Aleph printed circuit boards

xcel

Member
2001-09-12 3:23 pm
Almere
Dear DIYers,

First of all, allow me to introduce myself; I'm Martin Prenger, age 31, I live in the Netherlands and at the moment I'm building a set Aleph 1.2's.

For this project I've designed a set of printed circuit boards. I'm planning on having more PCB's made than I actually need (it's cheaper that way). So far I've received various commercial offerings to produce the PCB's and I'm going to place an order within the foreseeable future.

I know that a lot of people want to build Aleph's but are scared off by the fact that there are no PCB's to help them do it. I guess that I'm one of the privileged people that owns professional PCB design software and has boards made on a regular bases.

I was wondering if there's any interest in the DIY community in these boards. If there is maybe we could combine orders to cut prices...So let me know if you're interested ! When enough people are interested, I'm willing to discuss the design in more detail.

Greetings, Martin
 

Nelson Pass

The one and only
Paid Member
2001-03-29 12:38 am
We are preparing a DIY resource site Passdiy.com which
should be up in about 60 days or so, and one of the items
on the agenda is making Aleph boards available. In the
meantime, I have no objection to you offering your own
boards for sale.
 

xcel

Member
2001-09-12 3:23 pm
Almere
Dear mister Pass,

First of all, thank you for the swift reply. Your statement has answered a lot of questions which I know are out there in the DIY-community. I'm very appreciative of the fact that you have no objection to me offering my boards for sale. The fact that you allow other people to sell PCB's for your (patented)designs tells me that you are truly supporting the DIY community.

Martin Prenger
 
Passdiy.com

I will be very interested in seeing this site. Based on my experience the most difficult parts to obtain for those wanting to roll their own, are the boards, heatsinks, and suitable enclosures. The latter is generally a personalised option, however the former 2 would be nice :)

Good luck with it.

Cheers,

Pete
 
Nelson,
You should really consider offering a Passkit! PCB, MOSFETS, heatsinks and torroid. Look what you've started.......everyone's building em.

Martin,
I would really be interested in seeing them. How have you split up the output MOSFETS? I am planning on 3 banks of 4 MOSFETS on each 7" high section of Wakefield 1245 heatsink, and then this on each side of the monoblock to accomodate the 24 devices. Total of six 7" sections of heatsinks total per amp. Should look like a killer, and it will be if one trips and falls into it!
The chap in Austrailia has also an on-line downloadable set of pcb layouts that will work for the 1.2 with a minor addition of an extra resistor to those on the output leg. His output board is also easy to modify for for my mounting 4 MOSFETS per sink. However, I would still like to know more about yours.....Are they 1 oz or 2 oz copper? ground plane? Is it all on one pcb, etc.
Thanks,
Mark Gulbrandsen
Salt Lake City, UT
 

xcel

Member
2001-09-12 3:23 pm
Almere
Dear Mark (and other DIYers of course),

I’ve split the Aleph design into 2 separate boards;

Model 1: a 20x20 cm board which serves as a central circuit board. It holds the power supply circuitry, the front end circuitry and connects the power stages together. Everything connects to this board; the inputs, outputs, transformer secondaries, mains etcetera.

Model 2: a 5x15 cm board that holds the power circuitry. This board holds a bank of 3 MOSFET’s and their respective power resistors. It is meant to be attached just above the heatsinks because I’m going to use the TO247 version of the IRFP240 MOSFET’s. The leads of the MOSFET’s are soldered to this board while their casing is mounted on the heatsink.

As you can see I’ve used the same setup as Pass originally did with the Aleph 1.2, which means that for each monoblock you’re going to need 1 model 1 and 8 model 2 boards. This combines to a total of 18 boards for a stereo set.

Model 1 is a doublesided and model 2 a singlesided board. Both boards are of professional quality which means that;

1) they have a soldermask (a protective finish applied to the PCB to prevent solder from bridging between adjacent traces and pads)
2) they have a silk screen (The text and package outlines that are printed on the PCB to identify components).

I’ve used the top side of model 1 for the supply voltages and as a ground plane. The bottom side is primarily used to tie the power stages together. Tracewidth on this side can range well over 20 mm on this side. Since I’m going to use Caddock MP915/930 low inductance precision power resistors, I’ve taken into account their transistorlike shape. This means that this board can accommodate ordinary power resistors (Dale for instance), but also more exotic ones like the Caddocks.

The model 2 board uses trace widths up to 16 mm (max) and is also suited to use both Caddock and regular power resistors.

The various boards will be connected with Nordost Flatline Gold Mk II cable. I’ve been using this speakercable for over a year now and I’m very satisfied with its performance (Lord knows I’m not one of these Voodoo kind of tuning types). Any other cable can be used as well of course.

For the massive power supply I will be using Philips longlife electrolytic capacitors with screw terminals. These capacitors will be connected to the Model 1 board directly through these screw terminals: in effect they are going to form a “pedestal” for the Model 1 board.

Allow me to emphasize that both boards can be used for the various Aleph’s that have been on the market. The model 1 board can just as well be used for an Aleph 2,3 and of course every Aleph model can use the model 2 boards. You don’t necessarily have to use them together, use anything you like.

I hope that I’ve given you enough insight into the work that has gone into designing these boards. If anyone has any questions, please feel free to contact me !

Greetings, Martin.