1.7A Mu Follower
ZM -
I'm new to Spice and other aspects of design. I used your ACA top half model and played a bit to get a desired low distortion 1.7A CS Mu Follower.
Can you opine on whether the attached is a good idea vs say an opto?
ZM -
I'm new to Spice and other aspects of design. I used your ACA top half model and played a bit to get a desired low distortion 1.7A CS Mu Follower.
Can you opine on whether the attached is a good idea vs say an opto?
opto or "just" bjt - that's just matter of bias , in other word - Iq
having enough voltage across big resistors and using mosfet as main part , bjt solution is adequate .....contrary to case where , for instance , Semisouth is used , having smaller Ugs , and making things complicated for , then , almost voltage starved bjt
varying ratio of big resistors will give you different percentage of AC current contribution of upper half , thus different THD spectra
look here : LTspice Tutorial | The Complete Course
having enough voltage across big resistors and using mosfet as main part , bjt solution is adequate .....contrary to case where , for instance , Semisouth is used , having smaller Ugs , and making things complicated for , then , almost voltage starved bjt
varying ratio of big resistors will give you different percentage of AC current contribution of upper half , thus different THD spectra
look here : LTspice Tutorial | The Complete Course
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I tried a few configurations and the BJT output was very similar (In terms of amplitude and waveform) whether an opto or BC was used. I doubt I will absorb the LT Spice manual as I am not a technical person. Is there an issue that jumps out at you?
even if I'm seeing things these dayz even less clearly then usual
, let's say - nothing just go for it
Increasing the bias decreases the distortion. More bias is better.
There is no 'downside' to the resistor mod, it is a fix to set the amp to it's most optimal operating point, and the difference in sound is remarkable -- because it is playing/operating as designed, and without the mod it is essentially a 1W amp...
There is no 'downside' to the resistor mod, it is a fix to set the amp to it's most optimal operating point, and the difference in sound is remarkable -- because it is playing/operating as designed, and without the mod it is essentially a 1W amp...
even if I'm seeing things these dayz even less clearly then usual
just go for it
If you have thoughts on ways to evaluate the circuit in LTSpice please let me know. As I said, I'm new to Spice. I built the circuit, but without a distortion analyzer, I'm shooting in the dark.
I have built ACA # 1.
My speakers are Dynaudio Foccus 4 ohms.
In my board I added 0R47 parallel to R1 and R2, and 0R68 parallel to R3 and R4.
R12 replaced with 150K.
12.5 volt power supply with load.
The sound was unbalanced at high frequencies and low frequencies were few.
I then replaced parallel 0R47 with 0R68, and parallel 0R68 with 1R.
The sound has changed, now it is balanced, low frequencies are deep and controlled. I am very satisfied.
If you'll build F5, I have to make adjustments with my speakers?
My speakers are Dynaudio Foccus 4 ohms.
In my board I added 0R47 parallel to R1 and R2, and 0R68 parallel to R3 and R4.
R12 replaced with 150K.
12.5 volt power supply with load.
The sound was unbalanced at high frequencies and low frequencies were few.
I then replaced parallel 0R47 with 0R68, and parallel 0R68 with 1R.
The sound has changed, now it is balanced, low frequencies are deep and controlled. I am very satisfied.
If you'll build F5, I have to make adjustments with my speakers?
Very Cool.
sir! did you try to review angain with your circuit drawing ?. I've founded some diffirence between circuit with PCB ..
My ACA is finished
i just finished my first project. I am very happy with the soud (connected to Lowther DX3) no agressivenes whatsoever.
Actually the ACA is connected to a DAC2 from W4S.
Any suggestion for a pre-amp (DIY) that would give substantially better results ?
Thanks for the very clear instructions and to mister Pass for the design.
Walter
i just finished my first project. I am very happy with the soud (connected to Lowther DX3) no agressivenes whatsoever.
Actually the ACA is connected to a DAC2 from W4S.
Any suggestion for a pre-amp (DIY) that would give substantially better results ?
Thanks for the very clear instructions and to mister Pass for the design.
Walter
Since finishing the ACA I have been attempting to learn how it works. I think I'm making progress but have a question about start up.
When I first turn the amp on there is a very quiet high pitched charging sound (presumably one of the caps) from my speakers. Is this normal?
Rather than build other projects I want to get the most out of the ACA and try to tart it up with additional mods. Not necessarily to improve the sound but more as a learning exercise. Things I have in mind:
-input selector and possibly a volume control to make it a sort of integrated amp.
-soft start, maybe this will help with the startup tone I described earlier.
-Build my own mains power transformer.
-speaker protection circuits. probably not neaded as it's low powered but nonetheless it would be good to learn how they work.
Am I right in thinking that the soft start boards and speaker protection circuits available from the store won't work due to the lower power?
if I'm right is it a case of getting a calculator out and changing component values or will the changes needed be more in depth?
cheers.
When I first turn the amp on there is a very quiet high pitched charging sound (presumably one of the caps) from my speakers. Is this normal?
Rather than build other projects I want to get the most out of the ACA and try to tart it up with additional mods. Not necessarily to improve the sound but more as a learning exercise. Things I have in mind:
-input selector and possibly a volume control to make it a sort of integrated amp.
-soft start, maybe this will help with the startup tone I described earlier.
-Build my own mains power transformer.
-speaker protection circuits. probably not neaded as it's low powered but nonetheless it would be good to learn how they work.
Am I right in thinking that the soft start boards and speaker protection circuits available from the store won't work due to the lower power?
if I'm right is it a case of getting a calculator out and changing component values or will the changes needed be more in depth?
cheers.
hello
I am new to the diy. I currently working on my ACA, my pcb is complete, and I work on the chassis. My first idea is: aluminum, wood and lexan.
the assembly may not be easy, but I still trust.
power is not yet done, but my brain bubbles ..... for preamp that could go with. may one day be a "camp amp preamp" .
is not very endow in electronics, a simple diy would be welcome. you think of a headphone amp could do the work if possible as the ACA. implementation simple, affordable and exelente sonority.
I thought for example O2 headphone amp.
do you think this way would respect the design of Mr Pass?
I am new to the diy. I currently working on my ACA, my pcb is complete, and I work on the chassis. My first idea is: aluminum, wood and lexan.
the assembly may not be easy, but I still trust
.power is not yet done, but my brain bubbles ..... for preamp that could go with. may one day be a "camp amp preamp"
.is not very endow in electronics, a simple diy would be welcome. you think of a headphone amp could do the work if possible as the ACA. implementation simple, affordable and exelente sonority.
I thought for example O2 headphone amp.
do you think this way would respect the design of Mr Pass?
