Hi Terry !
Nice to hear that you got them running ! You have 2 ways to set the bias,
1, You connect your dmm at output of amp and upper leg of one of the 0.22ohms, and turn the bias pot until you read 12mv
2, Connect the dmm between the upper legs of both 0.22ohms and turn the biaspot until you read 24mv. This the more precise method.
With this bias and the size of your heatsinks you will barely notice any warmup.
Symasym has that high gain (~32db,1:40) to be able to be driven without preamp if needed.
About bridging, it should be possible, but ONLY with 8ohm speakers. But as you use the MJW instead of the MJL you should be careful, even unbridged into 4ohms you have the risk of overheating these devices, the MJW has only a rating of 125watts compared to the MJL with 200watts. The TO-264 case is very superior to the TO-247.
But as you already noticed, the power from symasym should be way enough for home use.
If your speakers are 8ohms, i see no problem keeping the MJWs.
BTW, you'd better not show this pic in the Aleph thread... 😀
About the WIMAs, i forgot that it is a german company, of course it is easy here to get them.
I am looking forward to your first listening impressions...
Ben, i used digikey myself, i got my Toshibas from there, for ~1,40Euro each. I also ordered plenty of mpsa18/2n5401/2n5551 there, all genuine onsemi. As i took care what they had on stock, they needed only 2 days for delivery. BTW, reichelt does not have the mpsa18, don't ask why... (not really an exotic device) At least the 2n5401/5551 from reichelt were nice fairchild devices.
Uwe, these MJLs do look like genuines, so reichelt seems a possible source for these.
Carlos, COMMERCIAL !!! Har har, do you get paid from Hugh ? 😀
Mike
Nice to hear that you got them running ! You have 2 ways to set the bias,
1, You connect your dmm at output of amp and upper leg of one of the 0.22ohms, and turn the bias pot until you read 12mv
2, Connect the dmm between the upper legs of both 0.22ohms and turn the biaspot until you read 24mv. This the more precise method.
With this bias and the size of your heatsinks you will barely notice any warmup.
Symasym has that high gain (~32db,1:40) to be able to be driven without preamp if needed.
About bridging, it should be possible, but ONLY with 8ohm speakers. But as you use the MJW instead of the MJL you should be careful, even unbridged into 4ohms you have the risk of overheating these devices, the MJW has only a rating of 125watts compared to the MJL with 200watts. The TO-264 case is very superior to the TO-247.
But as you already noticed, the power from symasym should be way enough for home use.
If your speakers are 8ohms, i see no problem keeping the MJWs.
BTW, you'd better not show this pic in the Aleph thread... 😀
About the WIMAs, i forgot that it is a german company, of course it is easy here to get them.
I am looking forward to your first listening impressions...
Ben, i used digikey myself, i got my Toshibas from there, for ~1,40Euro each. I also ordered plenty of mpsa18/2n5401/2n5551 there, all genuine onsemi. As i took care what they had on stock, they needed only 2 days for delivery. BTW, reichelt does not have the mpsa18, don't ask why... (not really an exotic device) At least the 2n5401/5551 from reichelt were nice fairchild devices.
Uwe, these MJLs do look like genuines, so reichelt seems a possible source for these.
Carlos, COMMERCIAL !!! Har har, do you get paid from Hugh ? 😀
Mike
Yeah!...the same payment i received from you....nothing!
Ahahahahhaha!
As i never made this as a business, i was not waiting to collect more than friendship.
At least he use to listen my suggestions...Hugh do that and use to applied in circuits and evaluate...the same you did....har har har.
This way i am also a little bit Aksa inside my soul too...but i have a leg inside Symassym too.....if i can remember i have.
Well, the best cooperative guy was John...he was the first to recognize the early days problems.... well..i can remember, as i turn old but did not loose entirelly my memory.
Have you visited your Mum..... hehe..... i hope she recognized you.... as you change a lot.... turn a little bit more old and respectable.
But related payment.... at least Graham was fast to pay my efforts, he disappeared from the forum....ahahahaha...let me speaking alone... i had to disappear from the thread too.
But the best one was Pinkmouse...yeah..this one was very fair.
Well, there are more 30 thousand guys in the forum.... and they deserve our attention....so, let's keep the ball running.
Carlos
Ahahahahhaha!
As i never made this as a business, i was not waiting to collect more than friendship.
At least he use to listen my suggestions...Hugh do that and use to applied in circuits and evaluate...the same you did....har har har.
This way i am also a little bit Aksa inside my soul too...but i have a leg inside Symassym too.....if i can remember i have.
Well, the best cooperative guy was John...he was the first to recognize the early days problems.... well..i can remember, as i turn old but did not loose entirelly my memory.
Have you visited your Mum..... hehe..... i hope she recognized you.... as you change a lot.... turn a little bit more old and respectable.
But related payment.... at least Graham was fast to pay my efforts, he disappeared from the forum....ahahahaha...let me speaking alone... i had to disappear from the thread too.
But the best one was Pinkmouse...yeah..this one was very fair.
Well, there are more 30 thousand guys in the forum.... and they deserve our attention....so, let's keep the ball running.
Carlos
Humm, I don't think is very ethic or elegant to be plugging the
Aksa in the Symasym thread!....
But we all know the reason of that.....
Even we amateurs have a code of ethics!..... That's my thought!
Aksa in the Symasym thread!....
But we all know the reason of that.....
Even we amateurs have a code of ethics!..... That's my thought!
Oh! John...i am sorry because of that, and not a propaganda as you perceived
As forum normally do not sell things, only some ideas.
Forum sales, related Aksa are not big.... those things are directly made by owners that demonstrate to other friends.
So, any try related Marketing here will not result, people want to design, construct...the complete diy normally.
Yes.... ethic is important and honorable thing to remember...the second time you teach me how to be more decent, and i have to apologize and thank you for that.
I remember you told me that you have faced someone that was burning speaker coils connecting in the amplifier output.... coils without the magnet...i cannot forget your cooperation to show me what is decent and friendly and what is not decent...thanks.
Also you shown me how to protect ourselves when our friend burned some digital amplifier inverting the polarities, you teached me how to defend friends and how to figth for the things that are rigth...you are one example John, off a decent man.
So..if you are saying that Aksa name is used in the Symassym thread, i will have to silent, in respect to the respectable and deeply honored man that you are.... and because some guys, alike you, can understand that as advertising
I have asked Hugh how many guys have Aksa, related our forum friends, because is strange that the schematic is not already discovered, and having many guys, at least one can produce some leakage... and he told me the number, and that shown me that our forum it is not an effective place to advertising, and also inadequate too...i show another option, with big power, as many can be shown...also i use to tell that GEM is wonderfull...i always did that!
Do you think can be more adequated to silent related my opinnions or to say that those units are bad.... I think that talk positive is more kind.... i know many bad amplifiers...but i prefer not to go repeating that they are bad..... i use to say good things, and to protect the amplifiers i feel as good ones...i am just beeing myself...the same.
Also, beeing ethic, i have to say that forum people are not idiots, they already know i use to make enormous noise related Symassym, Gem and Aksa....what is the difference now?....they already made their own discounts related my exagerated personality.
Be happy John...and never mind
regards,
Carlos
As forum normally do not sell things, only some ideas.
Forum sales, related Aksa are not big.... those things are directly made by owners that demonstrate to other friends.
So, any try related Marketing here will not result, people want to design, construct...the complete diy normally.
Yes.... ethic is important and honorable thing to remember...the second time you teach me how to be more decent, and i have to apologize and thank you for that.
I remember you told me that you have faced someone that was burning speaker coils connecting in the amplifier output.... coils without the magnet...i cannot forget your cooperation to show me what is decent and friendly and what is not decent...thanks.
Also you shown me how to protect ourselves when our friend burned some digital amplifier inverting the polarities, you teached me how to defend friends and how to figth for the things that are rigth...you are one example John, off a decent man.
So..if you are saying that Aksa name is used in the Symassym thread, i will have to silent, in respect to the respectable and deeply honored man that you are.... and because some guys, alike you, can understand that as advertising
I have asked Hugh how many guys have Aksa, related our forum friends, because is strange that the schematic is not already discovered, and having many guys, at least one can produce some leakage... and he told me the number, and that shown me that our forum it is not an effective place to advertising, and also inadequate too...i show another option, with big power, as many can be shown...also i use to tell that GEM is wonderfull...i always did that!
Do you think can be more adequated to silent related my opinnions or to say that those units are bad.... I think that talk positive is more kind.... i know many bad amplifiers...but i prefer not to go repeating that they are bad..... i use to say good things, and to protect the amplifiers i feel as good ones...i am just beeing myself...the same.
Also, beeing ethic, i have to say that forum people are not idiots, they already know i use to make enormous noise related Symassym, Gem and Aksa....what is the difference now?....they already made their own discounts related my exagerated personality.
Be happy John...and never mind
regards,
Carlos
Thanks for the follow-up. Btw, how much did you pay in shipping and customs fees ? I quickly made an estimation at Reichelt and can get everything to fill two boards, included heatsinks, for like 50€. It seems that Digikey would cost me around the same, but aren't shipping costs way higher, without even speaking of the custom fees ?MikeB said:
Have you tried changing the input capacitor to something else than MKS2 ? I like the wima MKS for decoupling but find them overly harsh in the signal path compared to simple MKP caps (the wima mkp are good enough however).
Thanks for the help on this project, wonderful thread. 😱
Wima caps
Hi Terry
Wima caps are available in the USA from several retailers:
Newark IN One
Digikey
Welborne Labs
Taw Electronics, out in Burbank, Cal
to name a few.
This last one, Taw Electronics seems to be the one with more
selection, even though I never did bussiness with. Good thing
I did a Google on that because this way I'll reference it for my
own sake.
I'm very happy for you about your Symasym working, sometimes
is like that, you overlook a simple thing and you go gainst the
wall asking for the reason. We all have episodes like that, don't
be discouraged.
BTW, isn't this amp something sweet and OUT OF THE ORDINARY?
Hi Terry
Wima caps are available in the USA from several retailers:
Newark IN One
Digikey
Welborne Labs
Taw Electronics, out in Burbank, Cal
to name a few.
This last one, Taw Electronics seems to be the one with more
selection, even though I never did bussiness with. Good thing
I did a Google on that because this way I'll reference it for my
own sake.
I'm very happy for you about your Symasym working, sometimes
is like that, you overlook a simple thing and you go gainst the
wall asking for the reason. We all have episodes like that, don't
be discouraged.
BTW, isn't this amp something sweet and OUT OF THE ORDINARY?
Terry,
The one big question that you might have expected sooner than later, how does the Symassym sound compared to your Aleph-X?
The one big question that you might have expected sooner than later, how does the Symassym sound compared to your Aleph-X?
00940 said:
The input cap -- that was the first point I would go to for "tuning" too. But remember that a 4µ7 MKP is really huge. Maybe there are other alternatives?
Samuel, if you can inform me this Aleph schematic, using direct mail, i can think to
Construct it to evaluate by myself.
Is this Nelson Pass schematic?
All rigth, please, inform me the link.
Thank you in advance.
nanabrother@yahoo.com
regards,
Carlos
Construct it to evaluate by myself.
Is this Nelson Pass schematic?
All rigth, please, inform me the link.
Thank you in advance.
nanabrother@yahoo.com
regards,
Carlos
00940, thank you...i will visit and will construct.
Tomorrow it will be ready.
regards,
Carlos
Tomorrow it will be ready.
regards,
Carlos
Hi Ben, i had 18Euro shipment and 15Euro afterwards for custom fee. This is quite much and the disadvantage of buying oversea. The order itself was 75Euro.
About the inputcap, the alternative i tried were elyts, but quickly rejected. I know that PETs are not highly regarded for their sonic qualities, but i was happy with the sound, and it seems to be best choice regarding the size and costs. It seems that paper in oil are the best here, but man, look at the size of that thing !
Listening to the symasym5_3 using the MKS2, the last thing i can say about the sound is harshness. I used the MKS2 from the beginning of designing, so maybe symasym and the MKS2 are now made for each other ?
Pavel, don't you also use the MKS2 for inputcap ? At least on photo it looks like.
Ben, if you have a 4.7uf MKP, maybe you can compare, you could replace the mks with a wire and place the big cap external for testing.
Carlos, if i remember correct, the Aleph uses mosfets, might be a problem for you ?
Mike
EDIT: About Caps: http://members.aol.com/sbench102/caps.html
About the inputcap, the alternative i tried were elyts, but quickly rejected. I know that PETs are not highly regarded for their sonic qualities, but i was happy with the sound, and it seems to be best choice regarding the size and costs. It seems that paper in oil are the best here, but man, look at the size of that thing !
Listening to the symasym5_3 using the MKS2, the last thing i can say about the sound is harshness. I used the MKS2 from the beginning of designing, so maybe symasym and the MKS2 are now made for each other ?
Pavel, don't you also use the MKS2 for inputcap ? At least on photo it looks like.
Ben, if you have a 4.7uf MKP, maybe you can compare, you could replace the mks with a wire and place the big cap external for testing.
Carlos, if i remember correct, the Aleph uses mosfets, might be a problem for you ?
Mike
EDIT: About Caps: http://members.aol.com/sbench102/caps.html
00940, thanks for pitching in.
Carlos, it would be easiest to construct the Aleph-X with single output devices and run it off +-15 to 18 volts. Remember that this is a Class A design and requires big heatsinks. Also the type of N-channel device used at the output (read capacitance) together with the total bias current will determine the quality of the Aleph-X. Since the X designs cancel out even harmonics to a large extent and there are not too many dominating distortions left, the sonic signature of the pre-amp also influences the final sound.
Carlos, it would be easiest to construct the Aleph-X with single output devices and run it off +-15 to 18 volts. Remember that this is a Class A design and requires big heatsinks. Also the type of N-channel device used at the output (read capacitance) together with the total bias current will determine the quality of the Aleph-X. Since the X designs cancel out even harmonics to a large extent and there are not too many dominating distortions left, the sonic signature of the pre-amp also influences the final sound.
Yes Samuel, i realised that.... will not be simple, but i will do it.
Thank you, i am already selecting parts.
Carlos
Thank you, i am already selecting parts.
Carlos
Mike: I plan to use old caps actually, that's what I use in most of my projects. I prefer those to blackgates and basic audyn (and they were cheap on ebay). They're only 2uf though, I'll have to go parallel. Apparently, they're Eastern German copies of Siemens PIO.
Size is not really worrying me. They're still quite small compared to all the power supply caps 😉 I'm planning to use an old computer case, I'll have plenty of space. Those are what I call big caps otoh (I used the audyn at the output of an headphone amp) 😀
Carlos: you really plan to build the aleph-x overnight ? 😱
An externally hosted image should be here but it was not working when we last tested it.
Size is not really worrying me. They're still quite small compared to all the power supply caps 😉 I'm planning to use an old computer case, I'll have plenty of space. Those are what I call big caps otoh (I used the audyn at the output of an headphone amp) 😀
An externally hosted image should be here but it was not working when we last tested it.
Carlos: you really plan to build the aleph-x overnight ? 😱
Unfortunattelly i have not enougth FETs here to start.
So, i must search in my friends home if i can have some.
My first construction is alike a spider, and i use to make it in 3 to 4 hours when parts are already selected.
When i have to separate parts, of course i delay much more.
When i like the sound, i construct it once again less Ugly...but always very Ugly.
This one will delay a little bit more...but you will receive news from me when i finished.
My dear friend Michael may send some from Germany.
regards,
Carlos
So, i must search in my friends home if i can have some.
My first construction is alike a spider, and i use to make it in 3 to 4 hours when parts are already selected.
When i have to separate parts, of course i delay much more.
When i like the sound, i construct it once again less Ugly...but always very Ugly.
This one will delay a little bit more...but you will receive news from me when i finished.
My dear friend Michael may send some from Germany.
regards,
Carlos
Re: Wima caps
Hi Mike,
Thanks for the info about bias. That is exactly what I needed. PMA is a funny guy. 😀
If my heatsinks are over-kill I may use something smaller.
Strange, I hadn't noticed that I used the wrong outputs. I'll get the right ones. Easy enough to change.
I must say, the sound was a nice surprise. I don't think I've ever heard an amp sound this good right out of the gates. I don't even have a proper PSU hooked up to it yet. I played it for about an hour last night and was very impressed. It is difficult to compare at first listen because it is so high gain. Switching to any other amp always makes the other amp sound weak at first. Once I get it in a case with its PSU together I'll be able to give it a real listen. I have a pair of JBL 4425 monitors that only go up to about 16kHz. I don't think they have ever sounded better than they did last night with the Symasym. I used some bipolar electros for C1 and it worked fine. I'll get some Wimas and swap them out later.
Thanks, I'll check them out. I could have sworn that I checked Digikey and couldn't find them. I'll keep looking.
Yes the amp does seem to be out of the ordinary.
Well, I'm not sure I should say anything yet. I am very disappointed with the sound of my Aleph-X. It may be the way I built it and the output devices I used. I used the OnSemi FETs rather than the IR's. They have higher capacitance that the IR's and I'm told that will make a difference. The A-X is my least favorite of all of the amps I've built. This Symasym seems very "In your face" at first listen. The highs and lows are very good from what I've heard. It will take some more time listening for me to tell how well I like the mids. I'm pretty stoked right now. It's hard to believe I'm hearing all of this nice sound coming out of something I can't cook on. 😀
Blessings, Terry
MikeB said:
Hi Mike,
Thanks for the info about bias. That is exactly what I needed. PMA is a funny guy. 😀
If my heatsinks are over-kill I may use something smaller.
Strange, I hadn't noticed that I used the wrong outputs. I'll get the right ones. Easy enough to change.
I must say, the sound was a nice surprise. I don't think I've ever heard an amp sound this good right out of the gates. I don't even have a proper PSU hooked up to it yet. I played it for about an hour last night and was very impressed. It is difficult to compare at first listen because it is so high gain. Switching to any other amp always makes the other amp sound weak at first. Once I get it in a case with its PSU together I'll be able to give it a real listen. I have a pair of JBL 4425 monitors that only go up to about 16kHz. I don't think they have ever sounded better than they did last night with the Symasym. I used some bipolar electros for C1 and it worked fine. I'll get some Wimas and swap them out later.
jmateus said:
Thanks, I'll check them out. I could have sworn that I checked Digikey and couldn't find them. I'll keep looking.
Yes the amp does seem to be out of the ordinary.
Samuel Jayaraj said:
Well, I'm not sure I should say anything yet. I am very disappointed with the sound of my Aleph-X. It may be the way I built it and the output devices I used. I used the OnSemi FETs rather than the IR's. They have higher capacitance that the IR's and I'm told that will make a difference. The A-X is my least favorite of all of the amps I've built. This Symasym seems very "In your face" at first listen. The highs and lows are very good from what I've heard. It will take some more time listening for me to tell how well I like the mids. I'm pretty stoked right now. It's hard to believe I'm hearing all of this nice sound coming out of something I can't cook on. 😀
Blessings, Terry
If you are telling me that!...no more Aleph!
Also i could not find identical FETs....i have 12, but they are not adequated....they are bigger and different.
regards,
Carlos
Also i could not find identical FETs....i have 12, but they are not adequated....they are bigger and different.
regards,
Carlos