Hi guys, i'm back !
I just wanted to tank some sun, without travelling too far, so teneriffa was best choice...
Carlos, i did tell you of my holiday in several mails, maybe you really should check your spamfilter ? Seems that no mail reached you in the last weeks...
Okay, now going to read many pages in this thread... Phew...
Pavel, thanks for the comparison !
Mike
I just wanted to tank some sun, without travelling too far, so teneriffa was best choice...
Carlos, i did tell you of my holiday in several mails, maybe you really should check your spamfilter ? Seems that no mail reached you in the last weeks...
Okay, now going to read many pages in this thread... Phew...
Pavel, thanks for the comparison !
Mike
Hello Carlos, yes many people are still afraid when going to the dentist. It is something I see all day long, it is nothing that I think someone should be ashamed about. Fear is a feeling that protects us in many cases, I never think bad things when I see someone in fear.
Well, last time I listened to my Symasym, it was a bunch of wires connected to the PCB, and with a different (inferior) PSU. Now that is in a case, I will do some more serious listening tests. But it is too late for listening now, tomorrow surely.
For the time, I see it is completely silent, just a small "ssshh" when you hold your ear on the tweeter.
Cheers...
😉
Well, last time I listened to my Symasym, it was a bunch of wires connected to the PCB, and with a different (inferior) PSU. Now that is in a case, I will do some more serious listening tests. But it is too late for listening now, tomorrow surely.
For the time, I see it is completely silent, just a small "ssshh" when you hold your ear on the tweeter.
Cheers...
😉
Dimitris,
You have very generous heat sinks, and if exposed to free air circulation (no cover) you should have no problems. With a cover, you would probably need a fan for extended play at fairly high volumes. I'm not suggesting changes, as your construction looks quite reasonably neat, but for future projects, you could probably use heatsinks half that size if they are oriented vertically so that you get a convection aided flow (warm air rising) through the fins. Air passing over the heatsinks is much more effective than just radiation cooling. Also, your placement of the heatsinks, while nice looking, insures that your power supply components will get almost as warm as the sink as the warm air is trapped under the sinks. Again, in your case probably not a problem, but for the caps, cooler extends lifetime.
Sheldon
You have very generous heat sinks, and if exposed to free air circulation (no cover) you should have no problems. With a cover, you would probably need a fan for extended play at fairly high volumes. I'm not suggesting changes, as your construction looks quite reasonably neat, but for future projects, you could probably use heatsinks half that size if they are oriented vertically so that you get a convection aided flow (warm air rising) through the fins. Air passing over the heatsinks is much more effective than just radiation cooling. Also, your placement of the heatsinks, while nice looking, insures that your power supply components will get almost as warm as the sink as the warm air is trapped under the sinks. Again, in your case probably not a problem, but for the caps, cooler extends lifetime.
Sheldon
Dimitri, your construction is not ugly, i ensure you that i use to make worst than
that, even when i want to make them pretty...i am a pig related constructions....i have any patience, i want to listen only...and as fast as possible.
In the reality, i feel some envy related those guys that have this capacity.
Your wiring is the only thing i can see as not perfect, or not professional...so....keep them hidden only...install a card protection, or a metal protection over.... yeah..... you have silver...try copper or black material...anodized aluminium maybe...cartoon of paper.
or reduce wire lengh and diameter to panels....as in reality 1 milimeter diameter wire can hold more than 10 ampéres...and those heavy gauges are needed only to long distances....
Also...if you prefer to make it perfect.... produce a long cable, constituted of coloured wires inside.... and small holes under... with a curve metal tool... you can "fish the wire needed to some point and descend it into the board or connector...over...will be seen only the cable cover.
Do not put AC travelling inside this cable...power AC have to be short and separated, not to induce noise...only audio and DC can go together...
The small fan Sheldon told is important.... put them up if possible..between your heatsinks and the cover...having the cover a grille to the fan....as i know this amplifier, even your big heatsinks..... inside enclosure...without many holes and fan...hehe.... i think may produce problems...the damn amplifier (damn because turns hot...produces power, and overheat) can pump more than 130 watts over 4 ohms...depending the supply you use....38 plus 38 goes easy to 130!...this will produce more than 200 watts of heat each channel if continuous tone is inserted in the input to testing..... 400 watts of heat if 2 channels operating with steady tone....and this tone can be that low frequency warble that is used inside submarines or space crafts....the tone is continuous...to produce fear....listening to DVDs and using your amplifier you will face some continuous tone...using 4 ohms!.... too much hot, your heatsinks will not be enable to hold that...and if not holes (and 2 fans) under the cabinet, and upper the cabinet....booooom!
I respect Symassym very much...it is a hell good amplifier, have power and dinamics to satisfy half world....but, works hot when pumping basses or continuous tones...naturally.
Excepting the wiring....your construction is pretty...it is nice and you may feel some pride of it.....serious...i like it.... and you will see...near future, that i will do the same stile.
I will produce fast sketch...to show you what i am talking about related wire cabling.
regards,
Carlos
that, even when i want to make them pretty...i am a pig related constructions....i have any patience, i want to listen only...and as fast as possible.
In the reality, i feel some envy related those guys that have this capacity.
Your wiring is the only thing i can see as not perfect, or not professional...so....keep them hidden only...install a card protection, or a metal protection over.... yeah..... you have silver...try copper or black material...anodized aluminium maybe...cartoon of paper.
or reduce wire lengh and diameter to panels....as in reality 1 milimeter diameter wire can hold more than 10 ampéres...and those heavy gauges are needed only to long distances....
Also...if you prefer to make it perfect.... produce a long cable, constituted of coloured wires inside.... and small holes under... with a curve metal tool... you can "fish the wire needed to some point and descend it into the board or connector...over...will be seen only the cable cover.
Do not put AC travelling inside this cable...power AC have to be short and separated, not to induce noise...only audio and DC can go together...
The small fan Sheldon told is important.... put them up if possible..between your heatsinks and the cover...having the cover a grille to the fan....as i know this amplifier, even your big heatsinks..... inside enclosure...without many holes and fan...hehe.... i think may produce problems...the damn amplifier (damn because turns hot...produces power, and overheat) can pump more than 130 watts over 4 ohms...depending the supply you use....38 plus 38 goes easy to 130!...this will produce more than 200 watts of heat each channel if continuous tone is inserted in the input to testing..... 400 watts of heat if 2 channels operating with steady tone....and this tone can be that low frequency warble that is used inside submarines or space crafts....the tone is continuous...to produce fear....listening to DVDs and using your amplifier you will face some continuous tone...using 4 ohms!.... too much hot, your heatsinks will not be enable to hold that...and if not holes (and 2 fans) under the cabinet, and upper the cabinet....booooom!
I respect Symassym very much...it is a hell good amplifier, have power and dinamics to satisfy half world....but, works hot when pumping basses or continuous tones...naturally.
Excepting the wiring....your construction is pretty...it is nice and you may feel some pride of it.....serious...i like it.... and you will see...near future, that i will do the same stile.
I will produce fast sketch...to show you what i am talking about related wire cabling.
regards,
Carlos
dtrif said:
Thanks Pavel, case is ready, will show pictures soon.
After I saw your contstruction I decided to NOT show pics of mine, as the comparison will be crushing. But finally, I changed my mind.
Hi Dimitris,
it would be wrong decision not to show the photos of your amplifier. This is a DIY forum and people are interested to see the results. We can learn together, one from another. This is a great advantage of the forum. Wish you excellent sound and satisfaction with your amp.
Pavel
Re: Dimitri, your construction is not ugly, i ensure you that i use to make worst than
Carlos,
just a small comment, very friendly. Not all the power is dissipated in output transistors, a lot of the power goes to loudspeakers as well 😉
The worst case of power dissipated in output transistors is for some 30% - 50% of the rated output power, then about 50% of the rated output power is dissipated in ouput transistors, so the numbers would never be that bad as you showed. For more info, please check Rode's pages:
http://sound.westhost.com/efficiency.htm
On the other hand, I agree that capacitor bank should be placed free, not under the heatsinks.
destroyer X said:
Carlos,
just a small comment, very friendly. Not all the power is dissipated in output transistors, a lot of the power goes to loudspeakers as well 😉
The worst case of power dissipated in output transistors is for some 30% - 50% of the rated output power, then about 50% of the rated output power is dissipated in ouput transistors, so the numbers would never be that bad as you showed. For more info, please check Rode's pages:
http://sound.westhost.com/efficiency.htm
On the other hand, I agree that capacitor bank should be placed free, not under the heatsinks.
Regarding output transistors, power supply voltage and symasym's capability to provide high power from one pair of output devices I would like to mention another Rod's excellent article:
http://sound.westhost.com/soa.htm
To all, please keep this in mind, especially for reactive loads with severe phase changes, I made some measurements into my dummy load (evaluation page), and some speakers might be a bit dangerous for the life of output devices. Reactive loads are about peak current and peak power values, rather than RMS.
http://sound.westhost.com/soa.htm
To all, please keep this in mind, especially for reactive loads with severe phase changes, I made some measurements into my dummy load (evaluation page), and some speakers might be a bit dangerous for the life of output devices. Reactive loads are about peak current and peak power values, rather than RMS.
It's fair Pavel....i already have read all Rodd Site many times.
And i do not make precise calculations..... just some idea of entire heat dissipation.
You can make to us the kindness to provide correct numbers, more exactly values.
As heatsink area needed, when outside and inside cabinets.
Heat produced when maximum undistorted power, 4 ohms, is produced...i use Sankens...so... 4 ohms are easy here.
Heat when both channel is driving simultaneously.with continuous tone (not so normal...but may be the maximum possible) driving into distortion.
Those values, can be helpfull to all guys, including me, as i know how to make some "eyed fast evaluation" because long experience with those things...but i know that my error can go to 30 percent.....maybe more!
So.... do not suggest us to read Elliot, when you can supply exact numbers for our case, easy and fast, as you are here with us...and Rodd is not!
regards,
Carlos
And i do not make precise calculations..... just some idea of entire heat dissipation.
You can make to us the kindness to provide correct numbers, more exactly values.
As heatsink area needed, when outside and inside cabinets.
Heat produced when maximum undistorted power, 4 ohms, is produced...i use Sankens...so... 4 ohms are easy here.
Heat when both channel is driving simultaneously.with continuous tone (not so normal...but may be the maximum possible) driving into distortion.
Those values, can be helpfull to all guys, including me, as i know how to make some "eyed fast evaluation" because long experience with those things...but i know that my error can go to 30 percent.....maybe more!
So.... do not suggest us to read Elliot, when you can supply exact numbers for our case, easy and fast, as you are here with us...and Rodd is not!
regards,
Carlos
Carlos,
well, give me some time, as the recommendation should be serious and based on calculations, I will spend some evening to do it.
Regarding Rod's page, I just wanted to give a source of valuable information, for some of the guys here I believe it might be appreciated, and some of them can make their own calculations based on Rod's hints.
well, give me some time, as the recommendation should be serious and based on calculations, I will spend some evening to do it.
Regarding Rod's page, I just wanted to give a source of valuable information, for some of the guys here I believe it might be appreciated, and some of them can make their own calculations based on Rod's hints.
Hi SheldonSheldon said:
Thank you for the kind and useful suggestions. I will think of them seriously next time, since I think you are absolutely right. Yes, heatsinks should be vertically and could be smaller. But it wasn't easy to find the right size and I prefered bigger (than small). Also placing vertically such big heatsinks means a huge case, which I wanted to avoid. Perhaps I should have searched more for the right size of the heatsinks, and then everything else would be ok.
Fans is not an option for me. I prefer putting the whole amp in the refrigerator than puttting a fan. I don't like fans because of the noise. Circuits that switch fans on and off add complexity, too. I can hardly bare my computer's fan, and I often listen to music in low volume, late at night.
Have a nice evening and many greetings....
🙂
PMA said:
Pavel you are right, Carlos's and Sheldon's remarks were very useful for me and next time I will be better. I would have never known their opinion if I hadn't post my pics.
Cheers...
Carlos, your remarks, your photo edit, sketches, what can I say, I don't know. Such a great contribution and help for me and so many others. Yes, your contructions may be ugly and I think mine are a bit, too. Because I don't make them to be pretty, but because I want to keep all those cables in a box, and to be able to connect and disconnect speakers, preamplifiers etc. easily. I, too, am always unpatient to listen, and I also don't like mechanical work. Put all these together and you can see why my cases are not very pretty. But, they are ok with me, and it seems that if I pay big attention to the cases, constructions take for ever to complete, and I lose my patience. I prefer to have more amps for now, than few and pretty. Perhaps I will, sometime, when I have more time, make a SUPER Construction, with great care in every aspect. But I will have to find the right circuit, the BEST (for me), to put inside. Still searching, though...
During its first hours of work, Symasym doesn't seem to get hot at all.
I listened to 30 minutes at party level and if you put your hand on the heatsinks it was very difficult to know if this amp had even one electron pass through his transistors. You could perhaps think that it was never turned on! Then I left him silent, but switched on, for 1.5 hours. Heatsinks were very very lightly warm, because of the Iq, which is 110 mA. Speakers are 8 Ohms, PSU Voltage +-32.7V.
Carlos my cables may be a little longer than needed and not very neat, but they are not too thick! The thick red cables are shielded, and going to the input of the amp. Output cables should be thick, I think, preferably from some good speaker cable.
Thank you very much for your remarks and your nice words. Really really valuable...😉
During its first hours of work, Symasym doesn't seem to get hot at all.
I listened to 30 minutes at party level and if you put your hand on the heatsinks it was very difficult to know if this amp had even one electron pass through his transistors. You could perhaps think that it was never turned on! Then I left him silent, but switched on, for 1.5 hours. Heatsinks were very very lightly warm, because of the Iq, which is 110 mA. Speakers are 8 Ohms, PSU Voltage +-32.7V.
Carlos my cables may be a little longer than needed and not very neat, but they are not too thick! The thick red cables are shielded, and going to the input of the amp. Output cables should be thick, I think, preferably from some good speaker cable.
Thank you very much for your remarks and your nice words. Really really valuable...😉
If you don't mind a little metalwork and it wouldn't take much, it looks like you could cut one of those sinks in half (across the fins) and mount each half with the fins oriented vertically on the rear of the case. You could cut out part of the back panel so that the transistors are directly on the sink and the rest is inside the case. Then pull your power supply forward and you can close up the whole thing, no worries. See Pavel's site for an example of the heatsink configuration. http://www.pha.inecnet.cz/macura/pma1_en.html
Or ... just leave it as is.
Sheldon
Or ... just leave it as is.
Sheldon
PCB solded
Hello MikeB and PMA,
i have just finished the soldering of four PCB sysasym V5-2.
They look very nice and now i must drill the heatsinks and assembling the PCB on the heatsinks.
Look:
Soon i can also start listening !
Hello MikeB and PMA,
i have just finished the soldering of four PCB sysasym V5-2.
They look very nice and now i must drill the heatsinks and assembling the PCB on the heatsinks.
Look:
An externally hosted image should be here but it was not working when we last tested it.
Soon i can also start listening !