Thanks. I agree, but its kind of hard to learn if you start at the wrong place. I do my homework, I read for hours, I ask... but it's different if you don't have the all the required background knowledge yet.
And, unfortunately, no Zen Mod... if one asks, its not necessarily answered. I did ask elsewhere, and your kind and always spot-on reply was characterized by other member as "ZMs f/u reply...".
You are one of the great minds / knowledge here. But your answers are usually way above what non-electronic engineers can understand. Ok, I won't generalize... they are way above what I understand. And I am not usually considered among the dumb of the group.
Thanks anyway, best regards,
Rafa.
And, unfortunately, no Zen Mod... if one asks, its not necessarily answered. I did ask elsewhere, and your kind and always spot-on reply was characterized by other member as "ZMs f/u reply...".
You are one of the great minds / knowledge here. But your answers are usually way above what non-electronic engineers can understand. Ok, I won't generalize... they are way above what I understand. And I am not usually considered among the dumb of the group.
Thanks anyway, best regards,
Rafa.
Yes I see that.. just to be sure of avoiding mistakes.
I am preparing the parts...but the delivery at this season is unpredictable!
Could you tell about the power supply used in the picture?
Impressive build. The LSK pre is my favorite one I have built. I am planning on building Wayne's pre when a board becomes available.
Yes I see that.. just to be sure of avoiding mistakes.
I am preparing the parts...but the delivery at this season is unpredictable!
Could you tell about the power supply used in the picture?
Power supply is Jung super regulator, pcb available from diyaudio store. It is fed by an old peter Daniels universal psu board (mur860/nichicon kg then nichicon kz).
I have built two of Juma’s current mirror preamps. I’ve done a lot of preamps (jfet boz, b1 rev2, ba-3, mini f5, Salas DCG3) this one is probably my favorite in my system (f5t turbo amp). It just gets the sense of space right and it’s not too hard sounding. If you don’t need large amounts of current on output of pre why use a big mosfet or bjt when a small one will sound better?
If you follow the layout in post 492 it is very easy to do on perfboard.
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Hi Hikari1, it is good to hear that.
I also tried BA-3 and I was wondering what this pre is like against BA-3 pre.
My main amp is DIY Sony Vfet front end with paralleled 2SK82s+IRFP9240 DEFiSIT. I assume this is quite similar to your F5T since both have the same front end
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Preamps are difficult to judge except in one’s own system...so my conclusions might not be the same as yours. To me ba-3 has a too smooth sound, kind of bleached compared to others. Probably due to no feedback. Dcg3 is very, very good...Iam using it as my main headphone amp but for some reason just prefer Juma’s preamp with speakers. I don’t like no gain buffers in my system. They just don’t soundstage the way I like it.
All of them have strengths and weaknesses.
But all of this depends on your system and what you listen too.
All of them have strengths and weaknesses.
But all of this depends on your system and what you listen too.
I also have built most of the pre's Hikari mentions and like him prefer the LSK one for one with gain. But I do use and like my B1 version2 as well. I also have built a number of tube pre's along with the Korg but they are just not my taste. Too much 2nd harmonic. All this is subjective depending on your taste, equipment used and environment. I have built 2 or more of the BA-3 pre's. Excellent with the BA-1 and BA-2 amplifiers, I have both, but not my taste as a stand alone pre. I ordered 8 of the LSK170 and LSJ74 C grade ones and matched them as close to IDSS 15 as I could. Not exact but with some pots instead of just resistors on the last stage and using the Arta software I adjusted the 2nd harmonic to my taste. Juma's mirror one sounds excellent as well but more trouble to build on a proto board. Boards were once available for his build but I doubt any are available now.
Following Hikari1's comment, I began anyway. I am waiting for BC547 557 and resistors.
I hope I can taste this in the year 2019?
I believe Hikari and I are talking about the Nelson Pass LSK pre presented at the BAF. If you are using BC547 and 557 you are building Juma's pre which is harder to build on a proto board. Not that hard, I built mine on a proto board, but more involved than the simple NP LSK linestage. It will sound excellent with very little difference in sound compared to the NP LSK linestage. When finished do show pictures and give a review. The previous poster has a left over Juma board already stuffed. If not you someone should consider buying those boards if they want a great linestage to drive their Firstwatt clone.
I am planning to do this circuit of Juma, which I understand is simple with 220-ohm output impedance without the buffer.
That offer of the stuffed board is tempting but with two higher supply voltages (bipolar 33V and 45V?).
I thought this attached one is easier for me.
But it seems that this circuit and the GB circuit are quite different in performance?
I tried to figure out reading the posts here. There are many circuits along with Juma's experiments.
That offer of the stuffed board is tempting but with two higher supply voltages (bipolar 33V and 45V?).
I thought this attached one is easier for me.
But it seems that this circuit and the GB circuit are quite different in performance?
I tried to figure out reading the posts here. There are many circuits along with Juma's experiments.
Attachments
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