Bibin hi!
Normally we use bridge connectivity when the supply is low like the 12 volt car/boat battery. This is why the high power car amps all have an invertor that push the voltage supply to whatever your need may be. There should be no reason not to do it as far as I know.🙂😱
OT here, but need to clarify one thing.
Dear Bibin,
I prefer to be addressed Prasi here (if you read my posts and my profile).
I do not know whats with Prashant (Prasi) that you used twice while answering my post😕.
If you need more clarification on my identity, you can always contact by PM🙂 or by email.
reg
Prasi
hope that comes thru attachment
this is static model! no back emf and further simplified : no vent
Thank you for the quick update and clarification.
Bibin,
Beautitul work😎
Sa muli,
Albert
[formerly Abetir]
Thank you Albert for the comment.
Just like the majority of modern amplifiers, the C. can be bridged: it has both inverting and non-inverting inputs, the rest is a question of resistors and topological optimization.
I will try to offer something effective and sensible.
Note that the C. can work with voltages as low as 10~12V (must be somewhere in the thread, I don't know exactly where), but as there are no miracles or free lunches, the output power will be limited by Joule's law.
For a modest yet significant upgrade without the complications of a full-feature regulated converter, you can always turn to Boostor, a simplistic unregulated charge-pump converter:
http://www.diyaudio.com/forums/power-supplies/212945-boostor-ideal-companion-circlophone-move.html
Here is an example of bridging; it does not particularly shine for its originality, but at least it should work without problems:
Attachments
Here is the test using your 3 way model, first the "normal" way. I have paralleled two networks to push the amplifier to its limits in order to show possible problems:
The trace shows the distortion residue extracted by subtraction from Vs.
Most of the THD is pretty mundane, mainly 3rd and fifth, and a small Xover residue-like is also visible. It is caused by the high current flowing through the 2N3055's causing an accumulation of charge carriers that aren't evacuated perfectly, in spite of the circlo-engine. The engine has a limited loop gain and manages to reduce the artifacts without eliminating them completely.
We have to keep in mind that these are extreme stress condition and that the THD in these conditions is 0.002%, of which a very small fraction only is due to these artifacts: well below the ppm level.
Now, let's see what happens in the conditions you described: here, the output is driven from an external 22V sine source (10% higher than the supply rails) through your doubled model network (which is not particularly gentle, as it drops to 3Ω at some frequencies).
V(Nout) is the residue present at the output now acting as a virtual ground: it shows nothing abnormal, just a very low and slightly non-linear impedance, something to be expected from a decent amplifier driven well beyond its limits.
No sign of latchup or similar pathological behavior.
These are sims of course, but the actual tests I made and the experience of circlophone builders seem to confirm the good behavior of this amplifier, even under harsh conditions
Attachments
Thanks a lot Elvee, that was so quick. Actually one of my friend asked me about this possibility. I will share this with him.
Thanks,
Bibin
For maniac detail nitpickers, R42 should preferably be increased to 510 ohm, but that's really icing on the cake.
In fact, it could probably be increased even more, as there is some gain stability margin, but the benefits would be quite minor, if any
In fact, it could probably be increased even more, as there is some gain stability margin, but the benefits would be quite minor, if any
Current drive
Sir, Elves, I refer to your post #1635.
First off, my profound apologies for this much-delayed response. A series of personal upsets/upheavals, though not serious per se, had kept me away from the hobby circuit; only now am I able to try and pick up the lost threads. Kindly accept my sincere gratitude for the current drive mod to the Circlophone that you had presented. You have no idea how helpful that is going to be.
You are right in that the current breed of speakers are designed for high powered voltage drive, though the amp=speaker relationship is far from ideal. But a low power current drive amp makes a wonderful combo with a good full range driver. A better bet would be to split the LF somewhere below 500 Hz, and use an active 2-way system (I use minidsp for its sheer convenience factor), which, IMHO, can easily beat a SET amp/full-range combo if you are attempting to evoke realism.
Where does the Circlophone ( my favourite amp....in a long time!) come into this formula? I fell in love with the Circlophone when current drive was not in my agenda. Now, with your kind help, I shall be able to compare side-by-side both voltage drive and current drive, using the same drivers. For such comparisons, my practice is to use limited-range (no 20 Hz to 20 kHz stuff) single and group vocal live recordings and listen and listen, looking for the closest approach to the original.
Your gracious help will be of immense value to me -- soon, I fervently hope and pray! Thank you, sir, once again! Current drive or no current drive, you can be proud that the Circlophone is one great amp topology!
Sir, Elves, I refer to your post #1635.
First off, my profound apologies for this much-delayed response. A series of personal upsets/upheavals, though not serious per se, had kept me away from the hobby circuit; only now am I able to try and pick up the lost threads. Kindly accept my sincere gratitude for the current drive mod to the Circlophone that you had presented. You have no idea how helpful that is going to be.
You are right in that the current breed of speakers are designed for high powered voltage drive, though the amp=speaker relationship is far from ideal. But a low power current drive amp makes a wonderful combo with a good full range driver. A better bet would be to split the LF somewhere below 500 Hz, and use an active 2-way system (I use minidsp for its sheer convenience factor), which, IMHO, can easily beat a SET amp/full-range combo if you are attempting to evoke realism.
Where does the Circlophone ( my favourite amp....in a long time!) come into this formula? I fell in love with the Circlophone when current drive was not in my agenda. Now, with your kind help, I shall be able to compare side-by-side both voltage drive and current drive, using the same drivers. For such comparisons, my practice is to use limited-range (no 20 Hz to 20 kHz stuff) single and group vocal live recordings and listen and listen, looking for the closest approach to the original.
Your gracious help will be of immense value to me -- soon, I fervently hope and pray! Thank you, sir, once again! Current drive or no current drive, you can be proud that the Circlophone is one great amp topology!
Current drive-R22
I shall be much obliged if you could offer some guidance as to how to select the current sense resistor (R22) in relation to the speaker impedance - perhaps a rule-of-thumb formula?
Thanks in advance, Sir.
I shall be much obliged if you could offer some guidance as to how to select the current sense resistor (R22) in relation to the speaker impedance - perhaps a rule-of-thumb formula?
Thanks in advance, Sir.
Thread Compilation
I am re-joining after a long time, and that has brought in its own difficulties, the most tedious being leafing through the page after page of posts.
How helpful it would be if somebody could come up with a program for compiling all the posts (or, say, Pages 1 to xx) into a large text/doc file, with attachments etc. Or, has it been done already?
I am re-joining after a long time, and that has brought in its own difficulties, the most tedious being leafing through the page after page of posts.
How helpful it would be if somebody could come up with a program for compiling all the posts (or, say, Pages 1 to xx) into a large text/doc file, with attachments etc. Or, has it been done already?
Diyaudio is designed for 90's computers on dial-up, so you only get 10 posts per page. However, if you click thread tools and choose enhanced print view, you can see all posts at once. This, however, costs money.
A builders thread exist's perhaps you may find here all the help that you needed.😉
http://www.diyaudio.com/forums/soli...tion-parts-accessories-beginner-friendly.html
Regards,
Albert
The ratio of Zload to R22 should reflect the gain of the amplifier (~22 in this case)