I have to find 2x18vac toroid for XJ version (1 KVA)
I have stopped at two brands Noratel - have to purchase custom and Talema
are there Interested purchasing specified toroid or at least buy more pcs to get lower price
I have stopped at two brands Noratel - have to purchase custom and Talema
are there Interested purchasing specified toroid or at least buy more pcs to get lower price
http://www.diyaudio.com/forums/showpost.php?p=1856064&postcount=91can someone post a copy of the schematic for the daughter board with resistor values etc.
Except for two additional resistors which values are already suggested (RG & RS), all other resistors are exactly the same as in a regular AJ version with possible exception of CCS resistor(s). RG installs directly on binding posts.
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Except for two additional resistors which values are already suggested (RG & RS), all other resistors are exactly the same as in a regular AJ version with possible exception of CCS resistor(s). RG installs directly on binding posts.
Did you already hear your aleph j-x? I have your boards here, to be honest I wanted to wait for your results.
Aleph JX spice model
I am a little uncertain about the power rails.
Let me no of any other problems you can detect.
I have already run this and it does work, but improvement over the original is minimal.
I have also run this with 8 output mosfets (4 on each half) but for some reason it runs terrible.
This is an LTspice file
I am a little uncertain about the power rails.
Let me no of any other problems you can detect.
I have already run this and it does work, but improvement over the original is minimal.
I have also run this with 8 output mosfets (4 on each half) but for some reason it runs terrible.
This is an LTspice file
Attachments
Here is the first fruit of Peter's boards pretty much ready to go ...
Going to try the Aleph J stereo first, then maybe AJ-X
Were did you get those sweet turrets?

Keystone terminals from Mouser (stock) and Digikey (not stock). You need the staking kit and appropriate anvils but they are great for the power supply where you tend to solder and then re-solder it for different boards. I just bought the kit and a few bags of them to fit .062 thick PCB and .062, .090, .112, etc. holes.Were did you get those sweet turrets?![]()
JX SPICE Model
I have been playing around with this circuit a little bit.
Initially, I adjusted DC offset by adjusting the RS resistor values on the daughter board. Doing this I get dominant second harmonic and then it falls away gradually for each consecutive harmonic.
I then changed the RS values back to 1K each and adjusted the dc offset by adjusting one of the JFET drain resistors. Doing this I get More dominant even order harmonics, ie dominant 2nd then 4th greater than third, sixth greater than fifth etc.
What is the recommended method for adjusting dc offset?
The two approaches above work but what is the recommended way.
I have been playing around with this circuit a little bit.
Initially, I adjusted DC offset by adjusting the RS resistor values on the daughter board. Doing this I get dominant second harmonic and then it falls away gradually for each consecutive harmonic.
I then changed the RS values back to 1K each and adjusted the dc offset by adjusting one of the JFET drain resistors. Doing this I get More dominant even order harmonics, ie dominant 2nd then 4th greater than third, sixth greater than fifth etc.
What is the recommended method for adjusting dc offset?
The two approaches above work but what is the recommended way.
I am curious as to which particular Pass preamp some of you will use to provide the balanced input for this project in the X configuration. I really prefer to use a simple buffer type input but have not yet seen one in a balanced input scheme.
Any ideas?
Tad
Any ideas?
Tad
The amp will work with unbalanced sources as well, just ground one of the (balanced) inputs.
I was going to ask about how to wire the inputs to drive this from a single ended source. Would it be better to ground the + in or - in? Or does it not make much difference?
It makes a difference with regards to polarity: normally - IN should be grounded. If you ground +IN the output will have inverted polarity.
It makes a difference with regards to polarity: normally - IN should be grounded. If you ground +IN the output will have inverted polarity.
That makes sense, thanks 🙂
I have a couple more questions...
1. I'm getting ready to stuff my amp boards, for a standard J config I do not install R22 and R27 right? And I thought I might have read that I don't need R7, but I can't seem to find that post right now.
2. I picked up someone elses unfinished Twisted Pear Buffalo 24 project so I will have a balanced source in the future. I want to install RCA and XLR inputs for my J, I see from pictures that the original J uses shorting jumpers in the XLR sockets when using unbalanced input. I thought that a convenient solution would be to use a DPST toggle switch to short -IN to ground. Any problem doing it that way?
1. I'm getting ready to stuff my amp boards, for a standard J config I do not install R22 and R27 right? And I thought I might have read that I don't need R7, but I can't seem to find that post right now.
2. I picked up someone elses unfinished Twisted Pear Buffalo 24 project so I will have a balanced source in the future. I want to install RCA and XLR inputs for my J, I see from pictures that the original J uses shorting jumpers in the XLR sockets when using unbalanced input. I thought that a convenient solution would be to use a DPST toggle switch to short -IN to ground. Any problem doing it that way?
1. I'm getting ready to stuff my amp boards, for a standard J config I do not install R22 and R27 right? And I thought I might have read that I don't need R7, but I can't seem to find that post right now.
Those resistors are needed for any version: either standard or X. Just follow the schematic that was included with the boards.
Toggle switch for selecting balanced/unbalanced inputs is a good idea.
bigger or better?
For the regular, stereo Aleph J build, which is the better transformer choice - a 300VA, 18v+ 18v Plitron (best quality and expensive), or a 400VA 18v+ 18v Antek (theoretically quieter?) - and why?
I'm about to order the transformer and could use some guidance. Thanks.
-Alex
For the regular, stereo Aleph J build, which is the better transformer choice - a 300VA, 18v+ 18v Plitron (best quality and expensive), or a 400VA 18v+ 18v Antek (theoretically quieter?) - and why?
I'm about to order the transformer and could use some guidance. Thanks.
-Alex
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