fredlock said:Nice subwoofer! Is that a 12"/ 4ohms? Is it Dayton or peerless? The way it looks will give you a lot of bass.
hi
that sub is a TC Sounds, TC-3000 15" quad voice coil it is rated at 2000wrms lol
its a really sweat sub. super loud drop dead lows, and the SQ is extremely low good.
once i get the bigger amp running im going to design and build an enclosure and use it in the house.
just an update.
I finally got the output to reach the rail voltage. the output wave is a healthy +53v and -53v thats right before clipping. im going to make a new board to support 4 pairs of transistors because this boar only takes 2 pairs and at that voltage it will only take the 4ohms load for 3 to 4 minutes before it cuts off from over heating, i guess if i install them on the bigger heat sink they may keep on running. it destroyed a 75w speaker with a 200Hz sine wave and the output transistors are still fine. very rubout the MJL1302AG and MJL3281AG are a very nice set of transistors, they sound good, they take the beating and keep on ticking. lol.
I finally got the output to reach the rail voltage. the output wave is a healthy +53v and -53v thats right before clipping. im going to make a new board to support 4 pairs of transistors because this boar only takes 2 pairs and at that voltage it will only take the 4ohms load for 3 to 4 minutes before it cuts off from over heating, i guess if i install them on the bigger heat sink they may keep on running. it destroyed a 75w speaker with a 200Hz sine wave and the output transistors are still fine. very rubout the MJL1302AG and MJL3281AG are a very nice set of transistors, they sound good, they take the beating and keep on ticking. lol.
Hi boricuaso,
My LME49810 kit has arrived from the supplier. My kit uses the equivalent 2SC5200 and 2SC1943 power transistors and equally good drivers.
I believe by using this combo I can get similar performance comparable to those using purely discrete implementations eg Symasym5, Destroyer HRII, or similar designs.
Obviously the original kit detailed design is very different from the above discrete design however the topology is essentially the same. By tweaking the design ie by adding and removing a few components here and there I would be able to achieve the sonic quality similar to the above design. This assumes the fact that similar topology amps sound similar, the character is the same which is excellent bass extension(better than chipamp like Lm3886) and more dynamic. The reason being o/p drivers can deliver higher peak current.
You may like to experiment with your amp topology and after you have completed that you may want to look at how Symasym5, Destoyer HRII, design their amps and borrow the good design aspects and implement them in your amp, I am sure it will improve your amp.
cheers happy developing.
My LME49810 kit has arrived from the supplier. My kit uses the equivalent 2SC5200 and 2SC1943 power transistors and equally good drivers.
I believe by using this combo I can get similar performance comparable to those using purely discrete implementations eg Symasym5, Destroyer HRII, or similar designs.
Obviously the original kit detailed design is very different from the above discrete design however the topology is essentially the same. By tweaking the design ie by adding and removing a few components here and there I would be able to achieve the sonic quality similar to the above design. This assumes the fact that similar topology amps sound similar, the character is the same which is excellent bass extension(better than chipamp like Lm3886) and more dynamic. The reason being o/p drivers can deliver higher peak current.
You may like to experiment with your amp topology and after you have completed that you may want to look at how Symasym5, Destoyer HRII, design their amps and borrow the good design aspects and implement them in your amp, I am sure it will improve your amp.
cheers happy developing.
thanks for the input, im kind of using a similar output stage as they would for a fully solid state amplifier, at least i think i am, if you know of anything that could be improved or just changed for the best on my amplifier. feel free to comment, and i will be more then happy to try the new changes and report on it.
laters
laters
I am experimenting with this chipset now if I found something interesting I will let you know.
Firstly you should look at M. Bitnner or Destroyer cct diagrams, your o/p design is different from theirs but similar to Nap140 or its clone. By experimenting with the o/p config you may get the sound you want.
One easy experiment is to change the slew rate cap. to 22pf instead of 10pf, some refer 22pf better, tell me what you think.
Firstly you should look at M. Bitnner or Destroyer cct diagrams, your o/p design is different from theirs but similar to Nap140 or its clone. By experimenting with the o/p config you may get the sound you want.
One easy experiment is to change the slew rate cap. to 22pf instead of 10pf, some refer 22pf better, tell me what you think.
ttan98 said:
well in reference to the slew rate cap i tryed 10pf, 20pf, 30pf, 50pf and 60pf the change i noticed the most is the harshness at loud volumes, at 10pf it can take the most loudness, at 60pf it sounds the best at reasonably audible to above a bit higher then mid level loudness, i have mine at 50pf, although it gets harsh at all most full tilt, it sounds great at midlevel loudness, at full blast it is house party loud, an can damage a 180wrms 4way speakers towers with a 15"sub in it. and i think i had stability issues with a 10pf cap but not 100% sure.
each individual builder should try a couple diferent caps and see what sounds best with each different circuit schematic out there.
Thanks for sharing.
I think your amp is constructed from a breadboard, ie testing stage, you have components hanging off the board, I think once you finalise the PCB and put all the components together in a PCB you may have to change you slew rate capacitor. This because the layout of the PCB affects the slew rate/lag compensation capacitance.
Cheers.
I think your amp is constructed from a breadboard, ie testing stage, you have components hanging off the board, I think once you finalise the PCB and put all the components together in a PCB you may have to change you slew rate capacitor. This because the layout of the PCB affects the slew rate/lag compensation capacitance.
Cheers.
the current amp is on an actual pcb, im sure the slew rate cap will have to be changed once i finish my new pcb with all the transistor on the same horizontal plane.ttan98 said:
ionomolo said:
for bypass caps im using .1uf caps 1 caps "they are small and red in color in the pictures" per output transistor right by it and another set of .1uf right at the ic power pins also at those pins i have a 470uf cap per rail, and then at the very entrance point of power in to the board i have a 1000uf cap per -+voltage rail.
http://picasaweb.google.com/powernaudio/AudioElectronics/photo#5199367421105236258
http://picasaweb.google.com/powernaudio/AudioElectronics/photo#5199367416810268946
http://www.putfile.com/pic/8132984
http://www.putfile.com/pic/8132983
i hope those links work they are for the schematic and the current pcb.
laters
picture update of how far from finish is at.
for those that may have an interest on this project, i wanted to post some pics of the amp, last night i finished assembling it, tonight i might test it out and see how it performs. hopefully it wont go up in smoke.
for those that may have an interest on this project, i wanted to post some pics of the amp, last night i finished assembling it, tonight i might test it out and see how it performs. hopefully it wont go up in smoke.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
boricuaso,
Your amp looks good. It started from scratch.
I don't have the patient like you, I bought my kit($26 per channel) from Monkey. It worked very well, no problems.
Now I am trying to modifying it(standard cct, o/p is emitter follower). The o/p will be modified as Complementary Sziklai Output ie driver used as common emitter driving the o/p which acts as common emitter as well. I heard those who tried it gets good results ie wider bandwidth and hence extended high freq. response.
I anticipate some problems, unstability, etc. Will report back.Will try it this weekend.
This is stage 1, more stages to come, ie parallel the o/p devices....Watch this space.
The objective of this exercise to use LME49810 as the building block of constructing high quality amp(low and high powered amp) at minimal cost.
cheers.
Your amp looks good. It started from scratch.
I don't have the patient like you, I bought my kit($26 per channel) from Monkey. It worked very well, no problems.
Now I am trying to modifying it(standard cct, o/p is emitter follower). The o/p will be modified as Complementary Sziklai Output ie driver used as common emitter driving the o/p which acts as common emitter as well. I heard those who tried it gets good results ie wider bandwidth and hence extended high freq. response.
I anticipate some problems, unstability, etc. Will report back.Will try it this weekend.
This is stage 1, more stages to come, ie parallel the o/p devices....Watch this space.
The objective of this exercise to use LME49810 as the building block of constructing high quality amp(low and high powered amp) at minimal cost.
cheers.
ionomolo said:Parallel output transistors? Your neighbours aren't going to like it!
lol yah, one pair was really enough two pairs is insane,
the only reason i added the second pair was to try and handle 4ohm loads at +-55volts +-60volts max, with out over heating the transistors too much. im using these trafo that came out of a used stereo system i was given, it has a +-30v winding as well so i can run the amp at +- 45 or so, but it still gets pretty hot with a single pair at that voltage so i just run it at the higher voltage and two pairs. and with the two pairs its so much louder and the head room is excellent.
the next model im working on is the 5 pairs for a subwoofer, maybe more. not sure how many ill need to push my TC 3000 15" sub. not looking to max it out. but im looking to at least get it to break the 130db.
ttan98 said:
the truth is my LME chips and transistors where samples. and most if not all of the parts of the first prototypes i built came from scrap audio systems and misc electronics.
and the few things i have bough have been cheap.
nothing wrong with buying kits, i just learn and have my fun from researching, and finally building.
either way im looking forward to your modifications.
keep us updated.
I just powered it up and played it, it sounds really good, the bass is strong, punchy and sustained. the highs are crisp, sharp and accurate.
the mids are not hidden or colored, the music feels like its being equalized at it plays, nice and flat from the get go. i like my bass, so i kind of give it an extra boost, but like the fact that the amp can boost it with out straining. even with a small size heatsink, as the one im using right now, the temperature stayed way below mid level. with the volume past comfortable level were you cant speak to some one else and understand them. but not too far past the mid level on the volume control. the sound was still musical and not tiering to the ear. this is a very nice amp and worth the time and money to build. i recommend it.
i still have to do a bit more tweaking. im waiting for my Silver Mica Capacitors for the compensation cap, im a be using a 15pF to start and ill double it from there if needed. and what ever other tweaks i can find suitable till it performs at 100%.
laters
the mids are not hidden or colored, the music feels like its being equalized at it plays, nice and flat from the get go. i like my bass, so i kind of give it an extra boost, but like the fact that the amp can boost it with out straining. even with a small size heatsink, as the one im using right now, the temperature stayed way below mid level. with the volume past comfortable level were you cant speak to some one else and understand them. but not too far past the mid level on the volume control. the sound was still musical and not tiering to the ear. this is a very nice amp and worth the time and money to build. i recommend it.
i still have to do a bit more tweaking. im waiting for my Silver Mica Capacitors for the compensation cap, im a be using a 15pF to start and ill double it from there if needed. and what ever other tweaks i can find suitable till it performs at 100%.
laters
ttan98 said:
boricuaso,
Stage 1 started, I managed make the Complementary Sziklai Output to work, initial impression seems promising because of its wide bandwidth, the high freq. is very smooth, midrange is very good, the bass seem lacking(could be o/p impedance is higher than emitter follower config, maybe more parallel o/p transistors are required to lower o/p impedance). More experimentation is required.
Will keep this thread alive over many few weeks to come. The LME48910 chipset, very versartile.
A number options I like to experiment after this,
1. Using quasi complementary output.
2. High powered version, >100W
3. Class A version.
4. Reonder's o/p config.
not necessary in this order.
etc.
and the front end remains the same, LME49810
I'm very interested in making output stages faster. Which transistors did you use?
driver:2sc5171/2sa1930 ft=200mhz very good and you
can buy them. you can also use 2SC4793/2SA1837
power:J4315/J4215 equivalent to 2sa5200/2sc1943
Can you show any schematic of the working version?
see this site on the o/p section:
http://sound.westhost.com/project3a.htm
with R11 = R12 = 47ohm so the driver works closer to class A, you can reduce to even lower to 18 ohm. Also you must include C6=100pf.
Which cutoff frequency and phase shift do you get?
havn't tested yet. From hearing the music I am confident the freq bandwidth has to wider than emitter follower config..
cheers.
driver:2sc5171/2sa1930 ft=200mhz very good and you
can buy them. you can also use 2SC4793/2SA1837
power:J4315/J4215 equivalent to 2sa5200/2sc1943
Can you show any schematic of the working version?
see this site on the o/p section:
http://sound.westhost.com/project3a.htm
with R11 = R12 = 47ohm so the driver works closer to class A, you can reduce to even lower to 18 ohm. Also you must include C6=100pf.
Which cutoff frequency and phase shift do you get?
havn't tested yet. From hearing the music I am confident the freq bandwidth has to wider than emitter follower config..
cheers.
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