2 layers, but first upload the Gerber files. Then it will display the PCB. Upgrade options will be available but I usually accept the standard.
Screenshot of JLCPCB webpage after Gerber files uploaded:
I usually do not make any changes. The defaults work just fine for the amplifier.
I usually do not make any changes. The defaults work just fine for the amplifier.
Maybe someone can help me with this problem...
My goal is to build four mono Hammond 193v Choke Loaded 2sk180 amps but with THF-51S SIT's, for each of my loudspeaker driver.
There are three drivers per side. The drivers are:
103dB wideband driver (Lii song platinum10), filtered at 160Hz (highpass).
97dB Lii song F15, (lowpass).
And 95dB Lii song W15 subwoofer for extra low.. (these have a class D amp).
So my question is about the amps that drive the Lii song platinum10's.
The Platinum10's and F15's get the same amps for coherency. I tried different amps but the sound is not quite right, a bit off. Difficult to describe...
For the platinum10's I tried loads of different amps, SET tube amp with 6C33C, Audionote tube amps, Eggshell tube amp, First watt F5.
For the F15's I tried all sorts of transistor amps... but it just dit not sound great. Good, but a bit off.
Than an audio friend advised me to try two of the same amps. So I tried that.. I bought two of the same cheep class D stereo amps... That was a shock.
There was the coherency my friend was talking about! Not the sound quality of course, but I understand now why better to use the same amps in my system!
Just for reference I also tried different loudspeakers, DACs, cables...you name it.. that I had laying around. I also found that I have DC problems. But the current setup sounds best to me. Especially the Platinum10's with the Oris front horns, custom made by Bert Doppenberg from BD-Design.
I use a PLLxo filter with volume pot between the DAC and pre-power amps. This sounds better to me than having the xo filters passive at the loudspeakers.
So when I finish my Hammond 193v Choke Loaded (THF-51S) amps I can maybe put the filters in the same enclosure as the pre/Hammond 193v Choke Loaded THF-51S amps.
So here is were I get lost...
I need a preamp to drive the Hammond 193v Choke Loaded (THF-51S) amps.
The pre I use is going to be the Jfet Boz from Nelson Pass, powered with a 9V battery. In the schematic of the Jfet Boz the 10uF capacitor and 2.2K resistor form a first order highpass filter. So I could change these to 1uF and 1K to get a highpass filter at 160Hz, but I dont know if this makes this preamp instable?
Or maybe I can remove the 4uF (C2) capacitor in the THF-51S amps and replace this with a wire? Or does this have consequenses?
Or I could change the 10mF (C6) in the THF-51S amps to 124,33uF to get 160Hz? This last has my preference... Now I can use non electrolytics....
Or do I just keep all caps and resistor values the way they are in the schematics and use my original filter with volume pot between the DAC and pre-power amps?
So it is clear there is a lot I do not fully understand...
Can anyone help?
Here is the preamp schematic.
My goal is to build four mono Hammond 193v Choke Loaded 2sk180 amps but with THF-51S SIT's, for each of my loudspeaker driver.
There are three drivers per side. The drivers are:
103dB wideband driver (Lii song platinum10), filtered at 160Hz (highpass).
97dB Lii song F15, (lowpass).
And 95dB Lii song W15 subwoofer for extra low.. (these have a class D amp).
So my question is about the amps that drive the Lii song platinum10's.
The Platinum10's and F15's get the same amps for coherency. I tried different amps but the sound is not quite right, a bit off. Difficult to describe...
For the platinum10's I tried loads of different amps, SET tube amp with 6C33C, Audionote tube amps, Eggshell tube amp, First watt F5.
For the F15's I tried all sorts of transistor amps... but it just dit not sound great. Good, but a bit off.
Than an audio friend advised me to try two of the same amps. So I tried that.. I bought two of the same cheep class D stereo amps... That was a shock.
There was the coherency my friend was talking about! Not the sound quality of course, but I understand now why better to use the same amps in my system!
Just for reference I also tried different loudspeakers, DACs, cables...you name it.. that I had laying around. I also found that I have DC problems. But the current setup sounds best to me. Especially the Platinum10's with the Oris front horns, custom made by Bert Doppenberg from BD-Design.
I use a PLLxo filter with volume pot between the DAC and pre-power amps. This sounds better to me than having the xo filters passive at the loudspeakers.
So when I finish my Hammond 193v Choke Loaded (THF-51S) amps I can maybe put the filters in the same enclosure as the pre/Hammond 193v Choke Loaded THF-51S amps.
So here is were I get lost...
I need a preamp to drive the Hammond 193v Choke Loaded (THF-51S) amps.
The pre I use is going to be the Jfet Boz from Nelson Pass, powered with a 9V battery. In the schematic of the Jfet Boz the 10uF capacitor and 2.2K resistor form a first order highpass filter. So I could change these to 1uF and 1K to get a highpass filter at 160Hz, but I dont know if this makes this preamp instable?
Or maybe I can remove the 4uF (C2) capacitor in the THF-51S amps and replace this with a wire? Or does this have consequenses?
Or I could change the 10mF (C6) in the THF-51S amps to 124,33uF to get 160Hz? This last has my preference... Now I can use non electrolytics....
Or do I just keep all caps and resistor values the way they are in the schematics and use my original filter with volume pot between the DAC and pre-power amps?
So it is clear there is a lot I do not fully understand...
Can anyone help?
Here is the preamp schematic.
The capacitor at the amplifier input is required as it blocks the DC bias voltage from the amplifier input. However the capacitor value may be adjusted to change the high pass frequency.
I can't help with the drivers and crossovers as I do not have any experience with that. I do see that your two drivers have different sensitivities so besides high pass and low pass filters, signal level to each driver will need to be adjusted. Perhaps Nelson's DIY Biamp Active Crossover may work for you:
https://diyaudiostore.com/products/diy-biamp-6-24-crossover
https://www.firstwatt.com/wp-content/uploads/2023/12/art_diy-biamp_6-24_-crossover.pdf
https://www.diyaudio.com/community/threads/diy-biamp-6-24-crossover.357657/
I can't help with the drivers and crossovers as I do not have any experience with that. I do see that your two drivers have different sensitivities so besides high pass and low pass filters, signal level to each driver will need to be adjusted. Perhaps Nelson's DIY Biamp Active Crossover may work for you:
https://diyaudiostore.com/products/diy-biamp-6-24-crossover
https://www.firstwatt.com/wp-content/uploads/2023/12/art_diy-biamp_6-24_-crossover.pdf
https://www.diyaudio.com/community/threads/diy-biamp-6-24-crossover.357657/
Thanks Ben!
I know the Platinum10's have a higher sensitivity, but I can adjust with the volume pot from the Jfet Boz.
I have been looking at Nelson's DIY Biamp Active Crossover befor. I think my crossover works very well. And a lot less parts.
Thanks for your input.
I know the Platinum10's have a higher sensitivity, but I can adjust with the volume pot from the Jfet Boz.
I have been looking at Nelson's DIY Biamp Active Crossover befor. I think my crossover works very well. And a lot less parts.
Thanks for your input.
I do not have any experience with the JFET BOZ but it may not have enough voltage output for this amp, since the amp is a follower with no voltage gain. I think the JFET BOZ may also have quite high harmonic distortion when pushed to its voltage limit.
I am familiar with Nelson's DIY FE 2022, and I recommend it. I use it as a preamp for my follower amps.
I am familiar with Nelson's DIY FE 2022, and I recommend it. I use it as a preamp for my follower amps.
Befor I try Nelson's DIY FE 2022 I would like to try the jfet boz. It has a gain of 24. With a powersupply of 35V it could give 12.5V. Maybe it can take 40V, than it can give 14V...
Maybe Nelson's DIY FE 2022 pre is a good candidate for the Hammond 193v Choke Loaded (THF-51S) amps that drive the F15 mid/bass.. Those need enough voltage output.
Ben, howmuch voltage output does the preamp need to drive the Hammond 193v Choke Loaded (THF-51S)?
According to Nelson Pass the jfet boz has the least distortion with a 16V ps. This could be a battery ps..
According to Nelson Pass the jfet boz has the least distortion with a 16V ps. This could be a battery ps..
Is the 12.5V peak to peak, peak, or rms? If it is rms or even peak, that seems high for a resistor load.
If the amp is run at 2.5A, the maximum power output at 8 Ohm is about 25W. Taking into account for losses etc, that would need an input of about 16Vrms, or about 23Vp.
I do not think the DIY FE has feedback.
Another option is to use the DIY FE as a front end, installed in the amplifier chassis and powered by the amplifier power supply, and keeping the JFET BOZ as a preamp.
Note that the DIY FE has much lower distortion than the JFET BOZ. So using the DIY FE as a preamp will probably sound a bit different than using the JFET BOZ as a preamp. You can only determine which you prefer after you hear it and compare it to the JFET BOZ.
So.. do you prefer Nelson's DIY FE 2022 as preamp? How dows it sound? Does it have enough voltage output?
I'm not stuck at using the jfet boz... I just want a good sounding preamp to suit the Hammond 193v Choke Loaded (THF-51S) amps.
This can also be a good tube preamp.. as long as the tube pre does not hummmm.
What appeal to me at the jfet boz is the low ammount of parts... but that says nothing about the sound of couse..
So if the DIY FE 2022 works good, than I like to use that...
This can also be a good tube preamp.. as long as the tube pre does not hummmm.
What appeal to me at the jfet boz is the low ammount of parts... but that says nothing about the sound of couse..
So if the DIY FE 2022 works good, than I like to use that...
Ben, just an idea.. Can you put an extra Hammond 193v Choke at the drain? So it has a Hammond 193v Choke both at the drain and source? I assume the choke at the drain gives the amp gain. Is this correct?
Yes, I like the DIY FE. I have not heard a JFET BOZ so I cannot give my thoughts on its sound. I have built and listened to preamps with higher distortion (second harmonic dominant) and I prefer the lower distortion of the DIY FE. You can find information here:
https://www.diyaudio.com/community/threads/diy-front-end-2022.394339/
My DIY FE 2022 preamp:
https://www.diyaudio.com/community/threads/diy-front-end-2022.394339/post-7312224
Adding a choke to the SIT drain will not give the amplifier voltage gain. If you read the first entries of this thread, you will find that I started with a choke loaded 2SK180 amplifier with both voltage and current gain. Later, I changed to a follower configuration with only current gain. If you compare the two schematics you will see the difference. If you compare the distortion measurements of both versions you will see that the first version had much higher distortion. In the end I preferred the sound of the follower version (no voltage gain).
https://www.diyaudio.com/community/threads/diy-front-end-2022.394339/
My DIY FE 2022 preamp:
https://www.diyaudio.com/community/threads/diy-front-end-2022.394339/post-7312224
Adding a choke to the SIT drain will not give the amplifier voltage gain. If you read the first entries of this thread, you will find that I started with a choke loaded 2SK180 amplifier with both voltage and current gain. Later, I changed to a follower configuration with only current gain. If you compare the two schematics you will see the difference. If you compare the distortion measurements of both versions you will see that the first version had much higher distortion. In the end I preferred the sound of the follower version (no voltage gain).
Ben thanks again for explain everything and thanks for your patience with me, much appreciated!
Would you send me the Gerber files of the DIY FE please?
Would you send me the Gerber files of the DIY FE please?
Ben, maybe another stuped question... the supply voltage you use for the DIY 2022 FE was +62VDC? Or AC?
The voltage was 62VDC. See this post: https://www.diyaudio.com/community/threads/diy-front-end-2022.394339/post-7313031
The power transformer that I used had a 48VAC secondary.
I assume that the Gerber files that you requested are for the power supply. The PCB for the DIY FE 2022 is available from the diyAudio Store:
https://diyaudiostore.com/products/diy-front-end-2022
I should note that these projects are not simple complete kits with detailed step by step instructions. If you have not had any experience building preamps and amps and their power supplies from scratch following schematics, you may find these projects very challenging.
The power transformer that I used had a 48VAC secondary.
I assume that the Gerber files that you requested are for the power supply. The PCB for the DIY FE 2022 is available from the diyAudio Store:
https://diyaudiostore.com/products/diy-front-end-2022
I should note that these projects are not simple complete kits with detailed step by step instructions. If you have not had any experience building preamps and amps and their power supplies from scratch following schematics, you may find these projects very challenging.
Thanks for the info!
Yes, the the Gerber files that I request is for the power supply. I found the PCB for the DIY FE 2022 at the diyAudio Store.
I know I have very little experience building amps, however I have a few friends near home that are willing to help me with this project. I would not be able to do this on my own...
Yes, the the Gerber files that I request is for the power supply. I found the PCB for the DIY FE 2022 at the diyAudio Store.
I know I have very little experience building amps, however I have a few friends near home that are willing to help me with this project. I would not be able to do this on my own...