Sheldon said:
I know the fins work better mounted vertically but this amp runs so cool that I doubt it will ever be a problem. I ran it pretty hard for about an hour into a 4ohm load and I could put my finger right on the outputs and they were barely warm. I bought these heatsinks a long time ago on ebay and have not been able to use them because of the Class A amps I was building. I'm glad to finally be able to use them.
Thanks for the compliment. I used an aluminum blade on my table saw. Works fine.
I used this same diamond plate to build my first amp and someone said it looked funny. I shouldn't have listened to him. I love the way this stuff looks.
Blessings, Terry
Hi Terry,
Another one finished! 😀
Looks great AND sounds great, what more can you want?
When you complete the Symasym 5_2, why don't you try one PSU per channel. Is supposed to improve channel separation and therefore the soundstage on AKSAs, so I would imagine a similar effect on Mike's Symasym. It would be interesting to find out in a side by side test.
Have you tried enamelled copper wire (magnet wire) for the inductors? The offcuts from the toriods might be good and long enough.
regards
Another one finished! 😀
Looks great AND sounds great, what more can you want?
When you complete the Symasym 5_2, why don't you try one PSU per channel. Is supposed to improve channel separation and therefore the soundstage on AKSAs, so I would imagine a similar effect on Mike's Symasym. It would be interesting to find out in a side by side test.
Have you tried enamelled copper wire (magnet wire) for the inductors? The offcuts from the toriods might be good and long enough.
regards
I like the location of the different stuff in the box.
Makes possible for short and minimal wiring.
This is a good rule.
Keep wires as short as practically possible.
very good job, still4given
🙂
Makes possible for short and minimal wiring.
This is a good rule.
Keep wires as short as practically possible.
very good job, still4given
🙂
Greg Erskine said:
Hi Greg,
The off cuts from the toroid were just insulated wire. If I ever find a good supplier for that enamaled wire I will buy some and start using it. I did try using two toroids and couldn't hear any difference. That doesn't mean it wouldn't measure better. My 5_2 boards are working but I have them on kind of large heatsinks and I don't really want to make the case that big. I may try some smallish sinks and see how it does.
Blessings, Terry
lineup-
I like the location of the different stuff in the box.
---------------------------------------
me too, it is very neat layout
I like the location of the different stuff in the box.
---------------------------------------
me too, it is very neat layout
still4given said:
Thanks Terry,
I have only used 2 different brands of toriods and assumed everyone built them the same. 😱 All our local generic electronics stores seem to have magnet wire (not much else!) so I just assumed it was easy to get. Ignorance is a blessing sometimes. In Australia, we have to get a lot of the "good" stuff from overseas.
Interesting about your tests with 2 toriods. I have only done tests with Gainclones on my test system, and I wasn't able to tell the difference. On all my discrete amps I have always used 2 toriods so I don't really know if it is better?
Good luck with the Symasym 5_2. I've been playing with bi-amping and my intial impressions are good. A bi-amped Symasym seems a very promising solution to me. 😉
regards
Hi Terry !
Wow, nice casework !
One thing, it looks a bit like you have reversed polarity on the right speaker output ?
And, you used shielded wire for the speakercables, but you maybe shouldn't connect that shield to signal-gnd, on photo it looks like you connected it to the left RCA ? It should be enough to connect on amp side to power-gnd.
That's no critic, i just want it to be "perfect"... 🙂
Mike
Wow, nice casework !
One thing, it looks a bit like you have reversed polarity on the right speaker output ?
And, you used shielded wire for the speakercables, but you maybe shouldn't connect that shield to signal-gnd, on photo it looks like you connected it to the left RCA ? It should be enough to connect on amp side to power-gnd.
That's no critic, i just want it to be "perfect"... 🙂
Mike
MikeB said:Hi Terry !
Wow, nice casework !
One thing, it looks a bit like you have reversed polarity on the right speaker output ?
And, you used shielded wire for the speakercables, but you maybe shouldn't connect that shield to signal-gnd, on photo it looks like you connected it to the left RCA ? It should be enough to connect on amp side to power-gnd.
That's no critic, i just want it to be "perfect"... 🙂
Mike
Good eyes Mike. You were right. I had reversed the wires on the right side. Thanks!
Those aren't shielded cables on the speakers though. They are short lengths of the speaker cable I use. It is 16ga stranded. I did use shielded on the inputs though. That is connected correctly I think. I connected the shield to RCA ground and the pin next to the input lead pin, the speaker ground to the ground pin on the PCB and then took the other ground pin on the PCB to star ground. If either the input shield or the speaker ground needs to go to star ground, let me know and I will rewire it.
Blessings, Terry
Great job Terry, it looks like the initial mishaps paid off and were
only a small snag... Good
And I thought mine were ok, nah....
At first the steel looked a bit odd but after a while the overaul
aspect of the cabinet seems to make sense.
I also noticied the wiring being in the wrong place....
Congratulations, a job well done.
only a small snag... Good
And I thought mine were ok, nah....
At first the steel looked a bit odd but after a while the overaul
aspect of the cabinet seems to make sense.
I also noticied the wiring being in the wrong place....
Congratulations, a job well done.
Terry congratulations for your casing, really very nice work on the most difficult part of such contructions: mechanical work!
I am a fan of completely seperate PSU's for each channel also. But I can't also confirm a difference in sound, since all my constructions (of power amps) have always been with seperate PSU's. So , I haven't done a comparison.
Regards,
Dimitris.
I am a fan of completely seperate PSU's for each channel also. But I can't also confirm a difference in sound, since all my constructions (of power amps) have always been with seperate PSU's. So , I haven't done a comparison.
Regards,
Dimitris.
It survived!
It survived Mike!!!!!!!!!!!!!
Aleluia! The Symasym survived the ultimate test of the
electrostatics, I was so afraid to smoke the amplifier that I waited and waited until....the suspense was killing me.
First, as I said before, I ran one channel with 2.2uF´ and 8 ohms just to see on the scope how it would react. (I'm
sending you the pictures) As you can see the top square wave is the one with 2.2uF, the bottom is just the regular
8 ohm load. As you can see there was just that ringing which I found of less importance (I've seen tube amplifiers with bigger ringing), besides that no signs of major (or
minor) disturbance. That gave me the remaining courage to connect the amplifier to the ESL.
Unconditionally stable, no heat, no disaster.
As the amplifier has so much gain, as a precaution I
reduced a tiny bit the HV to the ESL that could cause distortion but then I increased it little by little to the very same point which is almost 5 Kvolts. OK so far!
On the other hand can you imagine the sound that comes out of those speakers?
I'leave that to your imagination!
LONG LIVE THE SYMASYM1
btw, I don't erect your statue in my yard as I promised....just because it's winter, it's too cold but I'll do it in summertime!
It survived Mike!!!!!!!!!!!!!
Aleluia! The Symasym survived the ultimate test of the
electrostatics, I was so afraid to smoke the amplifier that I waited and waited until....the suspense was killing me.
First, as I said before, I ran one channel with 2.2uF´ and 8 ohms just to see on the scope how it would react. (I'm
sending you the pictures) As you can see the top square wave is the one with 2.2uF, the bottom is just the regular
8 ohm load. As you can see there was just that ringing which I found of less importance (I've seen tube amplifiers with bigger ringing), besides that no signs of major (or
minor) disturbance. That gave me the remaining courage to connect the amplifier to the ESL.
Unconditionally stable, no heat, no disaster.
As the amplifier has so much gain, as a precaution I
reduced a tiny bit the HV to the ESL that could cause distortion but then I increased it little by little to the very same point which is almost 5 Kvolts. OK so far!
On the other hand can you imagine the sound that comes out of those speakers?
I'leave that to your imagination!
LONG LIVE THE SYMASYM1
btw, I don't erect your statue in my yard as I promised....just because it's winter, it's too cold but I'll do it in summertime!
Hi jmateus,
You could build a snowman in Mike's honour.
Just put it in the freezer and take it out again next year. 
I am looking forward to completing a pair more and more now.
-Chris
You could build a snowman in Mike's honour.
Just put it in the freezer and take it out again next year. I am looking forward to completing a pair more and more now.
-Chris
Hi Anatech
The only problem is there is no snow around here and the temperature is between 7 and 10 degrees centrigrade.
But that could be a hell of an idea if:
-There was snow on the ground
-If I didn't feel so cold outside.
But anyway, I'll keep that in mind, Mike knows I'm kidding even
though I think he deserves some kind of attention at least from
me who doens't have his kind of habilities.
You're refering to another pair of Syms, aren't you?
Good luck, how do you like it? Isn't this amp a true killer?
Specially now that it drives ESL, wow!
The only problem is there is no snow around here and the temperature is between 7 and 10 degrees centrigrade.
But that could be a hell of an idea if:
-There was snow on the ground
-If I didn't feel so cold outside.
But anyway, I'll keep that in mind, Mike knows I'm kidding even
though I think he deserves some kind of attention at least from
me who doens't have his kind of habilities.
You're refering to another pair of Syms, aren't you?
Good luck, how do you like it? Isn't this amp a true killer?
Specially now that it drives ESL, wow!
Hi jmateus,
I have not built a set yet. I hope to soon. Once it is built, I'm going to play with it a bit.
The fact the amp drives your ESL's with no troubles is excellent. Your report on the sound quality is heartening. I have already decided to build some, and now I can't wait! 😉
-Chris
I have not built a set yet. I hope to soon. Once it is built, I'm going to play with it a bit.
The fact the amp drives your ESL's with no troubles is excellent. Your report on the sound quality is heartening. I have already decided to build some, and now I can't wait! 😉
-Chris
Parallel outputs?
Hi all,
Any opinions if there is anything to gain by paralleling another set of outputs on this circuit? I'll be driving 4-ohm speakers most (if not all) of the time, and I understand there might be some benefit to doing so (i.e. keeping the currents within the linear region of the 3281/1302 pairs)...
TIA!
Hey Chris,
Should be there in a few more days, I hope! In the meantime I'm waiting for completion of my transistor set!
Cheers
Clem
Hi all,
Any opinions if there is anything to gain by paralleling another set of outputs on this circuit? I'll be driving 4-ohm speakers most (if not all) of the time, and I understand there might be some benefit to doing so (i.e. keeping the currents within the linear region of the 3281/1302 pairs)...
TIA!
Hey Chris,
Should be there in a few more days, I hope! In the meantime I'm waiting for completion of my transistor set!
Cheers
Clem
Hi Clem,
I'm watching the mailbox! I didn't expect them to arrive until sometime next week.
Adding some outputs isn't hard, why not try it to see if you can hear a difference? If not, disconnect them. Your 4 ohm loads shouldn't be a problem unless the supply voltage is raised.
-Chris
I'm watching the mailbox! I didn't expect them to arrive until sometime next week.
Adding some outputs isn't hard, why not try it to see if you can hear a difference? If not, disconnect them. Your 4 ohm loads shouldn't be a problem unless the supply voltage is raised.
-Chris
Hi Chris,
Actually deciding if I will go to the extent of building a small "output" board or just using point-to-point for the extra outputs / emitter resistors.
Ah but yes, build the basic amp first.. 🙂 🙂 🙂
Cheers!
Clem
Actually deciding if I will go to the extent of building a small "output" board or just using point-to-point for the extra outputs / emitter resistors.
Ah but yes, build the basic amp first.. 🙂 🙂 🙂
Cheers!
Clem
Hello John !
That is really great news, symasym happily driving your ESLs ! (I would be happy with a snow man... )
Did you install the safety diodes at output (output to rails) ? Your outputdevices are MJ21193/4 ?
How do your ESLs sound with the symasym ? 🙂 I attached your scopeshot for the others to see.
Hi Clem, i don't think that is necessary to add a 2nd outputpair, i also drive 4ohm speakers and symasym is happy to drive them. As you have >100watts into 4ohms it is unlikely that symasym plays mostly at very high levels, keeping the MJLs in their linear region anyway.
I also have some news, yesterday i received the MJL0281A/MJL0302A devices and "quickly" swapped the Toshibas against them. OnSemi did a good job with these brandnew devices, they sound brilliant, the trebles got a bit cleaner, the bass improved and the sound got "tighter" and warmer.
I can't really tell if these new MJLs are better than the Toshibas, at least in symasym they are excellent.
I also have to admit, these MJLs were all from the same batch (NPN and PNP), maybe an advantage for them ?
Mike
That is really great news, symasym happily driving your ESLs ! (I would be happy with a snow man...
)Did you install the safety diodes at output (output to rails) ? Your outputdevices are MJ21193/4 ?
How do your ESLs sound with the symasym ? 🙂 I attached your scopeshot for the others to see.
Hi Clem, i don't think that is necessary to add a 2nd outputpair, i also drive 4ohm speakers and symasym is happy to drive them. As you have >100watts into 4ohms it is unlikely that symasym plays mostly at very high levels, keeping the MJLs in their linear region anyway.
I also have some news, yesterday i received the MJL0281A/MJL0302A devices and "quickly" swapped the Toshibas against them. OnSemi did a good job with these brandnew devices, they sound brilliant, the trebles got a bit cleaner, the bass improved and the sound got "tighter" and warmer.
I can't really tell if these new MJLs are better than the Toshibas, at least in symasym they are excellent.
I also have to admit, these MJLs were all from the same batch (NPN and PNP), maybe an advantage for them ?
Mike
Attachments
Hello Mike
Yes, those are the outputs I'm using, TO3 cases.
About the snowman, unfortunately there is no snow on the ground, so this will be postponed for a later date.
You know, yesterday after I had the amplifier running with the
electrostatics that's when I remember the diodes, I completely
forgot about them. Sym plays without them, eh,eh,eh.....
But I'll do that when the time comes, it's a measure of precaution.
The sound is astonishing, of course I have the ESL full range
even though they are not known for its extended bass, specially
of this size. But it does its job, what is amazing is the
extreme clarity of the mid range and treble, smooth and detailed
as I always wanted. I think it does a better job than the tube
amplifier I was using before and a very good one by the way.
Again Diana Krall sounds out of this world.....
These new outputs from Onsemi, are they expensive? A bit
curious...
Thanks for posting the picture, I've always problems in uploading
pictures, no matter what I do the board always tells me that's
a too big of a file to insert.
In any case for everybody to know the upper wave is the channel
loaded with 2.2uF with 8 ohms in parallel it shows a bit of ringing
nothing serious I suppose (tube amplifiers look worst sometimes)
and the bottom picture is the other channel loaded with 8 ohms
only.
Good call.....
Yes, those are the outputs I'm using, TO3 cases.
About the snowman, unfortunately there is no snow on the ground, so this will be postponed for a later date.
You know, yesterday after I had the amplifier running with the
electrostatics that's when I remember the diodes, I completely
forgot about them. Sym plays without them, eh,eh,eh.....
But I'll do that when the time comes, it's a measure of precaution.
The sound is astonishing, of course I have the ESL full range
even though they are not known for its extended bass, specially
of this size. But it does its job, what is amazing is the
extreme clarity of the mid range and treble, smooth and detailed
as I always wanted. I think it does a better job than the tube
amplifier I was using before and a very good one by the way.
Again Diana Krall sounds out of this world.....
These new outputs from Onsemi, are they expensive? A bit
curious...
Thanks for posting the picture, I've always problems in uploading
pictures, no matter what I do the board always tells me that's
a too big of a file to insert.
In any case for everybody to know the upper wave is the channel
loaded with 2.2uF with 8 ohms in parallel it shows a bit of ringing
nothing serious I suppose (tube amplifiers look worst sometimes)
and the bottom picture is the other channel loaded with 8 ohms
only.
Good call.....