Another Improvements
Hi all, I made a big upgrade to my amplifier in lst two days. Powersupply got changed a lot. First I had this: 10,2uF PIO - 4H choke - 10uF PIO - 6H choke - 150uF Vishay electrolyte with 20uF PIO nearest tubes as possible. This was when I had AZ1. The bass was normal, but not punchy. I tried to remove the electrolyte and replacet it with 46uF motor oil capacitor. I think that highs and mids were more open and there was more space, but there was NO bass. No punch, no low frequency and it was no-listenable. So I added the 150uF elco back.
Then I added toroidal trafsormer from another tube amp which provides 6.3V 6A (I used a dropping resistor to get something like 4V on rectifier) for AZ4 rectifier tube. Wich has small internal resistance and can do 200mA of current. This dimensation has VERY good influence to sound! EVERYTHING improved. Bass is tighter, deeper, has more punch, midrange and trebles are almost the same but there is more space and 3D to the music. The AZ4 runs on half of its current maximum and the 4654 runs pretty hot, 15Watts anode dissipation. This is SO much better than the previous (4654 tubes runs cold and AZ1 was on its current limit).
Again, as before, I tried to experiment with new AZ4 powersupply. I again removed the electrolyte, leaved only 20uF PIO as lash filtration capacitor. And there was NO DIFFERENCE in bass! Bass was the same deep as with the 150uF elco, but I think more clear and with even more punch! The mids and highs were even more clear, and there was more punch too. It is waay better than before with AZ1.
I will try to add another AZ4 parallel, or I will use PV200/600 - great rectifier which can provide 200 miliamps even at 600 volts - this is monster!
One people told me that more dimensation on rectifier is always better, and he was 100% true.
And I added NIPPON-CHEMICON 136uF electrolytic bypassed with wima 0.1uF foil to cathode resistor - I have more gain and this had good influence on bass too. I will have 220uF Elna SILMIC II, so I think this will be another big improvement.
I attached new schematic and new photos - I rebuilded the whole amp into testing board. If there is someone else who experiments like me, please reply and we can discuss more
Best regards Michal
Hi all, I made a big upgrade to my amplifier in lst two days. Powersupply got changed a lot. First I had this: 10,2uF PIO - 4H choke - 10uF PIO - 6H choke - 150uF Vishay electrolyte with 20uF PIO nearest tubes as possible. This was when I had AZ1. The bass was normal, but not punchy. I tried to remove the electrolyte and replacet it with 46uF motor oil capacitor. I think that highs and mids were more open and there was more space, but there was NO bass. No punch, no low frequency and it was no-listenable. So I added the 150uF elco back.
Then I added toroidal trafsormer from another tube amp which provides 6.3V 6A (I used a dropping resistor to get something like 4V on rectifier) for AZ4 rectifier tube. Wich has small internal resistance and can do 200mA of current. This dimensation has VERY good influence to sound! EVERYTHING improved. Bass is tighter, deeper, has more punch, midrange and trebles are almost the same but there is more space and 3D to the music. The AZ4 runs on half of its current maximum and the 4654 runs pretty hot, 15Watts anode dissipation. This is SO much better than the previous (4654 tubes runs cold and AZ1 was on its current limit).
Again, as before, I tried to experiment with new AZ4 powersupply. I again removed the electrolyte, leaved only 20uF PIO as lash filtration capacitor. And there was NO DIFFERENCE in bass! Bass was the same deep as with the 150uF elco, but I think more clear and with even more punch! The mids and highs were even more clear, and there was more punch too. It is waay better than before with AZ1.
I will try to add another AZ4 parallel, or I will use PV200/600 - great rectifier which can provide 200 miliamps even at 600 volts - this is monster!
One people told me that more dimensation on rectifier is always better, and he was 100% true.
And I added NIPPON-CHEMICON 136uF electrolytic bypassed with wima 0.1uF foil to cathode resistor - I have more gain and this had good influence on bass too. I will have 220uF Elna SILMIC II, so I think this will be another big improvement.
I attached new schematic and new photos - I rebuilded the whole amp into testing board. If there is someone else who experiments like me, please reply and we can discuss more
Best regards Michal
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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Yes, i will try it but according to simulations in PSU Designer, with choke input it increase hum a little bit. But in reality it can be little different. I have one powertrafo with high voltage, but I havent big choke, I need something bigger than 6 henries, i will leave this choke in place. I will try the choke input in some preamp or something like that which i will plan i the future.
Hey Micky,
Good to read you made improvements.
What I woud do :
Make your star-ground at the 1st C in the PSU .
According to your schematic you use separate wires to ground.
Tie all ground points per stage (including psu C) and go from each stage with one wire to star-ground .
This improves channel separation, performance and stability .
And I say it again, use negative bias, improves dynamics a little and easier to adjust the power of the 4654's .
Good to read you made improvements.
What I woud do :
Make your star-ground at the 1st C in the PSU .
According to your schematic you use separate wires to ground.
Tie all ground points per stage (including psu C) and go from each stage with one wire to star-ground .
This improves channel separation, performance and stability .
And I say it again, use negative bias, improves dynamics a little and easier to adjust the power of the 4654's .
Yes I already have star grounding, for each channel each star, according to this picture:. But I dont know if will be good idea to havestarground even on first PSU capacitor. Trough first and second cap there are biggest currents, I think that using star ground on first psu cap will lead to ground loop.
And by negative bias, you mean fixed bias?
Thank you Michal
And by negative bias, you mean fixed bias?
Thank you Michal
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I always give each stage it's own psu C .
But you don't so your ground looks good .
As long as you use only one ground to chassis there will be no ground loops .
I was told to always use the first psu cap for star ground .
It might not have the biggest capacitance but has to deal with the most rubbish and you don't want to transport that in your amp .
Edit: yes fixed bias
But you don't so your ground looks good .
As long as you use only one ground to chassis there will be no ground loops .
I was told to always use the first psu cap for star ground .
It might not have the biggest capacitance but has to deal with the most rubbish and you don't want to transport that in your amp .
Edit: yes fixed bias
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Yes, you are right with first cap in psu and its big garbage, I have 0.1uF cap nearest tube, and then 10uF cap which is first "filtering" cap. I dont have aluminium chassis, I have just wooden base and in fiture, I will have wooden chassis, so I avoid chassis ground loops and connections. But on the other hand, wood has zero shielding capabilities. Every solution has its own pros and cons. I think that you must choose what is best FOR YOU as person. When I started to live with this opinion, my amps got better too, I think.
That's the right attitude if you keep an open mind
When I started building tube amps I followed the tips of my "tube guru" and learned a lot, but now we sometimes completely disagree on what sounds better .
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Yes, I also have 2 persons wich help me a lot when I dont know what is best. There are some things that are personally dependent, and things that aare 100% true everywhere and everytime. Its important to know differrnce between these to. Even for me its sometimes hard, but not often. But some dilemas are very hard to solve, for example, I will build DAC output stage with directly heated tube.
I dont know what to choose, 4P1L or E443 (dh output european pentode)
Gain is not important for me, because my DAC will output 2volts peak peak. Even if the tube will have amplification factor 10, I will still get 20Volts output, which is good for driving my output tubes. I will use resistor load. This is the first dilema - 4p1l or e443.
The second dilema is, how to heat the directly heated tubes. I have only one winding on my transformer. Is it possible for hwat 2 dhts with this, and I will have two bridge rectifiers, two filament supply filters etc? Simply one winding, with two separate filters (rectifiers, capacitors, dropping resistors etc) attachet to it?
I dont have much experience with dhts. Thank you a lot for any idea. Best regards, Michal
I dont know what to choose, 4P1L or E443 (dh output european pentode)
Gain is not important for me, because my DAC will output 2volts peak peak. Even if the tube will have amplification factor 10, I will still get 20Volts output, which is good for driving my output tubes. I will use resistor load. This is the first dilema - 4p1l or e443.
The second dilema is, how to heat the directly heated tubes. I have only one winding on my transformer. Is it possible for hwat 2 dhts with this, and I will have two bridge rectifiers, two filament supply filters etc? Simply one winding, with two separate filters (rectifiers, capacitors, dropping resistors etc) attachet to it?
I dont have much experience with dhts. Thank you a lot for any idea. Best regards, Michal
UPDATE on driver tube AC2: I tried many driver tubes, including 6N6P resistor loaded, 6N1P resistor, 6N2P resistor, ECC82 resistor (RFT), 2P24B resistor (russian pencil tube), 2J27L resistor,6N23p resistor, 6N1P srpp, 6N23P srpp, E88CC Tesla goldpin resistor. And I found out that NONE of these tubes CANT beat AC2 telefunken.... Its the best driver tube I had and heard....... If you can try it, please do it. You will be satisfied with the sound!
No surprise you didn't like the ecc82, I don't even understand why people use them.
The only nice driver tube from the ecc series is the ecc81 if it's Philips or Telefunken .
I'm getting curious about this AC2, I'm using a C3M now but have mounted P-sockets as well to eventually try the EL3N as driver .
The only nice driver tube from the ecc series is the ecc81 if it's Philips or Telefunken .
I'm getting curious about this AC2, I'm using a C3M now but have mounted P-sockets as well to eventually try the EL3N as driver .
Hello,
Like the French did in the eighties with the 310A/B and 300B combo you will have to look for the right mix of in- and output tube. Each tube will have its own '' sweet spot '' . When comparing different brands for the same tube one could state which one of them you fancy.
Recently i have tried to gather some '' judgements '' on the Obbligato film in oil caps because i want to use one as the output cap in an Allen Wright shunt supply for a pre amp a friend of mine is going to assemble in Hong kong. Found people who told other people to first change that terrible Obbligato cap and i found a site where it is given a 9 where 10 is maximum.
On that site some mkp caps used by people here in their power supply get so so marks. These are professional capacitors used in industrial applications with impressive figures but they do sound bad. I have come across professional caps that do sound good. The original poster is using Russian caps. The ones i used so far do sound very nice. My favourite is the k75-10 which can be found on ebay. Greetings, Eduard
Like the French did in the eighties with the 310A/B and 300B combo you will have to look for the right mix of in- and output tube. Each tube will have its own '' sweet spot '' . When comparing different brands for the same tube one could state which one of them you fancy.
Recently i have tried to gather some '' judgements '' on the Obbligato film in oil caps because i want to use one as the output cap in an Allen Wright shunt supply for a pre amp a friend of mine is going to assemble in Hong kong. Found people who told other people to first change that terrible Obbligato cap and i found a site where it is given a 9 where 10 is maximum.
On that site some mkp caps used by people here in their power supply get so so marks. These are professional capacitors used in industrial applications with impressive figures but they do sound bad. I have come across professional caps that do sound good. The original poster is using Russian caps. The ones i used so far do sound very nice. My favourite is the k75-10 which can be found on ebay. Greetings, Eduard
Its all about how it sounds to you... Yeah, russian caps are great, I also tried motor run capacitors,which are also good but not as good as russian PIOils. I have bought ASC oil filled non inductively wound cap to power supply.... I will test it... For signal coupling I like K40Y-9. Very good PIO, some people say that they as good as golden mundorfs...
Hello,
Miky will soon try a choke input with the right kind of choke because in my opinion the biigest return on investment can be made in the power supply.
I remember buying Siemens MKV caps for less than 5 euro/$
There are still caps being made that are similar by brands like Arcotronics, Kemet, TDK. Kemet acquired Arcotronics some time ago. Some caps can be found on ebay but not all of them are good.
Some people swear there must be oil to sound good?? There is the old paper in oil and now there are metalized caps with oil. The oil is there for a reason and it is not for the few audiofools!
The French in the past wrote about real expensive caps like CSI, Autovox but they also make loads of caps that can NOT be used in a DC power supply. Especially on ebay you can find some by sellers who dont know s... about the possible use. You dont wanna put 800 volts DC on a cap that is designed for a limited number of charge and decharges like the ones in defibrallators.
Greetings, eduard
Miky will soon try a choke input with the right kind of choke because in my opinion the biigest return on investment can be made in the power supply.
I remember buying Siemens MKV caps for less than 5 euro/$
There are still caps being made that are similar by brands like Arcotronics, Kemet, TDK. Kemet acquired Arcotronics some time ago. Some caps can be found on ebay but not all of them are good.
Some people swear there must be oil to sound good?? There is the old paper in oil and now there are metalized caps with oil. The oil is there for a reason and it is not for the few audiofools!
The French in the past wrote about real expensive caps like CSI, Autovox but they also make loads of caps that can NOT be used in a DC power supply. Especially on ebay you can find some by sellers who dont know s... about the possible use. You dont wanna put 800 volts DC on a cap that is designed for a limited number of charge and decharges like the ones in defibrallators.
Greetings, eduard
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