Aleph J illustrated build guide

Jump to Latest
Zen Mod

Zen Mod

Official Court Jester
Joined 2003
zenmod.in.rs/
Paid Member
Aleph X is relativelly big project, not exactly available in "ready to go" form

it can't be anything but very hot

it can't go out of A class, so what you have of Cojones to drive tougher loads, that's it

it can be tricky to get relative offset ( voltage potential of both output phases ref. to GND) well behaved and steady

so, moral of the story ( which is having several more remarks, but ZM lazy as usual) is - read, think, calc, ask, read answers to your questions, think again

and then, when you have complete mental picture of everything you want, need and must - think about Gerbers

builder's thread .......you have plenty of info, even if thread is long

luckily, Eric made great page of his own build, plus drekload of linked content: https://sites.google.com/bucknell.e...cs-home-theater/aleph-x-clone-amps?authuser=0
 
  • Like
Reactions: 2 users
J

JeyDee

Member
Joined 2020
Well? I have been giving my twin paralleled Aleph J:s some incoming added rails some cap love. 🙂🤚

A4F42DB0-90F4-460E-BBDD-0307C7E84B6B.jpeg
 
J

JeyDee

Member
Joined 2020
And this i did in combination with the:

https://www.diyaudio.com/community/threads/quasimodo-results-only.313202/

Well, smooth as Hulk butter. Brutally scull crackingly absolutely deadly, granade firm bass with still, a loving warmth.

The parallel Alep J twins will easily knock your socks absolutely clean off. And lovingly rip your entire soul into small musical pieces.

I really like it!

So? Crankit! Can your system take this, and deliver it to ya scull crackingly dynamic but still glass clear and honey smooth? 🙂


 
S

Surf21

Member
Joined 2023
I'm starting to gather all the materials to build a dual mono Alpha J.

1. The Metal Film Resistors-Through Hole 0.47 ohm 3w 5% Panasonic Mouser #667-ERX-3SJR47 on the BOM is no longer available. I did the search for similar products but come up with a couple of expensive Vishay (40 would cost $70) options or a bulk option that requires 1,000 unit purchases (I don't need that many). I don't mind spending more on quality parts, but I don't think the resistors are the place to do that. Since Mouser doesn't seem to have the equivalent product in stock is there a good substitute? Or will the below substitute from Digikey work? I was trying to buy everything from mouser, but maybe that won't be the case.

https://www.digikey.com/en/products/detail/te-connectivity-passive-product/RR03JR47TB/2385069

2. C1-looks like some folks like upgrading the WIMA Film Capacitors 250V 1uF 10%. Would Cornell Dubilier - CDE Film Capacitors POLY MET 250V 1uF be a reasonable way to go (I realize the sizing is slightly different and I'd have to fit them to the board)? I'm using these in my B1 Korg Nu Tube Preamplifier and thought it would be worth integrating them into the Alpha. Thoughts? Other suggestions?
https://www.mouser.com/ProductDetail/5984-250V1-F

Thanks-
 
Extreme_Boky

Extreme_Boky

Member
Joined 2003
I performed the test on those Panasonic resistors.... they are extremely reliable - I exposed them to a very large current (8A) at 48V DC... they started cooking, changing colour, and smoking... but they did not fail-open. At the same time, the associated wiring started to melt the insulation.... So, they are really good at ensuring the DC voltage at the output of Aleph J will stay at 0 volts (they do not fail-open) even if there is a serious problem with the amp, which is good for your speakers :)... of course, the mains fuse should be sized carefully...
 
  • Like
Reactions: 1 user
N

neric34

Member
Joined 2023
Hi,
I want to build an Aleph J but some components are not available. Are theses substitutions corrects ? Need your help please :) ...If you have any advice...

I follow https://diyalephj.blogspot.com/

For the toroidal power transformer from Toroidy, do you know if "Supreme audio grade" ones are really better than "Audio grade" ones ?

For the amp board :

For the PSU board :
- https://www.mouser.fr/ProductDetail/75-WKP332MCPEJ0KR --> https://www.mouser.fr/ProductDetail/Vishay/440LD33-R?qs=yu3MOCb6XhIKa3TTaweSBg==

For the soft start (diyaudiostore one) :

For the speaker protector (diyaudiostore one) :

Is it correct ?

What kind of power transformer is needed for the speaker protector ? (12VAC)

With solft start, should I put thermistors like this : https://diyalephj.blogspot.com/2020/11/building-assembling-and-testing-power.html
How should I place the soft start ?

Thanks,
Eric
 
S

Surf21

Member
Joined 2023
Continuing to collect the pieces for a dual mono Alpha J build. Just need to settle on a chassis.

Considering the Dissipante 3U 400 or 500 chassis to keep a lower profile aesthetic. Any reason this wouldn't be appropriate? Having a hard time figuring out if the heat sinks will be sufficient for a dual mono. Seems like there should be enough space for the components inside from my initial sketch. Thanks for the thoughts.

​

 
Mikerodrig27

Mikerodrig27

Member
Joined 2014
Paid Member
neric34,

The 0.47ohm resistors that you linked to will work. Although they are pretty expensive. I assume these are for the source resistors which any metal oxide or metal film will work. I believe Arrow and Newark still have 0.47R 3w panasonics. Order a bunch if you get them from there as the are sprinkled throughout these pass designs.

The Yageo's should work fine assuming same wattage, tolerence and type

Soft start and DC protection board questions would be better placed in their respective threads. I skimmed through the soft start board selection and didn't see any obvious issues.

You don't need the thermistors with the soft start. Make sure you place the soft start in an open area. If for some reason the relay is ever to fail, the whole load continiously goes through the resistors which could get cooked. Honestly, a couple of CL-60's is probably a simpler more reliable solution for a simple Aleph J. Softstart comes in handy when you are charging a huge cap bank.

1684371273613.png
 
N

neric34

Member
Joined 2023
@ItsAllInMyHead Thanks, 22k 3W are R9 R10 for PSU, I made a mistake. :blush:

@Mikerodrig27 Thanks, No soft start needed if I put thermistors.
What about speaker protectors ?

For 0.47R 3W resistors, I find this. Can I trust with ebay ones ?

https://www.ebay.fr/itm/39449024503...xp3iN89VM94ZWZEf0aeMxlQNcEfe|tkp:BFBM1pbm3IVi

https://composant-electronique.fr/resistance-0-47-ohm-3w-mor03sj047ka19

I will ask questions on PSU soft start and speaker protection threads.

About power transformer, is anyone know Toroidy ones for advice ?

Thanks a lot !
 
ItsAllInMyHead

ItsAllInMyHead

Member
Joined 2019
Paid Member
No worries re: the 22k resistor. I assumed that's what you were using. That's the bleeder resistor for the PSU. You can vary that to your liking depending on how quickly you'd like to discharge the caps. 22k is just fine.

The pictures for the Ebay listing of the Panasonic resistors look legitimate. However, for your own sleuthing and some fun learning about parts, I'd encourage you to look up the spec sheets for the ERX / ERG series of Panasonic resistors and compare their part number to their description. I'd ask the seller for the exact part number as part of your experience. Overall, I doubt VERY seriously that there will be a difference in performance, but it is wise to begin looking at spec sheets. Note the overall composition of the resistor. Also note the different types of leads available and the overall sizes. None of this is too meaningful in this application (IMO), but others are passionate about material used to provide the resistance, the lead material and resistance tolerance (particularly for certain applications).

Long way of saying... not all Panasonic 3W resistors even in that family are equal. But... in this case, all should work wonderfully (IMO). Others may disagree. Either way, they'll be much cheaper than the Vishay Dale you linked.

If you do choose to buy them, ensure you pay in a way that allows buyer protection just in case. 50 should give you enough for a few projects. The price is reasonable.

Edit - No personal experience with Toroidy transformers, but they seem to be highly regarded.
 
You must log in or register to reply here.
Top Bottom