I see, that virus has an effect on just about everything.
Well, let me/us know if/when they become available again.
Why not to choose best of both world? I gave a try and building varuos CEN SEN to my pcm1704 dac's to se which sounds best. one of them in SEN use 8x 2sk117GR (4 paraleled) capacistance is low of those comapring to sk170 ( i do not see reason why one use sk117BL which have nearly same Ids as sk170BLand higher impedance)
any reason not to go further and use use 6x sk117GR in paralel(12 total) in SEN? I have matched them to variuos Ids and getting some 3-3.1mA Ids. From Patrick thougths i understand that pcm1704 really prefers low input impedance (~10ohm)
Listening impression is the most interesting part 
. Being absolutely clueless(and wanting to stay that way) on active electronic circuits i rely on other people knowledge. Once again, Patrick, thanks for sharing your intelectual property with us.
My hopes are boldly high for this IV stage.
Hope to achieve similar or better subjective performance than ( Mark Levinson IV stages or complex bipolar IV gain stages ) my other dac's IV in all aspects , except maybe driving next stage. But still hope i can skip buffer(especialy with 8x paraleled sk117GR)
i have this genue OEM IV stage with toshiba j-fets on one of my dac (pcm1702k) and its really not up to task drive 10K input of power amp. needs bufer for sure.
BTW for 4x pcm1704 balanced dac with xlr outputs I need 4 SEN stages totaling 32 pieces of sk117GR?
. Being absolutely clueless(and wanting to stay that way) on active electronic circuits i rely on other people knowledge. Once again, Patrick, thanks for sharing your intelectual property with us.My hopes are boldly high for this IV stage.
Hope to achieve similar or better subjective performance than ( Mark Levinson IV stages or complex bipolar IV gain stages ) my other dac's IV in all aspects , except maybe driving next stage. But still hope i can skip buffer(especialy with 8x paraleled sk117GR) i have this genue OEM IV stage with toshiba j-fets on one of my dac (pcm1702k) and its really not up to task drive 10K input of power amp. needs bufer for sure.
BTW for 4x pcm1704 balanced dac with xlr outputs I need 4 SEN stages totaling 32 pieces of sk117GR?
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Rebuilding the Sen Board for the Oppo 105d
Hi,
Rebuilding a custom Sen board for my Oppo 105d.
Please take a look and let me know if you have any thoughts or concerns.
cheers
PhopsonNY
Hi,
Rebuilding a custom Sen board for my Oppo 105d.
Please take a look and let me know if you have any thoughts or concerns.
cheers
PhopsonNY
Attachments
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Cause SK170GR are hard to get ! Nice to see some design with the old Kaneda fav SK30A !
But I'm sure there are good equivalent in smd nowadays...
In your last reg scheme I would choose UKZ but with a lower C3 47 uF (according the need of the load) but greater V (the 100V in the UKZ line are way better than the others, a little better ESR) For C2 I would not choose an UKZ though.... something with not so low ESR, from instinct I'd choose a Panasonic FC here, though I fear it's too much good ESR for that task ? I'm not sure cause I see R1 is lowering the impedance perhaps...
Why not here using the Darlington in emitter follower with the load ? Does it not worth to filter locally the TL431 (1000 uF?) ?
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I noticed an errant connection in the left channel - all fixed.
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Today I built up this same supply that @elviukai mentions in his post to see can I operate SEN without using batteries. Its partly curiosity, wondering would a different power supply have a different effect on sound, and party thinking that its easier to house a "normal" mains power supply that turns out with the rest of the unit.
So the parts arrived from Reichelt and I got to work. You'll see from the photo its just made on perfboard and I had a little trouble shooting to do on the first to get it working (I had the pinout for BD140 incorrect - watch out for this, if you google BD140 pinout the first image up has the collector labelled as emitter, had me scratching my head for a while). Building the second one then was just a matter of copying the first.
I want to say that its a little more dynamic than using the batteries (Lidl branded drill Li-ion packs) but I don't know that I can reliably tell the difference. It will take longer listening to see a more mature opinion on it. My implementation is not perfect either - the supply should be in a separate box well away from the DAC and SEN and it is not. However, there is only faint noise with the amps turned up to crazy high levels, way beyond very loud listening levels. So not as quiet as batteries, but less than the noise floor of most amps I think.
So why am I even posting this - well, from reading the thread, very few people have built this power supply, and using a power supply vs batteries pops up again and again. So its just to confirm that this supply will work with SEN. Watch that BD140 pinout and don't make my silly mistake!!
Fran
So the parts arrived from Reichelt and I got to work. You'll see from the photo its just made on perfboard and I had a little trouble shooting to do on the first to get it working (I had the pinout for BD140 incorrect - watch out for this, if you google BD140 pinout the first image up has the collector labelled as emitter, had me scratching my head for a while). Building the second one then was just a matter of copying the first.
I want to say that its a little more dynamic than using the batteries (Lidl branded drill Li-ion packs) but I don't know that I can reliably tell the difference. It will take longer listening to see a more mature opinion on it. My implementation is not perfect either - the supply should be in a separate box well away from the DAC and SEN and it is not. However, there is only faint noise with the amps turned up to crazy high levels, way beyond very loud listening levels. So not as quiet as batteries, but less than the noise floor of most amps I think.
So why am I even posting this - well, from reading the thread, very few people have built this power supply, and using a power supply vs batteries pops up again and again. So its just to confirm that this supply will work with SEN. Watch that BD140 pinout and don't make my silly mistake!!
Fran
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Thanks woodturner-fran, I was not able to built any power suply for SEN which would not have big hum. I tried diferent powersuply layout, diferent SEN layout, I have tried CEN, I have tried even 2KVA isolating medicine conditioner- nothing have helped.. only bateries worked. Its such pitty, as i really like sound of SEN- detailed, dark but airy, fast,microdynamics is also stuning.
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@ Fran,
Hi, Is it a reversed darlington, I have the souvenir of an emiter at the right of the base, not at the left side towards the LM317 ?
You should try to rotate it : collector towards the LM317 emitter towards the load, TL431 loading the base with the pot controlling the voltage //; 220 uf just in local for filtering the TL431.a big cap after the LM317, same value as C1. After the emitter towards the load: no caps, just a little film decoupling cap near transistor of the CEN (for instance a 0,1 uf Kemet MKP, 5 mm pitch or an acrylic/PEN smd film cap.
Hi, Is it a reversed darlington, I have the souvenir of an emiter at the right of the base, not at the left side towards the LM317 ?
You should try to rotate it : collector towards the LM317 emitter towards the load, TL431 loading the base with the pot controlling the voltage //; 220 uf just in local for filtering the TL431.a big cap after the LM317, same value as C1. After the emitter towards the load: no caps, just a little film decoupling cap near transistor of the CEN (for instance a 0,1 uf Kemet MKP, 5 mm pitch or an acrylic/PEN smd film cap.
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LM317 is charging C1 from then the Darlington take the power. Putting just a little load after the emitter near the load gives a subjective fast transient.
I will choose C1 after the LM317 between 1000 to 2200 uF Pan FC.
You can filter the TL431 with 470 to 1000 uF // 0,1 MKP as well, but local, i.e. just for the tl431. below the pot to the Gnd, there is a resistor : my bad drawing style, sorry !
I will choose C1 after the LM317 between 1000 to 2200 uF Pan FC.
You can filter the TL431 with 470 to 1000 uF // 0,1 MKP as well, but local, i.e. just for the tl431. below the pot to the Gnd, there is a resistor : my bad drawing style, sorry !
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![20210728_003726[1].jpg](/community/data/attachments/874/874008-982d2f0dc2d3d1b15c9ce4f8a6cb3bb9.jpg)
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