I drew this from the actual amp, it is correct. I am unable to find a schematic.
I presumed you're drawn it, and I 'presume' it's not quite correct - there should be something (an output) connected to the second cathode, pin 8. Assuming this is hard wired? (and not a PCB) sometimes it's easy not to be able to see a connection.
It is point to point not a PCB. I do now see another wire from the second cathode, It goes to a cap then on to a socket for an external speaker cabinet. I didn't notice it before, it is quite cramped in there. Now it makes sense, thank you for pointing that out.
Attachments
What's the thing driven from? I thought at first the .001µF on the input was a bootstrap, but there's a cathode bypass capacitor, so it's essentially rolling off high frequencies.
And while the cathode follower is giving a decently low output impedance, with that 47k it's not capable of driving current into it.
And while the cathode follower is giving a decently low output impedance, with that 47k it's not capable of driving current into it.
I Now it makes sense, thank you for pointing that out.
I've drawn a LOT of circuits out over many years - if it doesn't make sense it's almost always because you made an error
In this case it didn't help the actual way you had drawn it (I usually draw it out roughly, and then rearrange it to be in a normal configuration), but it was a standard looking circuit IF there was a connection to the second cathode, and no reason for the second triode if there wasn't any connection.
The thing with drawing circuits out is you really need to know what it's going to look like before you start
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
- Home
- Live Sound
- Instruments and Amps
- strange preamp