Read the article again and found no explanation of the sound. Reminded me of another one his writings where he stated how he had grown tired of saying how it sounds. Looks like Generg will be the first to tell. I have a feeling it will be good. THank goodness i have two sets of F4 boards sitting around. Drop those nasty input pairs and we have the beginnings of something real NICE. Guess i will have to compare it to Juma's F5 and the Aleph J of course.
It just so happens that I stumbled upon some recently. I thought you might be coming with an SRPP VAS, as they apparently do well with large loads Like the F4. Or was it the Mu follower. TOO many amps floating around in my head🙂 What is the input impedance of the output stage?
perhaps this is a good reason to use my last 6x68.000uF caps😀
can try both BA-2 and BA-3 front ends on thesame amp🙂
sounds like a nice deal😀
Great service here! Thank you very much! (I hope the German customs won't let me wait once again for 3 months, before they decide to release them.)
Of course it will! Thank you so much for sharing this gem!
I guess it will perfectly drive the SemiSouth output stage circuit that's circulating here?Interesting "Pass"-Clarity Caps populating the board. What's the story of them?
Actually the "MR" Clarity Cap is my favorite (high pass) crossover cap at the moment. I use them in my Thor Evos. They are expensive, but really excellent!
Besides the stinking name, 🙄, Darmstadt has wonderful woods indeed.......😀😀😀
@ tea-bag: I think some of the 30db 😱 gain is lost in R13, as Nelson writes.
@ tea-bag: I think some of the 30db 😱 gain is lost in R13, as Nelson writes.
The idea was to have the boards ready for you in the diyAudio store when the article came out! And they ARE ready to ship!
http://www.diyaudio.com/store/
http://www.diyaudio.com/store/
o.k. 😀
another problem using the F5 boards, this boards leads the gate resistor directly to the caps and you hear nothing..........!🙁
Even when the DC values are correct, Ac is fed to the rails, ha,ha😀
so I can only recommend to use the original boards.....😛😛😛
I tried to make no faults but I made three......
😱
to a first sound check:
one channel Babelfish J2,
the other channel crippled F4 and BA-3
speakers Tiny Open Baffle from Jons idea
playing Ella Fitzgerald monaural recordings ......so charming...nevertheless which amp!
Semisouth solution has as always its own charm, sounding a bit darker and giving voices bit more body
BA-3 and F4 combined has more precision in sound for example piano, and sounds very relaxed and natural .....
buy the boards.........!
another problem using the F5 boards, this boards leads the gate resistor directly to the caps and you hear nothing..........!🙁
Even when the DC values are correct, Ac is fed to the rails, ha,ha😀
so I can only recommend to use the original boards.....😛😛😛
I tried to make no faults but I made three......
😱
to a first sound check:
one channel Babelfish J2,
the other channel crippled F4 and BA-3
speakers Tiny Open Baffle from Jons idea
playing Ella Fitzgerald monaural recordings ......so charming...nevertheless which amp!
Semisouth solution has as always its own charm, sounding a bit darker and giving voices bit more body
BA-3 and F4 combined has more precision in sound for example piano, and sounds very relaxed and natural .....
buy the boards.........!
better that than Schweifurt
regarding tests - you can compare BA3 FE with follower type amp/output vs. regular amp strictly in informative purposes ;
too much gain in system with former...... ( waste of signal energy )
Last edited:
oh, I know Zen Mod....🙂
I had only a 10k pot before
- Semisouth Mu follower solution with 20db (not really Babel J2, but a modified version, to be absolutely correct)
and
- BA-3 combined with (special crippled) F4
@tea-bag: the difference in loudness is small between BA-3 amplification and the 20 db of SemiSolution.....so no problem to use it as a pre too....
and you know how difficult it is to describe Amplifer solutions on such a high level we are used to, in their sound differences....... and we all know he Mu-follower, we use, has more k2 and F4 and BA-3 more k3........so my description is very understandable!
in the evening the second channel is made...... second BAF night planned!
have fun build an AMP!😀😀😀
@variac: my BA-3 boards are ordered............
I had only a 10k pot before
- Semisouth Mu follower solution with 20db (not really Babel J2, but a modified version, to be absolutely correct)
and
- BA-3 combined with (special crippled) F4
@tea-bag: the difference in loudness is small between BA-3 amplification and the 20 db of SemiSolution.....so no problem to use it as a pre too....
and you know how difficult it is to describe Amplifer solutions on such a high level we are used to, in their sound differences....... and we all know he Mu-follower, we use, has more k2 and F4 and BA-3 more k3........so my description is very understandable!
in the evening the second channel is made...... second BAF night planned!
have fun build an AMP!😀😀😀
@variac: my BA-3 boards are ordered............
Last edited:
I think BA-3 front end will work fine even for these "poor man followers" 😀, (like SEWA amp), making a nice synergy where the total quality exceeds the sum of its parts 🙂
Oh, and not to forget: Thanks Nelson!
Oh, and not to forget: Thanks Nelson!
@generg - you still running a rock in the front end of the F4?
I am also interested in what Mr. Rothacher is scheming with this front end.
I have an idea, but only a guess.
I am also interested in what Mr. Rothacher is scheming with this front end.
I have an idea, but only a guess.
Well, I thought I should build myself one of these fabled "Burning Amps".
Actually, I'm a robo-consumer pod person. It said Pass on the label and I automatically clicked "BUY".
Last edited:
Many thanks to Nelson and everyone else who have helped bring this project to us proletariat. Very exciting (my wife just agreed—irony or enlightenment?) Just read the article and there’s more in there I understand than when I read the BA-2 details 18 months ago. However, a couple of things. Nelson mentions C3 and suggests using polyprop, electrolytic or both; so 5uF of polyprop and 5uF of electrolytic (got to be Silmic II ) would be OK? Would save on size and cost perhaps.
The other thing is these Toshiba JFETs. Can anyone say if there is a difference between 2SJ74 and 2SJ74BL and also 2SK170 BL/GR/V. I’ve checked the spec sheet but it doesn’t mention these.
Chris
The other thing is these Toshiba JFETs. Can anyone say if there is a difference between 2SJ74 and 2SJ74BL and also 2SK170 BL/GR/V. I’ve checked the spec sheet but it doesn’t mention these.
Chris
Pa wrote about Ids in article
that means BL grade ( even if you can find some of V grade sissy enough
)
usually GR-BL-V ( for some Y-GR-BL)
for Japanese Jfets - ranges of Ids
for BJTs - similar suffixes and some other are for Beta ranging
that means BL grade ( even if you can find some of V grade sissy enough
)usually GR-BL-V ( for some Y-GR-BL)
for Japanese Jfets - ranges of Ids
for BJTs - similar suffixes and some other are for Beta ranging
Last edited: