You can find more info about my DIY project here:
http://www.diyaudio.com/forums/showthread.php?threadid=250
http://www.diyaudio.com/forums/showthread.php?threadid=250
12AX7 Pictures
Asen,
Very Nice - also, good job on the internal wiring. Thank you for for taking time to post the pictures. I will need to get a few pictures off on my latest preamp project as it progresses. Thank you and nice work.
ALBQ
FYI - link to my webpage - need updating with latest projects
http://mywebpages.comcast.net/gillespie147/AlbuquerqueAudio-MainPage.html
Asen,
Very Nice - also, good job on the internal wiring. Thank you for for taking time to post the pictures. I will need to get a few pictures off on my latest preamp project as it progresses. Thank you and nice work.
ALBQ
FYI - link to my webpage - need updating with latest projects
http://mywebpages.comcast.net/gillespie147/AlbuquerqueAudio-MainPage.html
Thank you all for the comments!
fdegrove,
I tried it without cathode caps but I didn't like the results. Also I don't think the input voltage divider is quite a problem. It is the same thing to have a 250k pot and to turn the volume just a little. The resistor gives me more possibilities to play around with the volume control.
Regards
fdegrove,
I tried it without cathode caps but I didn't like the results. Also I don't think the input voltage divider is quite a problem. It is the same thing to have a 250k pot and to turn the volume just a little. The resistor gives me more possibilities to play around with the volume control.
Regards
Found it!
Happy to say that I have found the issue! Just need to work out exactly how I will solve it.
I spent so much time with a multimeter looking over the components and connections, looking for a dry joint. I started to think my amp was fine in that regard. This amp is so simple.
I haven't really gone with a stock layout, so based on what I read elsewhere I thought about the wiring and where things were located. I unscrewed the pot and pulled it out with the wires on it. The amp came to life and sounds great.
The centre wire on the pot is likely the issue. It is picking up interference from the heater wire, or perhaps it is picking up interference from the wire going to the primary of the power transformer.
Just need to experiment and work out where that wire can go.
Happy to say that I have found the issue! Just need to work out exactly how I will solve it.
I spent so much time with a multimeter looking over the components and connections, looking for a dry joint. I started to think my amp was fine in that regard. This amp is so simple.
I haven't really gone with a stock layout, so based on what I read elsewhere I thought about the wiring and where things were located. I unscrewed the pot and pulled it out with the wires on it. The amp came to life and sounds great.
The centre wire on the pot is likely the issue. It is picking up interference from the heater wire, or perhaps it is picking up interference from the wire going to the primary of the power transformer.
Just need to experiment and work out where that wire can go.
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