Simple Symetrical Amplifier

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#1,081
guitar89 said:
Is it possible to use some substitute BJT onto the simple version ? (I saw mosfet at first page ?)
I have some spare MJL3281 and 1302 pairs, what other component should i change with the change of BJT ? (It would be good if you could provide diagram/link, even better if had simple specification like load available & maximum wattage)

And what is the difference in the ADVANCED(more complicated though) improved SSA, compare to its simple version ? (i only know its power output is more ?)
Click to expand...

I think too that following Bigun's thread is a nice learning curve and should result in a nice complete product.
 
#1,082
#1,083
what i found of simple BJT SSA is following link (not yet search through the whole thread yet)
http://www.diyaudio.com/forums/solid-state/193923-simple-symetrical-amplifier-20.html#post2671747
http://www.diyaudio.com/forums/solid-state/193923-simple-symetrical-amplifier-20.html#post2671820
Both of them are on page 20.
Click to expand...
I was wondering, if i were to change the all the transistor, what else would i change to "couple" with my transistor.(MJL3281 & MJL1302 in my case)
I'm have not much knowledge, but into construction any guideline would be appreciate

(i notice it is using NJL3281,1302 pair, what is the different compare to my MJL3281,1302 ?)
 
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#1,084
guitar89 said:
what i found of simple BJT SSA is following link (not yet search through the whole thread yet)

I was wondering, if i were to change the all the transistor, what else would i change to "couple" with my transistor.(MJL3281 & MJL1302 in my case)
I'm have not much knowledge, but into construction any guideline would be appreciate

(i notice it is using NJL3281,1302 pair, what is the different compare to my MJL3281,1302 ?)
Click to expand...

MJL3281,NJL3281,2SC3281, same thing ,just different manufacturer
 
#1,091
2sc was made obsolete by Toshiba and a new version (2sa1943/c5200) was released to try to overcome the copying and faking that was rampant a decade or so ago.
Since then the replacement has been faked and copied.

Toshiba are so popular and relatively expensive that there is big business in the faking industries.
 
#1,092
AndrewT said:
2sc was made obsolete by Toshiba and a new version (2sa1943/c5200) was released to try to overcome the copying and faking that was rampant a decade or so ago.
Since then the replacement has been faked and copied.

Toshiba are so popular and relatively expensive that there is big business in the faking industries.
Click to expand...
aw..... that means buying 2SA/2SC product is a big risk curse those fakers :bomb:
 
#1,094
hm........ that....... hope nothing will further worst, but leave that apart (we are contaminating the thread ?)

I'm have been scanned through 60 pages of this thread, seems no update in SSSA (super simple symmetrical amplifier, esspecially BJT version )
But i will be patient, and follow until the end ^^
 
#1,095
Also been wondering, for some things over the diagram...... (post #197 for reference)
(I) What is the value of zener diodes ? 16V or 12V ? Does it need to change if the supply voltage is different ?(example of 40V) (what is the use of zener at here anyway ?)
(II) what is the requirement of the diode ? (minimum amp rating, etc)
(III) There are 2 potentio, 50 and 5k, which is for DC offset and Iq ? (how to bias instruction would be nice) and what is "MT" means ?
(IV) Those resistor and capacitor which don't have voltage and wattage rating, what should be the minimum value ?
(V) Is that the latest available simplest BJT SSA ? You mentioned very quiet, but how "quiet" is it ?
 
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#1,098
AKSA said:
I have a notion that the SE circuit will have higher even than odd order distortion.

Again, thank you,

Hugh
Click to expand...

I've come around to the concept that the symmetric design is just as suitable if you want 2nd harmonic. With the SSA amp, you have an awful lot of places you can tweak for H2 if you want - and you can do it in the purest sense, by creating a little disparity in the gain between the top / bottom half of the signal. Heck, without the capacitor joining the two feedback nodes together the tolerance in the feedback resistors will give you H2. It's very flexible and you can do it without many capacitors.


I'm gonna order the parts this weekend if it kills me. I need to build my version soon.
 
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#1,099
guitar89 said:
hm.... multi turn is for precision, isn't it ? X.x it is expensive too, its not common in my local store...
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According to my simulations you need to be able to tweak the adjustable resistors fairly accurately. In my TGM5 (the one that you said was too complex 😕 ) I'll be using aditional series or parallel resistors so that the trimmer pots are working over a narrower range which I hope will make it easier to set up the best operating conditions.
 
#1,100
Bigun said:
According to my simulations you need to be able to tweak the adjustable resistors fairly accurately. In my TGM5 (the one that you said was too complex 😕 ) I'll be using aditional series or parallel resistors so that the trimmer pots are working over a narrower range which I hope will make it easier to set up the best operating conditions.
Click to expand...
haha, you have the point X.x anyway, TGM5 wasn't complex actually, just not simple, alot of additional component and duplicate(parallel) output to increase its capability.
(anyway, what TGM stands for ?)

I will do that, using single turn but more narrow range with help of few resistor.
 
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