I want to build one Nelsons amps but not sure which one.
My speakers are 100db back loaded horns (wideband with tweeter from 7.5khz) and I have a Stereo Coffee passive pre amp. Sources are TT and CD.
I currently use a push pull 6550 valve amp, which does a great job, but want to try a SS class A design.
My speakers are 100db back loaded horns (wideband with tweeter from 7.5khz) and I have a Stereo Coffee passive pre amp. Sources are TT and CD.
I currently use a push pull 6550 valve amp, which does a great job, but want to try a SS class A design.
Choose a very simple one to cut your teeth on.
Maybe a SE mosFET from a single sided supply?
and try both the resistor load for the mosFET and then try a CCS as the mosFET load.
By the time you have completed listening tests on these two builds, you might have a better idea what you want.
Maybe a SE mosFET from a single sided supply?
and try both the resistor load for the mosFET and then try a CCS as the mosFET load.
By the time you have completed listening tests on these two builds, you might have a better idea what you want.
I recommend to build the AlephJ.
And if you can follow build instructions, controlling your work at every step and make a clean work, i would not build the easy amp first.
Because imho its wasted money. If your easy amp work you will build an bigger and maybe better amp -->or better, i would do that😀
For example my first build was an AlephJ. PCBs was made on perfboard.
Running at first turn on without burning down.
And it is still running without problems.
And what to do if alephJ was the easy amp? now building really slowly an Aleph60 ->the bigger amp😀😀😀
I`ve also get good results with the ACA this is an really easy amp.
But it was to weak for me with 92db Speakers.
F5 is easy to build i`ve done it on perfboard too. really good sound but i prefer the aleph.
A Tip->don`t build it perfborad. its a laborious work. Buy the pcbs here in the shop will be much easyer.
hopefully this could help you.
And if you can follow build instructions, controlling your work at every step and make a clean work, i would not build the easy amp first.
Because imho its wasted money. If your easy amp work you will build an bigger and maybe better amp -->or better, i would do that😀
For example my first build was an AlephJ. PCBs was made on perfboard.
Running at first turn on without burning down.
And it is still running without problems.
And what to do if alephJ was the easy amp? now building really slowly an Aleph60 ->the bigger amp😀😀😀
I`ve also get good results with the ACA this is an really easy amp.
But it was to weak for me with 92db Speakers.
F5 is easy to build i`ve done it on perfboard too. really good sound but i prefer the aleph.
A Tip->don`t build it perfborad. its a laborious work. Buy the pcbs here in the shop will be much easyer.
hopefully this could help you.
Hi,
thanks for that, I was torn between the Aleph J and F5, may well order both sets of PCB's plus PSU and a 4U case so I can build the F5 afterward and try it just by swapping the amp pcb's,
Cheers
Des
F5 has only 4 active devices. It should be very easy to assemble especially using the DIYaudio PCBs.
But we are seeing dozens of builders getting it very wrong !
Don't start with an F5 and definitely not an F5t.
Thanks Andrew,
the plan was to start with the Aleph, what are people getting wrong with the F5? Although few in parts are they difficult to assemble properly?
Cheers
the plan was to start with the Aleph, what are people getting wrong with the F5? Although few in parts are they difficult to assemble properly?
Cheers
I thought the F5 so simple when I saw it, I never imagined that so many can get is wrong and wrong in a big way.
It turns out that for many Members, 4 active devices is just too many to understand and what they are supposed to be doing.
It turns out that for many Members, 4 active devices is just too many to understand and what they are supposed to be doing.
Then ist time to ask, despearce whats his skills in electronics and assembly of such things.
If he works in a Office and has never get in touch with such things, then ist maybe not a good idea to work with mains voltage and/or high currents.
But if i look at me, ive had an simple electronics course at my education for industrial mechanik. so i roughly knows how not to kill myself accidentally.
And then ive only worked with the F5 Manual and the amp runs.
Things i have taken care about:
-to buy no fake semiconductors,
-stuff your boards right
-do not reverse polaritys / pinouts of things wich have a polarity or pinout
-do not short the circut
-Keep in mind your own safety
-double tripple checked everything
and follow carefully the instructions
this could not be much more difficult in kingdom😀😀😀😀
greets alex
If he works in a Office and has never get in touch with such things, then ist maybe not a good idea to work with mains voltage and/or high currents.
But if i look at me, ive had an simple electronics course at my education for industrial mechanik. so i roughly knows how not to kill myself accidentally.
And then ive only worked with the F5 Manual and the amp runs.
Things i have taken care about:
-to buy no fake semiconductors,
-stuff your boards right
-do not reverse polaritys / pinouts of things wich have a polarity or pinout
-do not short the circut
-Keep in mind your own safety
-double tripple checked everything
and follow carefully the instructions
this could not be much more difficult in kingdom😀😀😀😀
greets alex
With your speakers? Honestly any of the amps will work, and very well.
That said, build an Aleph J. IMO, it's the most beautiful, precise, musical, and tuneful of these amps.
Look at this page, lots of good info in the descrpion, and many useful links - Aleph J (2 PCBs included, which makes 2 channels) - Circuit Boards
Illustrated build guide - http://www.diyaudio.com/forums/pass-labs/241729-aleph-j-illustrated-build-guide.html
Check your PM.
That said, build an Aleph J. IMO, it's the most beautiful, precise, musical, and tuneful of these amps.
Look at this page, lots of good info in the descrpion, and many useful links - Aleph J (2 PCBs included, which makes 2 channels) - Circuit Boards
Illustrated build guide - http://www.diyaudio.com/forums/pass-labs/241729-aleph-j-illustrated-build-guide.html
Check your PM.
trimming two pots at once with two voltmeters may make F5 too much of a start (assuming you do not even use the later added P3 pot); this is of course unless you are already knowleadgable in the field. Aleph also will require tuning in a few spots. for your speaker efficiency, and with a preamp to drive lowish input impedance, I believe ACA is the nobrainer answer. 
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I've managed to build a linear psu, LDR passive pre, hagerman bugle 2 kit (and mod it with better parts and change the gain to a custom setting), a SUT and the speakers mentioned.
I was a Physics teacher for 15 years and am comfortable wiring the house (and then having a qualified sparky check it) but I'm no expert. I could probably read schematics easily and work things out (if I spent some time researching/refreshing knowledge)...
I was a Physics teacher for 15 years and am comfortable wiring the house (and then having a qualified sparky check it) but I'm no expert. I could probably read schematics easily and work things out (if I spent some time researching/refreshing knowledge)...
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