Hi Tube community at DIY Audio, I was hoping to get some help. I've been very fortunate to get hold of a pair of what I'm certain are a clone of Audio Note Kegon - Balanced for a steal... I'm confident that they're made by Alp Audio, who used to be Peak Audio, who distributed Audio Note in Hong Kong.
Unfortunately, it came with two out of five tubes. I know two of the tubes are 300b's and there is a gain stage with a 6j7G (which deviates from a AN Kegon but came with amp). The Kegon is a 10Y - Interstage - 300bPSE.
It appears to be a 6j7G - Cap Coupled - unknown tube (10Y?) - to 2x 300b's. The other tube I'm unsure of is the Rectifier. I would assume it's a 5U4G, as the other amp I got is and the majority of Audio Notes amps are too.
Anyone have an idea on where to start?
Pictures say a 1000 words:
Unfortunately, it came with two out of five tubes. I know two of the tubes are 300b's and there is a gain stage with a 6j7G (which deviates from a AN Kegon but came with amp). The Kegon is a 10Y - Interstage - 300bPSE.
It appears to be a 6j7G - Cap Coupled - unknown tube (10Y?) - to 2x 300b's. The other tube I'm unsure of is the Rectifier. I would assume it's a 5U4G, as the other amp I got is and the majority of Audio Notes amps are too.
Anyone have an idea on where to start?
Pictures say a 1000 words:
Hey Claudio, thanks for jumping in.
I am measuring without the Rectifier as I haven't managed to identify that yet and therefore unsure on B+. Pin 1 and 4 are measuring at 11v with no load. I chanced a 10Y, as that's what I suspect it is, and pin 1 and 4 is measuring at 7.8-7.9v. I'm unsure on Cathode. Pin 1 and 4 are connected to a POT with a resistor each in between, but the pot doesn't impact the DC voltage and I'm assuming it for variable fixed bias.
Correction, I think it's a hum pot - thanks to a friend helping.
The two brown 2w resistors at the bottom left are the ones connected to Pin 1 and 4. Pin 1 and 4 are the bottom two and the orange-grey wire is from the filament Regulator. The reg is made up of two transistors, 6 caps and has different parts to the other with no pot to move the voltage.
I am measuring without the Rectifier as I haven't managed to identify that yet and therefore unsure on B+. Pin 1 and 4 are measuring at 11v with no load. I chanced a 10Y, as that's what I suspect it is, and pin 1 and 4 is measuring at 7.8-7.9v. I'm unsure on Cathode. Pin 1 and 4 are connected to a POT with a resistor each in between, but the pot doesn't impact the DC voltage and I'm assuming it for variable fixed bias.
Correction, I think it's a hum pot - thanks to a friend helping.
The two brown 2w resistors at the bottom left are the ones connected to Pin 1 and 4. Pin 1 and 4 are the bottom two and the orange-grey wire is from the filament Regulator. The reg is made up of two transistors, 6 caps and has different parts to the other with no pot to move the voltage.
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The pot on the 4 pin driver socket is a hum pot. From your emails to me the wiper (middle pin) is connected to the cathode resistor and bypass cap. There are a further 2 resistors to the filament pins from each end. To start with the pot should be in its centre position. Hum pots are usually used with AC heating but here you have DC.
7.8V does look like a 10Y. It's a trifle high - I'd prefer to see it at 7.5V or below. But trimming that down requires a better knowledge of the whole schematic. It would help to draw as much of the schematic as you can and post it.
I'd also guess that the rectifier is a 5U4.
7.8V does look like a 10Y. It's a trifle high - I'd prefer to see it at 7.5V or below. But trimming that down requires a better knowledge of the whole schematic. It would help to draw as much of the schematic as you can and post it.
I'd also guess that the rectifier is a 5U4.
Thanks Andy and Claudio!