| fjromero |
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| ACD |
| 300 Watts output with only two pairs of output devices :hot: |
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| fjromero |
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| fjromero |
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| Gold_xyz |
the first TIP29 NPN and MJ15004 PNP ? :scratch:
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| fjromero |
error, sorry
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| edl |
That's the TA-3600 KIT.
It's like Phase Linear 700/II.
On the margin: TIP29C/30C and BD245C/250C - these are only 100V Vceo devices!
And hey, in the input 470p and 10k gives only 34kHz.
In the feedback: 270 and 33u, that's 18Hz... Not much...
This amp's bandwith is a tragedy, i think!
And 2 pair of MJ15003 isn't much for 350W/4ohm, at 45° or 60° phase angle. See SOA! |
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| djk |
"And 2 pair of MJ15003 isn't much for 350W/4ohm, at 45° or 60° phase angle. See SOA!"
Vceo(sus) is only 140V, inadequate for the ±75V rails (not to mention the SOA folding back above 40V).
Three pair of MJ15024, suitable drivers and predrivers, copy the PL schematic, and it will work. |
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| SlowDead |
MJ15003/4 Uce max 140 V ...
this sch +-75V ?!?!?!?!?:bigeyes: :bigeyes: :bigeyes: |
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| ACD |
| Please note that with regard to SOA, second breakdown and phase angle you need at least 6 pairs of output devices (Vce 250V) to avoid danger :att'n: |
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| djk |
"Please note that with regard to SOA, second breakdown and phase angle you need at least 6 pairs of output devices (Vce 250V) to avoid danger "
True, but with a good dual-slope limiter there are many good PA amps with three pair of MJ15024/25 running off of ±75V.
Believe in both a belt and suspenders?
I built up a ±80V amp with 10 pair of MJ15024/24 for outputs, another pair as drivers, and the 2N3584/2N6241 as predrivers. |
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| K-amps |
| quote: | Originally posted by djk
"And 2 pair of MJ15003 isn't much for 350W/4ohm, at 45° or 60° phase angle. See SOA!"
Vceo(sus) is only 140V, inadequate for the ±75V rails (not to mention the SOA folding back above 40V).
Three pair of MJ15024, suitable drivers and predrivers, copy the PL schematic, and it will work. |
Ah the joys of exceptional cases... :D .
I have used a similar circuit with 70vce rails. It gave 350 watts into 4 ohms and 240 into 8 ohms. Then I added 2 more pairs of Motorola 15003/4's and the suckers kept alive as I jacked up the rails...higher and higher I went.
In the end I had them at +/- 90vdc rails. 4 pairs per channel. Cranked out 700 watts into 4 ohms. No worries.
Caveat Emptor. Initially I had non MOT devices which burnt out as my vendor ran out of MOT's at higher Vce's However when I switched all to MOT, they were fine.
I know what their Vce rating is and I know they ran fine into +/-90vdc.
So this circuit is not all that outlandish. You guys underrate the MOT MJ15003/4's ;) |
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| CBS240 |
| quote: | Originally posted by K-amps
So this circuit is not all that outlandish. You guys underrate the MOT MJ15003/4's ;) |
IMHO if you want reliability at driving larger phase angle impeadence, it is better to underate in general, also taking into account thermal derating...which is better with TO-3 case but still to be taken into figure if heatsinking is only moderate.
:2c: :) |
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| lineup |
The
Max VCE value in short data is set to a value
that has got a reasonable safety margin.
In a mass production there will be a few transistors that wont take more than this voltage.
These will determine the value that manufacturer can promise, in worst case.
But most exemplars will take more
and some few in a mass production line will take Considerably MORE voltage.
Even for a longer time, hours, continuous output at maximal levels.
-----------------------------
- Now, different manufacturers has got different qualities in production methods.
There are no-names manufacturers where quality control is not as extensive.
The difference between best and worst exemplars will be a wide spread.
- There are others, which put more effort on high average quality.
To those we can count well known and respected brands like Motorola.
There may even be some, that does not sell those exemplars with lower performance.
They just sort them out, before delivery to public distributors.
Those 'bad exemplars' will be delivered under no-names label,
for low price bargain resellers.
In more detailed databooks, you see often two values for max current.
For small signal transistors.
For example BC547 has got:
IC = 100 mA, max average collector current.
ICM = 200mA, max peak shorter spikes collector current.
Bottomlines:
- Short form data for semiconductors are not absolute values.
- No exemplar will match every single data.
- Near all exemplars will match within the MIN MAX values.
- Most exemplars will have the TYPE value.
- Many exemplars will have considerably better performance than worst case value.
lineup |
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| CBS240 |
| I dig that! I'm sure price is certainly an indicator. |
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| edl |
| hmmm. I had two pairs of MJ15003/15004 Onsemi samples. They measured 280V Vceo! :cool: |
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| K-amps |
| I think the newer 15003/4's are 21195/95 in disguise :-) |
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| djk |
Selection is always an option for those who have the equipment and a sufficient stock to work from. The average home constructor or small repair shop generally doesn't.
Keep in mind most transistor testers measure Vceo with a narrow pulse (say 300µS) and a limited duty cycle (say 2%), and not forward biased (like an audio amp) , and that secondary breakdown may remain unchanged in samples that measure higher than normal Vceo.
In the past I have had problems at ±57V with a Motorola part with a 120V Vceo and 180W SOA at 60V rating. In theory this should have been within the capabilitues of the device. In practice it was best to run no more than ±52V without selection of the NPN devices, the PNP were always fine. |
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| lineup |
| quote: | Originally posted by djk
In the past I have had problems at ±57V with a Motorola part with a 120V Vceo and 180W SOA at 60V rating. In theory this should have been within the capabilitues of the device. In practice it was best to run no more than ±52V without selection of the NPN devices, the PNP were always fine. |
Hey.
Even if there is some MAX Data like gain, Vceo, Ft .... that can be override, exceeded by some 'good exemplars'
I have a feeling there are some MAX Data that NOT should be challenged.
Such data, I think, is power data = thermal characteristics.
I think these is very constant values, and most every transistor will have the same.
Example of such important data, in MJ21194| quote: | MJ21193, MJ21194
Total Power Dissipation @ TC = 25°C (PD) = 250 W
Derate Above 25°C 1.43 W/°C
Operating and Storage Junction Temperature Range (TJ, Tstg) = − 65 to +200 °C
THERMAL CHARACTERISTICS
Thermal Resistance, Junction−to−Case (RJC) = 0.7 °C/W
. |
Such values we should NOT override!
Much better to construct with a good safety margin for these values.
Max inner, junction, temperature in MJ21194 is +200 °C.
But when determine heatsinks needed, we should not have have any higher
worst case target value, than +100 °C (maybe +125 °C as this is a TO-3, +200 °C unit)
Most other CASES like TO247, TO220 etc
have maximal junction temperature 50 degrees lower = +150 °C
For Cooling needed, we can have target values of max junction temperature = +80 °C
(maybe +100, +110 if transistor is not used in Amplifier output stage, but some other circuit).
The transistor will work less good and so cause more distortion if running very hot.
Even if temperature is well below max +150 °C.
------------------------------
As a final note:
Nelson Pass has told he runs his Class A HEXFET at a comparatively very low junction temperature.
He use very good cooling, big heatsinks and he is soon to parallel his output IRFXXX devices.
This way his output transistors, even if running a lot of Class A power,
will work at a very moderate temperature and so keep the good performance.
lineup |
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| fjromero |
to see if this scheme is the correct one, warm greetings.
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| K-amps |
| If you are open to changing the OP devices, why would you not use the much better MJ21195/96? Stability? |
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| ACD |
| Three pairs of output devices are still not enough to safely handle 280/350W at a 45 degree phase angle ;) |
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| K-amps |
Took another look... its an old design (maybe later) with 20 year old parts... TL071???
Lowering the rails to +/-70 should do it... or add another pair.
I have used a similar design with +/-68vdc. 4 pairs of 15003/4 and they ran four jbl 2225's all day. i.e. 2 ohm loads. |
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| edl |
| quote: | Originally posted by ACD
Three pairs of output devices are still not enough to safely handle 280/350W at a 45 degree phase angle ;) |
Hi,
PL400-II (almost the same schematic) used 3 pairs of MJ15024 at 80V rails!
Regards, |
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| ACD |
| quote: | | PL400-II (almost the same schematic) used 3 pairs of MJ15024 at 80V rails! |
The Phase Linear 400-II are notorius known for their weak output circuit.......
I have personally repaired/replaced output devices on app. 20 different PL400's over the year, even though the PL400 never was very popular in little Denmark and I have never worked at an official PL workshop :bigeyes: |
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| K-amps |
| quote: | Originally posted by ACD
The Phase Linear 400-II are notorius known for their weak output circuit.......
I have personally repaired/replaced output devices on app. 20 different PL400's over the year, even though the PL400 never was very popular in little Denmark and I have never worked at an official PL workshop :bigeyes: |
Not having touched one before, was the heatsinking adequate? Didnt Bob carver use a 125v mains cap with 130v supply in one design? ;) |
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| ACD |
Heatsinking was ok I think ...
However I never actually measure the temperature ;)
Bob Carver did made some strange choices in his desig, however so did many others....
Remember the Onkyo M504 ?? Output caps did go :hot: all the time, even though it was a good amp :D
Just because it was a commercial amp, doesn't make the circuit right.... That's why we make DIY ;) |
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| fjromero |
That it seems to you this other scheme.
greetings
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| K-amps |
| Personally I like this one better.... non-reactive 2 ohm load is possible with this depending on supply droop. Though I still prefer the MJ21193/4/5/6 because of better gain.. either that or you get more robust drivers.... Though I have always liked the 669/649's... |
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| edl |
That's a copy too...
See attachment. |
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| lineup |
| quote: | Originally posted by fjromero
That it seems to you this other scheme.
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fjromero
Yes, look very good schematic circuit! :cool: :cool: :cool:
No problems use MJ15003 / MJ15004 with TO3 package. Very good!
MJ15003-4 has been used many, many times before.
In good hifi power amplifiers by good professional audio designers.
....but
lineup, me personal, thinks
MJ15024 and MJ15025 .... a little bit better ....
Regards
lineup
..................................................................................................................
I post schematic#1 with MJ15024.
I post schematic#1 with MJ15024. Person#1 say: Why not use MJL3281
I post schematic#2 with MJL3281. Person#2 say: Why not use MJ21194
I post schematic#3 with MJ21194. Person#3 say: Why not use MJ21196
I post schematic#4 with MJ21196. Person#4 say: Why not use MJ15004
I post schematic#5 with MJ15004. Person#5 say: Why not use MJ15024
I post schematic#1 with MJ15024, again.
..................................................................................................................
Garden Party
But it's all right now
I learned my lesson well
You see
ya can't please everyone
so ya got to please yourself
RickyNelson.com
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| K-amps |
:) Lineup, whats your pref with going with 15024/25 over the MJ21193/4/5/6?
I have used the 15024/25 and did not like the sound in a couple of designs/ The 15003/4 sounded better in the same circuit.
Krell used (I think) the 15024/25 in the KSA-250 and I found the same edgy steely sound in that too... Dan D then had MOT design newer TO-3's which then spawned the MJ21193/4/5/6. That sound better.
regards, |
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| lineup |
| quote: | Originally posted by K-amps
:) Lineup, whats your pref with going with 15024/25 over the MJ21193/4/5/6?
I have used the 15024/25 and did not like the sound in a couple of designs/ The 15003/4 sounded better in the same circuit.
Krell used (I think) the 15024/25 in the KSA-250 and I found the same edgy steely sound in that too...
Dan D then had MOT design newer TO-3's which then spawned the MJ21193/4/5/6. That sound better. |
I did say I prefer MJ15024 / MJ15025 over MJ15003 / MJ15004.
I did NOT include MJ21194/3 in this compare.
I said this with the following reason in mind:
No question it is more easy in most part of world, even very remote countries,
to get either of MJ15003/4 or MJ15024/5
.... than is to find a distributor in your home country
that sells either one or both of the complementary MJ21194 + MJ21193.
If somebody can find MJ15003-4, it is a fair chance they also can get MJ15024-5.
This is the choice most people of the world have, if even there is such a choice.
These topics are read by many many more diyaudio home builders, than actually do post or even are registered.
I do not want to put pressure and maybe make people sad
if they actually can't easily buy a better transistor.
( Not to speak of the exotic, never heard of recommendations you see here sometimes.)
Not when there are more common devices, that will work well enough.
Even if I live NOT REMOTE, I had to search very long,
before I found a distributor in my country that had MJ21194 in his lists.
If he actually has got them in supply, I don't know ...
Let's hope ...
If I decide I want to but some of these GREAT DEVICES!
Nelson Pass is very good and considerate in this way:
-- He cares for audio builders to not have too difficult find those MOSFET.
-- They belong to the mainstream and can be bought most everywhere
-- And if not, he can give a good replacement suggestion.
Mister Pass, if anyone, would surely know the most exotic devices, that would be superior.
Such devices made maybe in some 100 exemplars totally,
to find at only one distributor probably in the world. :bigeyes:
But why make people feel distressed and frustrated, when there is no need or point in doing so.
==========================================
I say like this now:
For those minorities of www.diyaudio.com members who can get
MJ21194 / MJ21193:
Have a listen to K-amps and lineup and get your exemplars as soon as you can!
.... ( don't bother with MJ21196 / MJ21195, they are no better for most audio amps! )
For all others, the great silent majority of any big forum:
Your amps will work just great with
1.) MJ15024 / MJ15025 or with
2.) MJ15004 / MJ15003.
Any difference will hardly be noticeable at all normal use of an audio amplifier!
Regards
lineup :cool: clears this issue up
==============================================
PS.
lineup has designed this
15-20 Watt N-Channel True Class A Power Follower Amplifier
using ........ that's right! .... Two MJ21194, with very good simulated data.
There are 2 smaller driver transistors, making this a simple 4 Transistors amp.
Easy to build.
Data, analysis and full schematic can be found here, if anybody missed it:
Jerluwoo MJ21194 Output Stage - by Lineup Audio Lab
Please, Read the following posts, too.
Because I posted final circuit schematic later in that topic
:cool: |
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| K-amps |
One would like to think that it would be good to give people all the information and let them decide what to use based on availability/price etc.
I (respectfully), strongly disagree with this "policing" attitude of keeping information from others in hopes of allying any false fears.
The MJ2119x's are not blood Diamonds... they can be had if one wanted...
If I needed patronizing of that kind, I'd go to my mother-in-law for advice. |
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| fjromero |
This w is pcb of the circuit of 400 w.
greetings
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| fjromero |
And the this scheme.
greetings |
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| fjromero |
And pcb of the end of power.
greetings
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| groov |
| quote: | Originally posted by fjromero
And pcb of the end of power.
greetings
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Can you provide the dimensions of the pcb boards, this way if it is decided to use your boards then they can reproduce with the exact dimensions. Thanks |
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| groov |
| quote: | Originally posted by fjromero
This w is pcb of the circuit of 400 w.
greetings
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ditto....dimensions to this board as well...thanks |
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| lineup |
| quote: | Originally posted by K-amps
One would like to think that it would be good to give people all the information and let them decide what to use based on availability/price etc.
I (respectfully), strongly disagree with this "policing" attitude of keeping information from others in hopes of allying any false fears.
The MJ2119x's are not blood Diamonds... they can be had if one wanted...
If I needed patronizing of that kind, I'd go to my mother-in-law for advice. |
Maybe you are right, K-amps.
If so, in my opinion, there is no reason to get upset or use strong words.
:)
And I have my ways and my caring or parenting attitude are a part of me.
It wont change much because of this.
I am too old to change in this matter and even if I could, I wouldn't want to.
I will continue to base my audio advices regarding transistor choice moderated,
while keeping a thought onto all which I am possibly talking to
and try to imagine what can be like, where some of my readers are living.
And sure is, that the topic and context ,where I contribute my words,
will make a difference what I say.
I don't blame those with another approach than me, too much. Only little.
They do it their way, in their full rights.
There are plenty enough around here doing most things differently
than
lineup
...........................................................................
I see you went for MJ15003 / MJ15004, fjromero
And PCB has got option for 4 pairs. This will do good!
Nice PCB works ...
I am sure there are several others, not posting ;)
that will try this amplifier project.
Because I see there are new members asking for 300-400 Watt amplifiers every week.
Some never can get enough of that power.
It is a like drug in DIY :clown:
lineup |
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| K-amps |
I agree, there is so much DIY demand for 300-500watters that it is amazing we do not have a lot more "makeable" and modern designs.
Nelson, maybe this is your next calling. :) |
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| fjromero |
The real dimensions of the PCB, they are 140x96 for the part of control and 276x68, for the part of the end.
Greetings |
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| fjromero |
Photos the 400w.
regeards
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| jneutron |
| quote: | Originally posted by edl
hmmm. I had two pairs of MJ15003/15004 Onsemi samples. They measured 280V Vceo! :cool: |
I take it you measured BVceo, and not Vceo(sus).
Vceo(sus) at 200 mA is a different beast.
If you try Vceo(sus) on these at 200 mA, I suspect you will find the device cramps up.
Cheers, John |
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| Gold_xyz |
| quote: | Originally posted by fjromero
And the this scheme.
greetings |
Hola ! :D
ThankYou for schematics and PCB ! :)
I like a lot this schematics above all for the symmetry of the project.
This amp remembers me for some aspects the Leach.
I think that the result will be really excellent! :up:
bye :) |
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| fjromero |
Here teneis the PWB for 200 or 400 w, the schemes and the PWB of the end, ok working to the 100%.
The schemes are equal, but with the opportune modifications, like the PWB of control.
greetings
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| fjromero |
Photos the 200 w.
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| rlg_200 |
hi fellow diyers,
how about the construction manual?
rlg;) ;) ;) |
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| dedepc |
""how about the construction manual?""
yes, yes!!!!! |
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| lineup |
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! fjromero !
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:cool: COOL :cool:
amplificador superba!
grazias a la muchos!
:cool: COOL :cool:
lineup
Lineup Audio
http://lineup.awardspace.com/ |
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| fjromero |
I think that will not be warmed up, to see the photo.
Greetings
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