Hello Tryalx,
Why 2N5551 and 2N5401 ? They are just highly suitable really -- the fact I can get them locally for around £0.04 each has nothing at all to do with it
-- no, they are very suitable with a 0.6 amp current rating and 160 volt Vce. Do transistors sound different ? such as the 2SA and 2SD types etc.
Erm, probably going to ruffle a few feathers now. Different transistors have different characteristics as we know, junction capacitance, the actual size of the wafer of silicon etc. These characteristics do influence the way a circuit behaves. There is no magic audio property however, the laws of physics determine transistor operation. Now I class this amp as a low frequency device, and transistor type (general purpose small signal types) should have very little bearing on performance.
I have never seen so called matched pairs of laterals offered for sale, however laterals are acknowledged to be "more complementary" than most so called complementary Bjts. The price of laterals as well makes it a bit impractical to to have a lot to hand to sort through. The very nature of laterals as well means you can parrallel them without the problem of unequal current sharing that would happen with Bjts. It's not a problem.
The drivers will be fine as well with two pairs of outputs. If you use the BUZxxx remember these are TO3 package -- not as easy to mount perhaps.
Hum and noise is mostly down to correct layout and grounding.
Low rail ripple is a major concern in a Class A amp, much less so in Class B or AB. Oversize caps cause massive charging currents in the bridge rectifier, wiring and transformer windings due to the very short angle of conduction of the bridge--- it has to put all the energy taken from the reservoir caps back, and in a very short time. Remember the bridge conducts only when the incoming AC exceeds the rail voltage - for most of the time the bridge is non conducting.
Were you thinking of making your own PCB's.
Here is the missing 10 ohm.
Why 2N5551 and 2N5401 ? They are just highly suitable really -- the fact I can get them locally for around £0.04 each has nothing at all to do with it
-- no, they are very suitable with a 0.6 amp current rating and 160 volt Vce. Do transistors sound different ? such as the 2SA and 2SD types etc.Erm, probably going to ruffle a few feathers now. Different transistors have different characteristics as we know, junction capacitance, the actual size of the wafer of silicon etc. These characteristics do influence the way a circuit behaves. There is no magic audio property however, the laws of physics determine transistor operation. Now I class this amp as a low frequency device, and transistor type (general purpose small signal types) should have very little bearing on performance.
I have never seen so called matched pairs of laterals offered for sale, however laterals are acknowledged to be "more complementary" than most so called complementary Bjts. The price of laterals as well makes it a bit impractical to to have a lot to hand to sort through. The very nature of laterals as well means you can parrallel them without the problem of unequal current sharing that would happen with Bjts. It's not a problem.
The drivers will be fine as well with two pairs of outputs. If you use the BUZxxx remember these are TO3 package -- not as easy to mount perhaps.
Hum and noise is mostly down to correct layout and grounding.
Low rail ripple is a major concern in a Class A amp, much less so in Class B or AB. Oversize caps cause massive charging currents in the bridge rectifier, wiring and transformer windings due to the very short angle of conduction of the bridge--- it has to put all the energy taken from the reservoir caps back, and in a very short time. Remember the bridge conducts only when the incoming AC exceeds the rail voltage - for most of the time the bridge is non conducting.
Were you thinking of making your own PCB's.
Here is the missing 10 ohm.
Attachments
Hi Karl
Yes you ruffelled some feathers allright,
Transistors influence the performance quite a lot. The magic audio property is low cob, high early voltage,low nose for input, the use of specific transistor accordingly to design operating Ic parameters .
Since this thread was initially about renardsons amp, i suggest you go read up on those pages lineup has posted.
You wanted to know how to improve your amp, a good start would be better trannies. Better types are more expensive offcourse but would inhance performance without more circuit complexity. Ballance the cost of better parts versus complexity factor. Look at renardsons input stage, the cfp, try it, but first read up on Input stage distortion by renardson to understand why. There are trannies that far outperform the 2n devices you use in all the above mentioned respects and yes they are all 2sc, 2sa types. As for the mosfets look at the attached pdf.
I have built his mjr6 as prototype which is very musical indeed, i just dont like the single supply rail for the simple reason of the introduction of caps on the output although his circuit can be taillored for dual supply.
I like your design, it should have simillar characterestic sound ableit less warm.
Alex
Yes you ruffelled some feathers allright,
Transistors influence the performance quite a lot. The magic audio property is low cob, high early voltage,low nose for input, the use of specific transistor accordingly to design operating Ic parameters .
Since this thread was initially about renardsons amp, i suggest you go read up on those pages lineup has posted.
You wanted to know how to improve your amp, a good start would be better trannies. Better types are more expensive offcourse but would inhance performance without more circuit complexity. Ballance the cost of better parts versus complexity factor. Look at renardsons input stage, the cfp, try it, but first read up on Input stage distortion by renardson to understand why. There are trannies that far outperform the 2n devices you use in all the above mentioned respects and yes they are all 2sc, 2sa types. As for the mosfets look at the attached pdf.
I have built his mjr6 as prototype which is very musical indeed, i just dont like the single supply rail for the simple reason of the introduction of caps on the output although his circuit can be taillored for dual supply.
I like your design, it should have simillar characterestic sound ableit less warm.
Alex
Hi Karl
Yes you ruffelled some feathers allright,
Transistors influence the performance quite a lot. The magic audio property is low cob, high early voltage,low nose for input, the use of specific transistor accordingly to design operating Ic parameters .
Since this thread was initially about renardsons amp, i suggest you go read up on those pages lineup has posted.
You wanted to know how to improve your amp, a good start would be better trannies. Better types are more expensive offcourse but would inhance performance without more circuit complexity. Ballance the cost of better parts versus complexity factor. Look at renardsons input stage, the cfp, try it, but first read up on Input stage distortion by renardson to understand why. There are trannies that far outperform the 2n devices you use in all the above mentioned respects and yes they are all 2sc, 2sa types. As for the mosfets look at the AN1645 application notes by national.
I have built his mjr6 as prototype which is very musical indeed, i just dont like the single supply rail for the simple reason of the introduction of caps on the output although his circuit can be taillored for dual supply.
I like your design, it should have simillar characterestic sound ableit less warm.
Alex
Yes you ruffelled some feathers allright,
Transistors influence the performance quite a lot. The magic audio property is low cob, high early voltage,low nose for input, the use of specific transistor accordingly to design operating Ic parameters .
Since this thread was initially about renardsons amp, i suggest you go read up on those pages lineup has posted.
You wanted to know how to improve your amp, a good start would be better trannies. Better types are more expensive offcourse but would inhance performance without more circuit complexity. Ballance the cost of better parts versus complexity factor. Look at renardsons input stage, the cfp, try it, but first read up on Input stage distortion by renardson to understand why. There are trannies that far outperform the 2n devices you use in all the above mentioned respects and yes they are all 2sc, 2sa types. As for the mosfets look at the AN1645 application notes by national.
I have built his mjr6 as prototype which is very musical indeed, i just dont like the single supply rail for the simple reason of the introduction of caps on the output although his circuit can be taillored for dual supply.
I like your design, it should have simillar characterestic sound ableit less warm.
Alex
Hello Alex,
It's good to have discussion on these things,
All you have mentioned are, 1. Identifiable. 2. Measurable. 3. Not magic.
My personal feeling is that substituting the transistors would not make an audible difference. Personal opinion as I say
In what way would you expect the performance of the amp to differ if other devices were used. I accept the noise figure of the 2N5401 as an input device could be bettered, but I have long since concluded low noise (hiss) is way down the list of what makes an amp sound good. In any case noise is more a function of the various impedances in the circuit-- the feedback network, input resistance etc. You are probably looking at under 0.5 dB improvement in overall SNR by going for a device with a lower noise figure.
I genuinely believe my circuit is pretty well immune to differences in the semiconductors used (within reason of course), the exception being the TLO71 which isn't in the audio path anyway.
I will certainly have a read at the articles you mention and the National Application note.
Thanks for the interest and comments,
Regards Karl
It's good to have discussion on these things,
homemodder said:
All you have mentioned are, 1. Identifiable. 2. Measurable. 3. Not magic.My personal feeling is that substituting the transistors would not make an audible difference. Personal opinion as I say
In what way would you expect the performance of the amp to differ if other devices were used. I accept the noise figure of the 2N5401 as an input device could be bettered, but I have long since concluded low noise (hiss) is way down the list of what makes an amp sound good. In any case noise is more a function of the various impedances in the circuit-- the feedback network, input resistance etc. You are probably looking at under 0.5 dB improvement in overall SNR by going for a device with a lower noise figure.
I genuinely believe my circuit is pretty well immune to differences in the semiconductors used (within reason of course), the exception being the TLO71 which isn't in the audio path anyway.
I will certainly have a read at the articles you mention and the National Application note.
Thanks for the interest and comments,
Regards Karl
hi Karl
True its not magic, but its part of what makes some amps sound magically good and it takes months, sometimes years of research and subjective listening to get right. Details are very important, and thats how guys like H Dean, N Pass, J curl make very fine amps.
Concerning Audible differences maybe you should play a bit around with diffrent trannies and look at harmonic spectrums you get. Maybe just with a simple circuit. It is audible. As an example a input stage anomoly because of being at a very low amplitude might not be audible yes, but keep in mind that this signal is going to be amplified with that same anomoly and it will then most certainly be audible, the same like low noise resistors, why use them??? / simple answer because they have lower noise and its audible. Using improved trannies will most certainly drop your THD figures somewhat but may also change your harmonic spectrum for the better. I think we all know by now THD gives little bearing on what a amp sounds like and what matters is the spectrum of this. Harmonic spectrum can be manipulated by not only topology but also device selection. When you combine low THD with favourable spectrum thats when you start getting into very good sounding amps, Renardson has done it well. After youve read Renardson youll understand why i suggested the cfp and note how much effort he put into chosing the right trannies to make up that cfp. All small details. The parts you have used are by no means bad at all, ive seen bad selections here on this forum but its my two cents on how to improve your amp. This single transitor input topology can sound wonderful, is one of my favourite topologies and since i like to keep things as simple as possible my reasoning for better trannies. You may find that you can do better than .5 db improvements and definetly audible. Biggest improvements on subjective side comes from wider more precise sounstaging, black backgrounds and fine detail.
Alex
True its not magic, but its part of what makes some amps sound magically good and it takes months, sometimes years of research and subjective listening to get right. Details are very important, and thats how guys like H Dean, N Pass, J curl make very fine amps.
Concerning Audible differences maybe you should play a bit around with diffrent trannies and look at harmonic spectrums you get. Maybe just with a simple circuit. It is audible. As an example a input stage anomoly because of being at a very low amplitude might not be audible yes, but keep in mind that this signal is going to be amplified with that same anomoly and it will then most certainly be audible, the same like low noise resistors, why use them??? / simple answer because they have lower noise and its audible. Using improved trannies will most certainly drop your THD figures somewhat but may also change your harmonic spectrum for the better. I think we all know by now THD gives little bearing on what a amp sounds like and what matters is the spectrum of this. Harmonic spectrum can be manipulated by not only topology but also device selection. When you combine low THD with favourable spectrum thats when you start getting into very good sounding amps, Renardson has done it well.
After youve read Renardson youll understand why i suggested the cfp and note how much effort he put into chosing the right trannies to make up that cfp. All small details. The parts you have used are by no means bad at all, ive seen bad selections here on this forum but its my two cents on how to improve your amp. This single transitor input topology can sound wonderful, is one of my favourite topologies and since i like to keep things as simple as possible my reasoning for better trannies. You may find that you can do better than .5 db improvements and definetly audible. Biggest improvements on subjective side comes from wider more precise sounstaging, black backgrounds and fine detail.Alex
Hi Alex,
I do have an open mind on what you say I agree that it's the spectrum of any harmonics that make can amp sound better one over another. I found reverting back to the single ended input configuration to make the most difference to me.
Your last sentence. EVERYTHING you say-- this amp delivers--
Now thats magic
I do have an open mind on what you say
I agree that it's the spectrum of any harmonics that make can amp sound better one over another. I found reverting back to the single ended input configuration to make the most difference to me.Your last sentence. EVERYTHING you say-- this amp delivers--
Now thats magic
Hi Karl, guys
Thanks for the updated schema and for your explanations. I am listening and learning
I will soon start purchasing the componets. Nikko (http://www.dalbani.co.uk/) has the transistors and also http://www.profusionplc.com/. Yet, I haven't found any US distributor, I was hoping to get cheeper rates. Has anybody any idea where to buy them in US?
Also does anybody know any website for purchasing the heatsinks?
Thanks Alexandru
Thanks for the updated schema and for your explanations. I am listening and learning
I will soon start purchasing the componets. Nikko (http://www.dalbani.co.uk/) has the transistors and also http://www.profusionplc.com/. Yet, I haven't found any US distributor, I was hoping to get cheeper rates. Has anybody any idea where to buy them in US?
Also does anybody know any website for purchasing the heatsinks?
Thanks Alexandru
Hi Alexandru
Interesting name you have, my full name is alexandre, thats the portugeuse way.
This caps thing is a very interesting subject. I hope you have read renardsons views on this, he explains the effects that caps have on the harmonic spectrum. The effects it has Im pretty sure is correct as you will notice other investigators have delved even deeper into this and have same conclusions. Look at the refence he gives, thats a very thorough investigation done. As the caps would produce very low lower order harmonic distortions which to the ear is pleasant sounding it would be difficult to hear but now you said the right word CLARITY. Studies done have shown that low order harmonics tend to mask. I agree with the other investigators, it is audible, for me it is anyway. He claims that differences are so small and presents a blind test of way back of the seventies to reinforce his views but that was nearly 30 years ago, amps and components are so much better now that differences can be heard. I must state that he very cleverly places those caps inside the feedback loop to minimise those effects but i think he is also not convinced of himself as he states to use the best quality caps that you can find. If inaudible why the best caps??? I prefer to not use capacitor coupled outputs.
For parts look here www.bdent.com
Alex
Interesting name you have, my full name is alexandre, thats the portugeuse way.
This caps thing is a very interesting subject. I hope you have read renardsons views on this, he explains the effects that caps have on the harmonic spectrum. The effects it has Im pretty sure is correct as you will notice other investigators have delved even deeper into this and have same conclusions. Look at the refence he gives, thats a very thorough investigation done. As the caps would produce very low lower order harmonic distortions which to the ear is pleasant sounding it would be difficult to hear but now you said the right word CLARITY. Studies done have shown that low order harmonics tend to mask. I agree with the other investigators, it is audible, for me it is anyway. He claims that differences are so small and presents a blind test of way back of the seventies to reinforce his views but that was nearly 30 years ago, amps and components are so much better now that differences can be heard. I must state that he very cleverly places those caps inside the feedback loop to minimise those effects but i think he is also not convinced of himself as he states to use the best quality caps that you can find. If inaudible why the best caps??? I prefer to not use capacitor coupled outputs.
For parts look here www.bdent.com
Alex
Hi Alex,
I was born in Romania and somehow ended up in the middle of the Pacific, which isn't bad at all
Yes, I read again through the information provide by Renardson... I guess I will need to try and see how it sounds. Maybe the clever tricks with the feedback do a good job in reducing the lower order harmonic. I would like to have an amplifier that has a warm and very clear sound allowing to distinguish the fine details in the music fabric.
An amplifier with symmetrical rail voltage would be indeed preferable, and there is Mooly's amplifier.
Thanks, Alexandru
I was born in Romania and somehow ended up in the middle of the Pacific, which isn't bad at all
Yes, I read again through the information provide by Renardson... I guess I will need to try and see how it sounds. Maybe the clever tricks with the feedback do a good job in reducing the lower order harmonic. I would like to have an amplifier that has a warm and very clear sound allowing to distinguish the fine details in the music fabric.
An amplifier with symmetrical rail voltage would be indeed preferable, and there is Mooly's amplifier.
Thanks, Alexandru
Hello Alex,
Been having a look at M Reynardsons site. Very interesting. I see in his article on earthing around the volume control he came against the same problems I found. I had to smile at his balance control. I did the same (well not quite) as his implementation will cause response and phase differences if the time constants seen by the two channels are not equal. I called mine an "Image center or localisation" control
I even went as far as modeling the grounding with two opamp based power amps and analysed it as a DC problem to try and see what really goes on. I deliberately scaled all the supply and ground resistances up to around 10 ohms to make it easier to appreciate.
I shall continue reading.
Regards Karl
P.S. I never mentioned the "balance" control but here it is. It's a multiturn pot.
Been having a look at M Reynardsons site. Very interesting. I see in his article on earthing around the volume control he came against the same problems I found. I had to smile at his balance control. I did the same (well not quite) as his implementation will cause response and phase differences if the time constants seen by the two channels are not equal. I called mine an "Image center or localisation" control
I even went as far as modeling the grounding with two opamp based power amps and analysed it as a DC problem to try and see what really goes on. I deliberately scaled all the supply and ground resistances up to around 10 ohms to make it easier to appreciate.
I shall continue reading.
Regards Karl
P.S. I never mentioned the "balance" control but here it is. It's a multiturn pot.
Attachments
homemodder said:hi Karl
True its not magic, but its part of what makes some amps sound magically good and it takes months, sometimes years of research and subjective listening to get right. Details are very important, and thats how guys like H Dean, N Pass, J curl make very fine amps.
Concerning Audible differences maybe you should play a bit around with diffrent trannies and look at harmonic spectrums you get. Maybe just with a simple circuit. It is audible. As an example a input stage anomoly because of being at a very low amplitude might not be audible yes, but keep in mind that this signal is going to be amplified with that same anomoly and it will then most certainly be audible, the same like low noise resistors, why use them??? / simple answer because they have lower noise and its audible. Using improved trannies will most certainly drop your THD figures somewhat but may also change your harmonic spectrum for the better. I think we all know by now THD gives little bearing on what a amp sounds like and what matters is the spectrum of this. Harmonic spectrum can be manipulated by not only topology but also device selection. When you combine low THD with favourable spectrum thats when you start getting into very good sounding amps, Renardson has done it well.
Alex
The importance of the harmonic spectrum is inversely proportional to the THD.
It will not make a jot of difference, sound wise, if the distortion of an amplifier with .001% THD is predominantly second or third, but it can make a significant difference to an amplifier with high THD - such as valve amps.
The funny point - that is constantly overlooked - is that no resistor in the world can be lower than the thermal noise it produces. And that thermal noise is for usual values much higher than the additional noise introduced in the manufacturing.
What 'low noise' really claims is that the total noise of the resistor is dominated by its thermal noise - and not even higher by crappy manufacturing.
That's the reason every high quality resistor is also 'low noise'.
All the best, Hannes
So what?
You're comparing apples and oranges here as I very well explained you the reasoning for my choice regarding the special amp you're referring to.
Someone may find this interesting
www.profusionplc.com/pro/gex/prodGen.html?prdtyp=medium power-driver
www.profusionplc.com/pro/gex/prodGen.html?prdtyp=medium power-driver
Hi Mooly
Indeed profusion keep some good transistors around, i purchase output bjts and now lately have ordered some small signal trannies which i use to purchase from the states there. For lateral fets the 2sa1209 are indeed good. There are others that outperform all those mentioned there mainly from toshiba and sanyo. Theres one thing they dont mention there though, and that you dont find on datasheets and that is the importance of high early voltage. Have a look at 2sa1016k as small signal input transistors and compare to 2n5401, Ive been using them for over 15 years, you wont find anything better on the market.
Alex
Indeed profusion keep some good transistors around, i purchase output bjts and now lately have ordered some small signal trannies which i use to purchase from the states there. For lateral fets the 2sa1209 are indeed good. There are others that outperform all those mentioned there mainly from toshiba and sanyo. Theres one thing they dont mention there though, and that you dont find on datasheets and that is the importance of high early voltage. Have a look at 2sa1016k as small signal input transistors and compare to 2n5401, Ive been using them for over 15 years, you wont find anything better on the market.
Alex
Hi,
Electrolytics are not nearly ideal capacitors having high dielectric absorption, small operating frequency range and poor linearity.
a confusing statement, I certainly would not put it that way. Apropriate harmonic spectrum is a basic condition for natural sound. Numerous commonly used topologies cause severe departures from it, however some people are careful about the methods to achieve a close approximation.
Electrolytics are not nearly ideal capacitors having high dielectric absorption, small operating frequency range and poor linearity.
Hi Alex and Lumba Ogir,
All this talk of early voltage, transistors getting a cob on -- sorry having a low cob- is there a difference , output inductors in another thread, Space with his flying saucer heatsink- yes really.
You know what. I do something different with my amp-- I use it to listen to and enjoy music
All this talk of early voltage, transistors getting a cob on -- sorry having a low cob- is there a difference
, output inductors in another thread, Space with his flying saucer heatsink- yes really.You know what. I do something different with my amp-- I use it to listen to and enjoy music
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