generg

Hi guys, :Viannen_loungelizard: I think I have finished my journey through Semisouth amplifiers......I have heard the last days F1J, F2j, J2. Some wordsF1J: incredible defined sound, best bass but to harsh with Lowther, and the different notch filters took too much away from the qualities Lowther has.F2J: more mellow, good bass, good defined, did not need a notch filter with my PM6A, would be the best solution with Lowthers, if notJ2 had these lovely unbeatable medium area with the most tricky and maniac voices, smallest bass unfortunately. Introducing an resistor in series, I took 4,7 Ohm, did nor really better the bass.Result I go with J2 and will look or a good bassdriver and drive both with a small network.......later! :sarcastic_hand: :sarcastic_hand:

Hi Zen Mod, What a nice idea, the vice versa of damping the F1J........Pictures will come, I have to remount BJ2 in the case ..... But I did a very deep movement in tai chi chuan and tried to become a master....... Pain in the right back side ......three days.......I will no more want to became a master I stay better normal......Till later!:

Hi guys, I can continue the reviews about Semisouth implemented amps, Tea-bag started with his comparison of Babelfish J2 and FW2J you can read above.Because I changed finally to Lowther ( there was a very cheap offer I could not resist, only 9 months old, standing like written beer at the merchant, nobody wanted it), I can now use all First Watt amps. I still had in the basement F1J variant so I started comparing........The Babel J2 has the most lovely voices and a kind of being fluent, marvelous! Compared in this range the F1J is sharper and less spectacular.The F1J has more precision in the rest of the spectrum, he shows every detail more closely. J2 is more veiling details outside the lovely midrange.Babel J2 is more painting the colors, F1J is more painting the details.Not to forget, the F1j is an transconductance amp, it made of course a deeper bass, following the impedance curve. j2 had the smaller bass.Lowther shouting was no problem with Babel J2, the treble is soft and the voices have much body that compensates really the shouting.With F1J I had to use a small notch filter ( 10Ohm in series with 3uF parallel to the output)Most of you know F1J has 3rd grade distortion dominant and J2, as Nelson says, has the 2nd grade distortion dominant.Same Semisouths inside and such big differences in sound only by changing the circuit still unbelievable for me...To be continued with my impressions of F2J, only 5 Watt , hu,hu.........!

hi tea-bag, happy to hear that you finished your Babel J2 successfully!and thanks for the detailed comparison with F2J, which speakers did you use, your precious Lowthers?

Martina.....

What shall we do now?Hu,hu,hu,hu..........

Things go on.... audio nirvana is near

I do not worry, it is only for engineering reasons......

o.k. thanks Zen Mod! is it necessary that the IDSS of the J-Fets must be in the region of the current planned to go through them? may be a silly question to make it clearer.... Babel J2 wants in the input stage a current of 10mA going through one half of the coupled J74s. Must every J-Fet have at least an Idss of 10mA or better higher?Is less also allowed, when they are matched?THX

Hi Zen Mod, Did you implement the 5 ohm resistors of the SJ74 to compensate not properly matched parts?Or is there still another advantage?Curious generg

Hi Zen Mod, Meditating over the the circuit I wonder why we need such a big cap C3 when we have parallel R25 and R26 with only 600Ohm, in sum. In my case, I use the 0,25 variant for source and drain, I had to replace R26 by 100 Ohm. That means I have a parallel resistor of 220 + 100 means 320 Ohm. That could be nearly the value for a gatestopper and I can omit the cap.Where is my fault?

Correct....!

I am afraid I have to send tea-bag some bottles of Glühwein to help him this frustrating job to do ......

Yes I am Banana Joe!

Hi Zen Mod,Below C4 is a X in the line, is there any meaning I do not understand?

what I can say very clearly the sound changes clearly when you change the type of C3/C4. I tried it with Elna Simic II and with Panasonic FC.most of you know the differences, Elna is "Wodka" and "Blues" and "I am getting older" an Panasonic is champagne and "more drive" and "I feel Young".you can choose fitting to daytime, Elna in the evening and Panasonic in the morning don´t do it vice versa.....

I want stratospheric sound .......

don´t disturb me in my contemplation....... :character13:to MOX or not to MOX.....amp is in revision 21 ....... the potential is big!

the rest of my day........ :buehehe: :buehehe: :buehehe:

thank you Zen Mod, you are really a good guy-de in electronics ......... I hope our many questions and trials of modifications do not bother you ........ these details are our playground .... and we all learn something ..........where are you playing along?

I meant contribution to the power..... what did you mean with wellness of sound (distortion cancelation?)

can you give an estimated percentage of the contribution of the upper part to the total output?

dear Zen Mod, is it possible that C3 and C4 are in the signal path from the lower to the upper JFet?does that mean we can influence sound a little bit by choosing different caps or bypass caps?I yes and if we all took different caps, it may explain a bit the differences in sound impression between "wodka" or "champaign"......

Hi sp300b,Only for your information, I was reading many sides about mufollowers, the one tazzz recommended gives the lowest value to the upper resistor, but most sides advice to make the resistor in the middle the highest.That was your preferred constellation. Tomorrow I will choose 0,25/0,47/0,25 nearly the same like you and possible with the values I have.The second channel will have the original constellation so I can compare easily...I simply wish more body all other aspects are very good...

One pair of SemiS sound much better than two pairs, maybe not closely matched enough........I am still a little bit fascinated by 6x 0,25 Ohm and 1,4A@sp300b I am too lazy today to change to your values ..... tomorrow......and the Aleph 3 has 60W on my 4 Ohm box and Babelfish J2 13W, of cause Aleph 3 seems in some aspects more impressive....I now change to the Sonidos and compare both amps (but only channel, I have no two complete amps)