Thank you both. My starting point was something like Mark's estimate which does not sound promising for a max 45V V_CEO component. I must admit, WD, that I do not understand what 'assume the constant current source gets in the way' means as the collector of Q2 connects directly to the positive rail and its emitter must stay somewhere around to zero, otherwise Q2 would not conduct at all.
2N5551 seems to be compatible with the ZTX450 pinout (EBC), KSC1845 is different (ECB).
Btw, is there a simulation / measurement / educated guess about the current draw of the small signal parts of the amplifier? I found 8.3mA for Q5 and Q6 earlier in the discussion but nothing about the currents of Q1 and Q2 (which might be trivial to experts but I am none of those).
2N5551 seems to be compatible with the ZTX450 pinout (EBC), KSC1845 is different (ECB).
Btw, is there a simulation / measurement / educated guess about the current draw of the small signal parts of the amplifier? I found 8.3mA for Q5 and Q6 earlier in the discussion but nothing about the currents of Q1 and Q2 (which might be trivial to experts but I am none of those).
Thank you very much, Nelson! Would you mind sharing your thoughts on the above V_CEO rating question of ZTX450 as Q2 as well? You must have had a reason for choosing this component and suggest 50ish Volt rails at the same time. I am eager to learn about your considerations.
Best,
Miklos
Best,
Miklos
Hi,
I just finish my boards (Prasi boards). Gain is too high for me. R3 is already 1k. R35 is 10ohms.
Can someone what resistor should I modify ?
I got an old Denon transformer from an old Denon DRA-455 with 2x40Vac. Is that ok ?
Damien
I just finish my boards (Prasi boards). Gain is too high for me. R3 is already 1k. R35 is 10ohms.
Can someone what resistor should I modify ?
I got an old Denon transformer from an old Denon DRA-455 with 2x40Vac. Is that ok ?
Damien
How much gain is desired? I would lower R4. How much? Have to answer the first question... first. What is the value now? 22k I think? I'm not familiar with the AB100. Halving the value of R4 will definitely take the wind out of those sails...
I have only raised the gain, and I adjusted R3 down, from 1k to 475k and went from 27 up to 33 gain. I would imagine you could just go the other way to 1.5k (~22 gain) or even 2k (lower to ~15 gain) not sure the exact rate it will lower your gain?
Regarding the transformer, if that is unloaded VAC, then you will be fine by the time you account for 3-4v of loss you will end up at 50-53Vdc - I run mine with 52Vdc and haven't had any issue in a year.
Is there a ASC file with transistor data available. Is it there on any post.
Wanted to build it to run on +/-28.
I did read a few pages, still going through the thread.
Wanted to build it to run on +/-28.
I did read a few pages, still going through the thread.
So need opinions. Do people think you could get away with a 200VA trannie on this design? It only being a200 W design
So to increase my understanding why do you need almost double the capacity for a 100W p/ch amp?
I don't need
You need it, for amp you want to make
There are myriad of appropriate books on subject, and your understanding of processes involved will be much higher than based on just few replies on forum
One major fact - efficiency