20X or 20dB? 20dB is 10X which is the stock setup.
If you are at 20dB (10X) right now, you can try bumping it up to 15X by changing R3 and R4 to 150k. There is capacitor at both ends so even if a transistor blows the connected components should be shielded from DC. I am a experimenter/diyer and that is something I would try. However we all have different comfort levels so proceed at your own risk.
If I was doing it I would test it with a signal and test load, and check distortion, etc., before putting it into the system.
If you are at 20dB (10X) right now, you can try bumping it up to 15X by changing R3 and R4 to 150k. There is capacitor at both ends so even if a transistor blows the connected components should be shielded from DC. I am a experimenter/diyer and that is something I would try. However we all have different comfort levels so proceed at your own risk.
If I was doing it I would test it with a signal and test load, and check distortion, etc., before putting it into the system.
Would it help to replace the KSA992 with another higher power PNP, like the BA2018 for headphones?
I am not an expert so these are just my diyer thoughts. If the gain is increased but the maximum voltage output is not increased, then perhaps there is no need to change the output transistor. However if the output voltage is to be increased then a higher power output transistor and higher voltage power supply may be necessary.
You folks should try LT SPICE with this circuit. It plays very well. It can do everything you want and more.
The general behavior of the circuit will be proportional to the feedback, which from 20 to 26 dB implies twice the THD.
I don't expect any drama...
I don't expect any drama...
Ben Mah,
In the legal world an expert is simply someone who gets paid to give an opinion.
In my most unhumble opinion you are far better than an expert and your opinions are always needed.
Thanks to all for the guidance.
In the legal world an expert is simply someone who gets paid to give an opinion.
In my most unhumble opinion you are far better than an expert and your opinions are always needed.
Thanks to all for the guidance.
Hello, I need this be a balance input and balance output. Any suggestion on how to do it. I order 2 set of the boards.
I need to boost the range from approx 3000 to 20,000 Hz of a Celestion Axi-periodic driver.
I am in the process of assembling an FE2022 to do this but wonder if it would be OK to place 7000 pF caps on the inputs while setting it for a gain of 9 to get the gain in level I need without boosting the level where it is not needed.
Could there be a problem using capacitors this small on the input?
(My previous question concerned an FE2022 for the woofers)
Help is always appreciated.
I am in the process of assembling an FE2022 to do this but wonder if it would be OK to place 7000 pF caps on the inputs while setting it for a gain of 9 to get the gain in level I need without boosting the level where it is not needed.
Could there be a problem using capacitors this small on the input?
(My previous question concerned an FE2022 for the woofers)
Help is always appreciated.
Download LT SPICE and play with it 1st. Have some fun, then ask questions. This circuit can fold your sheets, make ice cream and order take out.
Very versatile. And you can get all bipolar with it. It is very grass roots basic goodness.
Very versatile. And you can get all bipolar with it. It is very grass roots basic goodness.
Some day, in this life or in the next, I want to finish my Pass 40W amp... PCBs made 3 years ago.
Being retired is a blessing - and a curse. Being able to to nothing is great - and I spent a lot of time on that.
So amp projects tend to pile up while I make way more PCBs than I actually build.
OK, call the shrink!
But here's the 40W, that may generate too much heat for the cooling bracket?
(I have commented on this elsewhere: Helion Audio is my imaginary Audio company. I don't sell anything and hardly make anything - except the occational PCBs,,,.)
Being retired is a blessing - and a curse. Being able to to nothing is great - and I spent a lot of time on that.
So amp projects tend to pile up while I make way more PCBs than I actually build.
OK, call the shrink!
But here's the 40W, that may generate too much heat for the cooling bracket?
(I have commented on this elsewhere: Helion Audio is my imaginary Audio company. I don't sell anything and hardly make anything - except the occational PCBs,,,.)
Hello rickmcinnis (post #1673),
I would do this with an active crossover. DIY biamp 6-24 AXO or ACN (active crossover network) from Nelson Pass comes to my mind.
But the active crossover has no gain. It's a buffer.
If I would do it, then I would add an input buffer + filter +output buffer before the FE2022.
Cheers
Dirk
I would do this with an active crossover. DIY biamp 6-24 AXO or ACN (active crossover network) from Nelson Pass comes to my mind.
But the active crossover has no gain. It's a buffer.
If I would do it, then I would add an input buffer + filter +output buffer before the FE2022.
Cheers
Dirk
I should have made it clear that the reason for this is I have started using Mr. Brueggemann's ACOURATE software.
Before I had used a xilica Solara and one could boost the top octaves - which I did in this region since it is usually not a region where much power is required.
FIR filters level everything out - so to regain the lost top octaves everything else has to be attenuated 12 or so dB.
I am wanting to boost the two top octaves with analog so that I can then flatten out the response with ACOURATE without losing so much gain everywhere else.
I am using FE2022 on the woofer section of the speakers at 20 dB of gain. (at one point I thought I needed to add gain here to match the overall gain I would use for the FE2022 on the compression driver but then I came up with the latest scheme)
I could apply whatever level of gain to the entire range of the compression driver but this seems foolish and that is when I thought up the idea of using the input caps as a high pass filter.
I am going to try 0.01uF and see what happens. The FIR crossover is at 450 Hz and it drops like a rock. I am using the crossover Mr Brueggemann designed and recommended. By the time the high pass filter starts having an effect in the cutoff region the FIR XO will have swamped its effect, or so I think! There will be a bump, I presume, in the 1kHz region that will be easy to erase. The driver is a Celestion Axi-periodic in a Klipsch K402 horn as an MEH per Chris Askew's instructions.
I am wondering if there are other effects from having such a small amount of capacitance as the input capacitors of FE2022?
THANKS for the cajoling of STOXX to use LTSpice and I assume that is a ready to go model he has given me. I have used LTSpice in the past but never became good at it. I will give it a go again! But real life experience means more to me and I wonder if anyone can see a pitfall I am not aware of. I readily admit there are millions of pitfalls I am not aware of.
Thanks to any who read through this and even more thanks to those who have something to say.
Before I had used a xilica Solara and one could boost the top octaves - which I did in this region since it is usually not a region where much power is required.
FIR filters level everything out - so to regain the lost top octaves everything else has to be attenuated 12 or so dB.
I am wanting to boost the two top octaves with analog so that I can then flatten out the response with ACOURATE without losing so much gain everywhere else.
I am using FE2022 on the woofer section of the speakers at 20 dB of gain. (at one point I thought I needed to add gain here to match the overall gain I would use for the FE2022 on the compression driver but then I came up with the latest scheme)
I could apply whatever level of gain to the entire range of the compression driver but this seems foolish and that is when I thought up the idea of using the input caps as a high pass filter.
I am going to try 0.01uF and see what happens. The FIR crossover is at 450 Hz and it drops like a rock. I am using the crossover Mr Brueggemann designed and recommended. By the time the high pass filter starts having an effect in the cutoff region the FIR XO will have swamped its effect, or so I think! There will be a bump, I presume, in the 1kHz region that will be easy to erase. The driver is a Celestion Axi-periodic in a Klipsch K402 horn as an MEH per Chris Askew's instructions.
I am wondering if there are other effects from having such a small amount of capacitance as the input capacitors of FE2022?
THANKS for the cajoling of STOXX to use LTSpice and I assume that is a ready to go model he has given me. I have used LTSpice in the past but never became good at it. I will give it a go again! But real life experience means more to me and I wonder if anyone can see a pitfall I am not aware of. I readily admit there are millions of pitfalls I am not aware of.
Thanks to any who read through this and even more thanks to those who have something to say.
Man, do I have a lot of Boards. Its fun to try them out on a powerful dual bench supply. I do have way too many though...