Please help! Fuse blows immediately; can't find issue.

TheCoolDoc · 3453

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Offline Strikkflypilot

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Reply #15 on: January 16, 2015, 07:43:40 PM
Can't be sure from the pictures but it looks like a short between A7-A8.
Check that there is good clearance between leads that aren't supposed to be soldered together.
After that do a voltage test and we might find out why the 6080 isn't glowing.

Home system:
Sources: Ibasso DX90, Google Chromecast Audio optical out
DAC: Schiit Gumby
Amp: Bottlehead Mainline
http://bottlehead.com/smf/index.php?topic=7463.0
Phones: HD800S

Office:
Sources: Iphone/ Ipod
DAC: Dragonfly Red+Jtrbug
Amp: Crack/Speedball heavily modded
Phones: HD580,HD600 grilles


Offline TheCoolDoc

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Reply #16 on: January 16, 2015, 07:58:48 PM
Can't be sure from the pictures but it looks like a short between A7-A8.
Check that there is good clearance between leads that aren't supposed to be soldered together.
After that do a voltage test and we might find out why the 6080 isn't glowing.

Just made sure the A socket terminals were completely fine. Still getting B3, B6, 7 and 9 as 0 on the voltage test. Every other reading is higher than it should be. Still no glow.



Offline Strikkflypilot

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Reply #17 on: January 16, 2015, 08:08:36 PM
How much higher?
Can You write up the voltages that are off by more than 10-15%?

Home system:
Sources: Ibasso DX90, Google Chromecast Audio optical out
DAC: Schiit Gumby
Amp: Bottlehead Mainline
http://bottlehead.com/smf/index.php?topic=7463.0
Phones: HD800S

Office:
Sources: Iphone/ Ipod
DAC: Dragonfly Red+Jtrbug
Amp: Crack/Speedball heavily modded
Phones: HD580,HD600 grilles


Offline TheCoolDoc

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Reply #18 on: January 16, 2015, 08:12:39 PM
Terminal Voltage (VDC unless otherwise specified)
1 75-90 = 99
2 170 = 240
4 170 = 240
5 75-90 = 99-100s
7 100 = 0
9 100 = 0
13 230s
15 240s
21 230s
A socket readings are supposed to be 90 but are 100
B1 90 = 100s
B2 170 = 240s
B3 100 = 0
B4 90 = 100s
B5 170 = 240s
B6 100 = 0




Offline Strikkflypilot

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Reply #19 on: January 16, 2015, 08:36:26 PM
Not sure, but might be that a cap or such is shot.
Suggest awaiting answer from Caucasian Blackplate

Btw, is the lead from the ceramic resistor (going from 15 to 21) touching the 4 connector from the power transformer?
« Last Edit: January 16, 2015, 09:17:48 PM by Strikkflypilot »

Home system:
Sources: Ibasso DX90, Google Chromecast Audio optical out
DAC: Schiit Gumby
Amp: Bottlehead Mainline
http://bottlehead.com/smf/index.php?topic=7463.0
Phones: HD800S

Office:
Sources: Iphone/ Ipod
DAC: Dragonfly Red+Jtrbug
Amp: Crack/Speedball heavily modded
Phones: HD580,HD600 grilles


Offline TheCoolDoc

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Reply #20 on: January 17, 2015, 05:49:28 AM
Not sure, but might be that a cap or such is shot.
Suggest awaiting answer from Caucasian Blackplate

Btw, is the lead from the ceramic resistor (going from 15 to 21) touching the 4 connector from the power transformer?

It is not even though it seems like so. Would it have caused the issue if it had touched in the past?

Btw, are these voltages in anyway safe for listening?



Offline Strikkflypilot

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Reply #21 on: January 17, 2015, 07:17:38 AM
The voltages are way out of specs. Wait till the experts are back. It seems no power is exiting the 6080 for the headphones, maybe the tube itself is broken. As I understand, heater voltage is applied as the 12AU7 lights up on both sides although the 6080 remains unlit.
« Last Edit: January 17, 2015, 07:47:23 AM by Strikkflypilot »

Home system:
Sources: Ibasso DX90, Google Chromecast Audio optical out
DAC: Schiit Gumby
Amp: Bottlehead Mainline
http://bottlehead.com/smf/index.php?topic=7463.0
Phones: HD800S

Office:
Sources: Iphone/ Ipod
DAC: Dragonfly Red+Jtrbug
Amp: Crack/Speedball heavily modded
Phones: HD580,HD600 grilles


Offline TheCoolDoc

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Reply #22 on: January 17, 2015, 07:51:12 AM
The voltages are way out of specs. Wait till the experts are back. It seems no power is exiting the 6080 for the headphones, maybe the tube itself is broken. As I understand, heater voltage is applied as the 12AU7 lights up on both sides although the 6080 remains unlit.

Yes it seems so. I've checked multiple times to make sure the tube is plugged in properly. For resistance readings I'm now getting overload on terminals where * is the targeted reading. Earlier I was getting it in the 100s. (1, 2, 4, 5, 13). Is this because of re-soldering?

I tried testing the voltages without the 6080 plugged in and still got wacky T1-T5 readings (higher than it should be). Then I properly plugged it back in and still no luck. T 7 and 9 are 0.



Offline Strikkflypilot

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Reply #23 on: January 17, 2015, 08:07:04 AM
If You want, You can test the individual caps by setting Your meter to ohms, unplugging the amp from the mains of course, and attach the test leads on either side of the caps, so the caps get charged by the battery in Your meter. Switch the leads, and the opposite happens.
If they react like this, at least the caps most likely are ok.

Home system:
Sources: Ibasso DX90, Google Chromecast Audio optical out
DAC: Schiit Gumby
Amp: Bottlehead Mainline
http://bottlehead.com/smf/index.php?topic=7463.0
Phones: HD800S

Office:
Sources: Iphone/ Ipod
DAC: Dragonfly Red+Jtrbug
Amp: Crack/Speedball heavily modded
Phones: HD580,HD600 grilles


Offline TheCoolDoc

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Reply #24 on: January 17, 2015, 08:18:25 AM
If You want, You can test the individual caps by setting Your meter to ohms, unplugging the amp from the mains of course, and attach the test leads on either side of the caps, so the caps get charged by the battery in Your meter. Switch the leads, and the opposite happens.
If they react like this, at least the caps most likely are ok.

Just tested all 5 capacitors and they're working I think. Got the 5s range for the blue ones attached to the octal socket terminal and for the three large ones I got 20s range and rising. Tested with the black/common prong on negative terminal at 2000kohms.

EDIT: Resistance check is back to normal, however, I've attached pictures of my tubes incase you were curious. I'm still not getting any voltage at 7 and 9, b3 and b6.
« Last Edit: January 17, 2015, 08:41:48 AM by TheCoolDoc »



Offline Paul Birkeland

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Reply #25 on: January 17, 2015, 08:43:29 AM
B7/B8 are the connections that make the 6080 glow.  Try reheating them.  Your voltages will be pretty high until the 6080 is conducting.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline TheCoolDoc

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Reply #26 on: January 17, 2015, 08:59:42 AM
B7/B8 are the connections that make the 6080 glow.  Try reheating them.  Your voltages will be pretty high until the 6080 is conducting.

-PB

Still no luck. Is the tube abnormal? The 6080 tube isn't getting hot anymore either now.



Offline fullheadofnothing

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Reply #27 on: January 17, 2015, 09:11:29 AM
That 6080 is gassy and will not work. You mentioned in your that you had to force it into the socket, you may have broken the glass while doing so. Was it always white at the top, or was it silvery when you first got it?

Joshua Harris

I Write the Manuals That Make The Whole World Sing
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Offline TheCoolDoc

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Reply #28 on: January 17, 2015, 09:13:06 AM
That 6080 is gassy and will not work. You mentioned in your that you had to force it into the socket, you may have broken the glass while doing so. Was it always white at the top, or was it silvery when you first got it?

It was always white, which is why I never considered it being dysfunctional. When it heated up that gave me even more conformation that it was perfectly fine. I never forced it in, it was just harder than I would find comfortable with a glass object, but it was snug.



Offline fullheadofnothing

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Reply #29 on: January 17, 2015, 09:22:53 AM
Email replacementparts at bottlehead dot com for a replacement of the 6080. It will go out on Tuesday.

Joshua Harris

I Write the Manuals That Make The Whole World Sing
Kit Packer Emeritus