Aleph 30 Class A amplifier courtesy of Nelson Pass

I've created this page as a resource for any novice considering building an Aleph 30. Depending on where you live in the world can influence decisons on purchasing - a case for example might have taxes added/deducted and shipping costs can be a big factor (it's worth asking about surface shipping - slow but cheap). Trying to collect all the parts  starts to give you some sympathy for those building nuclear subs! Try and order lots from one place to get free shipping and bear in mind lead times. Digikey, Mouser, Farnell

There is an excellent resource and community at DIYaudio (a lot of information here came from reading threads there) Aleph 30 Wiki

Excellent Chipamp v2.0 boards for Power, amp and output (click on order and scroll down to the bottom)
Bill of materials for above in Excel and Adobe PDF (updated and consolidated Nov 2011)
Schematic for above

Original Pass Labs Aleph 30 schematic
Original Pass Labs Aleph 30 owners/service manual

In addition to the Bill of materials you will need:

Multicore or Rosin solder (0.5-0.7mm)
16 x Mica pads, thermal grease or silpads - these electrically isolate the transistors
16 x M3 screw, nut, washer and insulating sleeve
an M3 tap and 2.5 drill for the heatsinks

IEC socket, CL60 thermistors, Slow blow 2A fuses
2 RCA female, 2 XLR 3 pin female for balanced , 4 x speaker posts
Solder tags (3.2mm id worked with the terminal blocks)
Terminal blocks
Earth/ground terminals
Wire for amp internals

15W soldering iron (Weller and Antex are both good makes) with a chisel tip
and in the very useful category - a secondhand analogue oscilloscope. Dual trace or dual beam, >=20MHz  (e.g. My Tek 2235, 100MHz, dual trace, 2mV/cm), a digital infra red thermometer


Rail voltage (assuming cap input filter) = transformer secondary voltage x 1.414
e.g. 18Vac x 1.414 = 25.4Vdc  but, the bridge rectifier steals a couple of volts, so your actual rail will be more on the order of 23Vdc

Amplimo - Netherlands 2 different qualities
Canterbury windings - UK Audio grade designs
Toroidy - Poland Audio class
Some nice
transformer cases

Cases (prices November 2011)
If supplied from EU 21% Tax will not apply outside EU, If USA supplied Import duty and VAT can apply outside USA

Aleph 30 dissipates 100w per channel so so heatsink requirement for 25C above ambient is 25/100 = 0.25C/W

Make and model   Construction Price Tax in EU Import duty Shipping Width Depth Height Fin mm  C/W  
Hifi2000  Pessante dissipante 4U Italy 4mm Al face, steel (10mm face +10 Euro) 115 Euro 21%   25 Euro 483 300 165 40 0.31  
Hifi2000  Pessante dissipante 5U Italy 4mm Al face, steel (10mm face +10 Euro) 152 Euro 21%   25 Euro 483 300 210 40 0.2  
Hifi2000  Pessante dissipante 5U Italy 10mm Al Face, 3mm Al rear, 3mm Al 192 Euro 21%   25 Euro 483 300 210 40 0.2  
THL PWAD-01 Taiwan 8mm Al face £106       402 260 134     Rear cutouts
Design & build ezPower NZ 3mm Al Face, 2mm Al rear, steel $225     $106 432 300 150   0.33 (30C rise) Pre punched rear, labels
Par Metal 22-17125B (ebay) USA 3mm Al Face, 2mm Al rear, 1.5mm Al $165   $33 $85 425 290 130 50    
Fischer Elektronik SKE 5 400 Germany   £334!       400 315 215 40    
Lite Audio A200 3 sinks per side HK   $189       480 430 150     Rear cutouts (+XLR)
VTC AR-998B HK 7mm Al Face, Steel $107       480 380 180 32   Cutouts and connectors

Audiokit sell the Hifi2000 cases


After you have gone cross eyed ordering all the parts it's time to get started. I decided to build the power supply board first and fell at the first hurdle - I looked at the caps and could not see the polarity (no laughing this is for novices) - it's not like the markings on a battery! For those that don't know. For LED's Anode is the long leg, Cathode is the short leg, Anode is the Triangle side of a circuit diagram ,Cathode is the Flat line of a circuit diagram

My first attempt at soldering went OK but no more. Simple fact was that the iron wasn't hot enough - I had to put the iron on the pad/leg for too long and the solder did not flow well. Turned the heat up and it was much better though you have to be quickk

Original heatsink was 25mm tall and 12.7mm wide - can go up to 16mm wide on the board. Heatsink I used (Aavid SW63-2) which have unequal channels use the smaller one, there is also a vertical groove into which the thermal pads slide which provide electrical isolation. The best pads for thermal conductivity are Mica with grease and Silpads (look for a low thermal resistance)

Bleeder resistors are a safety measure, they drain off the charge after switching off. The PSU will work without these installed, just bear in mind that when you're gonna do some maintenance the capacitors still hold a charge.
The other resistors form a first order RC filter with the final PSU cap. Example: With a 1 ohm resistor and a 10000uF cap in C3 you get a cut-off frequency of 15.92 Hz using this formula: 1 / (2*Pi*R*C)
The five resistors you can place are in parallel, choose a combined value for R, then calculate which values you have to place in parallel to get your value for R. You will want to use four or five 3Watt resistors in parallel so they share the load. Mount these resistors at least 0.25" off the board, they will get hot.

Soldering PCB video for novicess and an excellent guide use a crocodile clip as a temporary heatsink

Torquing TO-220
Heatsink/Mounting TO-220 and another and another and another

Not an Aleph 30 (an Aleph-X) but very useful
Guiseppe Bianco A30 (originally in Italian)