Aleph J illustrated build guide

mkane77g,

Let us know what the rest of your system is, post some more pics of your Aleph J innards, and give us your subjective impressions. Congrats on completing the build!

I just got back from visiting my folks in San Jose. Airport was practically empty!

Best,
Anand.


Most of it's DIY.
Wyn Palmer phono stage
GR Research OB
Sota Cosmos/Eclipse
AR XA modded
SL1200 mkII

I've been through many , many speakers and I'm finally very pleased.

A zillion tube amps

And quite a few medium priced phono stages.

The Aleph J is simply an amazing amp. It's very hard to find any faults compared to what I'm used to. It's the icing on the cake and I don't have to chase tubes anymore. I could kick myself for letting it sit on a shelf for 3 years. Probably cost me $15k.

I makes music sound effortless. Fantastic dynamics, acoustic space is amazing. Gets you right in the middle of things.
 

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I have a weird situation to report with my Aleph J.
I recently acquired a Raspberry Pi 4 and later coupled it with a Pimoroni Linestage Dac Hat.
I have used this in my house with great success hooked up to a large TV screen which is the monitor and also connected to the audio output is a Monoprice hybrid amp, a cheap unit probably made in China but sold in Canada for $200 with 50watts a side solid state output but with a valve preamp. This combination sounds pretty good. But not as good as the Aleph J obviously.
Upstairs in my guitarmaking workshop I have the Aleph J hooked up simply to a laptop running Windows 10 with a 2 terrabite hard drive which has my music library , mostly of MP3's on it.
This goes into a pair of small Bose tweeter allrounder thingos that I was given and at the moment my bass transmission line that is a work in progress. My sound up there is simply great. But when I get the crossover hooked up to limit the transmission line to max 300hertz I think it will come into it's own. I'm using B139 repros by Falcon Acoustics.
OK so I thought I would make the laptop obsolete with another Raspberry Pi , another Pimoroni and I would just use a small 7" screen to select my music and tune up VLC Media Player as I go.
However when I plugged that in I got a huge bad screaming square wave kinda nasty noise.
After a few swap arounds I set up a track to play, then pulled the screen out , then turned on the Aleph and that worked. So this small screen is not compatible with the AlephJ. I had previously plugged it in with the Monoprice and it worked fine.
Can anyone suggest why this is happening or if there's a way of making that work or if I just need to stick with the laptop or get a different screen?
I am thinking perhaps there's an earth missing somewhere.
 
.... I was gonna use (400va/20v) but they do have a 300va/20v for 41$ and a 500va/20v for 55$...which way should I go? 14$ isn’t much any advantage to the bigger transformer in a remote supply?

300VA for an Aleph-J is a bit small. 400VA is better, but if unavailable, I'd go to 500VA.

Nelson recommends a minimum of 7.5 times the output power of each channel. Aleph-J produces ~25wpc. 25 * 7.5 * 2 = 375VA. Then round up. DIY is also about over-engineering for safety/longevity and because we can.

My Aleph-J runs on a 750VA transformer. After hours of operation, that transformer gets pretty warm. I would think a 300VA will run very hot, shortening its service life.
 
300VA for an Aleph-J is a bit small. 400VA is better, but if unavailable, I'd go to 500VA.

Nelson recommends a minimum of 7.5 times the output power of each channel. Aleph-J produces ~25wpc. 25 * 7.5 * 2 = 375VA. Then round up. DIY is also about over-engineering for safety/longevity and because we can.

Thanks for the advice and the proverbs from papa, very helpful...I will go with the 500va happily.

Same subject I was planning on using the UPS board from diyAudio with approx 80k of capacitance per on the remote PS side and another approx 40k per on the amplifier side, does this sound reasonable? I haven’t been able to find a ratio or formula for this, thanks
 
I could tell you exactly, but knowing nothing about all other gear, except Aleph, isn't helping much
OK the screen is a 7" and I wanted to use it with a RaspberryPi4 with a Pimoroni DAC HAT linestage with a 2 terrabite hard drive with the music on it.
The idea was to make the laptop in my workshop redundant.
But as I say with the screen plugged in the noise is attrocious.

However I first tested the screen with the same RaspberryPi setup in the house where I run a cheap Monoprice hybrid amp until I get around to building another Aleph J. Generally I use a large screen which we use for watching videos. When I exchanged the large for the small screen it worked perfectly with no unwanted side effects. The DAC HAT actually gives a good sound in the house.

Therefore the screen is somehow incompatible with the Aleph which is annoying as I had wanted to use it as a stand alone for the sound system in the house eventually.

Maybe it needs a suppressor somehow?
 
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well, I understood all of that from you previous post, but there is simply not enough data

how power supplies are organized for each and every gadget , how signal lines are routed etc.

pictures could help, or we can simply wait to see is anyone having magic wand handy :)

taking in account that Aleph is on safety GND, some other gadget is either having one safety gnd connection too much, or too less

did you use all same cables in previous system?
 
We need to know how is that 7" screen powered up; does it have its own power supply, or it draws the required power from the RPi4's USB?

In general, you need to use a galvanically isolated DAC. This ensures that the DAC's analog stage ground has nothing in common with all that switching rubbish coming from the digital section's ground (and whatever else is plugged there... like that 7" screen with its own high frequency switching converter to power up the backlight <- these are VERY noisy things and should never be used in a digital sound decoding chain)

Aleph J is a very wide band, high input impedance amplifier; this in itself makes it very easy to drive AND very revealing of whatever's present at its inputs (ground noise included) + it is susceptible to ground noise because.... the internal hook-up wiring "travels" some 30-40cm from RCA's, until it gets terminated at amp PCB's

I assume Aleph J is used with RCA's, i.e. single-ended input? If YES, look at the ground-break resistor (10-15ohms) mod that helps...
 
The screen has it's own power supply. The RPI4 has a different power supply.
The connection from the DAC goes from the 1/8th" stereo plug to split to two RCA's.
I use that lead from the laptop too. It is the same setup in the house system but it is a different actual lead.
I can see how noisy the screen is as I plugged it into the laptop as an extension screen and that introduces a low hum in the system. So obviously the laptop has a lot more filtering than the RPI4 which reduces the effect of the screen.
I therefore have decided not to worry about the damn screen. Thanks guys, it was interesting.
Now I do have another question about introducing a volume control to the Aleph.
I thought it would be as simple as puting a pot in the input line so I hooked one up in the box I'm using for the intended preamp.
On zero resistance which is full volume there's a clean sound but increasing the resistance just makes a dreadful hum. There are two sets of RCA,s for in and out so I fed the signals straight into one sid of the pot and took the other side to the output plug. The earths of each are all connected to each other and the earth wire is twisted around each signal wire. They run about 30cm each way.
I am wondering if I need to fit the pots right next to the RCA's to minimise the length of these signal wires, but I also wonder why it would be clean on full volume but with bad oscillations with the knobs turned back a touch , getting louder with increasing resistance?