Hello everybody! This is my first post here, and also, I am very new to the hobby of electronics so please bear with my misunderstandings.
I am thinking about implementing Figure 5 from Zen Variations 1 but with my own twist.
https://www.passdiy.com/project/amplifiers/zen-variations-1
The twist is that instead of using a lamp and the whole circuit between the lamp and positive voltage as in Figure 5,
I will be using a benchtop PSU with constant current at 2A and raising it to 12V.
So the positive of the PSU will be where the lamp is instead of the lamp.
I think 12V 2A matches the conditions specified in the article but I am not entirely sure.
I want to know if this substitution is possible.
The article says you need a constant current source but
I am very new and unsure whether my benchtop qualifies as the 'constant current' source needed.
I have some more questions.
The output in Figure 5 is just a node hanging off to the right.
I have an 8 ohm full range speaker. Do I attach the speaker from 'OUTPUT' to ground?
The input in Figure 5 is just a node hanging off to the left.
Do I attach the positive of my PC audio cable splitter to 'INPUT' and the negative to ground?
(These grounds are all going to the negative of my PSU).
'The electrolytic capacitors should be voltage rated at the supply voltage, which in this project can vary from 40 to 80 volts DC.'
Also, I see my two electrolytics are rated at 25v and 35v, higher than the PSU's 12v but lower than the article's supply voltage at 40v-80v.
Could this be a problem?
Thank you.
I am thinking about implementing Figure 5 from Zen Variations 1 but with my own twist.
https://www.passdiy.com/project/amplifiers/zen-variations-1
The twist is that instead of using a lamp and the whole circuit between the lamp and positive voltage as in Figure 5,
I will be using a benchtop PSU with constant current at 2A and raising it to 12V.
So the positive of the PSU will be where the lamp is instead of the lamp.
I think 12V 2A matches the conditions specified in the article but I am not entirely sure.
I want to know if this substitution is possible.
The article says you need a constant current source but
I am very new and unsure whether my benchtop qualifies as the 'constant current' source needed.
I have some more questions.
The output in Figure 5 is just a node hanging off to the right.
I have an 8 ohm full range speaker. Do I attach the speaker from 'OUTPUT' to ground?
The input in Figure 5 is just a node hanging off to the left.
Do I attach the positive of my PC audio cable splitter to 'INPUT' and the negative to ground?
(These grounds are all going to the negative of my PSU).
'The electrolytic capacitors should be voltage rated at the supply voltage, which in this project can vary from 40 to 80 volts DC.'
Also, I see my two electrolytics are rated at 25v and 35v, higher than the PSU's 12v but lower than the article's supply voltage at 40v-80v.
Could this be a problem?
Thank you.
The benchtop PSU probably will not work well as a CCS drain load for the output mosfet. Power supplies usually have capacitors at their output to minimize ripple. Capacitors offer low impedance to AC which makes them good for minimizing PS voltage ripple but bad for the audio signal. Most if not all of the audio signal will be lost.
as Boyz said - your idea of CCS is sound, but use of lab supply in current limiting mode isn't exactly CCS - it's just current ramp with unknown or bad AC behavior
no problem resorting to any of CCS blocks Pa did show in numerous examples
or just implement something (CCS) you're familiar with
no problem resorting to any of CCS blocks Pa did show in numerous examples
or just implement something (CCS) you're familiar with
May I recommend looking at the ACA? It comes in a few different flavors and is an easy way to begin learning about Papa's amps.
If you are inclined to build a power supply, the original ACA circuit can run up to 30V on its power rail, and performs quite well with higher transconductance output devices in place of the IRFP240.
If you are inclined to build a power supply, the original ACA circuit can run up to 30V on its power rail, and performs quite well with higher transconductance output devices in place of the IRFP240.
I'm in agreement with Tungsten...If you want to get up and running and listen to one of Nelson's designs the ACA is a great way to go. BUT, if you're into experimenting and learning, just build a basic circuit using one channel on breadboard or perf board. Read the F5 article and make note of the Figure 3 COMMON SOURCE EXAMPLES. These are easy to build on breadboard and as stated "they work". Build both and connect them. You'll need to have a good size heatsink for the IRF 240 and run leads back to the breadboard. Easily powered by your lab supply assuming it's two channels (one for each circuit).
I think the most exhilarating moment for me in this hobby was building my first channel of the Zen on perf board, connecting to a lab supply, hooking up a source and speaker, and having it actually play music...IT WORKED, so simple but so rewarding (I knew very little about electronics).
Have FUN!
Oh, you'll need a source with volume control. I just used a iPod when I did my first experiment, along with a cheap speaker.
I think the most exhilarating moment for me in this hobby was building my first channel of the Zen on perf board, connecting to a lab supply, hooking up a source and speaker, and having it actually play music...IT WORKED, so simple but so rewarding (I knew very little about electronics).
Have FUN!
Oh, you'll need a source with volume control. I just used a iPod when I did my first experiment, along with a cheap speaker.
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A replacement for the 300W lightbulb can be a 20 Ohm 100W power resistor attached to the heatsink (a big heatsink).
A similar light bulb loaded amplifier: https://www.firstwatt.com/wp-content/uploads/2023/12/art_delite.pdf
A similar light bulb loaded amplifier: https://www.firstwatt.com/wp-content/uploads/2023/12/art_delite.pdf
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Where’d our O.P. go?
@rollin_ryan give us some feedback. In what direction are thinking of going and where are you coming from (as in your experience). Tons of members here willing to help you on your journey!
@rollin_ryan give us some feedback. In what direction are thinking of going and where are you coming from (as in your experience). Tons of members here willing to help you on your journey!