It's nuts how much time I spent when I started this DIY audio thing trying to track down buzz and hum—only to turn off my LED task light on the bench and witness the blissful silence....Plus my only "audio cabinet" option at the moment is a 1950s fully steel corporate credenza reclaimed office item. Not the best environment... but I've pretty much beat it with careful arrangements of power and signal runs—and keeping ALL DC bricks and computers outside and as far away as possible from anything sensitive....for a turntable though—it's a rock solid piece of supportive mass (marble top we added)—one can jump up and down in front of the deck and nothing happens.
Joists run the wrong way...BUT it's up against a load bearing wall, in a corner. 1950s wood construction, basement beneath... I think a lot of the stability is the cabinet....but the building has to be a part of it yes. Floor isn't level, deck is probably 3/16" higher in the front...
Distributed generation and battery is the future my friend. Especially if you have salacious tastes, aka Class A amps
Before I make the final decision using either 2SK209 or 2SK170 for P3 I ask this question:
If I have enough matched 2SK170 is there any reason I should use 2SK209 instead (I don't care which is easier to solder etc.)?
In an older thread comparing JFET noise there was this link which it quite interesting:
https://www.mvaudiolabs.com/diy/modern-jfet-noise-measurements/
It seems 2SK117 is same as 2SK209.
If I have enough matched 2SK170 is there any reason I should use 2SK209 instead (I don't care which is easier to solder etc.)?
In an older thread comparing JFET noise there was this link which it quite interesting:
https://www.mvaudiolabs.com/diy/modern-jfet-noise-measurements/
It seems 2SK117 is same as 2SK209.
The old thread is this:
https://www.diyaudio.com/community/threads/njfets-for-source-follower-applications.329131/
Here it seems 2SK209 has a bit more H2 and less H3 than 2SK170.
It is suggested that 2SK209 could be "nicer" to listen to.
It is a argument like this which could make the 2SK209 the preferred to use.
I don't want to build them both......so I need to decide.
I still have time......kit not yet received. It is in the Danish customs. Will soon get a bill to pay to get it released.
https://www.diyaudio.com/community/threads/njfets-for-source-follower-applications.329131/
Here it seems 2SK209 has a bit more H2 and less H3 than 2SK170.
It is suggested that 2SK209 could be "nicer" to listen to.
It is a argument like this which could make the 2SK209 the preferred to use.
I don't want to build them both......so I need to decide.
I still have time......kit not yet received. It is in the Danish customs. Will soon get a bill to pay to get it released.
Some time ago these speakers was demonstrated for me:
https://high-performance.dk/avantgarde-duo-gt
They are 107 dB and the ground noise (in idle) was so load that it was very audible in the listening position 4-5m away from the speaker.
For me this is a "no go"
The good thing about this forum is that you can make things almost perfect.
To buy same level of performance commercial would be very expensive.
https://high-performance.dk/avantgarde-duo-gt
They are 107 dB and the ground noise (in idle) was so load that it was very audible in the listening position 4-5m away from the speaker.
For me this is a "no go"
The good thing about this forum is that you can make things almost perfect.
To buy same level of performance commercial would be very expensive.
Two issues to deal with, magnetic and electrical.
You can try orienting the transformer to minimize the magnetic field impinging on the PCB -- and in this regard note that the P3 pcb is much less a "receiving antenna" than the P2 pcb. You can try a different transformer, say an EI vs toroid. You can encapsulate the transformer in a soup-can which is bi-metallic. (A 28 oz tomato can works well, need not be San Marzano!) . You can get a sample kit from muShield, or try the magnetic shielding tape from 3M.
Morrison's book which I cited last week (unlike Harvard, I cite my references) has a lot of detail on reducing magnetic interference, but I don't expect you to go to Ebay to find a copy! Perhaps some duplicative language of Morrison's explanation would be in order.
Electrical is almost always a grounding issue.
I tried to cover the Toroidy transformer as much as possible with Permalloy I think it is called (to my knowledge same as mu-metal).
Toroidy already has magnetic and static shield (according to spec) but I thought it could not harm to do a little more.
Next step would be to attached the umbilical and then assemble it fully. Then I am ready for the P3 kit.
Toroidy already has magnetic and static shield (according to spec) but I thought it could not harm to do a little more.
Next step would be to attached the umbilical and then assemble it fully. Then I am ready for the P3 kit.
