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Help me decide! Technics SE A100 vs SE A3

J

Jauk

Active Member
So I have the chance to get both but can only buy one... Actually I shouldn't buy any but you know the rest....:D
Anyway, specwise I prefer the A3. Yes, yes I already know the A100 has a special topology.. But the A3 is better spec wise in everything except distortion, which is not that different in practice with the A3's being also ridiculously small. And build quality wise probably one thing that a lot of you in the US don't know is that the transformers for Europe were more powerfull. The European version of the A3 has a total of 2300Watts in power transformers, at least that's what's marked on the back of the case and in the service and user manuals. The A100 has only 1350w. The capacitors are about the same, 80.000uf per channel so overall the A3 is better equiped. Also the heatsinks are bigger in the A3. Power output is also bigger on the A3, 200w@8ohm/320w@4ohm vs 170w@8ohm/240@4ohm...
I don't know....:sigh:

I've heard plenty amps with decent speakers and they didn't sound that different, provided they were solid state and powerfull enough, the room and speakers were what made the biggest difference. The New Class A synchro bias is also not bad.
The only thing I don't like about the A3 are the original transistors, which this one still has (which on the other hand might be a rarity by itself ...:)) but those can be changed later on, even if it's a PITA, I think there are replacements that preserve the original specs of the amp right ? I have read about people upgrading/replacing them and not mentioning any difference but I'd like to be sure the function/sound of the original design is preserved.

Help!
:D
 
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Heck, the European A3 has more powerfull transformers than the MK2 version, which has "only" 1700w....:scratch2:
 
Jauk said:
So I have the chance to get both but can only buy one... Actually I shouldn't buy any but you know the rest....:D
Anyway, specwise I prefer the A3. Yes, yes I already know the A100 has a special topology.. But the A3 is better spec wise in everything except distortion, which is not that different in practice with the A3's being also ridiculously small. And build quality wise probably one thing that a lot of you in the US don't know is that the transformers for Europe were more powerfull. The European version of the A3 has a total of 2300Watts in power transformers, at least that's what's marked on the back of the case and in the service and user manuals. The A100 has only 1350w. The capacitors are about the same, 80.000uf per channel so overall the A3 is better equiped. Also the heatsinks are bigger in the A3. Power output is also bigger on the A3, 200w@8ohm/320w@4ohm vs 170w@8ohm/240@4ohm...
I don't know....:sigh:

I've heard plenty amps with decent speakers and they didn't sound that different, provided they were solid state and powerfull enough, the room and speakers were what made the biggest difference. The New Class A synchro bias is also not bad.
The only thing I don't like about the A3 are the original transistors, which this one still has (which on the other hand might be a rarity by itself ...:)) but those can be changed later on, even if it's a PITA, I think there are replacements that preserve the original specs of the amp right ? I have read about people upgrading/replacing them and not mentioning any difference but I'd like to be sure the function/sound of the original design is preserved.

Help!
:D
Click to expand...
Yes the SE-A3 can be saved, the Toshiba 2SC5359 is the transistor..16 of them, supposedly being modern they will be matched close enough..my amp has been rebuilt with these devices and the amp sounds fantastic. Im not a tech..just looking at some paperwork thats telling me the part..a bit of work to do though.
My amp is a R&B series SE-A3..whatever that means.
 
I agree about the OD503.... I used 2SA1494 and 2SC3858 in sets I've worked on....

R&B was their Recording & Broadcast series... Was aimed at radio and studios at the time

I would take the A3 and refit the outputs.... When they're working properly the sound is awesome...
Though the A3MK2 is rated at 1700W consumption the output stage is superior. And then the sound of that is in its own league.
 
Jauk said:
Yes, yes I already know the A100 has a special topology.. But the A3 is better spec wise in everything except distortion, which is not that different in practice with the A3's being also ridiculously small.
Click to expand...
Both have a special topology. The A3 uses a sliding bias system to keep the power transistors on at all times, while the A100 uses a class B amp for the current drive and a class A section for voltage control (for the gap while the class B amp doesn't do anything).


Jauk said:
And build quality wise probably one thing that a lot of you in the US don't know is that the transformers for Europe were more powerfull. The European version of the A3 has a total of 2300Watts in power transformers, at least that's what's marked on the back of the case and in the service and user manuals.
Click to expand...
That power rating should never be considered as it is fully dependent on the norm that was present at the respective time. Sometimes it included average power consumption at xyz W, sometimes with a 4 ohm load, sometimes not, etc. You can never trust them.
Fact is though that both units have very big power transformers.


Jauk said:
The A100 has only 1350w. The capacitors are about the same, 80.000uf per channel so overall the A3 is better equiped. Also the heatsinks are bigger in the A3. Power output is also bigger on the A3, 200w@8ohm/320w@4ohm vs 170w@8ohm/240@4ohm...
Click to expand...
The A3 is a MUCH heavier beast than the A100. The latter is a great unit as well, but was produced in a time where cost-cutters were starting to gather power. Once again: don't get me wrong, both are good, but the A3 is just better: more beautiful construction out- and inside, bigger heatsinks, bigger transformers.


Jauk said:
The only thing I don't like about the A3 are the original transistors
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Oh come on! Just because one guy on the Internet wrote that they all fail it doesn't mean that it is true!

Okay, the infamous DLPT came in two versions: OD-503A-P and OD-503A-Q, the latter being a late (1981) revision of the original design.
It is a myth that they burn out easily. It just is not true.
Everything depends on how well you treat your A3. Give it plenty of air to breathe (left, right, especially top and also bottom). And don't crank it up hard all the time. The SE-A3 is not a PA amp and should not be driven at the edge of overloading all the time! And it is neither suitable for rack mounting.

Just for you to know: mine runs with the original OD-503A (Q version) since 1981.



To sum it up:
  • Both are very great and beautiful units
  • Both have an outstanding sound quality (you wouldn't be able to tell them apart)
  • The SE-A3 is a heavier monster than the A100
  • If you believe what the Internet says and, in combination, run your amp hot and loud, the A3 has a higher risk of burning

Decisions are therefore easy:
  • If you run your amp gentle, get the A3. More power, more vintage (always good ;)), better build quality, imho more beautiful outer design.
  • If you are anxious about it burning out, get the A100
  • If you already have an SU-A200, get the A100. If you have an SU-A4, get the A3 (just for looks; technically they are interchangeable).
  • If you don't care about any of the above: get the one you like most look-wise



Edit:
SVI2004A said:
R&B was their Recording & Broadcast series... Was aimed at radio and studios at the time
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Correct, and USA only iirc. However, there appears to be absolutely no difference between an R&B SE-A3 and a standard one (except for the badge).

SVI2004A said:
I would take the A3 and refit the outputs.... When they're working properly the sound is awesome...
Click to expand...
I would take the A3 and run it gently with the original outputs. Sounds exactly the same. And if you do it: give it a good overhaul (no new caps needed; just adjust DC offset and gain). The Technics service manual says that the Icq should be adjusted so that the THD is at the minimum… no good idea! Let the THD be at a certain level to prevent overheating of the transistors (if they really are as bad as people say).

SVI2004A said:
Though the A3MK2 is rated at 1700W consumption the output stage is superior.
Click to expand...
I agree with the output stage, but remember that the MK2 version is in an almost entirely different price league compared to the non-MK2 version.
 
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Thanks for the detailed comments...
I already got the A3 since yesterday morning, what a monster! I was already leaning toward it anyway, specially the build quality...
Pictures on the net don't make it justice.

Couple of questions :
1- I've tested it and there seems to be a very, I mean very very small hiss comming from the speakers if I put my ears about 30cm from the tweeter/mid. Is that normal ? My Pioneer M90a doesn't do that, it's totally silent, then again Pioneer went over the top on specs for those and it doesn't seem to sound as good, but admittedly this is most likely placebo...

2- Which brings me to the second question:3- Why no new caps ? They're very old now. As a curiosity those caps are big but I remember from old scanned marketing booklets I found that they're actually a combination of selected smaller ones inside. Bigger caps last longer right ?

3- Is there a way to distinguish which version of the transistors it has without dismantling it, maybe by the serial nr.

4- Regarding the output stage, I've done a quick search about advantages/disadvantages of a darlington output stage (A3Mk2) and overall there seems to also be disadvantages to it... And the Computer Drive thing is nothing special, only having 3 thermal states ... I have a V909 that's not working but when it was there was no difference to a V9 at all that I could notice.

Whatever I do it's can't be now, I'm recovering from a back problem due to a stupid exercise excess I've done over some years and this is a new slipped disk guaranteed :sigh:
 
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Haha I tweaked my back bringing in mine, as for the slight hiss at idle..affirmative, not a big deal but there ever so slightly.
 
Jauk said:
Thanks for the detailed comments...
I already got the A3 since yesterday morning, what a monster! I was already leaning toward it anyway, specially the build quality...
Pictures on the net don't make it justice.
Click to expand...
Congratulations! Excellent choice! And I agree: you'd have to see this beauty in front of you to get to know what it is like. Pictures on the net are for one part often bad (and scarce), and for the other just not as impressive as the unit itself.

Jauk said:
Couple of questions :
1- I've tested it and there seems to be a very, I mean very very small hiss comming from the speakers if I put my ears about 30cm from the tweeter/mid. Is that normal ?
Click to expand...
Depends on your speakers, but I don't think it is normal. I have a pair of leaf tweeters and, with my old amp, was able to hear a loud hiss even one meter apart. With the A3 they are totally silent unless I turn the volume knob up to the max.
The origin of hiss are the transistors and diodes. Since the configuration in the A3 is very good I am pretty sure it's all due to a missing alignment.

Give your A3 a proper adjustment (DC offset, Icq, clamp voltage, etc.) and I am sure the hiss will go away.

Jauk said:
My Pioneer M90a doesn't do that, it's totally silent, then again Pioneer went over the top on specs for those and it doesn't seem to sound as good, but admittedly this is most likely placebo...
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Yes it is, because Pioneer units are no better. The SE-A3 is as good as a Pioneer Exclusive power amp if you ask me.

Jauk said:
2- Which brings me to the second question:3- Why no new caps ? They're very old now.
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I have never ever seen an SE-A3 whose main filter caps were in need of replacing. Never. They just last. Then again, new capacitors are typically produced with a capacity at the lowest possible amount inside the tolerance of ±10%. Not that this would be a big deal sound-wise, but it's a good thing to know.

Jauk said:
As a curiosity those caps are big but I remember from old scanned marketing booklets I found that they're actually a combination of selected smaller ones inside. Bigger caps last longer right ?
Click to expand...
Yes they are; each "Super Audio Cap" is composed of four smaller caps. Replacing them would also mean ruining the beautiful looks inside (imho the most beautiful layout ever produced by Technics; more beautiful than in the A1).


If you really are in doubt about the caps and want to check at least the ESR: how long does your unit take from pressing the power button until it releases its first set of relays? Mine takes about 8 seconds (and it is totally fine like this). If your main filter caps are dried out it would take more time.


Jauk said:
3- Is there a way to distinguish which version of the transistors it has without dismantling it, maybe by the serial nr.
Click to expand...
Simple: take a flashlight and look through the cover into the heat sinks. You can just about see the transistors in there and say if they read "OD-503A-P" or "OD-503A-Q".
Also, I suspect the "Q" version was only installed in units from 1981 (maybe also late 1980), while the "P" editions were clearly a thing from 1980.
You can get your production date through the serial number:
technics-seriennummernschlussel_255718.png



Jauk said:
4- Regarding the output stage, I've done a quick search about advantages/disadvantages of a darlington output stage (A3Mk2) and overall there seems to also be disadvantages to it... And the Computer Drive thing is nothing special, only having 3 thermal states ... I have a V909 that's not working but when it was there was no difference to a V9 at all that I could notice.
Click to expand...
Darlington stages mainly spot a higher amplification factor compared to single stage outputs. However, they also require a good matching of transistors (all with about the same specs; ideally coming from the same die).
Sometimes manufacturers also put two (or more) transistors in parallel. This does not increase the amplification factor, but allows for much higher currents to flow through. Matching is even more important there.

The SE-A3 has both: two parallel configurations consisting of a Darlington stage (resulting in eight transistors per channel). Therefore a proper matching was absolutely crucial. According to Adrian Kingston Technics ought not to have done a very good job in this (at least in the "P" version of the OD-503A), which, in combination with that the transistors were very tightly packed in the DLPT, resulted in many A3's burning out.
I think they improved many things with the "Q" version. And once again: whichever version you have: don't run it too hard, give it air to breathe, spend some time on proper alignment (or have it done for you) and you're ready to go for the next decades!


About the computer drive: the A3 does not feature this (but the MK2 version). I personally don't believe that this makes a huge difference (for the A3 already does a very good job in amplifying an audio signal). Imho this is more a little gimmick than anything else. And I don't like the computer drive lights on the front panel of the A3MK2.


Jauk said:
Whatever I do it's can't be now, I'm recovering from a back problem due to a stupid exercise excess I've done over some years and this is a new slipped disk guaranteed :sigh:
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Ouch! Then just avoid lifting around the A3; it really is a heavy beast! Hope you'll get well soon.


Oh, btw:
:worthless

(no, not worthless, but we all love pictures of beautiful Technics amps; don't we?)
 
Congratulations! Another hopefully, well certainly lucky owner of this beauty!

Mine didn't have those metal plates on top of the heatsinks, consequently, the innards were a bit dusty. However, I believe it's for the better (quicker heat dissipation), I don't want to see the OD-503A burnt out…
 
I found out where the small hiss was coming. A cellphone tower near me! When I tested it back then I had taken off the cover to take a look inside. With the cover on it has less hiss. Finally using RCA short plugs I have to literally put my years on the tweeter to hear something.
We're getting bombarded with too much waves now days ....:(
 
:mad:Seems like the amp got fried today! I didn't do anything, just turned it on without speakers (as it's been in the last few days when I turned it on just for the sake of it...) and it stays in protection.
I opened the bottom cover and measured the transistors live with a multimeter. Measuring voltages around is probably easy even if I don't have experience with this.. The collector side of the right channel is wrong everywhere, I suspect it's because it's connected in parallel between all of the transistors.
Could it be one transistor got blown during warm up and protection is stopping the voltage on the collector side of all transistors ?
 
Jauk said:
I found out where the small hiss was coming. A cellphone tower near me! When I tested it back then I had taken off the cover to take a look inside. With the cover on it has less hiss. Finally using RCA short plugs I have to literally put my years on the tweeter to hear something.
We're getting bombarded with too much waves now days ....:(
Click to expand...
Uh huh...
I discovered yesterday that putting my cell phone near my amplifier or receiver did something similar.... And all I could think is yep cell towers and smart meters with all this RF with did not exist prior to the 1990s!
The designs of anyting from that era did not have engineering to keep out RF signals from all of these devices Wi-Fi routers etc etc smart meters and on and on
 
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