Darlington : exactly the same as yours . Resistor value and pot ? No idea here. I assume the first resistor is to bias the base, so why not the same as your shematic ? Can't help more.
the pot and the gnd resitor are just to adjust the voltage of the TL431, you can had a resistor as well between the pot and the tL431 kathode, but you needn't. Sims are not my cup of tea. But I have a reg like that and it sounds very good on a subjective point of view. Should work fine with your LM idea and the good filtering you showed before for you analog stage. Cheap to try.
the pot and the gnd resitor are just to adjust the voltage of the TL431, you can had a resistor as well between the pot and the tL431 kathode, but you needn't. Sims are not my cup of tea. But I have a reg like that and it sounds very good on a subjective point of view. Should work fine with your LM idea and the good filtering you showed before for you analog stage. Cheap to try.
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yep your shematic is what I meant. But there is no negative, it's a ground instead the minus in your shematic: i.e you need the opposite on the other side and adapt active parts for the negative rail. Share the Gnd (minus on your shematic), what you probably did at seing your verroboard. So a classic + Gnd - : as on your verroboard
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Custom Sen PCBs for Oppo 105d
Indulge me for a moment, but I want to share my small project.
Following on from my posts 2010, the custom PCBs, arrived, got loaded, and installed.
These don't move the goalposts and are based on EUVL's and NIC's base designs.
With respect to EUVL and everyone else, these are customized SEN and Charging board for the Oppo 105d player. They came out quite well I think and sound ok so far.
At some point, the Batteries and wires will be further tidied, but good for now
cheers
Indulge me for a moment, but I want to share my small project.
Following on from my posts 2010, the custom PCBs, arrived, got loaded, and installed.
These don't move the goalposts and are based on EUVL's and NIC's base designs.
With respect to EUVL and everyone else, these are customized SEN and Charging board for the Oppo 105d player. They came out quite well I think and sound ok so far.
At some point, the Batteries and wires will be further tidied, but good for now
cheers
Attachments
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@PhopsonNY nice design!
I also recently decided to build a new dac for myself based on 2xPCM1704 and SEN (2SK146) output stage. I'm experimenting the last with four-layer PCBs. This is my second four-layer PCB. I just sent it to production. I wonder what will come of this. Prototype sounds promising. For SEN power supply I use 8xLifepo battery per channel (aprox. 26V)
I also recently decided to build a new dac for myself based on 2xPCM1704 and SEN (2SK146) output stage. I'm experimenting the last with four-layer PCBs. This is my second four-layer PCB. I just sent it to production. I wonder what will come of this.
Prototype sounds promising. For SEN power supply I use 8xLifepo battery per channel (aprox. 26V)Attachments
Fantastic results.
After final adjustments, the Sen sounds very good.
Corrected a reversed cable on the balanced output and now, the instruments are so precisely placed in 3d space in a way that was not evident before.
Spent too much time listening to the system yesterday as a result.
Thanks for the project EUVL.
After final adjustments, the Sen sounds very good.
Corrected a reversed cable on the balanced output and now, the instruments are so precisely placed in 3d space in a way that was not evident before.
Spent too much time listening to the system yesterday as a result.
Thanks for the project EUVL.
In a word, no.
I had built the Joachim Gerhard one, and while the EUVL one offers better performance, I still had some residual noise from the supply that I thought wouldn't be resolved by the changes. On the other hand, I felt the sound was better than the Li-ion batteries I was using. So I sent it to a friend of mine who had a few packs of LiFePO4 batteries. He ran it from the Gerhard supply and the LiFePO4 packs and found no difference in sound - except that the stage was completely silent with the batteries.
So since then I have gone that route, series connecting 5 batteries per channel to give me around 16-17V floating and the sound is very good. The battery packs should last a very long time, so I put a note on them to remind myself to check them in a month or so. I reckon the current draw is low enough for the packs to last a lot longer than that.
So after a lot of experimentation, I am back to batteries, and to what I think is the king of them, the LiFePO4 type.
I had built the Joachim Gerhard one, and while the EUVL one offers better performance, I still had some residual noise from the supply that I thought wouldn't be resolved by the changes. On the other hand, I felt the sound was better than the Li-ion batteries I was using. So I sent it to a friend of mine who had a few packs of LiFePO4 batteries. He ran it from the Gerhard supply and the LiFePO4 packs and found no difference in sound - except that the stage was completely silent with the batteries.
So since then I have gone that route, series connecting 5 batteries per channel to give me around 16-17V floating and the sound is very good. The battery packs should last a very long time, so I put a note on them to remind myself to check them in a month or so. I reckon the current draw is low enough for the packs to last a lot longer than that.
So after a lot of experimentation, I am back to batteries, and to what I think is the king of them, the LiFePO4 type.
Thanks, Good report.
Have you experimented with more LiFePO4 batteries connected in series? (e.g. 6s-8s)
As Patrick wrote:
But at the same time, as you connect more batteries in series, the battery internal impedance increases (as well as jfets' heat dissipation).
I wonder if there is any optimum in the amount of LiFePO4 (for example ANR26650M1-B) batteries connected in series for SEN?
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Personally, I haven't experimented with this - it was down to how many cells I had to hand! I know i have a vague memory of someone else using 6 or 7 in series but maybe that was for something else. Also, I have a different use for this same battery pack, so it suited me to have a voltage around 16-18v.
On a completely different project, I have use 2 banks of 10 of these batteries and it worked very well.
On a completely different project, I have use 2 banks of 10 of these batteries and it worked very well.
Recently, I found an AD1865 chip in my DIYaudio junk. That's why I decided to make a new PCB with this chip (together with SEN and 2SK146BL) and add it to the DACs collection.
PCB based on 2xPCM1704 I already ordered 2 weeks ago.
The new AD1865 board has the same dimensions as the previous one (2xPCM1704), the same power supply, the same connectors/headers. I hope to be able to listen to both good old R2R DACs with SEN and switch easily between them depending on my preferences.
In some time (rather distant because unfortunately I have limited time for the DIYAudio hobby) we will see/hear what will come of it.
PCB based on 2xPCM1704 I already ordered 2 weeks ago.
The new AD1865 board has the same dimensions as the previous one (2xPCM1704), the same power supply, the same connectors/headers. I hope to be able to listen to both good old R2R DACs with SEN and switch easily between them depending on my preferences.
In some time (rather distant because unfortunately I have limited time for the DIYAudio hobby) we will see/hear what will come of it.
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@PhopsonNY nice design!
I also recently decided to build a new dac for myself based on 2xPCM1704 and SEN (2SK146) output stage. I'm experimenting the last with four-layer PCBs. This is my second four-layer PCB. I just sent it to production. I wonder what will come of this.
On your PCB I see only one 2SK146 per channel. I would have expected a second one or a pair of ... Do I understand something wrong about SEN?
Interesting.Thank you. Learned something again
Is 2SK146 the same as IFN146 ?
I don't know InterFET products and (IFN146 particularly) but I have little experience in electronics....
They seem to be trying to recreate the good audio parts that have disappeared from active sale.
In the data sheets they write: "The -50V InterFET IFN146 is a low noise high gain replacement for the Japanese 2SK146 JFET."
The price for one piece seems high. I wonder if these double jfets come with IDSS within 10mA and what about audio quality (compared to Toshiba).
