Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,401
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Post by Bigman80 on Mar 14, 2020 0:23:42 GMT
are they the smd ones ? Got a multimeter but what do i measure for? Anything lol. Alan will know the exact figures etc, have to wait for his input Check the wiring on the valve bases too, if its solid core, or can pop off with the heat changes |
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Post by firebottle on Mar 14, 2020 8:09:38 GMT
Did the sound stop immediately or just fade out? If a fade then there is probably a problem on the high voltage supply.
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Post by electronumpty on Mar 14, 2020 8:52:19 GMT
Did the sound stop immediately or just fade out? If a fade then there is probably a problem on the high voltage supply. Well I was in the next room and it seemed sudden. but cant really be sure. I swpped the pcc88s in case it was the valves and still no joy I dont have a spare ecc83 though to try. But they all glow strongly. Voltage going in is ok so its something on the board. |
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Post by nuff on Mar 15, 2020 11:30:43 GMT
Not good! I hope you've sorted it out.
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Post by electronumpty on Mar 15, 2020 11:44:31 GMT
Have had time to look at it yet, will try today probably.
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Post by electronumpty on Mar 15, 2020 17:34:31 GMT
ok so checked all the resitance of the power caps from the cap lugs to the point on the pcb where the leads are soldered all ok.
Checked the same for the valve holders from the socket to the corresponding point on the pcb where the flying leads are attached , all ok.
All valves glow fine.
Checked the voltage again when it enters the voard , it reads 173v and 18.1 so seems ok?
Not sure what else to look at really but I have tidied some of the soldering on the caps leads and the wire lengths so will plug in again and see what happens!
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Post by electronumpty on Mar 15, 2020 18:25:30 GMT
Still no outputs, think its gone into self isolation 😔
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Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,401
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Post by Bigman80 on Mar 15, 2020 18:57:23 GMT
Still no outputs, think its gone into self isolation 😔 I had that before, it was the fets. send me your address and i'll post you a couple down. They are Chinese BF862's so may not last forever, but they will be ok to show you whats up. |
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Post by firebottle on Mar 15, 2020 19:04:47 GMT
There is a 47 ohm resistor from one of the fet legs to ground.
You should get around 0.23 to 0.27 volts across this resistor, if you have the first stage is working OK.
If you haven't it doesn't mean the fet could be at fault, it could be another part of the first stage or the high voltage isn't making it to the first stage.
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Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,401
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Post by Bigman80 on Mar 15, 2020 19:08:06 GMT
There is a 47 ohm resistor from one of the fet legs to ground. You should get around 0.23 to 0.27 volts across this resistor, if you have the first stage is working OK. If you haven't it doesn't mean the fet could be at fault, it could be another part of the first stage or the high voltage isn't making it to the first stage. Ah..... |
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Post by electronumpty on Mar 15, 2020 19:21:54 GMT
Thanks Chaps, I'll give the resister a measure tomorrow to see what's up.
Cheers EN
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Post by electronumpty on Mar 16, 2020 12:43:36 GMT
ok so one side measured 35.6 mv and the other 29 mv
Is it worth changing the FETs?
ta
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Post by firebottle on Mar 16, 2020 13:16:48 GMT
That is low, however it would be good to know the High voltage is correct first.
There is a 3.3K resistor from each first stage anode. Measure from each end to ground (carefully), one end should have around 110V, the other end less. If you haven't got this voltage then there is another problem.
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Post by electronumpty on Mar 16, 2020 14:01:09 GMT
Thanks Alan will do
Cheers Andy
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Mar 16, 2020 14:04:16 GMT
The fact you are still posting is a good sign that you have not found 200V with your fingers.
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Post by electronumpty on Mar 16, 2020 14:08:48 GMT
The fact you are still posting is a good sign that you have not found 200V with your fingers.  Electronumpty by name Electronumpty by natu BBBBBZZZZTTT……. |
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Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,401
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Post by Bigman80 on Mar 16, 2020 14:42:39 GMT
The fact you are still posting is a good sign that you have not found 200V with your fingers. Haha brill. Love that |
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Deleted
Deleted Member
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Post by Deleted on Mar 16, 2020 14:42:49 GMT
I wish I had a BB3 to build at the moment. It looks like France is going to be shut for a month.
I think home deliveries are still on, but it is going to be difficult finding things to keep me occupied.
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Post by electronumpty on Mar 16, 2020 15:01:11 GMT
ok so this is r106,206 they measure 4.11v and 3.98v respectively which I guess means its not the fets?
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Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,401
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Post by Bigman80 on Mar 16, 2020 15:18:55 GMT
I wish I had a BB3 to build at the moment. It looks like France is going to be shut for a month. I think home deliveries are still on, but it is going to be difficult finding things to keep me occupied. Ahem...... Lol I may have 1 left over from the group buy. Won't know for sure until they arrive, which I have no idea when that will be. I'll keep you in mind |
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Post by firebottle on Mar 16, 2020 17:07:18 GMT
ok so this is r106,206 they measure 4.11v and 3.98v respectively which I guess means its not the fets? Do you mean that is the voltage across the 3.3K resistor or from one end to ground, zero volts? Either way that isn't right. Across the resistor should be in the region of 18V, but more importantly is there about 110V from one end to ground? |
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Post by electronumpty on Mar 16, 2020 18:12:00 GMT
Hi Alan
I measured from 1 end to ground I used the heat sink soldered connection as the ground as I understood them to be grounded is this correct? Also I checked I was measuring DC.
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Post by electronumpty on Mar 16, 2020 18:19:03 GMT
So might have to change my name to Routernumpty, managed to do the holes and a ventilation slot. If you look really really closely you might be able to spot my slight mistake. Crazy Router jig.  |
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Post by electronumpty on Mar 16, 2020 18:19:51 GMT
workshop shot  |
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Post by electronumpty on Mar 16, 2020 18:21:52 GMT
holes Quite pleased with the valve holes but the vent slot needs a bit of tidying   |
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Post by firebottle on Mar 16, 2020 18:22:04 GMT
Ok you haven't got the right level of HT getting to the first stage.
Send it over if you want.
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Post by electronumpty on Mar 16, 2020 18:29:08 GMT
Ok you haven't got the right level of HT getting to the first stage. Send it over if you want. Thanks Alan, I'll check again to be sure and send over tomorrow if I can get out. Much Appreciated. |
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Post by electronumpty on Mar 17, 2020 18:29:54 GMT
Stuck my 2m red mm on to have a listen to for a change throughthe otp.sounds pretty good. Think I'll leave it on for a bit then stick on my NA Tracer 3 before going back to the zyx. Thought I had a connection issue until I remembered I didn't need loading plugs in the otp, sounds good now. #Electronumpty strikes again! 🤪   |
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Post by firebottle on Mar 17, 2020 18:43:14 GMT
Yes that's the only drawback with using the Loading Socket approach, you have to remember what you are doing,  |
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Post by electronumpty on Mar 17, 2020 18:54:51 GMT
Yes that's the only drawback with using the Loading Socket approach, you have to remember what you are doing, Yeah I was checking speaker connections and all sorts lol |
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Electronumpty by name Electronumpty by natuBBBBBZZZZTTT…….