The Aleph-X

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#2,524
Is balanced = bridged amp? Is there any example of this "balanced" power amp schematic? I just develop this from aleph x. We can make bridged amp, by inverting one input to the other of 2 amps. But this is not it, because in Q1 and Q2, the transistors 100% effect each other, since the emitors are tied together. This is differential, but with both legs used.
 
#2,527
Tell me is I'm wrong, but I think that you can easilly bridge an Aleph-X, maybe even more easilly that a classical amp.

Use 2 amps, feed them with the same signal (and not inverted signals). Connect the 1st amp - to the 2nd amp +, and then the speaker to the 1st + and the 2nd -

You can also parallel them, like classical amps. Don't forget to add a smal series resistance to each of the 4 outputs.



But I'm not 100% sure if the bridging is possible, since the amp hasn't a floating ground.
 
#2,528
you would need to use some type of input transformer to isolate the grounds in the inputs. The grounds of the 2 amps must float or the outputs that are conected together would cause current loop through inputs of the amps. You would also need to be sure the case wasn't connected to amps ground or there will be voltage potential between the two.
 
#2,529
Varying Gain Structure in Aleph X

This post is from a relative novice, I mainly seek to understand where my ideas are wrong....🙄

What is the gain structure of the standard Aleph X? Input stage, output stage, and overall.

There is only feedback on the output stage, right? How much is that, and why is it important to the circuit performance?

I am interested in modifying Aleph-X rev 1.0 so that the output stage is a voltage follower with no feedback (I understand as a voltage follower it needs no seperate feedback connection because of the automatic feedback of the topology), and all the gain is in the input stage. Just like NP wrote that his original X-amps are structured. What changes would I need to make to the circuit?

Are there any obvious disadvantages of modifying as per the above?

Thanks for any help,
Grant
 
#2,532
Bricolo said:



Mr Pass, any advice on how to bridge 2 aleph-x?
Click to expand...

And why would one bridge an Aleph-X when it is already bridged? It sure is possible but since the design, AFAIK, would also benefit from higher supply rails then why not simply raise the rails a bit say to double the original effectively getting the same results as bridging? AFAIK, bridging would not increase the maximum output current so any increase in power would be for higher loads anyway.
 
#2,533
UrSv said:


And why would one bridge an Aleph-X when it is already bridged? It sure is possible but since the design, AFAIK, would also benefit from higher supply rails then why not simply raise the rails a bit say to double the original effectively getting the same results as bridging? AFAIK, bridging would not increase the maximum output current so any increase in power would be for higher loads anyway.
Click to expand...


I agree with you, but I tried to answear to a question that tomeone asked
 
#2,535
The reason a asked about bridgeing aleph`s and x`s was that I couldn`t understand Nelson`s statement that the aleph can easely be turned on A-X especialy if your output boards are separated. I had an impression (wrong one?) that aleph`s one monoblock circuitry (dif, + and - sense,... that is one main board) can control two complete aleph`s (+ an - chanal) outputs, one per side of the trasformed monoblock. That would be two, bridged aleph`s, shareing the same aleph main mono board circuit. Input section should be converted in X certanly but that should not be a problem on existing board.

marijan
 
#2,536
NP wrote:
We routinely include the output stage in the loop or not, depending on the sonic qualities. To exclude the
output from the loop, simply take the feedback from the
Gate drives to the output devices.
Click to expand...

OK, so if I move the feedback point to the gate of the output device, and I move the output tap to its source, I then have an output stage with a gain of one, no feedback, and high damping factor?

I would like to try that option, it may mean a higher damping factor than the standard output (a gain stage with feedback). Although I need help to find the output impedance of the standard Aleph-X, for comparison.

Trouble is, in converting the output stage to source follower, I have mucked up the amp's gain structure. That is why I would like to know the following:
- what is the gain of the standard Aleph-X output stage, and how is it calculated?
- what is the gain of the input stage, and how is it calculated?

With those answers I can reset the gain of the input stage to compensate for a source follower output.

Thanks,
Grant
 
#2,538
nowater said:
OK, so if I move the feedback point to the gate of the output device, and I move the output tap to its source, I then have an output stage with a gain of one, no feedback, and high damping factor?
Click to expand...

Sorry, I was referring to X amps which have follower output
stages. The Alephs and Aleph X can't do that as a practical
matter. 🙁
 
#2,540
I'm sorry!I didn't read all thread.I don't still know whether the Aleph-X was rewired.I don't still know whether one succed on Aleph-X
I can't attach my file which was repaired.The right hand of R16 will connect with pin G of Q7 and the left hand of R27 connect will connect with pin G of Q5. Can anyone understand me?
 
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