Here i am..uncle Charlie.
I have studied audio 53 years long... also studied audio in Japan...not entirely stupid i am...just half stupid alike mankind.
Listen the song.... "we live in a world of fools"....this song tell us my philosohy... and different from some other guys...i include myself in this world of fools.
Glad to met you sir.
regards,
Fool
Just type:
Carlos Eugênio Mergulhão
Also some video in Youtube:
https://www.youtube.com/user/destroyersoueu
If has some curiosity about me...can go to my Blog and my forum here:
| Se você gosta de construir amplificadores, este é o lugar certo! Entre, apresente-se e seja bem vindo! Sinta-se em casa.
But despite all that stuff i am half of nobody, because the world has billions of intelligent souls..and there are billions of planets around us....i am alike a small grain of sand in the ocean....half of anything or nothing..alike all of you.
regards,
Carlos
I have studied audio 53 years long... also studied audio in Japan...not entirely stupid i am...just half stupid alike mankind.
Listen the song.... "we live in a world of fools"....this song tell us my philosohy... and different from some other guys...i include myself in this world of fools.
Glad to met you sir.
regards,
Fool
Just type:
Carlos Eugênio Mergulhão
Also some video in Youtube:
https://www.youtube.com/user/destroyersoueu
If has some curiosity about me...can go to my Blog and my forum here:
| Se você gosta de construir amplificadores, este é o lugar certo! Entre, apresente-se e seja bem vindo! Sinta-se em casa.
But despite all that stuff i am half of nobody, because the world has billions of intelligent souls..and there are billions of planets around us....i am alike a small grain of sand in the ocean....half of anything or nothing..alike all of you.
regards,
Carlos
Attachments
ok... no not really but thanks
destroyer X... truly, you need to understand the Bias Sinful Nature of our mind/brain... an example is "You do not agree with me then I hurt/mame/kill/discredit you or I am happy for others to hurt/mame/kill/discredit you".
Fortunately, we can overcome (with help/assistance - preferably via the Holy Spirit) this natural (born with) mindset that pervades our lives. So there is hope that we can progress beyond our foolish nature, the choice is ours to make. Should we seek Good Significance or Bad Significance in our lives, because both have relevance to our existence. I would suggest that we always seek Good Significance in our lives not Bad Significance... thanks
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Hi Mike Gergen, thanks for your reply. Do you hear the 3rd harmonic distortion that destroyer X mentioned?...
I guess you must like the sound as you have 6 of them... thanks
Hi Peoples, I am considering the SKAGB150D or NAKSA125. Which one would you guys lean towards... thanks
Have you read about the SKA on Greg Ball's forum? There is a lot of information there.
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I have found it to be stable. But I'm using PCB's of my own design and used a simpler current source / thermal feedback loop - it is described on this forum under 'TGM7'. It is a very modern pcb design (i.e. SMD) that is more compact with fewer wires than Greg's boards. I would say it is a very good sounding amplifier, very good. It has strong bass and the high's are very clean without any irritation. To my ears it deserves to rank with the best.
Later, I designed and built my TGM8 amplifier to see if I could do better than the SKA amplifier and in some ways I think I did better it but listening tests are not yet concluded. My TGM8 follows more closely some of the philosophy that I believe Hugh uses in his designs, including the NAKSA series. It has on-board power supply and also on-board speaker protection. I have not been disappointed - it is really so good to my ears that after several years of learning, I no longer feel the need to design another Class AB solid state amplifier. I would expect the NAKSA to have more 'air' than the SKA.
So - there is no issue with the SKA amp, many people have built it and are very happy with it. It is certainly not alike the Leach amplifier, the input stage may be a dual differential on paper but it does not behave the same as a standard dual differential - the individual LTPs are not balanced and are bootstrapped. The output stage is a VAS in itself so also unusual.
However, I have had my own disappointment in Greg's behaviour and can not recommend you do business with him unless you are determined to have his amplifier. I would rather see you buy boards from another source (from me if you like my compact SMD based TGM7) and build it with help from this forum. All the parts you need are readily available from DigiKey.
Later, I designed and built my TGM8 amplifier to see if I could do better than the SKA amplifier and in some ways I think I did better it but listening tests are not yet concluded. My TGM8 follows more closely some of the philosophy that I believe Hugh uses in his designs, including the NAKSA series. It has on-board power supply and also on-board speaker protection. I have not been disappointed - it is really so good to my ears that after several years of learning, I no longer feel the need to design another Class AB solid state amplifier. I would expect the NAKSA to have more 'air' than the SKA.
So - there is no issue with the SKA amp, many people have built it and are very happy with it. It is certainly not alike the Leach amplifier, the input stage may be a dual differential on paper but it does not behave the same as a standard dual differential - the individual LTPs are not balanced and are bootstrapped. The output stage is a VAS in itself so also unusual.
However, I have had my own disappointment in Greg's behaviour and can not recommend you do business with him unless you are determined to have his amplifier. I would rather see you buy boards from another source (from me if you like my compact SMD based TGM7) and build it with help from this forum. All the parts you need are readily available from DigiKey.
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Hi PinPing,
I just finished my Ovation nx amp today. I took some time to make comparisons of about 5 amps including the nx, SKA, VSSA, DX Super A, & Honey Badger just because they were all handy. I have an A/B setup utilizing a dual pot arrangement and a speaker switch. The two pots allow me to equalize the volume of the two amps and the speaker switch allow both amps to share the same pair of speakers which gives me instant switchablity. I'm using a pair of JBL 4412 speakers for the test. I would love to have someone who thinks they could tell the difference between amps to come have a listen. They are all so close that one click on a pot, up or down could fool anyone. The SKA is oh so slightly less detailed than the others. That is a good thing on a lot of music. Especially now a days when the engineers think they need to add "air" to all the vocals. The SKA tends to tame that a little. Nothing is missing, just tamer. Perhaps that is why it gets compared to valve amps. If you are looking for someone to tell you one amp is superior to another, it won't be me. Ever since I built the A/B setup, I have realized that once you get amps to the level of the Blameless, Leach, VSSA, SKA.......well, they are so clean and full, it is just all but impossible to tell them apart. The SKA GB150 is a really good sounding amp. It doesn't require any unobtainium parts or even expensive ones. It is a fun build and fits in a small case with average size heatsinks. What's not to like? I say build it. If you don't love it, give it to someone that will and build something else. You wouldn't be here if you don't want to build and learn. Certainly you could just buy a nice amp on ebay if all you need is an amp.
Blessings, Terry
I just finished my Ovation nx amp today. I took some time to make comparisons of about 5 amps including the nx, SKA, VSSA, DX Super A, & Honey Badger just because they were all handy. I have an A/B setup utilizing a dual pot arrangement and a speaker switch. The two pots allow me to equalize the volume of the two amps and the speaker switch allow both amps to share the same pair of speakers which gives me instant switchablity. I'm using a pair of JBL 4412 speakers for the test. I would love to have someone who thinks they could tell the difference between amps to come have a listen. They are all so close that one click on a pot, up or down could fool anyone. The SKA is oh so slightly less detailed than the others. That is a good thing on a lot of music. Especially now a days when the engineers think they need to add "air" to all the vocals. The SKA tends to tame that a little. Nothing is missing, just tamer. Perhaps that is why it gets compared to valve amps. If you are looking for someone to tell you one amp is superior to another, it won't be me. Ever since I built the A/B setup, I have realized that once you get amps to the level of the Blameless, Leach, VSSA, SKA.......well, they are so clean and full, it is just all but impossible to tell them apart. The SKA GB150 is a really good sounding amp. It doesn't require any unobtainium parts or even expensive ones. It is a fun build and fits in a small case with average size heatsinks. What's not to like? I say build it. If you don't love it, give it to someone that will and build something else. You wouldn't be here if you don't want to build and learn. Certainly you could just buy a nice amp on ebay if all you need is an amp.
Blessings, Terry
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I guess that must be very much 'friends with Hugh related'
it was very clear this forum was too small for such huge personalities like Hugh and Greg
in my memory one was neither worse nor better than the other
just not enough space for both in one place
a thick book could based on who don't like who, and who have had problems with this or that
but most likely 99% of it would be nothing but false accusations and misconceptions
could we please try and leave out all the personal stuff, it is too disturbing, and just very boring ... please
Hi tinitus, were your posts directed to me? Have I done something wrong? I must say that I am not happy with DestroyerX's posts. I have no idea what they mean and why DestroyerX has directed them towards me (perhaps, it has something to do with this Hugh and Greg thing that you have mentioned). Bigun, has been helpful. so thank you to him for his posts... perhaps you can explain further so that I know what is going on here... thanks
Hi Bigun, thank you for your posts... I have been reading the TGM8 thread which is quite interesting AND long... to ask, would you say the TGM8 amp is better than the TGM7 amp, musically, etc... thanks
Hi Bigun, thank you for your posts... I have been reading the TGM8 thread which is quite interesting AND long... to ask, would you say the TGM8 amp is better than the TGM7 amp, musically, etc... thanks
2x no
Hi Bigun, thank you for your posts... I have been reading the TGM8 thread which is quite interesting AND long... to ask, would you say the TGM8 amp is better than the TGM7 amp, musically, etc... thanks
but that is OT here, and belongs in Bigun's TGM amp thread, and since such thread actually does exist, much better asked there
and btw, this will my last post in this thread , no matter what happens
good luck
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Hi Bigun, no worries... I have started reading the TGM8 thread which is quite interesting... would you say the TGM8 amp is better than the TGM7 amp, musically... thanks
It's very hard to say, they really are both very good but if my sister asked me to build her an amplifier I would use TGM8 because it's very convenient to have both the power supply filter caps and the speaker protection circuit on the same pcb as the amplifier - simple to wire up. Ranchu32 also built the amplifier (he helped out with choosing the final config.) and was similarly impressed. But unfortunately, I haven't done enough listening tests to say which amplifier I consider to be better - I am happy with the knowledge that I would find no fault with either.
Edit: sorry Tinitus - we cross-posted
No, that all predated my entry to the hobby. I was actually a member of Greg's forum and after he opened a thread where he made his design available and invited people to build it I jumped right in. He helped me debug my first attempt which had oscillation problems - the pcb layout is super-critical. I defended him when Jim's Audio ripped off his boards without permission. I then redesigned my pcb and posted the results with nice photos into his thread. He asked a couple of questions which I gladly answered. Then he deleted all my posts and closed the thread without reason. This is my reason for finding him an odd man - I was looking to him as a guru, with all his years of experience - I was so disappointed at this behaviour.
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When I first joined the forum it took me a little while to adjust to the way people communicate - try to not to read too much into some of the posts, don't let it make you feel uncomfortable - keep on asking questions and enjoy the hobby and you'll find the forum interactions will take care of themselves.
DestroyerX is what I call 'quite a character' - he means no harm, he's very knowledgeable and you may enjoy reading some of his older threads from 2008/9/10. His threads were one of the reasons I got addicted to this hobby...
good luck Hi Bigun/tinitus, I am not sure how to continue I had some strange responses on ASKA when I asked about SKAGB150 and NAKSA125, also. It must certainly be a contentious issue. It would seem best not to ask for a comparison of anything ASKA and SKA
... so, perhaps I should ask, what are the differences between the SKA150 here and the TGM7 (and TGM8 and VSSA, if allowed)... thanks
I had some strange responses on ASKA when I asked about SKAGB150 and NAKSA125, also. It must certainly be a contentious issue. It would seem best not to ask for a comparison of anything ASKA and SKA ... so, perhaps I should ask, what are the differences between the SKA150 here and the TGM7 (and TGM8 and VSSA, if allowed)... thanks
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So, they all sound and perform the same, ok
I shall do some more reading and perhaps do nothing...
Hi all, to ask, does anybody have any PCBs for this SKA150, a BOM list of preferred parts, and maybe even assembly and testing list... thanks
They are not exactly the same, but at this level they are so close that even A/B side by side can barely reveal any audible sound difference. I'm sure they probably measure differently. They really only start showing a difference as the volume is increased. The amp with higher power will breakup at a higher level than the lower powered units. If you play you music very loud you might want to go with the higher power amps. You might want to read through the http://www.diyaudio.com/forums/solid-state/248105-slewmaster-cfa-vs-vfa-rumble.html thread.
That said, here are the PCB's I used for my build and they work well. Search eBay for "Mosfet 150W+150W power amplifier GB150D PCB !" item #221279128666
If you want to make it easier on yourself, you can buy the partial kit and not have to worry about matching devices. Search dBay for "Mosfet-150W-power-amplifier-GB150D-partial-kit-matched-input-out-BJT-MOSFET" item #221287271767
Blessings, Terry
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I never tried it, but I don't think you should go with the servo right from the start - I believe the amplifier sounds superb with the NFB cap too (you can order a Nichicon MUSE - audio grade - bipolar cap for this position if you want). You can also replace the input cap with a piece of wire - the input cap is only needed if your pre-amp or source has dc on it's output (which is easy to measure and also very unlikely). You could still place an input cap into the signal off-board and use a large fancy cap (e.g. Auricap) too.
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