Each one of these are so fascinating and oddly satisfying to see them fixed. What's different on this one is that the RED/BLACK from the PSU are actually V+/- rails and the GND is passing through (lifted) 3R 3W resistors via grey wire. I bet this thing suffered from some pretty bad hum, even worse than what you might be experiencing currently. Just make sure you double and triple check your connections when you replace the PSU board.
I just also noticed the resistor across the input rcas. If these are 'true' aleph boards, see if there is an input- on the board. If there is, it should be jumpered to input GND.
Why do you still have hum? I'm sure the power wiring is contributing to a degree but probably not the only cause. If you get the PSU board out, I'm sure everyone would like to see the bottom. The creator had a habit of scratching together PSUs from self etched copperclad boards.
I just also noticed the resistor across the input rcas. If these are 'true' aleph boards, see if there is an input- on the board. If there is, it should be jumpered to input GND.
Why do you still have hum? I'm sure the power wiring is contributing to a degree but probably not the only cause. If you get the PSU board out, I'm sure everyone would like to see the bottom. The creator had a habit of scratching together PSUs from self etched copperclad boards.
Hello, I’m relatively new to DIY audio though I have lurked on various forums for years. In any case, I recently acquired a Rawson built Aleph J and upon trying to reach out to Randy via a PM discovered I’m under moderation.
Randy, assuming you see this, could you “start a PM conversation“ with me so I may share some info with you in hopes to determine reasonable next steps regarding this amp.
Thanks much for any consideration.
Randy, assuming you see this, could you “start a PM conversation“ with me so I may share some info with you in hopes to determine reasonable next steps regarding this amp.
Thanks much for any consideration.
IMHO, by default, we get moderated when we purchase a Rawson amp.
Randy seems to be the main exorcist around here.
Here is a quick article I wrote on my F5v2 journey with Randy's help......Looks horrible....Sounds absolutely amazing!
http://rvbprecision.com/stereo/nelson-pass-first-watt-f5-turbo-v2.html
http://rvbprecision.com/stereo/nelson-pass-first-watt-f5-turbo-v2.html
Your funny....I'm currently driving LRS Magnepans with the little ACA "Mini" amp! And they are filling a 12 X 24 X 8 living room....Three biggest lies in history...I'll love you in the morning, The checks in the mail, My Volvo is a great car and Magnepans need lots of power! (But they do need current!)
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Funny? Nope, just realistic... been there, done that as a matter of fact.
I've tried running the 1.7s with the SissySIT and the Mini myself.
It has NO right to sound as good as it does. BUT, it won't play loud and the bass lacks punch. I mean it sounds fantastic, within it's peak dynamic range. You can get used to it, I listened to it for two whole days, amazed, plain amazed. But then... I hooked it up to the A2s and reality hit me right on the forehead.
When I tried running the Mini last year it sounded very good, really good, but again, ran out of steam too soon.
In my book, the A2s do it for me... glorious 2nd order distortion and deep down bass drive. And, I'm not taking about Euro Techno or anything crazy like that... just normal acoustic dynamics.
I'm punching for a 100wpc SIT. That might do it. Or perhaps an F5T v3.
I've tried running the 1.7s with the SissySIT and the Mini myself.
It has NO right to sound as good as it does. BUT, it won't play loud and the bass lacks punch. I mean it sounds fantastic, within it's peak dynamic range. You can get used to it, I listened to it for two whole days, amazed, plain amazed. But then... I hooked it up to the A2s and reality hit me right on the forehead.
When I tried running the Mini last year it sounded very good, really good, but again, ran out of steam too soon.
In my book, the A2s do it for me... glorious 2nd order distortion and deep down bass drive. And, I'm not taking about Euro Techno or anything crazy like that... just normal acoustic dynamics.
I'm punching for a 100wpc SIT. That might do it. Or perhaps an F5T v3.
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The update took a bit longer than expected but I'm now enjoying Papa's F3. The right channel was fine once I made the updates and resoldered all the connections. The amp gets warm and now runs like a First Watt amplifier as opposed to burning your fingers, if you touched it.
I removed the resistor set up attached to the back panel, which had turned the amp into a toaster.
Bought a new transformer with the correct voltage.
Added a power supply board from Rthatcher, made to fit a small chassis. (The key to making this all work)
Added a star ground.
Replaced the cheesy speaker terminals.
Keratherm pads underneath all the Fets.
And plenty of CL-60s on the small board connecting the 120V in and also on the power supply board.
A big Thank You to Papa and Randy!
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Yep. Card carrying member of the club. I also have a chassis that was a non-working F5. I think I'll update it to the small M2 boards (updated layout by Prasi).
Re: F5M.... as I recall, Nelson introduced it as a "cheaper" alternative to the F5. He said that FYI'rs want it cheap and so he took out some parts that lowered the cost.
So, I read that as an effort to make a cheaper F5.
I don't recall any claims that it would sound better. It could be implied that less parts are better, but still... IMHO less parts.. easier to build, etc... yes, but how many parts are the minimum to make something sound good?
So, I read that as an effort to make a cheaper F5.
I don't recall any claims that it would sound better. It could be implied that less parts are better, but still... IMHO less parts.. easier to build, etc... yes, but how many parts are the minimum to make something sound good?
