Hey All,
I just completed an Aleph J build, and now I am burning the amp in my system. I only experienced one glitch during the build where I damaged the JFETs while installing them and tightening the ties. Fortunately, I was able to get a matched quad of the Toshiba 2SJ74 BL JFETs from eBay seller Punkydawgs where I have purchased transistors from in the past. This time, everything tested well and it sounds great right from the start. There is a faint hum, so I’ll rotate the toroidal transformer to eliminate it.
Anyway, thanks for this excellent build guide 6L6. It made building and testing this amp a lot easier.
This amp has a big sound if I can call it that. It is also very nicely detailed with great separation of musicians in the soundstage. I am very pleased with this amp. It sounds different from the Pass DIY Sony VFET amp and my McIntosh MC240 tube amp. They are all excellent in their own ways. To my ears, this amp almost has bloom like a tube amp. Is this due to the single ended nature of this amp design? I like it!
I need to get my measurement gear in place and analyze this amp’s output. Thanks again.
I just completed an Aleph J build, and now I am burning the amp in my system. I only experienced one glitch during the build where I damaged the JFETs while installing them and tightening the ties. Fortunately, I was able to get a matched quad of the Toshiba 2SJ74 BL JFETs from eBay seller Punkydawgs where I have purchased transistors from in the past. This time, everything tested well and it sounds great right from the start. There is a faint hum, so I’ll rotate the toroidal transformer to eliminate it.
Anyway, thanks for this excellent build guide 6L6. It made building and testing this amp a lot easier.
This amp has a big sound if I can call it that. It is also very nicely detailed with great separation of musicians in the soundstage. I am very pleased with this amp. It sounds different from the Pass DIY Sony VFET amp and my McIntosh MC240 tube amp. They are all excellent in their own ways. To my ears, this amp almost has bloom like a tube amp. Is this due to the single ended nature of this amp design? I like it!
I need to get my measurement gear in place and analyze this amp’s output. Thanks again.
Pass DIY Addict
Joined 2000
Paid Member
That's a nice looking build, Rich! Nice looking system as well! Along with rotating the transformer, you might want to braid/twist those AC wires (both primaries and secondaries) and see if you can pull the input signal wires closes to the side heat sinks.
Where did you find that nice looking chassis?
Where did you find that nice looking chassis?
Nice build, Rich! Along with Eric’s suggestion, you could also try running your ground with the +/- rail wires. Might help with the hum, or at least that’s been my experience.
Hi All,
Thanks for all the tips. I’ll route the ground with V+ and V- to each board. I’ll start with trying the transformer rotation and then change my wiring. I do like Zen Mod’s suggestion the best (ha ha), but I’m trying to coordinate the Aleph J with my Audio Research gear. I also have the B1 Korg preamp with the green LED and black Aluminum chassis.
The chassis is the 4U Deluxe chassis from the diyAudio.com store. I bought the optional handles and then drilled out 5mm dia. holes for the LEDs and countersunk the holes using. 1/4 in. bit on my drill press. I used a Sharpy permanent marker to color the drilled and countersunk holes and you’d swear it was anodized.
As the amp has been playing on, it’s really sounding great. I am very pleased with how this has turned out, and I am confident I can tackle the faint hum.
Thanks for all the tips. I’ll route the ground with V+ and V- to each board. I’ll start with trying the transformer rotation and then change my wiring. I do like Zen Mod’s suggestion the best (ha ha), but I’m trying to coordinate the Aleph J with my Audio Research gear. I also have the B1 Korg preamp with the green LED and black Aluminum chassis.
The chassis is the 4U Deluxe chassis from the diyAudio.com store. I bought the optional handles and then drilled out 5mm dia. holes for the LEDs and countersunk the holes using. 1/4 in. bit on my drill press. I used a Sharpy permanent marker to color the drilled and countersunk holes and you’d swear it was anodized.
As the amp has been playing on, it’s really sounding great. I am very pleased with how this has turned out, and I am confident I can tackle the faint hum.
That’s a great tip on the sharpie anodization! Makes me want to order the black faceplate for my chassis. Looks great
Pass DIY Addict
Joined 2000
Paid Member
Thanks, Rich. As I looked at your chassis some more, I was wondering if that was from the DIY store. I'm sure you'll get your hum squared away! Just be methodical and you'll get there.
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Pass DIY Addict
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What a creative build! Is that a special build intended for you AJ, or is that a repurposed chassis? That's some hunk of heat sink! If you put some taller feet (1-2") under that, you'll get better airflow for cooling.
The chassis was built for the AJ. I had two of the heatsinks waiting for an appropriate project for it. But then came my interest with AJ and I thought using two might be an overkill so I decided to risk with one. Turns out one is more than enough. Temp stays around 35-39degC, though in an Aircon room.
Pass DIY Addict
Joined 2000
Paid Member
Thanks, Eric. I am glad you like the build. All thanks to 6L6 for the wonderful comprehensive build guide.
Standoffs for IRF MOSFETS
Forum: Pass Labs
Assigned Moderators: N/A
Posted by: 6L6
Original Content:[/QUOTE]
Does anyone know the size of the standoffs in the DiyAudioStore backplate kit? I am about to place a follow up order with Mouser and have the IRF MOSFETS from the DiyAudioStore. I would like to include the longer standoffs in my order.
Thank you.
Jazzzman
Post: Aleph J illustrated build guide
Forum: Pass Labs
Assigned Moderators: N/A
Posted by: 6L6
Original Content:[/QUOTE]
Does anyone know the size of the standoffs in the DiyAudioStore backplate kit? I am about to place a follow up order with Mouser and have the IRF MOSFETS from the DiyAudioStore. I would like to include the longer standoffs in my order.
Thank you.
Jazzzman
M3
5mm tall.
Sometimes these are listed as 10 or 11mm since that’s the total length of the standoff part and the threaded male.
Amazon is a great source, though you’ll need to buy in qty. 50
5mm tall.
Sometimes these are listed as 10 or 11mm since that’s the total length of the standoff part and the threaded male.
Amazon is a great source, though you’ll need to buy in qty. 50
