Just a quick copy and note
It's been a long time and I look back wistfully, I just came across my old circuit board films... My Aleph5-mono clone - with BUZ because the IRFs were not available at the moment. My implementation from 2001, it was brewing in me for three years - and at the latest after I was allowed to listen to the original in silence and peace (probably in 1996 or 97), I realized that I loved this amp. What a fascination that was! To this day, this Aleph haunts my amplifier self in a positive way.
It's been a long time and I look back wistfully, I just came across my old circuit board films... My Aleph5-mono clone - with BUZ because the IRFs were not available at the moment. My implementation from 2001, it was brewing in me for three years - and at the latest after I was allowed to listen to the original in silence and peace (probably in 1996 or 97), I realized that I loved this amp. What a fascination that was! To this day, this Aleph haunts my amplifier self in a positive way.
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Perhaps a few words about the story
In the 1990s, only a few people in my environment had ISDN Internet access and even fewer used SPICE to simulate their ideas; they simply got started or copied a construction proposal from a magazine.
But Passlabs published the service manuals and so the circuit was now known. The first German fanatics even wired their experiments freely. Circuit boards were still etched in the cellar.
Well, I was infected and the original cube had done it to me - never before had I heard this natural, three-dimensional reproduction of a chain.
I couldn't afford to buy it, so at some point I thought my way into the circuit and tried to understand how the dynamic, modulated current source worked.
I was skeptical whether this (special) pull-along was a ground-breaking idea - but after the click I realized, at some point you build your own version or you have to win the lottery.
In the meantime, the German replicas were all over the scene and Passlabs was praised to the skies.
A few years later, I got down to work - somewhat half-heartedly, because I had other things on my mind than building the nth amplifier.
...
In the 1990s, only a few people in my environment had ISDN Internet access and even fewer used SPICE to simulate their ideas; they simply got started or copied a construction proposal from a magazine.
But Passlabs published the service manuals and so the circuit was now known. The first German fanatics even wired their experiments freely. Circuit boards were still etched in the cellar.
Well, I was infected and the original cube had done it to me - never before had I heard this natural, three-dimensional reproduction of a chain.
I couldn't afford to buy it, so at some point I thought my way into the circuit and tried to understand how the dynamic, modulated current source worked.
I was skeptical whether this (special) pull-along was a ground-breaking idea - but after the click I realized, at some point you build your own version or you have to win the lottery.
In the meantime, the German replicas were all over the scene and Passlabs was praised to the skies.
A few years later, I got down to work - somewhat half-heartedly, because I had other things on my mind than building the nth amplifier.
...
So after the millennium, I went to work fresh and innocent. Two heat sinks, two 19-inch cases, aluminum brackets, aluminum sheet ... were ready. Well, I thought I'd try it out - I also believed that a pair of IRFs should theoretically be enough (at just under 2A idle current). I etched a circuit board and realized that three pairs of IRFs might be more appropriate after all. They just fitted on the main heat sink. Wasn't it a bit too poorly dimensioned? I recalculated the thermal resistors, but it should fit. I didn't have any larger ones and a double mono setup didn't fit into the small housing, so everything finally fell into place. It had to be safe to touch, no hot external surfaces - so I stuck with the concept (of the structure).
I think you can (still) make out the cooling concept in the old photographs. I remember exactly how the main heat sink cracked when it reached 95°C. And I was wide-eyed, because the calculation didn't actually show any thermal problems, everything should just fit. But I was wrong. What should I do? And that after I wasn't satisfied with the whole mess of cables, a presentable setup looks different - I thought.
At this point GRollins was chatting publicly with Nelson Pass and the Aleph-X versions were already being created. Nelson described his approach to setting up an Aleph - and I followed it exactly, after I had given each MOSFET only 0.5Adc.
With a power dissipation of just under 93W, the hotspot settled at perhaps <70°C, right at the case of the transistors. To be honest, I can't remember exactly, maybe the temperature was only 65°C - in any case, it wasn't critical.
A 30-sec switch-on delay, two relays in the output, a perforated steel plate on top - and the end result didn't even look that bad.
I probably adjusted the frequency response compensation with a 10kHz square wave signal under load, of course.
...
I think you can (still) make out the cooling concept in the old photographs. I remember exactly how the main heat sink cracked when it reached 95°C. And I was wide-eyed, because the calculation didn't actually show any thermal problems, everything should just fit. But I was wrong. What should I do? And that after I wasn't satisfied with the whole mess of cables, a presentable setup looks different - I thought.
At this point GRollins was chatting publicly with Nelson Pass and the Aleph-X versions were already being created. Nelson described his approach to setting up an Aleph - and I followed it exactly, after I had given each MOSFET only 0.5Adc.
With a power dissipation of just under 93W, the hotspot settled at perhaps <70°C, right at the case of the transistors. To be honest, I can't remember exactly, maybe the temperature was only 65°C - in any case, it wasn't critical.
A 30-sec switch-on delay, two relays in the output, a perforated steel plate on top - and the end result didn't even look that bad.
I probably adjusted the frequency response compensation with a 10kHz square wave signal under load, of course.
...
Completely satisfied with the result, I added (up) my version of the balancend preamp - amazing!
Somehow later on, a master baker from the beautiful city of Ulm became aware of me. I continued to make all sorts of things, wanted an X.
Master baker continued to insist and I gave in and sold him the combination. Since then they have been on the move and changed owners several times in the scene. This bothered me and I turned my back on the scene.
#
Perhaps this thread can be of use to other Aleph stories. And other users write and share their experiences here - that would be great.
Somehow later on, a master baker from the beautiful city of Ulm became aware of me. I continued to make all sorts of things, wanted an X.
Master baker continued to insist and I gave in and sold him the combination. Since then they have been on the move and changed owners several times in the scene. This bothered me and I turned my back on the scene.
#
Perhaps this thread can be of use to other Aleph stories. And other users write and share their experiences here - that would be great.