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Old 17th June 2009, 11:18 AM   #101
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Peter,
Do you foresee any major problems with the addition of an X circuit to the J. Will a lot of tweeking of resistors and such be an issue.
I have been looking forward to building an X type amp but never got to the GB for the boards in time. Thanks for your efforts Tad
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Old 17th June 2009, 03:19 PM   #102
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I don't see any problems with that, the main boards will be exactly AJ circuit, and I simply add pads to mount daughter board (3 pins on each side for the gates, out and ground). The front end circuitry will be inside marked area and for X version not installed. The balanced input goes directly to the daughter board (the X amp will also work with unbalanced signal), the daughter board is powered with separate wires from main supply, output is taken from between output boards. That could be the best X amp ever
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Old 17th June 2009, 05:46 PM   #103
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Peter,
Sounds like a winner to me. Nelson was always very fond of this particular version of the Aleph series. The best yet would be a nice thing to achieve.
I will stay tuned to see how things progress.
Need to find some nice healthy heatsinks.

Thanks Tad
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Old 17th June 2009, 06:03 PM   #104
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Also interested in a stereo pair.

Thanks
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Old 17th June 2009, 06:21 PM   #105
SRMcGee is offline SRMcGee  United States
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Peter:

Are there any practical limits on the size of an Aleph JX amp? I currently have Aleph 1.2 monoblocks and would love to try to build something of similar size and power. Assuming it's plausible, count me in as well.

Many thanks,
Scott
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Old 17th June 2009, 10:42 PM   #106
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Peter,
What would the projected output be for the JX with 25-30 volt rails? It is now a balanced amp with + and - at the speaker terminals.

Tad
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Old 18th June 2009, 12:53 AM   #107
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I think your limited to about +/-24V, due to the voltage limitation of the JFets. An Aleph JX, shouldn't be much different in output wattage than a 12 output Fet AlephX, which for 22-24 volt rails gives around 100w into 8R, but I could be wrong.

-john
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Old 18th June 2009, 01:19 AM   #108
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Default Me two

Hi, I'd like two stereo boards as well, please. Thanks for doing this!

Anthony
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Old 18th June 2009, 04:40 AM   #109
Luke is offline Luke  New Zealand
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Hi Peter, Perhaps its possible to allocate holes for 2 or 3 pairs of parallel input jfets?
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Old 18th June 2009, 07:52 AM   #110
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Hello
My Aleph X it uses 8PC power mosfet one side (one channel)at 7A bias over 100W/ channel .Of course I do not push it to 100Watt never to drive my speakers .
So I think 12PC /channel is more than enough !
The IRFP type mosfet tend to sound much better in high bias than normal bias .I know that it will decrease the life time the mosfets but the sound of the amp is more important to me ! We can replace the mosfets every 5 years or so , depend how often U use your amp and the size of the heat sink is must be not under rated .
I use the Cristijan type of PC board and I can say I'm more than happy with the result .
Also I prefer tho connect the output mosfets direct to the PC board .
I tested the wiring method (just I added 2" wire and the sound be came awful compare the direct connected power mosfet to the PC board) I did tested , I just mode one channel at the time .Only I did it to spread the heat a bit better .But Peter wrote the X PC board would be 8" long .That is more than enough with a good heat sink .
I only interested high power version , is important to the IRFP mosfets the 24V power supp min. must .The master wrote that himself .
Mini Aleph X or something like that I think a waste of effort com pair a well biased not X version Aleph (that is my humble opinion ) I'd rather remain at the original J version than use low voltage power supp for the X-ed version !
These just my opinion .
But if the power supply voltage can be flexible a bit that would be great .So we could use transformer what we think is the best best solution for the good sound .
I read many people wrote they do not like the Cristijan type set up for the Aleph X .But please firs take a listening test and after have your opinion .I write these humble , I do not want to argue with no one .
Greets
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