Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: shroomalistic on April 19, 2023, 05:57:10 AM
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Hi guys, having issues. Something is definitely not right here
T01: -.9
T02: -.9
T03: 0
T04: -.9
T05: -.9
T06: 0
T07: 0
T08: 0
T09: 0
T10: 0
T11: 0
T12: 0
T13: -.9
T14: 0
T15: -.9
T16: 0
T17: 0
T18: 98.4
T19: 98.4
T20: 0
T21: 241
T22: 0
I get errors when i try to attach a picture
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T15: -.9
T21: 241
Terminals 15 and 21 are connected with a 270 ohm resistor. One end of that resistor is loose or poorly soldered.
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Terminals 15 and 21 are connected with a 270 ohm resistor. One end of that resistor is loose or poorly soldered.
I thought there was something wrong with that resistor, its dead. solders are great on it, it got super hot and i burnt my finger on it.
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any suggestions where to buy replacement?
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That resistor will only die if there's a catastrophic short, which should show up in your resistance checks. Just buying another one and replacing it will lead to more dead resistors. Is the other 270 ohm resistor in-tact? Usually that is the one that fails first.
Is that black wire that's supposed to go to 14U going to 15U instead? How were your resistance checks?
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resistant checks were all spot on. its the insulation pulled back off the wire there, its going to 14u
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looks like both resistors are dead. getting nothing from both when checking them
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Are pins 1 and 2 touching on the 9 pin socket?
Having both resistors burnt means that your resistances at terminals 2, 4, B2, and B5 should not measure correctly. Can you let me know what resistance values you get at those terminals?
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it does nothing when i measure between 12u and 2,4,b2, b5. man i hope im not reading my meter wrong. does the * in the manual mean there should be no resistance?
a1,and a2 dont touch pretty close but there is room for movement and still not connect
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No resistance would be 0 Ohms, which would be a short. If your meter says "OL", that would mean infinite resistance, which is desired.
For the resistors to go from 270 ohms to open without the cement housing cooking and falling off means they were shorted to ground, so this issue has to be found before replacing them. This doesn't happen on its own without a cause.
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would the cap being reversed do that, i had the wrong cap on 14u, 15u. didnt realize it they were all different. I then switched it with the right one and put it in backwards but I thought i caught it before powering up
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Yes, a backwards electrolytic will create a dead short.
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Just to clarify the electrolytic caps aren't all different. There are just two values supplied in the kit. The caps in the power supply around the power transformer are three 220uF 250V capacitors and the output coupling caps by the 6080 socket are two 100uF 160V capacitors.
Once power has been applied to a power supply filter cap that has been installed backwards it has been stressed to a point that it should probably be replaced even if it still seems functional.
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so i should buy new caps too?
Sorry, Im completely blind in one eye and a my other is going bad from old age. Its making this a real challenge for me even with magnifying glass
do you have suggestions on where to buy the parts?
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You can e-mail replacementparts(at)bottlehead(dot)com regarding these parts if you'd like to get them from us.
Otherwise these are what you need:
https://www.mouser.com/ProductDetail/Xicon/280-CR5-0.27-RC?qs=SXXIg1eCKOp1bN5Y9Kl0jA%3D%3D (https://www.mouser.com/ProductDetail/Xicon/280-CR5-0.27-RC?qs=SXXIg1eCKOp1bN5Y9Kl0jA%3D%3D)
https://www.mouser.com/ProductDetail/Nichicon/UCY2E221MHD3?qs=Ajmft%252BTTukEz8LAZjX8PHg%3D%3D (https://www.mouser.com/ProductDetail/Nichicon/UCY2E221MHD3?qs=Ajmft%252BTTukEz8LAZjX8PHg%3D%3D)
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got the new parts in, things are still off
T01: 84
T02: 215
T03: 0
T04: 213
T05: 196
T06: 0
T07: 122
T08: 0
T09: 195
T10: 0
i replaces all the caps at the power supply side and both wirewound resistors
LED's are not lighting also
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You kind of have to have one LED lit to have 84V at terminal 1.
The 196V at terminal 5 means that either the solder joint at A4/A5 isn't well soldered (which will cause one side of the 12AU7 not to glow) or the LED is open (this can happen from too much heat during soldering/resoldering). Posting your DC voltages at A3 and A8 can help clarify which problem you have.
The voltage issue at terminal 9 is an odd one and has me wondering if the octal socket is oriented properly (looks good in your photo) or possibly if the plastic keyway is snapped off of the 6080 tube. If they keyway isn't broken, it could still be shoved in really hard and be off two pins which would short pins 5 and 6 together on the octal socket and provide the voltage issue you're experiencing.
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i got 0v at A3 and A8
check the socket and tube, both are in right. Tried one of my old 6080's also and still same voltage.
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Pull the 6080 and recheck the voltage at terminal 9 to let us know if it changes with no 6080.
You can't have 0V at A3 and A8 and 84V at terminal 1. If your meter isn't auto ranging and it only has a higher voltage DC ranges, then it may not be able to resolve the ~1.5V or so that should appear at both A3 and A8.
Still, the 0V would tend to indicate a soldering issue at A4/A5.
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With 6080 out, i get 0v at terminal 9
I can try to reflow a4 and a5, but when i test them I get the same 3.2v at each
let me know if you need pictures of anything to help.
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redid a4 and a5 still same results.
my meter is a sperry dsa-500. its about 25 years old, used it in my old heating and ac days
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my brother dropped off his multimeter,
T01: 190
T02: 207
T03: 0
T04: 208
T05: 191
T06: 0
T07: 192
T08: 0
T09: 191
T10: 0
a3: 0
a4: 3.1v
a5: 3.1v
a8: 18v
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i double check the new wire resistors and they were grounded. UPS says the package was damaged in transit.
I had a couple more that ordered off ebay and they are working
T01: 144
T02: 160
T03: 0
T04: 160
T05: 145
T06: 0
T07: 144
T08: 0
T09: 145
T10: 0
a3: climbs slowly till it hits 200 then starts over
a4: 3.1v
a5: 3.1v
a8: 14.4
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i checked the 12au7 for resistance
saw in another post to check a9 to a4 and a9 to a5
a4 is 0
a5 is 7
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Your voltages have now gotten worse and neither side of the 12AU7 is conducting. Can you verify that the 12AU7 tube itself is glowing? You could also have loose wiring at B7/B8 or where the green wires land on the power transformer.
The 14.4V at A8 suggest that the LED there is damaged, and this happens from excessive heat being applied to the LED during soldering.
A3 can't climb to 200V, as there isn't a source in the amp for 200V DC.
Looking at your build photos again, A9 does not look particularly well soldered.
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looks like only one side of the 12au7 is glowing but im not sure what it would look like with both sides?
I bought a magnifying/light arm to help me threw the rest of this, should have did that first. I can actually see what im doing now.
I have another 12au7 on the way and ordered new leds from you guys.
i had to put everything up for now and only have a few hours window a day. Cant have it laying out with 4 kids running around.
Ill resolder a9 first thing tomorrow. Plus ill have a new multi meter here tomorrow also.
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Forgot to tell you guys, THANK YOU SO MUCH FOR HELP!
I really appreciate the time you are taking here.
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If one half of the 12AU7 is glowing, definitely recheck the joint at A4/A5. If it's loose at one of those connections, that will cause half of the tube to not light up.
-PB
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i have checked that multiple time and reflowed it.
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You can pull the 12AU7 out and check the DC resistance between pins 9 and 4 and pins 9 and 5. It should be a very low value.
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i checked the 12au7 for resistance
saw in another post to check a9 to a4 and a9 to a5
a4 is 0
a5 is 7
I did that too
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Is that the socket pins or the pins on the tube itself?
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tube its self, its not zero, there is just nothing on pin a4 to a9
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OK, zero would be the opposite of nothing, which is infinite.
It's possible that the tube pins are a bit oxidized, and inserting them into a lump of steel wool a few times may clean them enough to restore operation.
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cleaned up the pins and still nothing on a4 to a9, a5 to a9 still gives me 7
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It would be a good idea to try a different 12AU7 tube next. Can you post pictures of the 12AU7 you have?
A bad 12AU7 still doesn't explain why you had such high voltage on terminal 9, but we'll address that when the front half of the amp is working properly.
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No clue when the nos tube will be here, ordered it off ebay.
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so did i kill my tube? Im a little worried now, should i put the new one in when i get it?
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It would be very difficult to damage that part of the tube. I would just give the replacement a go to see if both its halves light up.
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who would i contact to get another 12au7 tube? Not sure whats going on with my ebay one. If i can purchase or get a replacement from you guys, I already have an order in for the LED's
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I don't know that BH sells tubes. If not, and you're leery of ebay, I recommend the online vendor Tube World. Not the cheapest prices, but every tube has its test results provided on the website. That's rare. The '60s Sylvania for $24.99 is what I'd get if I were you, but there are lots of good options for under $50.
https://tubeworldexpress.com/collections/preamp/12AU7 (https://tubeworldexpress.com/collections/preamp/12AU7)
Tube World ships quickly as well.
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You can contact replacementparts(at)Bottlehead(Dot)com regarding this issue. Be sure to post a link to this support thread with your request, along with your name and your order number if possible.
-PB
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so while im waiting for a new 12au7 to come in.... ebay guy still hasnt shipped, Im getting a short on the trs jack at the resistors. Should I desoldier the resistors to see if they are bad? I was looking at mouser for replacements but im not sure exactly what to get. 2.49k ohm 1/4w, but will any of them work if they are threw hole? I kinda want to start all over now just to be safe and now that i have the magnifying glass and all. When I place my leads on both sides of resistors, they read 0.00. The 270k 1w resistor read OL but I think thats because it hooked up with the cap?
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The jack shorts the outputs intentionally when no headphones are plugged in, so there's no issue there.
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new 12au7 is in
not sure if voltages are closer or not
1 - 147
2 - 168
3 - 0
4 - 168
5 - 148
6 - 0
7 - 146
8 - 0
9 - 147
10 - 0
a-3 13.1
a-4 3
a-5 3
a-8 13.8
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You need to replace both LEDs on the 9 pin socket and double check that the black wire going to the center pin of the 9 pin socket is well connected and well soldered on both ends.
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LEDs should be here sometime today, ive already got everything unsoldered there now.
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Finally, its working!!!!!
THANK YOU PAUL!!!!!!!!!!
Got the LEDs in there all nice and neat and all voltages got into line.
Thank you so much for walking me threw this and putting up with my crap.
Time to sell my darkvoice
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Sweet!