Hi,
Even though it seems I won't find time to try:
Shouldn't the Zen v. 9 make a nice preamp when substituting the power-fet with a famous 2sk170 and readjusting the currents & voltages?
Signalwise, it would be a purist SE-approach, and even the output-cap wouldn't hurt that much since it's inside the fb-loop.
The potential issue I can see is limited output current/highish output impedance.
I might have been tried by someone, cause it seems so obvious, doesn't it?
Rüidger
Even though it seems I won't find time to try:
Shouldn't the Zen v. 9 make a nice preamp when substituting the power-fet with a famous 2sk170 and readjusting the currents & voltages?
Signalwise, it would be a purist SE-approach, and even the output-cap wouldn't hurt that much since it's inside the fb-loop.
The potential issue I can see is limited output current/highish output impedance.
I might have been tried by someone, cause it seems so obvious, doesn't it?
Rüidger
Interestingly, I have played with this, and I found that cascoded
JFETs in a diff pair arrangement somewhat like the BOSOZ was
superior to a single JFET sonically, much as BOSOZ was better
liked than the BOZ.
JFETs in a diff pair arrangement somewhat like the BOSOZ was
superior to a single JFET sonically, much as BOSOZ was better
liked than the BOZ.
The quote thing wont let me quote the whole thing😱 This is pretty interesting, any chance to see a new Zen preamp with J-fets?? I would love to build a thing like that🙂
Steen😎
Wow, thats great. Cant wait to see it😎 Thanks a lot for responding😎
A new chapter in the Zen preamp history, who would have thought that? I was afraid that the statement "this pretty much finishes the preamp offerings in the Zen series" was gonna hold!!
Thanks a lot for reconsidering!
Steen🙂 (quite happy😀 )
steenoe said:
I don't wanna be rude-but why not susy then?
susy or blowtorch or whatever-they seems all are along the pretty similar line (except susy approach
)just for illustration-thinking of little ZM about these ideas......nothing new under the sun.....from other deviant thread 😉
http://www.diyaudio.com/forums/attachment.php?s=&postid=950209&stamp=1151491647
btw-I like boundaries and tasks stated from Papa....
he sometimes show almost psychotic urge to please the children
Choky, a little of your own medicine 😀 Anyone said it wouldnt be a susy?? Anyone said anything at all?? I am sure that Mr. Pass wont let us down. If we really gets a successor to the BoZ or BosoZ, I am sure it will be better than those😎
Steen🙂 (confident😉 )
I like twisted confirmations from Papa,sometimes even more twisted than I understand,but why he must do everything?
I mean -he does it already ....?
I mean -he does it already ....?
Hey thats easy to understand🙂 This is the Pass forum!! Loads of us guys around here knows Mr. Pass from the past!! Personally I know his amps way back from the late 70'es😀
Allways, allways was Mr. Pass's amp's superior! I have listened to loads of amp's, but the best are Pass's amps! I heard the Treshold A400 and 4000's and they were the greatest at their time!
Mr. Pass is "God" on this forum😎 Just in case you missed it😀
Steen😎
Err...Who is Papa😕 😕 😕 I think you may find something in the US Patent Office😀 If your looking for "Pass"
I think you may score a few hits on any search engine😕 😕
Not to forget, passdiy.com firstwatt.com and passlabs.com
And, you may find countless publications, highly praising his work...
You may even notice the title of this Forum Catagory😀 😀 😀
Without Mr. Pass... We would all be in the Solid State Forum??? Who is Mr. Solid State?
I think you may score a few hits on any search engine😕 😕
Not to forget, passdiy.com firstwatt.com and passlabs.com
And, you may find countless publications, highly praising his work...
You may even notice the title of this Forum Catagory😀 😀 😀
Without Mr. Pass... We would all be in the Solid State Forum??? Who is Mr. Solid State?
Hi,
that was exactly that kind of answer I hoped for: I tried, but something else seems to be better.
In quite a few MC-phono amps, we have a SE FET as first stage, sometimes cascoded, sometimes paralleled.
If we look at the ono's first stage, which is cascoded and is fed by a cap multiplier: is a aleph-style CCS beneficial or not? Might be worth to try...
thanks,
Rüdiger
that was exactly that kind of answer I hoped for: I tried, but something else seems to be better.
In quite a few MC-phono amps, we have a SE FET as first stage, sometimes cascoded, sometimes paralleled.
If we look at the ono's first stage, which is cascoded and is fed by a cap multiplier: is a aleph-style CCS beneficial or not? Might be worth to try...
thanks,
Rüdiger
j-fet pre
Are you thinking to use lovoltec power fet for the pre?
Is it possible to replace the IRFP610 with a cascoded j-fet?
Are you thinking to use lovoltec power fet for the pre?
Is it possible to replace the IRFP610 with a cascoded j-fet?
I had the Toshiba devices in mind🙂 The BoZ and the BosoZ were tuned at getting the best from a Mosfet, in this case IRF610's. I doubt that a Lovoltech is a direct plugin replacement.
The BoZ and BosoZ with their high'ish railvoltages, are dedicated to get the best from a mosfet.
Steen🙂
Re: j-fet pre
No, I my first try would be the 2sk170, small signal low noise fet from toshiba, well known in this forum. A 2sk369 should work if you need gain.
Rüdiger
Stefano said:
No, I my first try would be the 2sk170, small signal low noise fet from toshiba, well known in this forum. A 2sk369 should work if you need gain.
Rüdiger
I think the lovoltechs make their magic with low voltage and around 2 amps of current, so not likely a good candidate for a preamp unless you want to run it at power amp levels. The smaller jfets have less input capacitance too.
Lovoltechs vs. other JFets
The Lovoltechs have a triode / resistive region up to around 4V and in the Zen V9 they are operated exactly in this region. Maybe this region is even higher at lower currents
It might be still be a good idea to try a preamp with the Lovoltechs, and the low voltage isn’t an issue if you use them in a cascode circuit.
And there are countless preamp circuits around using SK170s so you would have to be very creative to come up with something that hasn’t been tried before.
The Lovoltechs have a triode / resistive region up to around 4V and in the Zen V9 they are operated exactly in this region. Maybe this region is even higher at lower currents
It might be still be a good idea to try a preamp with the Lovoltechs, and the low voltage isn’t an issue if you use them in a cascode circuit.And there are countless preamp circuits around using SK170s so you would have to be very creative to come up with something that hasn’t been tried before.
I'm bringing back this thread because I have a question that might have been raised (and answered) here, but I'm not sure.
Might the LU1014 serve well as the cascode device (replacing the mosfet) being controlled by a SK170 or the like? I'm thinking about this for a preamp (mc phono, to be precise) and not for the input stage which might be a transformer.
Might this be possible (does it have the, uh, guts)? Would it provide any benefit over the mosfet?
Might the LU1014 serve well as the cascode device (replacing the mosfet) being controlled by a SK170 or the like? I'm thinking about this for a preamp (mc phono, to be precise) and not for the input stage which might be a transformer.
Might this be possible (does it have the, uh, guts)? Would it provide any benefit over the mosfet?
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