A Question about some transistors to the specialists:
I have got a pair of toshiba (2SA1302 and 2SC3281), they are working with a C3421 instead of bd139...
so, what you mean, can i test them with this DXblameES or will it be a big blowout? shall i use BD139 or this C3421?
I have got a pair of toshiba (2SA1302 and 2SC3281), they are working with a C3421 instead of bd139...
so, what you mean, can i test them with this DXblameES or will it be a big blowout? shall i use BD139 or this C3421?
No problems to use 2SC3421 as second VAS...but i think will not bring advantage too
there are others that can be used..in the reality there are hundreds that can be used...you should try...if you perceive some AC voltage in the output (oscilation), without audio entering...then you should remove it and install BD139 in the place back again.
Sakis have tried some more modern Philips transistors.... BD829/BD839, in the driver and VAS position, he found sound much better than BD139/140... he is sending me some samples and i will try....i do believe these ones, released in 2002, may be third or fourth generation of the old and good BD139/140.... you should try these ones too...i would love to know your evaluation about.... the datasheet of these ones is attached.
I am using these old one from Toshiba you have mentioned in one of my Dx Blame ST.... i have two channels inside an enclosure..one channel uses these ones ( I do love them) and the other channel is using MJL4215 and MJL4315... also i have 2SC5200 and 2SA1946 in other amplifier, the one i use together my computer..the gray case one.
I have a fourth one using 2SC2922 and 2SA1216.... and i think all them sounds almost the same... a little bit more brigth to 2SC2922 (Sanken) compared to the others...but a very small difference in sonics.
The more mufled ones are 2SC5200 and 2SA1946....but this is very small, hard to perceive...almost none difference.
These ones, the 2SC3281 and 2SA1302, where the top transistors from Toshiba several years ago... then Toshiba has released the 2SC5200 and 2SA1946 to substitute the old ones... they are almost the same.... they are brothers or cousines.... all these power ones mentioned are models from competition, having almost the same parameters.
regards,
Carlos
there are others that can be used..in the reality there are hundreds that can be used...you should try...if you perceive some AC voltage in the output (oscilation), without audio entering...then you should remove it and install BD139 in the place back again.
Sakis have tried some more modern Philips transistors.... BD829/BD839, in the driver and VAS position, he found sound much better than BD139/140... he is sending me some samples and i will try....i do believe these ones, released in 2002, may be third or fourth generation of the old and good BD139/140.... you should try these ones too...i would love to know your evaluation about.... the datasheet of these ones is attached.
I am using these old one from Toshiba you have mentioned in one of my Dx Blame ST.... i have two channels inside an enclosure..one channel uses these ones ( I do love them) and the other channel is using MJL4215 and MJL4315... also i have 2SC5200 and 2SA1946 in other amplifier, the one i use together my computer..the gray case one.
I have a fourth one using 2SC2922 and 2SA1216.... and i think all them sounds almost the same... a little bit more brigth to 2SC2922 (Sanken) compared to the others...but a very small difference in sonics.
The more mufled ones are 2SC5200 and 2SA1946....but this is very small, hard to perceive...almost none difference.
These ones, the 2SC3281 and 2SA1302, where the top transistors from Toshiba several years ago... then Toshiba has released the 2SC5200 and 2SA1946 to substitute the old ones... they are almost the same.... they are brothers or cousines.... all these power ones mentioned are models from competition, having almost the same parameters.
regards,
Carlos
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Hey Carlos,
this are good news 🙂
On my way to search a test-case for the second amp i found a Gemini p-600 amp, 26 € 🙂) My only interesting was the case, but inside are these toshibas. So i will test them witch yor amp and i have a comparison to my sancens, which i love so much ;-)
this are good news 🙂
On my way to search a test-case for the second amp i found a Gemini p-600 amp, 26 € 🙂) My only interesting was the case, but inside are these toshibas. So i will test them witch yor amp and i have a comparison to my sancens, which i love so much ;-)
You comparison and evaluation much interests me.
I know you have know how to evaluate, also that you have good equipment, very good speakers, high end stuff in your home.
My speakers are generic ones...anything special or high end...some subtle differences are hard to perceive because my speakers....maybe you will come with a surprisingly interesting result of your own comparison...... i think not only that you are skilled (Rudi said) but also your speaker can reproduce details mine cannot...so..... i will be watching forward by your review about.
regards,
Carlos
I know you have know how to evaluate, also that you have good equipment, very good speakers, high end stuff in your home.
My speakers are generic ones...anything special or high end...some subtle differences are hard to perceive because my speakers....maybe you will come with a surprisingly interesting result of your own comparison...... i think not only that you are skilled (Rudi said) but also your speaker can reproduce details mine cannot...so..... i will be watching forward by your review about.
regards,
Carlos
I'm going to try 2SC3423 as VAS tomorrow 🙂
but frankly speaking I'm not expecting much benefit
regarding sonics
...will tell you more later as I try
but frankly speaking I'm not expecting much benefit
regarding sonics
...will tell you more later as I try
I would like to know your results dear Luka
I have not this transistor, so i cannot say if will result good or bad....... i think will be the same.....but..... we have our own "fooling" system... sometimes we want things to be different, or not different...and this changes a little our perception.
As i told friends before... i have tested my local friends many times... switching nothing to anything... just flipping a switch..... producing the click noise..another switch, connected to nothing...without a single wire... switching from nothing to anything....and i found my friends have perceived differences.
This proves that... when people wants to perceive differences or if you "induce" them to think something may happens..then they will perceive something.
The better way is to use one channel with the original and a single channel, the other channel, modified...and them to compare turning the ballance knob or switching channels or switching speakers.... having difference, then change speakers... install the rigth one in the left side..invert them and confirm... because sometimes difference comes from speaker.... mainly from speaker spatial, physical position, the acoustic surroundings affecting it more than real driver's and passive crossover differences..the place the speaker is what defines it sonics interacting to the environment..the room acoustics.
This natural human behavior, to be influenced by others, to be social and the need to be accepted by a group of friends, to be cooperative and friendly, use to reduce the precision of evaluations... this give room to snake oil sellers, unobtanium suppliers to go spreading, special burn in stripped capacitors, and other illusionist materials.... and these ones, sometimes, have only the price as special.
regards,
Carlos
I have not this transistor, so i cannot say if will result good or bad....... i think will be the same.....but..... we have our own "fooling" system... sometimes we want things to be different, or not different...and this changes a little our perception.
As i told friends before... i have tested my local friends many times... switching nothing to anything... just flipping a switch..... producing the click noise..another switch, connected to nothing...without a single wire... switching from nothing to anything....and i found my friends have perceived differences.
This proves that... when people wants to perceive differences or if you "induce" them to think something may happens..then they will perceive something.
The better way is to use one channel with the original and a single channel, the other channel, modified...and them to compare turning the ballance knob or switching channels or switching speakers.... having difference, then change speakers... install the rigth one in the left side..invert them and confirm... because sometimes difference comes from speaker.... mainly from speaker spatial, physical position, the acoustic surroundings affecting it more than real driver's and passive crossover differences..the place the speaker is what defines it sonics interacting to the environment..the room acoustics.
This natural human behavior, to be influenced by others, to be social and the need to be accepted by a group of friends, to be cooperative and friendly, use to reduce the precision of evaluations... this give room to snake oil sellers, unobtanium suppliers to go spreading, special burn in stripped capacitors, and other illusionist materials.... and these ones, sometimes, have only the price as special.
regards,
Carlos
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BD139 subs.
Hi Director X, guys
Ain't that the truth about listening tests!
The BD 829/830 referred to earlier. You know, someone could say they are just BD139/140 in a T0202 case (that's the very short plastic with thin metal plate to attach to heatsink. I couldnt get all the data but the low VCE, beta spread, all that stuff is the same. Modern transistors for audio nearly always have much higher voltage ratings than the old favourites.
I wouldnt get too enthusiastic, after all they don't look so nice (hehehe!) but someone else might know much better.
regards
Hi Director X, guys
Ain't that the truth about listening tests!
The BD 829/830 referred to earlier. You know, someone could say they are just BD139/140 in a T0202 case (that's the very short plastic with thin metal plate to attach to heatsink. I couldnt get all the data but the low VCE, beta spread, all that stuff is the same. Modern transistors for audio nearly always have much higher voltage ratings than the old favourites.
I wouldnt get too enthusiastic, after all they don't look so nice (hehehe!) but someone else might know much better.
regards
Usually we select transistors by the main parameters
gain, in these mid power units use to go from 100 to 200.... they are not so different from model to model and from factory to factory.
In the old days, in the past.... they used to publish better and more detailed graphics to allow us to know the best linearity point...to operate exactly in these points...now a days we have not more such a detailed instructions from the manufacturer.
Maximum Volts from Colector to Emitter is important, as we suppose the transistor will operate using supplies measuring half it's maximum colector to emitter voltage..... i suppose, it will be working fine this way... as rail to rail voltage will not exceed the maximum... and not considering the circuit losses, as saturations voltage..... so..... not interesting to use a 300 volts transistor in a circuit that has plus and minus 12 volts.
The current the device will face...we select devices able to face, at least, two time the maximum current your stage will face.... not to work too hot and to have long life.
The dissipation, the maximum power the unit can handle.... once again we use twice.
These are the main ones... and you can check they are almost the same watching these parameters... you will notice there are thousands that match your needs, not only BD139/140... these are the ones i like, the ones i trust, the ones i am using 40 years long...so... they were tested in thousand amplifiers.... this does not mean they are the best..... just that they are ready to use at my home, in big quantities, so, they are available... easier to find in electronic shops, so standard they are alike Coca Cola in restaurants.
Others can use MJE340/350.... i do not like them, but they can face higher voltage, and should work better in amplifiers that uses higher voltage supplies.
Fashion things Finch...there are models that are fashion because several factories uses...and one copy the other...if Marantz have elected XXXX transistor, then Pioneer will use too...and there are thousands with the same XXXX specification, but the one will be fashion may be XXXX because Marantz influences.
2SC2240 was fashion...but it is not different than several others.
Transistors does not sound... say, they do not equalize, they have not will to give preference to some frequencies instead of others...they have not soul nor empathy, no conscience and no brain...have not personality..they are not human.... the are transference resistance only, have parameters, maximum voltage, maximum current and so on.
People believe high frequency ones are better..... maybe a increase in slew rate...... faster transistors of course...but are counterproductive, because the ones loves to oscilate in high frequencies....and you know why?... because they can!..... boards, parts, copper tracks have resistances, inductances and capacitances...and sometimes these inductances and capacitances, associated, creates a tuned circuit (L/C circuit that ressonates) and this drives the transistors to charge and discharge in that speed..the tuned speed usually is high...if your transistor can oscilate..then it will oscilate for sure...so...will be more a problem creator than an advantage in some cases...... 1 gigahertz transistor operating in 20 kilohertz is really an overkill... you gonna have a nice oscilator in our board......modern ones goes to 200 Megahertz very easy...some times you need that, but usually not!
People believe they sound...i do not believe...but i use to suggest friends to test this.... they may surprise me with other kind of opinion... i will imagine they are beeing fooled but i will check that by myself as i think they have the same brain i have...nobody is stupid..... the only one is stupid is the one thinks others are stupid...we are almost the same.... stupidity and arrogance is to think we are best... we can be skilled, but others can be even more!
regards,
Carlos
gain, in these mid power units use to go from 100 to 200.... they are not so different from model to model and from factory to factory.
In the old days, in the past.... they used to publish better and more detailed graphics to allow us to know the best linearity point...to operate exactly in these points...now a days we have not more such a detailed instructions from the manufacturer.
Maximum Volts from Colector to Emitter is important, as we suppose the transistor will operate using supplies measuring half it's maximum colector to emitter voltage..... i suppose, it will be working fine this way... as rail to rail voltage will not exceed the maximum... and not considering the circuit losses, as saturations voltage..... so..... not interesting to use a 300 volts transistor in a circuit that has plus and minus 12 volts.
The current the device will face...we select devices able to face, at least, two time the maximum current your stage will face.... not to work too hot and to have long life.
The dissipation, the maximum power the unit can handle.... once again we use twice.
These are the main ones... and you can check they are almost the same watching these parameters... you will notice there are thousands that match your needs, not only BD139/140... these are the ones i like, the ones i trust, the ones i am using 40 years long...so... they were tested in thousand amplifiers.... this does not mean they are the best..... just that they are ready to use at my home, in big quantities, so, they are available... easier to find in electronic shops, so standard they are alike Coca Cola in restaurants.
Others can use MJE340/350.... i do not like them, but they can face higher voltage, and should work better in amplifiers that uses higher voltage supplies.
Fashion things Finch...there are models that are fashion because several factories uses...and one copy the other...if Marantz have elected XXXX transistor, then Pioneer will use too...and there are thousands with the same XXXX specification, but the one will be fashion may be XXXX because Marantz influences.
2SC2240 was fashion...but it is not different than several others.
Transistors does not sound... say, they do not equalize, they have not will to give preference to some frequencies instead of others...they have not soul nor empathy, no conscience and no brain...have not personality..they are not human.... the are transference resistance only, have parameters, maximum voltage, maximum current and so on.
People believe high frequency ones are better..... maybe a increase in slew rate...... faster transistors of course...but are counterproductive, because the ones loves to oscilate in high frequencies....and you know why?... because they can!..... boards, parts, copper tracks have resistances, inductances and capacitances...and sometimes these inductances and capacitances, associated, creates a tuned circuit (L/C circuit that ressonates) and this drives the transistors to charge and discharge in that speed..the tuned speed usually is high...if your transistor can oscilate..then it will oscilate for sure...so...will be more a problem creator than an advantage in some cases...... 1 gigahertz transistor operating in 20 kilohertz is really an overkill... you gonna have a nice oscilator in our board......modern ones goes to 200 Megahertz very easy...some times you need that, but usually not!
People believe they sound...i do not believe...but i use to suggest friends to test this.... they may surprise me with other kind of opinion... i will imagine they are beeing fooled but i will check that by myself as i think they have the same brain i have...nobody is stupid..... the only one is stupid is the one thinks others are stupid...we are almost the same.... stupidity and arrogance is to think we are best... we can be skilled, but others can be even more!
regards,
Carlos
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Continuing to talk, alike a parrot as i have anything better to do this saturday
morning.
For sure i know that i am old, and this makes my audition worse than young folks..so, i use to take this in account when people say different things compared to things i have tested..sometimes i am not able to perceive.
I have no good speakers, anything here is high end...all them average, common, regular things...so, i may not be able to listen things my speaker cannot reproduce....others may be able...and i noticed that, i know that my evaluation is not the universe truth.
About power units:
They publish 100 watts or 150 watts of dissipation....lie!..... transistor cannot do that..will burn, for sure, unless the case is giant..cannot transfere heat this way.
Do you know what factory does?..... they use an enormous block of metal, cooled with special machinery...the enormous block of metal is keept at 25 degrees celsius...the transistor metal case is maintained this way having not hot spots on there.... then they measure.
You have not this kind of thing....your environment can be hotter...mine is 29 degrees average, celsius degrees.....maybe a billion Fahrenheit (ahahahaha)...when our amplifier goes loud the transistor case temperature reaches 50 degrées celsius very easy..sometime more...under this new reality, you cannot count the dissipation will be high....i use to make them work, maximum dissipation at 40 watts to each one of them...this is what is very safe not to have them burning us, or burning themselves....others have different ideas..some folks do not even bother with heat.....some of them think the transistor can operate at 100 degrées..they use to say that modern ones can do that..can stand for this power....some use to say they are solid...metalic, that they are not made using butter....well.... mine never burned because of heat.
Ask them about their ones.
regards,
Carlos
morning.
For sure i know that i am old, and this makes my audition worse than young folks..so, i use to take this in account when people say different things compared to things i have tested..sometimes i am not able to perceive.
I have no good speakers, anything here is high end...all them average, common, regular things...so, i may not be able to listen things my speaker cannot reproduce....others may be able...and i noticed that, i know that my evaluation is not the universe truth.
About power units:
They publish 100 watts or 150 watts of dissipation....lie!..... transistor cannot do that..will burn, for sure, unless the case is giant..cannot transfere heat this way.
Do you know what factory does?..... they use an enormous block of metal, cooled with special machinery...the enormous block of metal is keept at 25 degrees celsius...the transistor metal case is maintained this way having not hot spots on there.... then they measure.
You have not this kind of thing....your environment can be hotter...mine is 29 degrees average, celsius degrees.....maybe a billion Fahrenheit (ahahahaha)...when our amplifier goes loud the transistor case temperature reaches 50 degrées celsius very easy..sometime more...under this new reality, you cannot count the dissipation will be high....i use to make them work, maximum dissipation at 40 watts to each one of them...this is what is very safe not to have them burning us, or burning themselves....others have different ideas..some folks do not even bother with heat.....some of them think the transistor can operate at 100 degrées..they use to say that modern ones can do that..can stand for this power....some use to say they are solid...metalic, that they are not made using butter....well.... mine never burned because of heat.
Ask them about their ones.
regards,
Carlos
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Thank you AndrewT...... i will take a look
I have found it..here is the link:
http://www.fairchildsemi.com/an/AN/AN-7516.pdf
They use pulse power.... this is not something we gonna find in real world..another crazy specifications to publish nice numbers.
Carlos
I have found it..here is the link:
http://www.fairchildsemi.com/an/AN/AN-7516.pdf
They use pulse power.... this is not something we gonna find in real world..another crazy specifications to publish nice numbers.
Carlos
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I can tell you, Carlos, heat dissipation, how to handle it, is a philosophy for itself.
I have been told (by IAN, Mr. Metal?): "Rudi, use a very large heatsink for your big SANKEN transistors."
I did, but also goggled in NAIM's (famous British manufacturer of AMPs) archives knowing NAIM used SANKENs in some of their "vintage models".
Here is a picture of a NAP140:
What did NAIM: mounted two big SANKEN transistors on a very small ALU U-profile rating it 50 Watts per channel.
My philosophy: do not take heat dissipation too earnest.
That is what famous manufacturers proved.
Best regards - Rudi_Ratlos
I have been told (by IAN, Mr. Metal?): "Rudi, use a very large heatsink for your big SANKEN transistors."
I did, but also goggled in NAIM's (famous British manufacturer of AMPs) archives knowing NAIM used SANKENs in some of their "vintage models".
Here is a picture of a NAP140:
What did NAIM: mounted two big SANKEN transistors on a very small ALU U-profile rating it 50 Watts per channel.
My philosophy: do not take heat dissipation too earnest.
That is what famous manufacturers proved.
Best regards - Rudi_Ratlos
Maybe they use average power Rudi...audio is not a constant source
Usually we have peaks and valleys.... the audio use to be listened, in the real world (try to meaure yours) is around 2 watts each channel..needing a very small dissipation.
Also, some factories offers service...they sell you amplifier by small price, already knowing, in advance, that you gonna left some money there (service shops) when the amplifier burned because excesses of heat (not good enougth heatsinks).....man.... watching it, you see the heatsink is too much small for amplifier that has more power than 25 watts RMS... the heatsink position is no good to heat transference.... in my imagination they know they do that way and have their reasons for that and we can imagine what reasons they are.
Do Naim have repair shops?.... exclusive repair only in Naim assistance places?
This one, seems have thermal grease and are using the enclosure as heatsink..maybe the enclosure is made of aluminium and may be a very big heatsink having huge surface to heat transference.
The average is much less stressing than a steady sine wave entering, near clipping over 4 ohms loads.... i use heatsinks able to face full power, at 4 ohms, unclipped, sinus signal entering.... and continuous..for long time (30 minutes)
I think they are saving money doing this way.
Well...our is DIY products..we do the way we want...we use to overkill as we do not need to save money, we want the best for ourselves.
I like the way you did..also the way Volker did...i really think Germans are very good producing things... clever people..has good schools..high level folks.
Give a try in your amplifier using small heatsinks alike Naim did Rudi..and do it in summer.
regards,
Carlos
Usually we have peaks and valleys.... the audio use to be listened, in the real world (try to meaure yours) is around 2 watts each channel..needing a very small dissipation.
Also, some factories offers service...they sell you amplifier by small price, already knowing, in advance, that you gonna left some money there (service shops) when the amplifier burned because excesses of heat (not good enougth heatsinks).....man.... watching it, you see the heatsink is too much small for amplifier that has more power than 25 watts RMS... the heatsink position is no good to heat transference.... in my imagination they know they do that way and have their reasons for that and we can imagine what reasons they are.
Do Naim have repair shops?.... exclusive repair only in Naim assistance places?
This one, seems have thermal grease and are using the enclosure as heatsink..maybe the enclosure is made of aluminium and may be a very big heatsink having huge surface to heat transference.
The average is much less stressing than a steady sine wave entering, near clipping over 4 ohms loads.... i use heatsinks able to face full power, at 4 ohms, unclipped, sinus signal entering.... and continuous..for long time (30 minutes)
I think they are saving money doing this way.
Well...our is DIY products..we do the way we want...we use to overkill as we do not need to save money, we want the best for ourselves.
I like the way you did..also the way Volker did...i really think Germans are very good producing things... clever people..has good schools..high level folks.
Give a try in your amplifier using small heatsinks alike Naim did Rudi..and do it in summer.
regards,
Carlos
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I had a very long talk with my nephew when he visited me
He is living in London, last 23 years he was there...his home is there.
I told him, during an overnigth conversation, that i dislike my country because people use music too much loud, and sometimes we call Police and they say that before 10PM they can do nothing, because "silence law" is after 10PM.
He said he loves brazil exaclty because we are free to do whatever we want, and nobody bothers about, and almost nobody cares (except me maybe..ahahahah!)
He said that in England, if someone complain, then the Police comes and stop the mess imediatelly....the way i want!...the way i wish we could have the same here.
So.... it is very possible that in England, people cannot listen too loud when living inside big towns..also 50 watts power may be 25 watts average..and these heatsinks shown, plus the enclosure, can dissipate 25 watts of average power (each channel) that means 40 watts of heat aproximatelly.
But, if people lives in open area, distant of people and can increase the volume till the distortion levels , and continuously playing this way, or using organs or steady tone generators, or modern electronic music..for sure, one day, they will have to visit Naim authorized service places..... if England temperature can reach 30 degrees celsius.
regards,
Carlos
He is living in London, last 23 years he was there...his home is there.
I told him, during an overnigth conversation, that i dislike my country because people use music too much loud, and sometimes we call Police and they say that before 10PM they can do nothing, because "silence law" is after 10PM.
He said he loves brazil exaclty because we are free to do whatever we want, and nobody bothers about, and almost nobody cares (except me maybe..ahahahah!)
He said that in England, if someone complain, then the Police comes and stop the mess imediatelly....the way i want!...the way i wish we could have the same here.
So.... it is very possible that in England, people cannot listen too loud when living inside big towns..also 50 watts power may be 25 watts average..and these heatsinks shown, plus the enclosure, can dissipate 25 watts of average power (each channel) that means 40 watts of heat aproximatelly.
But, if people lives in open area, distant of people and can increase the volume till the distortion levels , and continuously playing this way, or using organs or steady tone generators, or modern electronic music..for sure, one day, they will have to visit Naim authorized service places..... if England temperature can reach 30 degrees celsius.
regards,
Carlos
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I am not defending Naim, they don't need any help and particularly not mine.
But I will defend the philosophy.
The Naim NAP140 is a little quasi complementary power amp designed for domestic use where great output power is not required.
Typically quasi can be designed to require a very low bias current for minimal ClassAB crossover distortion. My 1704 Crimsons run almost cold.
If we listen to the Naim at typical average power levels of around -20dB ref max power then the output transistor have to dissipate the quiescent power + a couple of watts for that 500mW average output power.
Using the case bottom and the aluminium strip is probably a very economic way of cooling the amplifier adequately for it's intended duty. This is after all the cheapest Naim they introduced to allow the less wealthy to start listening to the Naim sound.
I see AndrewT...you have agreement... the defense was fair
and makes sense to me too.
regards,
Carlos
and makes sense to me too.
regards,
Carlos
I think you are right in your assessment of the "black box that cannot be named".
In this country they generally were owned by conservative well-to-dos and expatriate brits. You wouldn't think of these guys giving the amps "some stick" as we say.
In our climate, which is still many degrees cooler than Carlos' area, a few of those black boxes that I am aware of, met thermal runaway death. This was reputedly at well below clipping levels on standard musical program. I witnessed first one then the other channel rapidly follow on a 120 model on a hot (about 32 degree) evening.
Empirically, a stereo sixty watt class B amp. in our climate needs 0.6 degrees/watt sinking. On the Equator that might be more safely. 0.4 or even 0.3. Thats a lot of sink for a modest amp. but it permits safe loaded testing and extended domestic use at high program levels. Things were probably fine for the standard black boxes in careful hands in the UK but they should have been improved for use for elsewhere.
Somehow, I don't think Mr Verekher had that as a concern in those days.
The DX Blame ES is gonna be different though, guys!
regards
In this country they generally were owned by conservative well-to-dos and expatriate brits. You wouldn't think of these guys giving the amps "some stick" as we say.
In our climate, which is still many degrees cooler than Carlos' area, a few of those black boxes that I am aware of, met thermal runaway death. This was reputedly at well below clipping levels on standard musical program. I witnessed first one then the other channel rapidly follow on a 120 model on a hot (about 32 degree) evening.
Empirically, a stereo sixty watt class B amp. in our climate needs 0.6 degrees/watt sinking. On the Equator that might be more safely. 0.4 or even 0.3. Thats a lot of sink for a modest amp. but it permits safe loaded testing and extended domestic use at high program levels. Things were probably fine for the standard black boxes in careful hands in the UK but they should have been improved for use for elsewhere.
Somehow, I don't think Mr Verekher had that as a concern in those days.
The DX Blame ES is gonna be different though, guys!
regards
dear sir
greetings can you tell me meaning ofTest de suficienciaHalle RT en Ω, RT = 12kΩ || 18kΩ (tips: || = Paralelo, Ingrese solo el valor)
its written in spanish without completin this registration can not be done
to this spanish diy electronics
do we have to calculate 12k and 18k parallel resistance value
thanking you
andrew lebon
greetings can you tell me meaning ofTest de suficienciaHalle RT en Ω, RT = 12kΩ || 18kΩ (tips: || = Paralelo, Ingrese solo el valor)
its written in spanish without completin this registration can not be done
to this spanish diy electronics
do we have to calculate 12k and 18k parallel resistance value
thanking you
andrew lebon
Yes Andrewlebon....i think so...but my language is Portuguese, not Spanish
Brazil is surrounded by several spanish speaking countries....but we talk portuguese....we can understand one each other....but not very well and not very easy.
Enter the result of paralelling these resistances.
regards,
Carlos
Brazil is surrounded by several spanish speaking countries....but we talk portuguese....we can understand one each other....but not very well and not very easy.
Enter the result of paralelling these resistances.
regards,
Carlos
I do not use to answer or comment your posts dear Ian Finch
because i cannot understand what you mean....you have a sophisticated, or complicated, way of talk that only ¨"englanders" may understand you.
I am stranger my dear....wanna communicate with me?....so, please, use simple words ...alike:
- the book is on the table..... this is a pencil.... good morning mister Walker....how do you do?....what time is it?.....this is a chair....understood man?
regards,
Carlos
because i cannot understand what you mean....you have a sophisticated, or complicated, way of talk that only ¨"englanders" may understand you.
I am stranger my dear....wanna communicate with me?....so, please, use simple words ...alike:
- the book is on the table..... this is a pencil.... good morning mister Walker....how do you do?....what time is it?.....this is a chair....understood man?
regards,
Carlos
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