Salas hotrodded blue DCB1 build - Page 140 - diyAudio
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Old 7th October 2011, 04:30 AM   #1391
Salas is offline Salas  Greece
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DC on drain of one fet +V. DC on source of other fet -V. AC after pot continuing to 220R to gate of the +V fet, AC exiting to the other 220R between the two fets, AC on the output of engaged relay to RCA out.
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Old 7th October 2011, 02:32 PM   #1392
cersepn is offline cersepn  United States
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DC on drain of one fet +V. DC on source of other fet -V. AC after pot continuing to 220R to gate of the +V fet, AC exiting to the other 220R between the two fets, AC on the output of engaged relay to RCA out.
Okay.. this is real odd.
DC on fets - yes
AC after pot - yes
AC exiting 220R - no reading; AC reads as 0. I thought i was not probing it properly but it was connected properly.

I took out all the resistors and relay. Bought extra resistors the first time round and have an extra relay on hand, so might as well give it a go... fingers crossed it works
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Old 7th October 2011, 03:23 PM   #1393
cersepn is offline cersepn  United States
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Okay.. now i'm completely clueless.

I replaced the relay and all the resistors in the input and output section. Still the same problem, right channel with very very little volume and left channel 100% functioning. Fets measure fine too. RCA sockets have good solder connections. Unless it's possible for a RCA socket to spoil... ?

Anything else i should be trying?
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Old 7th October 2011, 05:09 PM   #1394
rmsds is offline rmsds  Portugal
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Originally Posted by cersepn View Post
I replaced the relay and all the resistors in the input and output section. Still the same problem, right channel with very very little volume and left channel 100% functioning. Fets measure fine too. RCA sockets have good solder connections. Unless it's possible for a RCA socket to spoil... ?

Anything else i should be trying?
I'm really just guessing here, but I've seen similar symptoms ("very very little volume") in other devices in case of a short circuit between signal and ground.
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Old 7th October 2011, 05:17 PM   #1395
Tea-Bag is offline Tea-Bag  United States
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I'm really just guessing here, but I've seen similar symptoms ("very very little volume") in other devices in case of a short circuit between signal and ground.
I've had a similiar issue, but it was amplifier speaker out hitting chassis ground.
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Old 8th October 2011, 08:41 AM   #1396
syklab is offline syklab  Hong Kong
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*If someone is perfectionist about matching the Verf LED gangs of 5, the best maniac party trick is to use a *12V battery, connect gate and source together in the specific 2SK170s that are going to feed those strings (those Jfets above 1R), feed (+) to the drain, connect g&s node to LEDS string, return string's other end to (-), and swap between enough glow bugs until you got 2 total across 5 LEDS Voltage matches, each to its own Jfet. For the cherry on the cake set DVM that measures diode drop (some got it) and find 2 Vbe matched BC550 & 560.
Practical benefit? Next to nothing. Aesthetic ritualistic benefit? Priceless.

*9V,1.5V,1.5V batteries in series that are common types, maybe already in remote controls on the coffee table, will do for 12V total. And don't post pics from the parking space tapping on the car's stuff.
Hi Salas,

Can I measure point A and B for Vf on the LED string for getting 2 sets of 3 LED strings with the closest value?

Click the image to open in full size.
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Old 8th October 2011, 11:42 AM   #1397
Salas is offline Salas  Greece
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Yes.
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Old 8th October 2011, 03:27 PM   #1398
cersepn is offline cersepn  United States
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Okay.. now i'm completely clueless.

I replaced the relay and all the resistors in the input and output section. Still the same problem, right channel with very very little volume and left channel 100% functioning. Fets measure fine too. RCA sockets have good solder connections. Unless it's possible for a RCA socket to spoil... ?

Anything else i should be trying?
Okay.. i replaced the RCA socket and still not working.

Does anyone have any more suggestions pretty please? I'm at my wit's end...
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Old 8th October 2011, 04:27 PM   #1399
Salas is offline Salas  Greece
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What happens if you swap channels?
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Old 12th October 2011, 04:53 PM   #1400
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maybe this is a st@p$d question, but if this is the hotrodded version, than what is the original and where can i find it?

kind regards, Mat
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