Aleph H Schematic - Revealed at Last

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#42
Hi
Have anyone ever tried using a pair of 12V batteries as PSU for the Aleph H? I happen to have both some aleph mini pcb's and a couple of 12V 3.4 Ah batteries that I could use to make an amp. Can anyone tell me if the 12V rails will work on Metalman's Schematic or does any of the component values need to be ajusted? I believe I have read somewhere that 12V should work on the Aleph Mini.
Regards
Mikkel
 
#46
I didn't.

The headphones I liked the most of all and bought are ridiculously easy to drive - 25 ohm and 106db/mW. An iPod will drive them to deafening levels without losing any clarity or control. The thought of making a headphone amp that could easily put 5 Watts into that load seemed a tad bit excessive, even by DIY standards.

That, and as I am finding my preferences in headphones are taking a distinct turn towards in-ear monitors, I have no need at all for power.

Anyway, the PSU board is given to a friend building monoblock F5T, along with another board and identical caps. The PD Aleph J boards will probably be made into a 'normal' Aleph J, I love that amp and will happily build another as a gift or something. (Or make a mini Aleph J with Toshiba 2SK313/2SJ2013 outputs...)

😀
 
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#50
Toroid voltage

I am confused about the power supply.

The schematic metalman posted has +15V and -15V rails, but the photo in the 6moons review shows a Plitron 2 x 15VAC toroid.

What kind of toroid is required? 2 x 12V or 2 x 15V?

Thanks,

Albert
 
#54
I want to build an Aleph H using the schematic shown in post#1.
I plan to use a 30VA 2 x 12VAC secondaries toroid and am using PSU designer to have some idea of how my choice of parts for the PSU is going to affect the size of the ripple. Problem is I have no idea how to work out how much current will be drawn by the circuit. How do you deduce that from the schematic?

Thanks,

Albert
 
#59
After "painting by numbers" for the B1 I recently completed (sounds great!), this build is a little more difficult because the schematic does not comply with the chipamp mini Aleph boards I will be using.

I have tried to match the item numbers on Metalman's schematic to the schematic 6L6 provided in post #14.
In enclose a pdf scan of my renumbering attempt.

I hope someone can check for me to see if I made any mistakes.

I have a few questions:

1. I will only be using SE input (from portable MP3 player). Can I leave out R2 and R3 (Metalman's numbering)?

2. Did I read correctly that Z3 and Z4 are for protection? Are they required or can they be left out? What would be the advantage/disadvantage of leaving them out?
I did not find them in the original Aleph 3 or Mini-A schematics.

3. In the photo's of the 6 moons article, only 1 3W 0R47 is shown but Metalman's schematic shows 2. How many are required?

4. In most schematics I have seen, Z1/Z2 and R4 (Metalman's numbering) go directly to ground but in the schematic for the boards there is an R0 (3R 3W). The photo in the 6 moons article shows that Metalman included a 3R 3W resistor.
Is it better to use R0 or is a jumper just as good?

5. There are a few small capacitors in the schematic for the chipamp mini Aleph boards (C4 10pF, C5 1nF, C6 47nF) that are not in Metalman's schematic (or the Aleph 3 or mini-A for that matter). What are the advantages and/or disadvantages of putting these in?

6. What would be the sonic difference if Q4, R15 and R16 are deleted (as in Aleph reloaded)?

Thanks,

Albert
 

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#60
1. yes , you can omit R2 and R3
2.put them later ; good to have in case of static zapps! , to protect gates of input mosfets
3.go by schematic ; logic is that you don't know when picture is taken , but you certainly know that Metalman drew that schm with care
4.you are around long enough to learn basics - everything is connected to audio gnd , case is connected to safety gnd and there is CL60 in between audio gnd and case
5.no disadvantage ; they're for anti-oscillation purpose
6.feel free to delete them ; your ears will be toasted anyway long before that protection goes in action :rofl:
 
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