Carpenter, I just read your last post, and this is how I got it:
Merry Christmas to all. May the Nelson successfully bring a wealth of information and inspiration to everyone.
Ok. Just kidding. Couldn't resist.
Seriously,
Marry Christmas to all. May the new year bring a lot of joy and happiness. May the burning amp fest 2008 be even better!
I wish I could send a big gift for Mr. Pass. Here, I can only say: Thank You!
Kind Regards,
Vix
Merry Christmas to all. May the Nelson successfully bring a wealth of information and inspiration to everyone.
Ok. Just kidding. Couldn't resist.
Seriously,
Marry Christmas to all. May the new year bring a lot of joy and happiness. May the burning amp fest 2008 be even better!
I wish I could send a big gift for Mr. Pass. Here, I can only say: Thank You!
Kind Regards,
Vix
Vix, you're such a tease!
Unless we take the time to appreciate and enjoy what Nelson, and everyone else for that matter, brings to this forum, nothing will evolve, no one will prosper in the Diy-Audio scheme of things.
So, here's a toast to our endless fascination with audio--and unbridled appreciation to those who make-it-so!
Merry Christmas, and happy holidays, everyone!
Unless we take the time to appreciate and enjoy what Nelson, and everyone else for that matter, brings to this forum, nothing will evolve, no one will prosper in the Diy-Audio scheme of things.
So, here's a toast to our endless fascination with audio--and unbridled appreciation to those who make-it-so!
Merry Christmas, and happy holidays, everyone!
Vix said:Christmasis approaching,
trees are decorated...I've been told that
will drop some presents through chimney...
But he has a problem... Open Baffle speakers are too big...therefore he will drop just plans...
Or, even better, he will post them here so all good kids who wished nice active OB's can build them...(provided that they did the homeworks)
Nelson, any chance for that?
As you can see, there was not. I do however have some plans
in the works. Last summer Matt made me about 25 pairs of
baffles of various sizes and such and I am still working my way
through the permutations and teasing out the best and seeing
to it that the crossover/eq project accomodates those, while
trying to pull out some good "rules of thumb".
It's still going to be a little while before it bears fruit.
Question for Papa
I know that you made it all ........
so - question is :
for moderate gain settings - say 5 times , what's better sounding for you:
- Pumpkin like stage ( SUSY core, with outputs with gain) or
- Pumpkin like core (SUSY ) with buffer outputs (unity gain) ..... say as Papa Borbely -like buffers ........
so - what's better singing for you ......
as always - TIA .
I know that you made it all ........
so - question is :
for moderate gain settings - say 5 times , what's better sounding for you:
- Pumpkin like stage ( SUSY core, with outputs with gain) or
- Pumpkin like core (SUSY
) with buffer outputs (unity gain) ..... say as Papa Borbely -like buffers ........so - what's better singing for you ......
as always - TIA .
Attachments
Re: Question for Papa
All of my line stages are gains of 1 to 4 (that is to say between
0 and 12 dB) including the X1 I listen to day-to-day.
I don't have any hard favorites here, except to note that these
days they are all JFET based, at least on the input.
Partly it depends on whether I want balanced or not, and how
much voltage swing, and what kind of load.
Currently I am evaluating several single-ended circuits for use
in an upcoming FW line stage, but the results are not in yet.
Zen Mod said:
All of my line stages are gains of 1 to 4 (that is to say between
0 and 12 dB) including the X1 I listen to day-to-day.
I don't have any hard favorites here, except to note that these
days they are all JFET based, at least on the input.
Partly it depends on whether I want balanced or not, and how
much voltage swing, and what kind of load.
Currently I am evaluating several single-ended circuits for use
in an upcoming FW line stage, but the results are not in yet.
Re: Re: Question for Papa
.......
Nelson Pass said:
All of my line stages are gains of 1 to 4 (that is to say between
0 and 12 dB) including the X1 I listen to day-to-day.
I don't have any hard favorites here, except to note that these
days they are all JFET based, at least on the input.
Partly it depends on whether I want balanced or not, and how
much voltage swing, and what kind of load.
Currently I am evaluating several single-ended circuits for use
in an upcoming FW line stage, but the results are not in yet.
.......Nelson,
I would like to ask a question regarding "how good is good enough" in matching discrete JFETs used in diff pairs. In particular I'm looking at creating DIY 2SK389's with matched 2SK170's.
On pg. 10-11 in your article on DIY op-amps there is excellent information on how to match different device types. But there isn't any advice on how on how close the match should be.
I guess the best way to put the question would be to ask you how loose would you tolerate the match if you were building something for your own system that you wanted to have sound really first rate?
Regards,
Graeme
I would like to ask a question regarding "how good is good enough" in matching discrete JFETs used in diff pairs. In particular I'm looking at creating DIY 2SK389's with matched 2SK170's.
On pg. 10-11 in your article on DIY op-amps there is excellent information on how to match different device types. But there isn't any advice on how on how close the match should be.
I guess the best way to put the question would be to ask you how loose would you tolerate the match if you were building something for your own system that you wanted to have sound really first rate?
Regards,
Graeme
Nelson Pass said:
As you can see, there was not. I do however have some plans
in the works. Last summer Matt made me about 25 pairs of
baffles of various sizes and such and I am still working my way
through the permutations and teasing out the best and seeing
to it that the crossover/eq project accomodates those, while
trying to pull out some good "rules of thumb".
It's still going to be a little while before it bears fruit.
Papa
I think that this drek can be interesting for you :
www.sonido.hu
or - this page - they have 3 different sizes :
http://www.sonido.hu/eng/products.htm
biggest one ( 8") is ~ 270E per pair , including HU VAT ......... per pair price ;
in short - these drivers have most wooden cone I saw in my life , in positive meaning , with all other tricks - copper ring on choke , weight compensation contrary to flexys etc .
from some wodoo babbles - their roots re somewhere in old Telefunken era .
in any case - ( that's funny story) - Vladimir can tell you more about their origin.. if you are interested .
I have no any connection with them , except as very satisfied customer .
edit:
few pics from me are starting from here :
http://www.diyaudio.com/forums/showthread.php?postid=1204930#post1204930
gl said:
This depends on the application, but generally you want to get
it as close as possible. I don't have an in-house standard as
we continue to use monolithically matched parts.
I have noticed that with JFETs run in opposition, either as diff
pairs or with a Drain-Source connection for output (example -
follower biased by a CSS) that there is a bias "sweet spot"
where the 2nd harmonic distortion of the two devices best cancels.
For tightly matched parts, this occurs at the same voltage and
current. For slightly mismatched parts it does not, but it's still
nearby, and if you have a distortion analyzer and the means to
adjust this, you can find the spot.
Zen Mod said:
To do things list for Z V9 is:
to match the J fets (vgs)
to match the Fets (vgs)
to match the power resistors for the jfet source
to precisely fine tuning the CCS to the same currents between channels
to precisely set the Aleph CCS resistor to my sweet taste ( around the 50 % )
stefanobilliani said:
To do things list for Z V9 is:
to match the J fets (vgs)
to match the Fets (vgs)
to match the power resistors for the jfet source
to precisely fine tuning the CCS to the same currents between channels
to precisely set the Aleph CCS resistor to my sweet taste ( around the 50 % )
Nifty little checklist
