Fets?
Are you referring to jfets? or mosfets?
I know the j176 could handle either 35 mA or 50 mA. It might be okay, but the zvp3310a could handle 50 mA for sure, since I recall it was rated more like 150 mA from memory, while the irf9610 could easily handle that task or even much higher since it was a lot more robust.
Now that we all know the original 4.75K ohm resister below the zener in the aleph 3 schematic does make the bass sound stronger or the high frequencies much higher, I may try the irf9610 again and see if I could get a better balance than the zvp3310a or j176. I recall the irf9610 for the current source had much better bass than all of them.
Perhaps I could simply adjust this current source resister to make the irf9610 have less bass but still better than Lyndon's while still getting better high frequencies.
The only difference between the last time you heard my Aleph 3 jfet was the 10 pF bypass cap over the feedback capacitor and a 680 pF silver mica on the base and collector of the mpsa18 for stability.
I think the .001 uF silver ceramic would be better or even the .047 uF silver ceramic that I saw in Lyndon's Aleph 3.
I recall the last time everyone liked the jfet conversion, I had about 3.6K to 3.8K ohms below my LED references. So, I will try those again and recheck the current to the j176 fet. I may even remove the 10 pF feedback cap to see if that sounds like I recall the last time we all liked it.
I think Lyndon's must not have any feedback bypass cap too, and we all seemed to like that better.
I emailed Lyndon about some photos of his boards to check my theory and he said he will have to get back to me later on since his usb camera cable is at school.
Bill
Mark A. Gulbrandsen said:
Are you referring to jfets? or mosfets?
I know the j176 could handle either 35 mA or 50 mA. It might be okay, but the zvp3310a could handle 50 mA for sure, since I recall it was rated more like 150 mA from memory, while the irf9610 could easily handle that task or even much higher since it was a lot more robust.
Now that we all know the original 4.75K ohm resister below the zener in the aleph 3 schematic does make the bass sound stronger or the high frequencies much higher, I may try the irf9610 again and see if I could get a better balance than the zvp3310a or j176. I recall the irf9610 for the current source had much better bass than all of them.
Perhaps I could simply adjust this current source resister to make the irf9610 have less bass but still better than Lyndon's while still getting better high frequencies.
The only difference between the last time you heard my Aleph 3 jfet was the 10 pF bypass cap over the feedback capacitor and a 680 pF silver mica on the base and collector of the mpsa18 for stability.
I think the .001 uF silver ceramic would be better or even the .047 uF silver ceramic that I saw in Lyndon's Aleph 3.
I recall the last time everyone liked the jfet conversion, I had about 3.6K to 3.8K ohms below my LED references. So, I will try those again and recheck the current to the j176 fet. I may even remove the 10 pF feedback cap to see if that sounds like I recall the last time we all liked it.
I think Lyndon's must not have any feedback bypass cap too, and we all seemed to like that better.
I emailed Lyndon about some photos of his boards to check my theory and he said he will have to get back to me later on since his usb camera cable is at school.
Bill
Humm, He must not have one of those "Smart cables".... but it'll be smarter after spending a few days in his class!
Mark
Mark
Re: Aleph 3 to jfet conversion
I have impression that all differences in sound you subscribed to sort of CCS ( changing from mosfet to jfet or even changing voltage reference in CCS) are just differences in resulting current through input differential stage ;
you really must try scientific approach ,writing down every change,and also results from that change ;
changing in one time just one parameter,then you will know what cause is.
for instance- resistor in drain of first LTP Jfet (this resistor is for biasing and modulating lower output mosfet ; if we presume that you always need same amount of DC level on that resistor for biasing (modulating gate of) output mosfet ,and you say that sound is better with lower value of that resistor -that (in fact ) means that sound is better with more current through differential stage ,to heck with resistor 😉
so- just use IRF9610 for LTP CCS (you can try led string for voltage refference instead one zenner 😉 ) and fiddle with differential stage and current through that LTP and mentioned resistor ;
you can burn those j176 to ,say,75% of allowed dissipation without risking that you'll burn them in dynamic regime....
just one thing more: NP sez that stock Alephs have DC offset from cold in range of 500mV........his words tells me something funny about everyday engineering and pilling a hair in two halves.......
that's what I can think right now
like always :
BillWW said:
I have impression that all differences in sound you subscribed to sort of CCS ( changing from mosfet to jfet or even changing voltage reference in CCS) are just differences in resulting current through input differential stage ;
you really must try scientific approach ,writing down every change,and also results from that change ;
changing in one time just one parameter,then you will know what cause is.
for instance- resistor in drain of first LTP Jfet (this resistor is for biasing and modulating lower output mosfet ; if we presume that you always need same amount of DC level on that resistor for biasing (modulating gate of) output mosfet ,and you say that sound is better with lower value of that resistor -that (in fact ) means that sound is better with more current through differential stage ,to heck with resistor 😉
so- just use IRF9610 for LTP CCS (you can try led string for voltage refference instead one zenner 😉 ) and fiddle with differential stage and current through that LTP and mentioned resistor ;
you can burn those j176 to ,say,75% of allowed dissipation without risking that you'll burn them in dynamic regime....
just one thing more: NP sez that stock Alephs have DC offset from cold in range of 500mV........his words tells me something funny about everyday engineering and pilling a hair in two halves.......
that's what I can think right now
like always :
Zen version 9 compaired to Aleph mini J
Today as promised on the Babbelfish thread, I brought a Mini aleph jfet over to Mark's along with the Zen version 9 to let Lucky Lyndon and Mark and I compare to see what we thought.
The Zen version 9 actually sounded impressive on Mark's dynaudios. It seemed more powerful than I would have expected, especially in recollection of how it compared with my 2 ohm 104/db/w horn speakers. I guess the 2 ohm load really takes too much out of this Zen to enjoy compared to Mark's Dynaudios.
The Zen had relatively impressive bass on Mark's speakers. It still seemed to stress the midrange in my mind and also was quite enjoyable to listen to. Mark suggested trying some different bypass capacitors, which might bring the highs out better. It seemed maybe for a full range speaker that may be too bright, this Zen might be a winner for a Lowther or Fostex with this duller highs.
The Zv9 seemed to have a unique sound compared to the Krell KSA 50 and also Aleph mini I brought over. It seemed like the bass of the Zv9 was deep and extended, but a bit puffy or less controlled somewhat. It had snappy dynamics Mark felt compared to other amps he has heard.
The Mini was still the winner, I felt in the highs and also well in the lows too. It seems to have a lot more higher frequencies than the Zen 9 did. It was very detailed, but not at all harsh sounding. It had probably double the power it seemed compared to the Zv9 on Mark's speakers. It has a very romanticized sound on guitar strings similar to some tube audio I have listened to, but without the distortion that usually goes along with tube audio. It was very delicate on voices and instruments. I am still going to play with the bias a bit more. Mark felt it did not have as deep of sound stage as his Aleph 30, so that suggests to me that the bias may be less. Usually, the sound stage opens up further with greater bias. We were running this Mini Aleph on his variac, since I did not have time to swap the transformers out, so there is room for improvement there. Or maybe not. Mark seemed to like it more forward sounding he said.
It seemed to be one level above the previous Aleph 3 that had double the input capacitance on the output mosfets. The highs were even more magical along with the bass being quite surprisinlgy good even compared to Mark's Aleph 30. Over all this mini Aleph Jfet sounded the best that we had heard so far.
I think I would use this for my highs in my horn setup and perhaps the Aleph 30 jfet version for the lows. All of the jfet versions using the j176 sound very nice so far.
I have not tried the Aleph 30 yet, but it seems like all of them will be fantastic for audiophile hobbyists. 😎
Bill
Today as promised on the Babbelfish thread, I brought a Mini aleph jfet over to Mark's along with the Zen version 9 to let Lucky Lyndon and Mark and I compare to see what we thought.
The Zen version 9 actually sounded impressive on Mark's dynaudios. It seemed more powerful than I would have expected, especially in recollection of how it compared with my 2 ohm 104/db/w horn speakers. I guess the 2 ohm load really takes too much out of this Zen to enjoy compared to Mark's Dynaudios.
The Zen had relatively impressive bass on Mark's speakers. It still seemed to stress the midrange in my mind and also was quite enjoyable to listen to. Mark suggested trying some different bypass capacitors, which might bring the highs out better. It seemed maybe for a full range speaker that may be too bright, this Zen might be a winner for a Lowther or Fostex with this duller highs.
The Zv9 seemed to have a unique sound compared to the Krell KSA 50 and also Aleph mini I brought over. It seemed like the bass of the Zv9 was deep and extended, but a bit puffy or less controlled somewhat. It had snappy dynamics Mark felt compared to other amps he has heard.
The Mini was still the winner, I felt in the highs and also well in the lows too. It seems to have a lot more higher frequencies than the Zen 9 did. It was very detailed, but not at all harsh sounding. It had probably double the power it seemed compared to the Zv9 on Mark's speakers. It has a very romanticized sound on guitar strings similar to some tube audio I have listened to, but without the distortion that usually goes along with tube audio. It was very delicate on voices and instruments. I am still going to play with the bias a bit more. Mark felt it did not have as deep of sound stage as his Aleph 30, so that suggests to me that the bias may be less. Usually, the sound stage opens up further with greater bias. We were running this Mini Aleph on his variac, since I did not have time to swap the transformers out, so there is room for improvement there. Or maybe not. Mark seemed to like it more forward sounding he said.
It seemed to be one level above the previous Aleph 3 that had double the input capacitance on the output mosfets. The highs were even more magical along with the bass being quite surprisinlgy good even compared to Mark's Aleph 30. Over all this mini Aleph Jfet sounded the best that we had heard so far.
I think I would use this for my highs in my horn setup and perhaps the Aleph 30 jfet version for the lows. All of the jfet versions using the j176 sound very nice so far.
I have not tried the Aleph 30 yet, but it seems like all of them will be fantastic for audiophile hobbyists. 😎
Bill
Re: Zen version 9 compaired to Aleph mini J
nice;
😉
tell us more about "party" part of this shootout......
😉
BillWW said:
nice;
😉
tell us more about "party" part of this shootout......
😉
Re: Re: Zen version 9 compaired to Aleph mini J
Choky,
There was not much going on this time. Mark told Lyndon, I would be two hours later, since I still needed to get the left channel to the aleph mini functioning.
Well, to Lyndon that meant show up much later in the evening, by the time Mark and I were done listening to the two amps.
So, we just listened a littel while longer when Lyndon showed up and then went out to dinner.
Mark teased Lyndon a bit by telling him Choky, would be showing up in about 30 minutes after Lyndon arrived.
Mark said he would have someone over Sunday, so he needed to get organized for this event.
So, we did not even get any photos due to all of the things going on with Mark's recent return trip.
It seems to me he lives more away from home than at his home. 🙄
We debated if Choky, uses babbelfish translator to correspond with us English language writers and that was why the thread to Babbelfish was named for? The usual gossip about which wines Nelson would prefer to listening etc...
Frankly, I believe too much alcohol consumed makes judgement of equipment less accurate. Everything sounds good, when in fact it is quite the opposite! 😀
So, I tend to be the sober one at these events, because I take listening serious--well truthfully I am just not a drinker. 😉
Zen Mod said:
Choky,
There was not much going on this time. Mark told Lyndon, I would be two hours later, since I still needed to get the left channel to the aleph mini functioning.
Well, to Lyndon that meant show up much later in the evening, by the time Mark and I were done listening to the two amps.
So, we just listened a littel while longer when Lyndon showed up and then went out to dinner.
Mark teased Lyndon a bit by telling him Choky, would be showing up in about 30 minutes after Lyndon arrived.
Mark said he would have someone over Sunday, so he needed to get organized for this event.
So, we did not even get any photos due to all of the things going on with Mark's recent return trip.
It seems to me he lives more away from home than at his home. 🙄
We debated if Choky, uses babbelfish translator to correspond with us English language writers and that was why the thread to Babbelfish was named for? The usual gossip about which wines Nelson would prefer to listening etc...
Frankly, I believe too much alcohol consumed makes judgement of equipment less accurate.
Everything sounds good, when in fact it is quite the opposite! 😀So, I tend to be the sober one at these events, because I take listening serious--well truthfully I am just not a drinker. 😉
BillWW, thanks for another nice piece of writing🙂 I think the ZenV9 has an extended topend and sounds very natural, at that. I wouldn't imidiately consider a more extended topend as a plus, Of hand I would suspect that a more extended topend would have to be a bit coloured? Hard to say, I havent heard your J-fet Aleph🙂
Steen🙂
steenoe said:
Well, it seems it would depend on which speaker you are using. Perhaps the extended top end of the Aleph mini j might be too bright on say a Lowther or driver that is not as flat in the highs?
That was what I was referring to previously, where the Zv9 might be better.
Mark liked the Zv9 really a lot and said he was surprised how just one transister could do so well. I owe him a set of Zv9 boards and power supply now. He liked it that much!
He said the Zv9 had excellent bass for a single transister capacitor coupled amp.
On my horn tweeters, the Aleph mini jfet with the extended highs helps out the high frequency roll off of that tweeter horn. So, it matters on which speakers you own.
I would not call the Aleph a bright sounding amp either. It just seemed to have more details in the highs compared to the Zv9. If you think about it, the Aleph mini j176 fets are about 20 or 30 pF, with the 1 irfp240 of about 1275 pF or total 1300 or maybe 1350 pF of input capacitance.
The other debate at this event was does the Lovoltech jfet with 1200 or 1300 pF in a differential combined with an irfp240 of 1275 pF add up to 2500 pF? If so, that would explain why the highs seemed rolled somewhat compared to the mini Aleph jfet of half the capacitance.
Later late in the evening at my home, I could not resist trying the mini Aleph J on my horns that evening and am again somewhat surprised. The Aleph J is having trouble driving my 2 ohm load. The Aleph 3 was much better. Single transister amps really shine on 6 or 8 or 16 ohm loads. They are quite amazing, but not on low loads I have decided. 😱
Bill
Bill,
Thanks for another fun report.
I'm wondering what rail voltage and bias level
are you using for the mini aleph?
Thanks,
Dennis
Thanks for another fun report.
I'm wondering what rail voltage and bias level
are you using for the mini aleph?
Thanks,
Dennis
mini Aleph Jfet
We initially tried 15 volts, but later a bit higher at 16.7 volts at Marks. I did remove the bias resister to the mpsa18 to keep things equal to the Aleph 3 biasing that I had done previously.
I really have not done the Aleph mini justice on how well it sounded. I have left that up to Mark to describe more so.
It just has a lot of clarity and brings out the slightest detail in a recording. For example, Mark had some symphony music with some chimes. They sounded more realistic in the highs with the Aleph mini Jfet versus the Zv9. Mark after hearing both and including his Krell felt the Zv9 seemed to be lacking some detail in the highs.
I should explain. I used all of the same parts in both amps to be fair, but Mark thought perhaps my Vitamin Q 2.5 uF bypass cap on the 10,000 uF Nichicon output cap was not ideal. Perhaps that was why it sounded rolled in the highs he thought. I would have to spend a lot of money on a better bypass cap, which frankly now that I am going back to school, do not have the funds for.
Bill
Dennis Hui said:
We initially tried 15 volts, but later a bit higher at 16.7 volts at Marks. I did remove the bias resister to the mpsa18 to keep things equal to the Aleph 3 biasing that I had done previously.
I really have not done the Aleph mini justice on how well it sounded. I have left that up to Mark to describe more so.
It just has a lot of clarity and brings out the slightest detail in a recording. For example, Mark had some symphony music with some chimes. They sounded more realistic in the highs with the Aleph mini Jfet versus the Zv9. Mark after hearing both and including his Krell felt the Zv9 seemed to be lacking some detail in the highs.
I should explain. I used all of the same parts in both amps to be fair, but Mark thought perhaps my Vitamin Q 2.5 uF bypass cap on the 10,000 uF Nichicon output cap was not ideal. Perhaps that was why it sounded rolled in the highs he thought. I would have to spend a lot of money on a better bypass cap, which frankly now that I am going back to school, do not have the funds for.
Bill
Re: Re: Re: Zen version 9 compaired to Aleph mini J
hehe-even Babelfish can't do so many mistakes in Engrish,as I do....😉
besides, Babelfish machine doesn't do Serbian -English,even if I use it sometimes for French and Italian translations to English....
Babelfish J is 'cause this is my attempt of Babelfishing Papa's Aleph J
hehe,I even make (initially) spelling (writing ) mistake with two "B" ins Babelfish..........
BillWW said:
hehe-even Babelfish can't do so many mistakes in Engrish,as I do....😉
besides, Babelfish machine doesn't do Serbian -English,even if I use it sometimes for French and Italian translations to English....
Babelfish J is 'cause this is my attempt of Babelfishing Papa's Aleph J
hehe,I even make (initially) spelling (writing ) mistake with two "B" ins Babelfish..........
Re: Re: Re: Zen version 9 compaired to Aleph mini J
hehe
Choky in Solt Lake at Mark's......with "Death of 12B4" in hands....
BillWW said:
.......
Mark teased Lyndon a bit by telling him Choky, would be showing up in about 30 minutes after Lyndon arrived.
hehe
Choky in Solt Lake at Mark's......with "Death of 12B4" in hands....
I didn't have anything to drink that night.....😱 .
Lyndon was late and he completely missed the fact that Choky was there and had already left to catch his plane by the time he had arrived.
We had dinner at Dee's.... nothing fancy... burgers. It was too hot here to cook out... 105 deg. We also kept the Ecaporative cooler running full blast to deal with the extra heat load of the A;eph and Zen power amps.
The Mini-A/ J was definately the better sounding amp but the Zen was quite a surprise driving my 89 db speakers to a very decent level.. its high end just didn't cut it though and hooking in the Mini-A/J was like rolllling up the window shade on the high end. I suggested to Bill that he might try some exotic bypass caps across the Zen's output cap to improve the high end a bit.
Yesterday i had a date with a nice lady so I kicked the guys out early so I could get the house organized..... She complomented me on how clean the place was for a guy... I told her she should have seen it yesterday when the guiys were over...
My daye and I ended up out in the desert in search of the heards of Wild Mustangs... we ended up finding four different heards... mighty impressive and I felt like Clark Gable in "The Misfits" taking Marlyn MOnroe out to see the horsees for the first time.... Nope ... she wouldn't let me catch any of em to sell for dog food😀 .
Mark
Attachments
BillWW said:
If you use the parts in a cascoded differential, you'll see about
half the capacitance of a single part. The key is not the
capacitance figure as such, but its linearity and how it figures
into the transconductance of the device.
Mark A. Gulbrandsen said:
that will be certainly just a bit
changing texture OK,(even that just in small amount) but quantity of highs with some other sort of cap...........
This reading is great. Nevertheless, I feel missing something.
Sounds like report of frequency research in bass, mid and treble.
No music. . . ?
Which one is more clssical music. . . ?
Which one is more jazz and blues music. . . ?
Which one is more hiphap music. . . ?
Which one is more rock and roll. . . ?
😎
Sounds like report of frequency research in bass, mid and treble.
No music. . . ?
Which one is more clssical music. . . ?
Which one is more jazz and blues music. . . ?
Which one is more hiphap music. . . ?
Which one is more rock and roll. . . ?
😎
Babowana said:
my kind of man 😉
and all those sorts on crappy Dynaudios.......
which one is best all rounder?
say-on medium sized,medium sensitive speakers...
when you power it in early morning and shut it down in late evening.....
Excactly😀 Mark, thats a wonderfull shot of those horses. I have a question for you: I always thought that the native horses of america were Mustangs! How come the local experts here in Denmark insist's on calling them Painthorse's? They even have specific names for the different colour variations. I guess this is totally OT, but nonetheless😉
Steen🙂
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