Hi Jarno !
I don't see any flaws in the etching, looks well done !
Obviously you have more than enough devices... Going to build a 5 channel ?
For resistors i use normal metalfilm 250mw resistors, except the
4.7/1.2/10 in outputstage, there i use 2watt version (also metalfilm). And the 0.22ohms are 5watts.
The trimpot is a normal Piher.
Happy drilling ! 😉
Mike
I don't see any flaws in the etching, looks well done !
Obviously you have more than enough devices... Going to build a 5 channel ?
For resistors i use normal metalfilm 250mw resistors, except the
4.7/1.2/10 in outputstage, there i use 2watt version (also metalfilm). And the 0.22ohms are 5watts.
The trimpot is a normal Piher.
Happy drilling ! 😉
Mike
Hello Mike
Drilling is tomorrows business... Now it´s time for a couple of biers.
You should have a few too!
This is way OT but I am beginning to be worried about myself. I got few friends over on the other room and I am here browsing throuhgt the forums
I´ll be back after drilling and assembly is done
Jarno
Drilling is tomorrows business... Now it´s time for a couple of biers.
You should have a few too!
This is way OT but I am beginning to be worried about myself. I got few friends over on the other room and I am here browsing throuhgt the forums
I´ll be back after drilling and assembly is done
Jarno
Hello !
I started to collect important informations about symasym into a webpage...
http://www.lf-pro.net/mbittner/Sym5_Webpage/symasym5.html
Suggestions/critics welcome !
Mike
I started to collect important informations about symasym into a webpage...
http://www.lf-pro.net/mbittner/Sym5_Webpage/symasym5.html
Suggestions/critics welcome !
Mike
Hi, mr MikeB.
Can I use this amplifier with 1ohm? How I can use it on 1ohm? Addiding more pair of output transistors?
Thanks a lot.
Can I use this amplifier with 1ohm? How I can use it on 1ohm? Addiding more pair of output transistors?
Thanks a lot.
Mike,
thanks for creating the webpage. This will greatly help diyers interested in the project.
Regards,
Pavel
thanks for creating the webpage. This will greatly help diyers interested in the project.
Regards,
Pavel
mod_evil said:
More output devices are not enough. To drive 1ohm load, You need to use predrivers between the VAS, and the MJEs.
sajti
mod_evil said:
Hi mod_evil !
Symasym was not designed to deliver THAT much current, it does easily drive a 4ohm speaker, but not 1 ohm...
To do that, it would need a complete redesign. The VAS does not supply enough current, and changing it to triple darlington like sajti suggested will make it oscillate without further modification.
One possibility would be changing the outputstage to mosfets, and put enough of them in paralell.
Mike
PMA said:
The highly biased MJEs in combination with the charge-suckout cap should be able to handle that, in theory...
Don't forget that the MJLs also have a very high input capacitance !
Mike
I have to thank you Mike, to include my name in your page
I am feeling honored to be together Pavel Macura, Greg Erskine and your person.
I feel myself very good....i feel pride to be together you guys.
My name associated to good amplifiers, as Aksa, GEM and Symassym are something more than i hope for.
Yeah!...i loved to see my complete, and strange name, there....by the way, Mergulhão means big diver...as some bird that dives to catch fishes in cold watters.
regards,
Carlos
I am feeling honored to be together Pavel Macura, Greg Erskine and your person.
I feel myself very good....i feel pride to be together you guys.
My name associated to good amplifiers, as Aksa, GEM and Symassym are something more than i hope for.
Yeah!...i loved to see my complete, and strange name, there....by the way, Mergulhão means big diver...as some bird that dives to catch fishes in cold watters.
regards,
Carlos
Michael,
input capacitance of large IRFs is about twice the capacitance of MJLs, and you suggested MOSFETs in parallel, that's why I commented. I remeber that you always told before that such changes should be tested.
Cheers,
Pavel
input capacitance of large IRFs is about twice the capacitance of MJLs, and you suggested MOSFETs in parallel, that's why I commented. I remeber that you always told before that such changes should be tested.
Cheers,
Pavel
Carlos,
we are very happy to have you here. If you were not here with us, this nice international co-operation would never start.
Cheers,
Pavel
we are very happy to have you here. If you were not here with us, this nice international co-operation would never start.
Cheers,
Pavel
I was lucky to turn the ignition key, to put this "motor" running.
Now we have many skilled people cooperating, analising, constructing, evaluating...this is great!
Thank you Pavel,
regards,
Carlos
Now we have many skilled people cooperating, analising, constructing, evaluating...this is great!
Thank you Pavel,
regards,
Carlos
Hi Carlos, yes you are our "motor" !
Pavel, using mosfets is only a theoretical possibility, of course this is untested and right now i can't recommend it.
I personally think, driving 1ohm directly is "nuts" and only asks for problems. An outputransformer might be best choice.
I can "guarantee" quality and stability of symasym only if it is unmodified.
Mike
Pavel, using mosfets is only a theoretical possibility, of course this is untested and right now i can't recommend it.
I personally think, driving 1ohm directly is "nuts" and only asks for problems. An outputransformer might be best choice.
I can "guarantee" quality and stability of symasym only if it is unmodified.
Mike
Yeah MikeB, Thanks a lot for your help. This speakers arrays of my making will be horrible to amplifier... Sorry I understand you.
A output transformer, cost higher than other solutions...
PMA,
Yeah... Carlos Eugenio, es uno mucho grande genio... Os ensinamentos que ele me deu vão ficar para o resto da minha vida... ( Yeah, Carlos Eugenio is a bigger genius, the ensiments he sent to me will be in here for the rest of my live. )
Good to have you in here.
A output transformer, cost higher than other solutions...
PMA,
Yeah... Carlos Eugenio, es uno mucho grande genio... Os ensinamentos que ele me deu vão ficar para o resto da minha vida... ( Yeah, Carlos Eugenio is a bigger genius, the ensiments he sent to me will be in here for the rest of my live. )
Good to have you in here.
Hi MikeB,
I think your homepage is simple and clear with good quality pictures! 🙂
Though the Eagle schematic have component text on top of each others making it a bit difficult to read, but I made a small effort and changed it! 😀
Cheers Michael
PS: Note for instance Q3 and Q9 text now have their right position, not that it makes any difference here as both transistors are the same!
I think your homepage is simple and clear with good quality pictures! 🙂
Though the Eagle schematic have component text on top of each others making it a bit difficult to read, but I made a small effort and changed it! 😀
Cheers Michael
PS: Note for instance Q3 and Q9 text now have their right position, not that it makes any difference here as both transistors are the same!
Attachments
Thank you Mod Evil.... very nice your appearance...hehe ...Carioca alike me!
I do not remember the meaning of Carioca...the indian name meaning....
Carioca is the name of Rio de Janeiro native people...we are very proud of that.
Amizadinha eu tôu na piôr deprê....my dear friend, i am very sad.... Graham decided to leave our forum....i was during last week trying to persuade him.... i jumped alike pop corn inside a hot can....i did all i could...i paint a very dark future to him.... the forum beeing catastrophic..... people giving up..... the evil comanding the place.... the post war picture....i said his amplifier will be shotted when he left forum.... that people will say that he is running because amplifier has input, output and a lot of things!
I have danced...jumped..... i made funny games, i used all i could to change his mind....if a gênius.... i am hidden inside a bottle, and and elefant is going to sit over me!
Reza forte!....i will ask God to his return...and them i will be making noise again...ehhehe!
You look nice... handsome Carioca!... will present you one of my daugthers....showing one of my girls.... her problem is that she disturb a little, as she use to kiss daddy many times a day!
regards,
Carlos
I do not remember the meaning of Carioca...the indian name meaning....
Carioca is the name of Rio de Janeiro native people...we are very proud of that.
Amizadinha eu tôu na piôr deprê....my dear friend, i am very sad.... Graham decided to leave our forum....i was during last week trying to persuade him.... i jumped alike pop corn inside a hot can....i did all i could...i paint a very dark future to him.... the forum beeing catastrophic..... people giving up..... the evil comanding the place.... the post war picture....i said his amplifier will be shotted when he left forum.... that people will say that he is running because amplifier has input, output and a lot of things!
I have danced...jumped..... i made funny games, i used all i could to change his mind....if a gênius.... i am hidden inside a bottle, and and elefant is going to sit over me!
Reza forte!....i will ask God to his return...and them i will be making noise again...ehhehe!
You look nice... handsome Carioca!... will present you one of my daugthers....showing one of my girls.... her problem is that she disturb a little, as she use to kiss daddy many times a day!
regards,
Carlos
Attachments
