[rickcr42]

a lot of DIYers have dabbled in Nelson Pass designs which have been available on the Pass Labs website for some time.Now ole Nelson has put up a site strictly dedicated to DIY projects.A couple of interest are a RIAA phono stage preamp using JFETS and a new ZEN amp design that uses incandescent light bulbs as bias resistors !
Very strange but very cool.
Also some soldering hints and other good info with more promised/
Check it out at http://www.passdiy.com/

 

[Apheared]

While only marginally related (the link is in the gallery section of passdiy)

THIS is what I wish I was cool like. THIS is what I would do if I had a garage or basement workshop.

I hate speakers... I'm headphones 101% of the time for over a year... but this rig. DIY everything. Check this one image, then cruise his handiwork.

CHECK OUT that 8" volume control! HEAHEHA!

To drool click here
http://www.marleylondon.com/DSC00021.jpg

here's his main audio htm
http://www.marleylondon.com/musicindex.htm

 

[erix]

Well this is just great, another thing to build...

Build Yer Own CDP

This one is for the machinists out there..

Top Loader

ok,
erix

 

[rickcr42]

then maybe something a tad easier ? Hmmmmm ?http://www.diyzone.net/
CDP made from a CDROM

And BTW-on anther forum Nelson Pass mentioned something about a headphone amp (and I think he mentioned he uses Grados

) so I would keep an eye on this site

EDIT : N.Pass uses Grado SR-325s with a mosfet follower as the amp (someone say szekeres ?).Not surprising

 

[paulb]

Indeed, I did mention that in Headwize land, he was using a Szekeres.
I still want to use his Son Of Zen (modified) to drive headphones, future project. Need to cut my cord to drive the phones in bridge mode.

But really, what could be better than using a small range of a FET in Class A than to use the differential voltage of two FETs in Class A?

 

[rickcr42]

SOZ scaled to say 12 to 15 volts -/+ and 1 amp per polarity would be workable and ease the heatsinking requirements.Bias the actual devices at around 200 to 500 ma .
Also,I have a schematic around here somewhere (really need to organize this 30 years of crap) by James Bongiorno of the Sumo Nine Class A power amp.
The topology (from memory) uses two identical amps per channel in a balanced configuration using only NPN devices.The output is then referenced to an artificial groundnetwork.Might be a solution that would prevent tearing up your headphones.I will try to find the schema

 

[paulb]

Man, this hobby's addictive. I'm thinking about the project after the project after the next project already.
Thanks, Rick.