Aleph J Schematic

[pmchoong]

Thanks, Zen.

Now, I have include the 3rd pair of mosfets into my Aleph J and I must say it really does improve the sound quality. I highly recommend this if your heatsink can cope with the heat. It is really very hot!

Please take a look at the attached images. In Diagram A, this is how I have wired the amp. In diagram B, I was thinking of connecting the speaker protection board via the speaker terminal. In diagram C, the Gnd is totally removed from the speaker protection board.

My question for Diagram B, does this make any difference from Diagram A?

Question for Diagram C, will the speaker protection still works if I omit the Gnd connection to the speaker protection board?

The reason is because one channel have this 'thump off' effect on the speaker. The other channel is fine so I do not know what is the problem. It would be the soft start or the protection board. Or the alternative wiring technique might help.

Thanks again.
PM Choong

 

[Zen Mod]

if you remove gnd from speaker protection board , thingie is floating , thus non functional

it measures potential between speaker terminals , to decide when to act or stay idle

 

[pmchoong]

Thanks, Zen. I will stick to my original wiring scheme and trouble shoot my softstart instead.

 

[Zen Mod]

pic will help

however - soft start isn't to be blamed - if wired correctly , that's just switch in series with speaker hot

 

[schultzsch]

didn`t saw anybody using vu meters on their alephs, why?
I want to build a 2-3 led(100mW, 1W and ~max power @ below distortion sensing) vu meter for each aleph
I`m taking in consideration the version with µAmpere-meter too

 

[Zen Mod]

whatever please you

😉

 

[tiefbassuebertr]

I haven't finished the service manual for publication, but it is
quite clear that many have become impatient.

www.passlabs.com/np/Aleph_J_sch.pdf

😎

this URL is death in the meantime.
here several others:
ºô¤ÍAleph5«á¯Å»s§@¤ß±o
Babelfish J
Pass / First Watt Aleph J - Phono - Restaurierung und Selbstbau - Analog-Forum

 

[schultzsch]

I don`t have so much space between front panel and the trafo so I think I will go for the leds
still looking for a schematic..a simple one

any ideas if the sound will be degraded?

 

[Zen Mod]

nope

 

[schultzsch]

nope

k.. so I can continue the search in peace 🙂

 

[schultzsch]

but finally I think I`ll keep it simple, as it was designed 🙂

 

[6L6]

A good idea. 😀 🙂 😀

 

[schultzsch]

the best!

 

[Zen Mod]

put Xmass tree on it

 

[schultzsch]

You know I was thinking too on this but where can I found one CT in this time of the year? They are nowhere to be found 🙁 if you wanna be a nice guy, as you always are, you could borough me yours.any chances?🙂)

 

[Zen Mod]

Mighty ZM is usually leaving trees where they belong , while using plastic Chinese one as surrogate

 

[schultzsch]

If it has lights and looks like a tree than it's more than enough :d

 

[Zen Mod]

even better - put this on it , or ..... under

An externally hosted image should be here but it was not working when we last tested it.

 

[schultzsch]

🙂)))

 

[schultzsch]

I`ll put it under `cause I read somewhere that improves the sound 🙂


seems it`s time for me to move to the next project..