I think this is not a problem (zener diode). This is voltage with no load ...
When I insert a single tube in a socket, I have no voltage after regulator 7805 at all ...
When I insert a single tube in a socket, I have no voltage after regulator 7805 at all ...
You may have a similar issue to one I've had with the actual heater voltage needed. Mine has been modified for 7V heaters by changing the 2.7V zener to a 2V.
Also change the two 8.2 ohm resistors to 4.7 ohms or you could add a 5.6 ohm resistor parallel to the 8.2 ohm resistors.
Double check all that before blindly following me though.......
Regarding the LEDs, are they in the correct way round?
Also change the two 8.2 ohm resistors to 4.7 ohms or you could add a 5.6 ohm resistor parallel to the 8.2 ohm resistors.
Double check all that before blindly following me though.......
Regarding the LEDs, are they in the correct way round?
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Managed to sort out the heaters (filaments).
I changed a new 7805 bought from Mouser to an old AN7805 and now it works. LEDs work aswel.
One last problem popped up ... right channel is clearly more "silent", like it has way less gain and no mids. But I hear sound from it.
Any suggestions?
I changed a new 7805 bought from Mouser to an old AN7805 and now it works. LEDs work aswel.
One last problem popped up ... right channel is clearly more "silent", like it has way less gain and no mids. But I hear sound from it.
Any suggestions?
I guess it could be any of the gain elements in that channel. Does it occur in both MM and MC settings?
Obviously assume you swapped inputs just to check what's coming in?
Obviously assume you swapped inputs just to check what's coming in?
I can't try MC, don't have an MC cart ... but, if it is save just to try, I can.
I've swapped tubes also, no luck. Voltages are all the same, as per Vivant instructions, so, it is working "like it should".
Any other suggestion?
I've swapped tubes also, no luck. Voltages are all the same, as per Vivant instructions, so, it is working "like it should".
Any other suggestion?
I would just double check all the "R" components for value and orientation where applicable.
Stick a hires picture of the board up too if you wish. The one above isn't big enough for me to see tbh....
Stick a hires picture of the board up too if you wish. The one above isn't big enough for me to see tbh....
Here are better pictures.
I've tried to swap C4L and C4R with no luck. They are styroflex, I wasn't sure if I accidentaly "overheated" them, but nothing. I'm looking at the both channels, can't seem to find an error. Frustrating.
Direct link (better resolution).
20200726-101535 — ImgBB
https://ibb.co/TMpNZGh
https://ibb.co/SKj4jrL
https://ibb.co/XJDVcpD
I've tried to swap C4L and C4R with no luck. They are styroflex, I wasn't sure if I accidentaly "overheated" them, but nothing. I'm looking at the both channels, can't seem to find an error. Frustrating.
Direct link (better resolution).
20200726-101535 — ImgBB
https://ibb.co/TMpNZGh
https://ibb.co/SKj4jrL
https://ibb.co/XJDVcpD
Solved the problem!
When I soldered BF862 (my local store has about 50pcs of them 😀 ), I've managed to short gate and source.
All working now.
When I soldered BF862 (my local store has about 50pcs of them 😀 ), I've managed to short gate and source.
All working now.
Listening, very happy for now.
I have to make side panels from wood and then I'll finish the enclosure.
Waiting for colder days to fire up GM-70.
I have to make side panels from wood and then I'll finish the enclosure.
Waiting for colder days to fire up GM-70.
