The Aleph Jango

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6L6

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You can't build just one... :D :D :D

No real news, I've just been lazy and haven't made the drawings to give to the machinist. I can't go any further until the enclosure is complete, because I need the real enclosure to measure for parts fit, and to see where things will actually place and mount.

The other delay is that I started a Sonos system, and having a Class-A amp (my F5) just cooking away for background music is a little silly... So I have a chipamp project that is taking what little time I have for building.

That said, this will get back on track, hopefully soon. :D
 
Here is a copy of the schematic that Nelson drew out for me at Burning Amp (well, he modified and made notes on an Aleph J schematic) Not significantly different than the original.

AlephJschematic.gif

Thinking about putting this together - have boards, psu and 4 ssR100s.

Is the pot that is added between input jfet and output jfet really 500k?

I ask because in the Semisouth Aleph J forum post !2 Nelson states

I think you can see significant improvement by simply
dropping the Jfet in on the negative side - the IRF240
on the top (aleph) side can be left as is.

To bias it properly you will need to drop the value of the
resistor from the Drain of the input transistor (and Gate
of the Jfet) to the negative rail to a lower value - I
recommend a 500 ohm pot.

Thanks

Bob
 

6L6

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Joined 2010
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Is the pot that is added between input jfet and output jfet really 500k?

I will change that, you are correct, it's 500ohm -- your comments about biasing it are spot on.


I think you can see significant improvement by simply
dropping the Jfet in on the negative side - the IRF240
on the top (aleph) side can be left as is.

Yes, that's how it's drawn.

My question in should I pursue this amp, or save my unobtanium R100s for an F6...

This project got royally derailed time-wise some time ago, but I was going through my various boxes and bins to realize that I have everything I need to build this amp except the transformer...
 
"My question in should I pursue this amp, or save my unobtanium R100s for an F6...

This project got royally derailed time-wise some time ago, but I was going through my various boxes and bins to realize that I have everything I need to build this amp except the transformer..."

6L6 - tough question
The F6 is a tremendous learning experience for me and it is great for driving the PHL mids in my system. If SITs became available I would probably want to try them in the F6. The Jango seems like another learning experience. Back to the Zen articles. I still use the Aleph 30 on the low end. My sealed SEAS W26s are not efficient as the PHLs and the Raven so I need the gain.

My friends say take the time and listen. The best way for me to do that is have amps that I can rotate in the system.

Thanks again to those friends and the great DIY community
 
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