might be the easiest option.
-PB
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My voltages on T1 is 82 V and on T5 is 78 V. Is this an issue.
I replaced the 5W 270ohm resistor over the transformer, but kept the other resistor on T13/15 in, which has a resistance of 290 ohm. Will replacing this resistor help?
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Resistance discrepancies:
Top TIP50 Base/Collector: infinite
Bottom: Jumps around 2K ohm
Top 2N222 Collector/Emmiter:9M
Bottom:infinite
Top TIP50 emmitter/31.6ohm joint closer to end of board:9M
Bottom:infinite
Same for TIP50 emitter to 2N222 emitter.
Hopefully that's enough.
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My voltages on T1 is 82 V and on T5 is 78 V. Is this an issue.
The manual specifies 75-90V.
I replaced the 5W 270ohm resistor over the transformer, but kept the other resistor on T13/15 in, which has a resistance of 290 ohm. Will replacing this resistor help?
290 Ohms is within the tolerance of the part. This is not where your problem is, we are already quite certain that your problem is on the top half of the large Speedball PC board.
-PB
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Resistance discrepancies:
Top TIP50 Base/Collector: infinite
Bottom: Jumps around 2K ohm
Top 2N222 Collector/Emmiter:9M
Bottom:infinite
Top TIP50 emmitter/31.6ohm joint closer to end of board:9M
Bottom:infinite
Same for TIP50 emitter to 2N222 emitter.
Hopefully that's enough.
None of these are showing shorts, but you don't have all the measurements. Each transistor should be measured for:
collector/emitter resistance
collector/base resistance
emitter/base resistance
-PB
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The manual specifies 75-90V.290 Ohms is within the tolerance of the part. This is not where your problem is, we are already quite certain that your problem is on the top half of the large Speedball PC board.
-PB
I get that, I'm just seeing if there should be any other issues that reduce problems down the line.
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None of these are showing shorts, but you don't have all the measurements. Each transistor should be measured for:
collector/emitter resistance
collector/base resistance
emitter/base resistance
-PB
Yes, I measured everything, I only put down discrepancies though. The rest were either infinite or ~15M and dependent on whether the red or black probe was attached (switching from 15M to infinite when probes were switched). I'll measure them if you like.
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When they blow, they blow shut, so you would measure between two legs and see something very close to 0 Ohms.
If your meter has a continuity beep, that is the setting to use to check for this.
-PB
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Continuity test (Black/Red probe):
Top:
C/B:.6
E/B:.6
Rest are not connection.
Bottom:
B/C:1.3
C/B:.6
E/B.6
E/C:.6
Rest are no connection.
New:
C/B:.6
E/B:.6
Rest are no connection
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2N2222 (Black/Red probe):
Top:
C/B:.66
E/B:.66
Rest are no connection.
Bottom:
C/B:.66
E/B:.66
Rest are no connection.
New:
C/B:.66
E/B:.66
Rest are no connection
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Bottom TIP50 out of board (Black/Red probe):
C/B:.6
E/B:.6
Rest are no connection.
Transistors are fine. Something else is funky.
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Yeah, perhaps you could borrow a camera from a friend this week to nab some decent photos of the PCB?
-PB
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Yeah, perhaps you could borrow a camera from a friend this week to nab some decent photos of the PCB?
-PB
Could you tell me what to look for on the board for now?
If anything, the top of the board is in better condition than the bottom. I also disconnected the red and black wires so the two parts of the board are completely separate. Took both TIP50s out and they were fine. Only one that changes readings is the bottom one when I put it in the board, but the top is the problem.
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I really don't know what other options there can be. There aren't a ton of options left for what's wrong, but you have one half of the board that works, one half that doesn't.
One other thing you can do is to flip the board around, so that the "Top" side is facing the other way, then see if the same side of the board continues to give you the same problem.
Beyond that, it's a matter of what's different between the non-working side and the functional side.
-PB
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Replaced both TIP50s. Same resistance for the TIP50s on board (meaning the good side of the board changed its connectivity again when put in). Everything is opposite by switching the board around. What is now top LEDs are on. However, the LED closer to center in what is now bottom board is on and lights up immediately. The one towards edge is out. Right small board and A3 LEDs are on. A8 has a very faint glow. Don't know if reflection or just barely on.
T1:20
T2/4/5:70
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I'll be damned. My webcam takes better close-ups than my phone. Hopefully these work.
And the 2N2222s are not connected either visually or via multimeter.
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First things first, your TIP-50 transistors are not mounted correctly, with those long legs exposed, you're asking for trouble. They also may be harder to solder in properly like that.
In photo 2, I see what looks like two solder blobs on the 2N2222 touching each other.
In photo 2, I can see that the TIP-50 legs aren't poking through the solder pads, this could really cause some problems.
In photo 4, I can see a similar solder blob on the 2N2222, it would be a good idea to get that off and trim the lead nice and short.
-PB
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First things first, your TIP-50 transistors are not mounted correctly, with those long legs exposed, you're asking for trouble. They also may be harder to solder in properly like that.
In photo 2, I see what looks like two solder blobs on the 2N2222 touching each other.
In photo 2, I can see that the TIP-50 legs aren't poking through the solder pads, this could really cause some problems.
In photo 4, I can see a similar solder blob on the 2N2222, it would be a good idea to get that off and trim the lead nice and short.
-PB
2N2222s aren't connected but I will clean it up. Maybe there is a jump in electricity?
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Still the same 70 70 70 20 V after cleaning it up. However, the lights on the top board do go on, it is just very dim so I never noticed before. LED on A3 lights up with rest of LEDs, but then goes out.
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We can sell you half of a Speedball, that might be the best route to go for now.
-PB
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We can sell you half of a Speedball, that might be the best route to go for now.
-PB
Would I have to buy half the kit. Could I just get the PCB?
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Would this work: http://www.avagotech.com/pages/en/leds/subminiature_lamps/domed-resistor_led_series/hlmp-6000/ (http://www.avagotech.com/pages/en/leds/subminiature_lamps/domed-resistor_led_series/hlmp-6000/)
Also, there is two other versions that have the suffix E0010 and G0010. Are they all usable?
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You want the HLMP-6000 without any suffix.
You'll have to contact replacementparts(at)bottlhead(dot)com in terms of what's available.
-PB
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Finally got a chance to go at it again. Replaced the board and everything lit up with some decent voltages. Only deviations are as follows:
T15:206V
T19:84V
T20:0V
T21:225V
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I suppose I should specify. I replaced the large PCB only. All the transistors, resistors, heat sinks, etc. where removed from the old and put in the new large PCB. What is the next step in diagnostics?
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T19 has no voltage measurement in the manual.
T20 is supposed to be 0.
Your voltages look pretty good, I wouldn't sweat it.
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My SB manual says the following:
T15:185V, this is pretty close to measured so I can live with that
T19:0V
T20:206V
There is no T21 listing in the manual but I figured I would measure it since it seemed there was something wrong in that area.
Was the Speedball manual updated recently?
Are you looking are the stock Crack manual because that seems to match your description?
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What is the date on your Speedball manual?
Revision 2-3-14 shows:
T15 - 185V (185V + 15% is 212.75V)
T19 - not listed
T20 - 0V
T21 - 206V
-PB
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SB revision 04-23-13.
Is it possible to get the new version online?
And any other changes I should be worried about before I run this thing?
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If you PM me with your e-mail, I can send along a download link to the new manual.
That voltage issue was a transcription error in that table I believe, there isn't anything awry beyond a few shifted voltages.
-PB
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When measuring the tip or ring on the TRS jack, the voltage is 47V for a half second when the power is switched on, and then goes to 14V or so for another half second and then it measures below 8V decreasing to 0V after ~15 seconds. Voltage goes to -14V when switched off and then back to 0V soon after. Is this a concern?
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Nope, the spike is very brief and is significantly lower with cans plugged in. There's a sticky on the Crack board related to modifying the amp to eliminate this if you prefer.
-PB