I can't see any problem with that
You can achieve a 'little' more gain by bypassing R13 with a quality electrolytic cap of say 220uF.
Question for Alan. When you say bypassing do you mean remove R13 and replace with cap, or fit cap in parallel with R13?
Thanks
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I have a problem now, I get no sound, nothing at all out of the BB. Light bulb says ok and the valves glow and the leds light up. But when I turn it on I normaly hear a little click, now I don´t hear that when I power it up. I would very much appreciate some guidance in my troubleshooting.
Thanks!
Thanks!
Haha, no! We all do daft stuff. Nice to see we're not alone in doing it [emoji6]It´s embarresing LOL. I was swithing to mc mode and happened to remove the signal wires
Good afternoon all.
I have a problem and need small help.
All parts according BOM.
Power transformer form Audiophonics with secondary voltage 182.5 and 10.75 x 2.
Voltage measurement across capacitors in Power supply:
C4P - 252.2
C5P - 138.3
C7P - 138.5
C8P - 138.1
C1P - 14.2
Voltage on tube sockets, without tubes installed:
Pin 1 and pin 6 , pin 3 and pin 8
V1 78.8 78,8 0 0
V2 88.8 88.8 0 0
V3 138.2 138.2 9.7 9.6
Heater voltage (pin 4 and 5) 7.8
Possibly consequences of first start up with transformer from ebay with secondary voltage 211 on HV.
Thank you in advance.
Sasha.
I have a problem and need small help.
All parts according BOM.
Power transformer form Audiophonics with secondary voltage 182.5 and 10.75 x 2.
Voltage measurement across capacitors in Power supply:
C4P - 252.2
C5P - 138.3
C7P - 138.5
C8P - 138.1
C1P - 14.2
Voltage on tube sockets, without tubes installed:
Pin 1 and pin 6 , pin 3 and pin 8
V1 78.8 78,8 0 0
V2 88.8 88.8 0 0
V3 138.2 138.2 9.7 9.6
Heater voltage (pin 4 and 5) 7.8
Possibly consequences of first start up with transformer from ebay with secondary voltage 211 on HV.
Thank you in advance.
Sasha.
Hi Sasha
Seeing no-ones replied I'll try and help with the heaters
I'm not going to be any help on the HT voltages, but on the heaters, are they all at 7.8? V2 should be lower than V1 & 3.
Have you got a 2v or 2.7v zener in ZD1P? 2.7 was originally specified due to the belief the PCC88's needed 7.6 v, but has been changed to 2v to give a 7v supply. That may possibly be the heater problem, with a 2v zener you should get 7v at V1 & V2, and 6.3 at V3
Sorry I can't be any help on HT voltages, Vivant is really the best person to talk to
Seeing no-ones replied I'll try and help with the heaters
I'm not going to be any help on the HT voltages, but on the heaters, are they all at 7.8? V2 should be lower than V1 & 3.
Have you got a 2v or 2.7v zener in ZD1P? 2.7 was originally specified due to the belief the PCC88's needed 7.6 v, but has been changed to 2v to give a 7v supply. That may possibly be the heater problem, with a 2v zener you should get 7v at V1 & V2, and 6.3 at V3
Sorry I can't be any help on HT voltages, Vivant is really the best person to talk to
Thank you Patrick for your help.
ZD1P as originally specified by BOM, 2.7v, I need to order and replace to 2V one.
I have check it again today.
if switch in position 6N2P Heaters voltage on V1 and V3 connected in parallel, and V2 have drop down 4R3 resistance. voltage a bit lower.
My guess, best way to measure with tubes installed.
Attached is pictures of BB.
Best regards.
Sasha.
ZD1P as originally specified by BOM, 2.7v, I need to order and replace to 2V one.
I have check it again today.
if switch in position 6N2P Heaters voltage on V1 and V3 connected in parallel, and V2 have drop down 4R3 resistance. voltage a bit lower.
My guess, best way to measure with tubes installed.
Attached is pictures of BB.
Best regards.
Sasha.
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I'll give @Vivant a nudge, as he is the troubleshooting expert for the BB3.
He's been on holiday and I'm not sure if he's back yet, but there are voltage figures somewhere in this thread.
Have a scroll back and see if you can find them. I think it was pretty recent.
The 2.7v Zener value changed quite some time back, so yes, 7v is required as Patrick rightly suggested. Thanks Patrick.[emoji106]
He's been on holiday and I'm not sure if he's back yet, but there are voltage figures somewhere in this thread.
Have a scroll back and see if you can find them. I think it was pretty recent.
The 2.7v Zener value changed quite some time back, so yes, 7v is required as Patrick rightly suggested. Thanks Patrick.[emoji106]
Dunno if it is the best. But the grounding wire from the tonearm...I connected to a central chassis grounding point....and then I connected that point to the ground of the output rca's. Tonearm input, signal input and output rca's floating with regard to the chassis.
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Hi All,
I just finished assembling my BB3. I am not getting any heat from my bulbs when I turn it on nor do I get any light in my LED's when switched on to MC. My voltages are as follows:
1 2 3 4 5 6 7 8 9
v1 136 0 0 57 57 137 0 0 0
v2 152 0 0 57 57 152 0 0 57
v3 238 17 15 57 57 239 17 16 0
Any one have any suggestions?
I just finished assembling my BB3. I am not getting any heat from my bulbs when I turn it on nor do I get any light in my LED's when switched on to MC. My voltages are as follows:
1 2 3 4 5 6 7 8 9
v1 136 0 0 57 57 137 0 0 0
v2 152 0 0 57 57 152 0 0 57
v3 238 17 15 57 57 239 17 16 0
Any one have any suggestions?
What's your low tension voltage from your transformer? I'd imagine the filaments in the valves have been blown with 57v going through them.
There should only be 9v in the LT supply, which is regulated to 5v by the 7805, then increased by a zener to 7v.
As far as I'm aware the 7805 has a maximum input of around 35v, I'm not sure what feeding it over 50 would do to it, but from what you're describing, it seems it's gone open and letting the whole 57 v through.
Make sure your transformer secondary is 9-0-9, and is connected correctly.
Then you'll need to replace the 7805, the 2v zener and I'd imagine fit new valves
The LEDs only work when the valves are operating.
Not sure what's going on with HT, but first things first. They don't look as drastically wrong as the LT.
There should only be 9v in the LT supply, which is regulated to 5v by the 7805, then increased by a zener to 7v.
As far as I'm aware the 7805 has a maximum input of around 35v, I'm not sure what feeding it over 50 would do to it, but from what you're describing, it seems it's gone open and letting the whole 57 v through.
Make sure your transformer secondary is 9-0-9, and is connected correctly.
Then you'll need to replace the 7805, the 2v zener and I'd imagine fit new valves
The LEDs only work when the valves are operating.
Not sure what's going on with HT, but first things first. They don't look as drastically wrong as the LT.
It'd be worth checking trafo voltages.
I posted my valve pin voltages in #909, with both supplies connected, but no valves in. Yours don't look that far away from mine.
It might be worth removing valves, disconnecting the HT and checking voltages on LT and at the heater pins.
Then if all OK, reconnect HT and remeasure. If still OK, valves in, remeasure.
IIRC the LEDs are only lit if you've got valves in *and* opted for MM.
There's a post somewhere from Vivant talking about voltages to be expected at some of the other components, but you'll have to dig those out.
FWIW with my valves, the heaters really didn't glow that much and in a sunny room they were near invisible, and that was with 6.9-7v from LV
I posted my valve pin voltages in #909, with both supplies connected, but no valves in. Yours don't look that far away from mine.
It might be worth removing valves, disconnecting the HT and checking voltages on LT and at the heater pins.
Then if all OK, reconnect HT and remeasure. If still OK, valves in, remeasure.
IIRC the LEDs are only lit if you've got valves in *and* opted for MM.
There's a post somewhere from Vivant talking about voltages to be expected at some of the other components, but you'll have to dig those out.
FWIW with my valves, the heaters really didn't glow that much and in a sunny room they were near invisible, and that was with 6.9-7v from LV