Nelson Pass Aleph-X build

[Surrealistix]

I built an Aleph-X biased to about 38 watts at 8 ohms last year. The amp puts out a lot of heat.

I have bult an Alelph-3, F5 in the past and a Hypex amp recently. Of all these the Aleph-x was a real test of patience. I blew up 8 mosfets in the build process and many other things went wrong. Finally got the whole thing to work after several months being at it.


It's sitting on the top shelf of my rack.
I had also built an Aleph-3 some years ago which is the 2 amp from the bottom. And the black box in the middle is a Hypex amp I built a couple of months ago.

 

[corElement]

Good god man, that looks like a monster!

How does it sound?

 

[sachu888]

Great amps,wanna build Pass F5 Turbo V2 Gb is open http://www.hifivision.com/diy/28245-diy-pass-f5-turbo-v2-initiated.html

Regards,
Sachin

 

[omishra]

Congratulations!
That's great power supply into the metal. Thank you for showing it us.
I am curious what made those MOSFets blow? Did you use smaller heatsink earlier? Or some bias problem? ( I have not read the literature)

 

[Surrealistix]

About the blown up Mosfets - where do I begin!

I had built the F5 and the Aleph 3 without any problems. So was reasonably confident about the Aleph-x build. I got one channel working without any problems. Then I decided to use premium parts and ordered them from PartsConnexion. Waited for 2 months for the parts to arrive, after which I made a series of embarrasing mistakes leading to Mosfets blowing up. I will list a few:


I forgot to discharge the Power Supply caps once and on touched the soldering iron to one of the biasing resistors - Smoked!


I think my multi-meter probe touched something it shouldn't have while biasing and resulted in one of the biasing resistors glow up like a build and the Mosfet was gone!

At this point, I had to match Mosfets again and while matching mosfets and putting them back on the Heatsink, I might not have tightened them enough and puff they went!



So all in all, the amp sounds great and packs a lot of punch so I can forget all about the smoking Mosfets and glowing resistors for now

 

[Surrealistix]

@Sachin - I saw the F5 Turbo GB thread. I don't think I need another amp any time soon. I already have three amps for my active speaker setup. It's tempting

 

[apk]

Very nice build. Congratulations! The Aleph-X is really a monster.

Since you have also built the F5, how would you compare the sound difference between the two? What speakers do you pair these amplifiers with?

 

[sachu888]

Hi Surrealistix,
you got a nice equipment rack.Did you get it from Magma?

Regards,
Sachin

 

[santhosh]

Nice build and thanks for sharing ^ mistakes with us - all easy mistakes and can happen to any of us.

Nice rack as well. Enjoy the system

 

[apk]

Hi Surrealistix,
you got a nice equipment rack.Did you get it from Magma?

Regards,
Sachin

+1 on the rack. Do share where you got the rack from?

 

[gobble]

Good stuff! Your build story is something I anticipated as a novice that I would not be able to handle and beyond my expertise, hence I dropped the idea of Pass builds and opted for a completely tested amp DIY kit.

How does it sound? Compared to mass market? Compared to F3?

--G0bble

 

[Surrealistix]

Rack - I had my carpenter put together the rack for me. It's made from wood that I recycled from a very old bed we had at home.

Aleph-X Sound - I haven't heard the Aleph-x much as I haven't had the chance to hook it up to my main speakers as yet. It does have an extended top end as compared to the Aleph-3 and the bass is definitely more articulate. As for stereo imaging and sound stage, I will know once I have it setup properly.

@APK - I am planning on using the Aleph-x to power the mid woofer for my 3 way active Emerald Physics CS 2.3 OB speakers. I will be using the Aleph 3s for the tweeters and the Hypex 400HGs for the 15 inch dual woofers.

@Gobble - The Aleph-x was a particularly difficult build for me. The F5 was much easier.

 

[Surrealistix]

Here are some pictures of the old Aleph 3 build from 2 years ago my first amp build. I did clear the mess inside to some extent before finishing up

I bent a 10mm aluminum plate to form a C shape and slapped on a pair heat sinks on the side.

 

[captrajesh]

I built an Aleph-X biased to about 38 watts at 8 ohms last year.

Nice looking build. I'm looking for heat sinks for my F5 Turbo. What are the dimensions of the heat sinks?

 

[anilva]

Nice looking build. I'm looking for heat sinks for my F5 Turbo. What are the dimensions of the heat sinks?

Capt,

Please go to perfectmetal.in and order the required heatsinks. They will deilver you home.

 

[captrajesh]

Please go to perfectmetal.in and order the required heatsinks. They will deilver you home.

From the website, they seem to deal mainly in decorative and some utility items: Metal Artwares,Wholesale Stainless Steel Cookie Cutter,Christmas Decorative Items Manufacturers

Nevertheless, sent them a mail with pics of heat sinks.

Edit: Just realised that it is perfectmetal.in and not perfectmetals.in.

I had discussed the issue at length with officials of perfect metals company located in Bangalore yesterday. According to him and also, according to their brochure, the widest heat sink available is 'N56' i.e. the one sourced by you. I had asked him if they have their rep in Chennai to which he has given me the reference of the very vendor whom I had contacted a couple of days back. Unfortunately, the main person is out of station and expected back only after 10th. The person in-charge was not very enthusiastic in attending to me though he was kind enough to let me inspect his stocks to see if I can find anything interesting.

I'm reserving my decision till the main person returns.