I know that lake😀 Did you notice the red berries, framing the water in both sides? Nice shot😉
Nice shot, too. Wonder if there could be some trout in there😉
Steen🙂
Zen version 9 jfet
I should have it up and running tonight in a couple of hours. Everything is done, except for putting silicon grease between the fets and bolting everything done that is already predrilled. I still just need to solder up the power to the board and speaker and input wires to the board.
Everything is already soldering to the various inputs and speaker terminals and various hook ups.
I should have music playing tonight as long as my boards do not have any problems.
The power supply is finished and tested in my wood case I built for this project.
It took a lot longer to build a wood chassis than it would have with aluminum, but I believe wood is a lot cheaper for prototyping, but I probably spent more time on this wood case than aluminum since I had to brace every couple of inches to support the thin wood I used.
Well, I am very excited to see how this amp compares to my Aleph 3 jfet versus the Lovotech's!!!
One stage versus two stages!!! 🙂
I should have it up and running tonight in a couple of hours. Everything is done, except for putting silicon grease between the fets and bolting everything done that is already predrilled. I still just need to solder up the power to the board and speaker and input wires to the board.
Everything is already soldering to the various inputs and speaker terminals and various hook ups.
I should have music playing tonight as long as my boards do not have any problems.
The power supply is finished and tested in my wood case I built for this project.
It took a lot longer to build a wood chassis than it would have with aluminum, but I believe wood is a lot cheaper for prototyping, but I probably spent more time on this wood case than aluminum since I had to brace every couple of inches to support the thin wood I used.
Well, I am very excited to see how this amp compares to my Aleph 3 jfet versus the Lovotech's!!!
One stage versus two stages!!! 🙂
Zen version 9
I got music tonight. My second amp I have ever built and I did not have any surprises. Everything is working the first try--music!!! 😎
What happened to your old name choky?
The zen version 9 is able to get somewhat loud with my 104 db/W corner horn. It seems to be doing better with my 2 ohm load than I would have expected.
It definately does not have the power of my Aleph 3, but it is too early to critique the sound. The gain is a lot less I noticed than my Aleph 3 jfet version.
So, far for the 15 minutes of listening, it reminds me of my Aleph mini in power. It might have slightly less dampening it seems, but sounds fine on my cornerhorn's bass.
I will have to run it for a while to burn the amp in, but it is really running quite hot around 55 to 60 celsius I would guess by how long I can keep my hand on the heatsink tunnel. I will need to do something better next time I build more Alephs or zens. Next time, all aluminum for heatsinking would be much better when I can aford right now.
Zen Mod said:
I got music tonight. My second amp I have ever built and I did not have any surprises. Everything is working the first try--music!!! 😎
What happened to your old name choky?
The zen version 9 is able to get somewhat loud with my 104 db/W corner horn. It seems to be doing better with my 2 ohm load than I would have expected.
It definately does not have the power of my Aleph 3, but it is too early to critique the sound. The gain is a lot less I noticed than my Aleph 3 jfet version.
So, far for the 15 minutes of listening, it reminds me of my Aleph mini in power. It might have slightly less dampening it seems, but sounds fine on my cornerhorn's bass.
I will have to run it for a while to burn the amp in, but it is really running quite hot around 55 to 60 celsius I would guess by how long I can keep my hand on the heatsink tunnel. I will need to do something better next time I build more Alephs or zens. Next time, all aluminum for heatsinking would be much better when I can aford right now.
Re: Zen version 9
I'm glad for ya!
regarding my old name-seems that Mods decided that I was too invasive on forum with my old skin,so they choose another one for me
heatsinks: did I mention already to you ApexJr tunnels?
are yours from there?
besides -he always have ultra cheap caps,even for my serbian standard
🙄
no any need to mention that I don't have any connection with Apex,except that I adore surplus places
BillWW said:
I'm glad for ya!
regarding my old name-seems that Mods decided that I was too invasive on forum with my old skin,so they choose another one for me
heatsinks: did I mention already to you ApexJr tunnels?
are yours from there?
besides -he always have ultra cheap caps,even for my serbian standard
🙄
no any need to mention that I don't have any connection with Apex,except that I adore surplus places
Re: Zen version 9 jfet
So?
I was patient enuf.
Learn from Nelson, but only good thing.
BillWW said:
So?
I was patient enuf.
Learn from Nelson, but only good thing.
Re: Re: Zen version 9 jfet
you have a mail
Babowana said:
So?
I was patient enuf.
Learn from Nelson, but only good thing.
you have a mail
Re: Re: Zen version 9
The heat tunnels were from Apexjr. I bolted a wood top and bottom plate to the tunnel using the tunnel as bracing through the center of the amp. It would be better to leave as much space around the heat sink to cool it better.
The capacitors, I had also previously boughten from Apexjr.
He has dirt cheap prices on parts compared to many places. He usually gives a discount to diyaudio members too, since he receives a lot of business.
He currently had 50 volt 12,000 uF Nichicon caps for a $1.00 a piece if mentioning this web site. I did buy some of those to try and with 40 V 400 Va toroids, my rail came under 49 volts, so those who would like to try this Zen amp for cheap could buy those $1.00 caps.
My rail ended up being 49 volts under load using 40 volt 400 Va toroids with pi filter for a dual mono power supply. The rail would drop even lower with one toroid, so those cheap caps would be a bargain for this project for others.
The Zen version 9 reminds me of my original "Return of Zen".
I feel my Aleph 3 jfet is in another higher league of class of amp due to the heavy biasing with the jfet front end.
In order to get the Zen version 9 to compete, I would need to bias it harder and maybe check the AC current gain along with the 20 pF bypass compensation cap on my scope.
I noticed adjustsments can make a huge amount in quality of sound. My Aleph with stock bias setting has less detail too like the Zen version 9, so I know the Zen version 9 needs further tweaking...
Simply, put I would need to tweak this Zen to sound better than my Aleph jfet that has had over a year of tweaking. I am very intrigued by the Zen version 9 in how it cancels distortion using the lovoltech jfet, so think it has great potential! I just need another year of tweaking! 😉
Zen Mod said:
The heat tunnels were from Apexjr. I bolted a wood top and bottom plate to the tunnel using the tunnel as bracing through the center of the amp. It would be better to leave as much space around the heat sink to cool it better.
The capacitors, I had also previously boughten from Apexjr.
He has dirt cheap prices on parts compared to many places. He usually gives a discount to diyaudio members too, since he receives a lot of business.
He currently had 50 volt 12,000 uF Nichicon caps for a $1.00 a piece if mentioning this web site. I did buy some of those to try and with 40 V 400 Va toroids, my rail came under 49 volts, so those who would like to try this Zen amp for cheap could buy those $1.00 caps.
My rail ended up being 49 volts under load using 40 volt 400 Va toroids with pi filter for a dual mono power supply. The rail would drop even lower with one toroid, so those cheap caps would be a bargain for this project for others.
The Zen version 9 reminds me of my original "Return of Zen".
I feel my Aleph 3 jfet is in another higher league of class of amp due to the heavy biasing with the jfet front end.
In order to get the Zen version 9 to compete, I would need to bias it harder and maybe check the AC current gain along with the 20 pF bypass compensation cap on my scope.
I noticed adjustsments can make a huge amount in quality of sound. My Aleph with stock bias setting has less detail too like the Zen version 9, so I know the Zen version 9 needs further tweaking...
Simply, put I would need to tweak this Zen to sound better than my Aleph jfet that has had over a year of tweaking. I am very intrigued by the Zen version 9 in how it cancels distortion using the lovoltech jfet, so think it has great potential! I just need another year of tweaking! 😉
Re: Zen version 9
Zen version 9 tweaking
Well, my first sucess!
I have it sounding very similar to my Aleph 3 jfet now. Maybe someone could tell me what is occuring.
I adjusted the 25K ohm pot initially as instructed from Nelson, but I found if I lower my one mosfet to about a 1/3 instead of 1/2 of the 46 volts the high frequencies sound much better--more sweet like my Aleph 3 jfet version, although the Zen seems to have a lot less power than the 1/2 voltage value now.
Is this changing perhaps the AC current gain indirectly?
Maybe that is all that I need to adjust?
Any ways, I am glad to see I have it sounding very similar to my Aleph with a fraction of the heat in my room for summer listening.
Bill 🙂
Zen Mod said:
Zen version 9 tweaking
Well, my first sucess!
I have it sounding very similar to my Aleph 3 jfet now. Maybe someone could tell me what is occuring.
I adjusted the 25K ohm pot initially as instructed from Nelson, but I found if I lower my one mosfet to about a 1/3 instead of 1/2 of the 46 volts the high frequencies sound much better--more sweet like my Aleph 3 jfet version, although the Zen seems to have a lot less power than the 1/2 voltage value now.
Is this changing perhaps the AC current gain indirectly?
Maybe that is all that I need to adjust?
Any ways, I am glad to see I have it sounding very similar to my Aleph with a fraction of the heat in my room for summer listening.
Bill 🙂
Re: Re: Zen version 9
Nai. AC current gain is decided only by f{R3,R4,R5,R13,R18,R19} (FIG8).
If the Vd (Q-voltage) is greater than 23V, the Vds of the JFET
would be also increased so tha you might loose the sweet spot
(kind of like a virgi. . . nai
a triode).
In addition, more heat in the JFET.
And, earlier clipping, too. . .?
BillWW said:
Nai. AC current gain is decided only by f{R3,R4,R5,R13,R18,R19} (FIG8).
If the Vd (Q-voltage) is greater than 23V, the Vds of the JFET
would be also increased so tha you might loose the sweet spot
(kind of like a virgi. . . nai
a triode). In addition, more heat in the JFET.
And, earlier clipping, too. . .?
Re: Re: Re: Zen version 9
I found what was occuring after I posted. Essentially, the jfet was changing on the voltage. So, I found by doing half the voltage as Nelson has suggested and then adjusting the jfet, to 1.8 volts made the Zen version 9 sound very similar to my Aleph 3 jfet.
I noticed now that their tone is very similar, the Aleph 3 j176 still has more spatiousness or in general still sounded more refined.
The only difference is the Aleph 3 j176 has a lot more current and much more power supply filtering.
So, is the Zen version 9 able to be biased harder on the irfp240? Or is this not possible due to the Lovotech exponential curves exceeding that range?
Thanks, Bill
Babowana said:
Nai. AC current gain is decided only by f{R3,R4,R5,R13,R18,R19} (FIG8).
If the Vd (Q-voltage) is greater than 23V, the Vds of the JFET
would be also increased so tha you might loose the sweet spot
(kind of like a virgi. . . nai
In addition, more heat in the JFET.
And, earlier clipping, too. . .?
I found what was occuring after I posted. Essentially, the jfet was changing on the voltage. So, I found by doing half the voltage as Nelson has suggested and then adjusting the jfet, to 1.8 volts made the Zen version 9 sound very similar to my Aleph 3 jfet.
I noticed now that their tone is very similar, the Aleph 3 j176 still has more spatiousness or in general still sounded more refined.
The only difference is the Aleph 3 j176 has a lot more current and much more power supply filtering.
So, is the Zen version 9 able to be biased harder on the irfp240? Or is this not possible due to the Lovotech exponential curves exceeding that range?
Thanks, Bill
Zen version 9
I would just like to encourage others to try adjusting their Lovotech R3 value if they find the highs rolled and the midranged too strong. This is what I changed and now the amp sounds wonderful. This took a lot less effort to get sounding nice compared to my Aleph project.
This amp has great potential!
Bill
I would just like to encourage others to try adjusting their Lovotech R3 value if they find the highs rolled and the midranged too strong. This is what I changed and now the amp sounds wonderful. This took a lot less effort to get sounding nice compared to my Aleph project.
This amp has great potential!
Bill
Re: Re: Re: Re: Zen version 9
you can always paralel more Jfets ,in fact -cascodes
BillWW said:
you can always paralel more Jfets ,in fact -cascodes
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