Well Nick you are no neophyte! Yes but tank is much easer to type. Anyway I can see your problem and it’s obvious – you need to ask your utility company to switch to 60hz AC and the Cornet will sound perfect. Oh I forgot you have upside down electricity down under so you will have to switch the wires around:^)
As for the ripple filtration stage for all my line level amplifies I employ CLCRC where C1 is calculated for ball park B+, L includes the tank circuit C2 filter, RC3 filter where R also server to fine tune B+. From C3 I branch to right and left channel with an additional RC filter/voltage divider/isolation circuit.
Good luck trouble shooting your phone and I hope I didn’t fill your head with too much garbage. Let us know what finally resolved your treble fatigue.
Cheers
33dot33rpm
As for the ripple filtration stage for all my line level amplifies I employ CLCRC where C1 is calculated for ball park B+, L includes the tank circuit C2 filter, RC3 filter where R also server to fine tune B+. From C3 I branch to right and left channel with an additional RC filter/voltage divider/isolation circuit.
Good luck trouble shooting your phone and I hope I didn’t fill your head with too much garbage. Let us know what finally resolved your treble fatigue.
Cheers
33dot33rpm
Here Here
Hi Again
Look I have to admit I am an unashamed dinosaur in some things..The thing is when I touch the power button of my amp(s) and I watch for that faint red glow and then hit the b+ after 20 seconds well its a feeling of acclomishment and amazement at tubes, their concept, their physics and their sound.... Likewise cc resistors arent so bad I dont think...If I wanted noiseless souless music Id go solid state ( i really hope they arent listening out there) CC resistors to some extent impart their sonic signature on the music and I, being carbon based, find it warm and appealing.
I concede that in some spots, bulk metal foil resistors are a boon. Mind you in Australia they cost 30 dollars each (for a .3 watt) so I will only maybe change the ones 33 dot suggested in my phono stage.
The same can be said of caps.. there these ones or those ones or russian pio caps made in the cold war or before which surprise surprise are the ones to get.
I respect everyones differing opinions and experiment where possible but it comes back to the fact that CC are cheap, mostly sound good and the ones I have been using seem to boast stability not once seen in older cc's because of newer or more precise manufacturing techniques.
So I agree with your comments for that article its about the measureable not the intangible. I was dissapointed to read in Morgan Jones book on valve ampos that he doesnt see the logic in SET power amps.. well I have 3 amps and the one I love the most is a 300B set so go figure.
The world is mad on measurements but thats not the whole picture now is it.
i will however report on using the bulk foil resistors in the places recommended and see what transpires.
I would like to thank all for the help, 33dot in particular.
Onwards and upwards
Hi Again
Look I have to admit I am an unashamed dinosaur in some things..The thing is when I touch the power button of my amp(s) and I watch for that faint red glow and then hit the b+ after 20 seconds well its a feeling of acclomishment and amazement at tubes, their concept, their physics and their sound.... Likewise cc resistors arent so bad I dont think...If I wanted noiseless souless music Id go solid state ( i really hope they arent listening out there) CC resistors to some extent impart their sonic signature on the music and I, being carbon based, find it warm and appealing.
I concede that in some spots, bulk metal foil resistors are a boon. Mind you in Australia they cost 30 dollars each (for a .3 watt) so I will only maybe change the ones 33 dot suggested in my phono stage.
The same can be said of caps.. there these ones or those ones or russian pio caps made in the cold war or before which surprise surprise are the ones to get.
I respect everyones differing opinions and experiment where possible but it comes back to the fact that CC are cheap, mostly sound good and the ones I have been using seem to boast stability not once seen in older cc's because of newer or more precise manufacturing techniques.
So I agree with your comments for that article its about the measureable not the intangible. I was dissapointed to read in Morgan Jones book on valve ampos that he doesnt see the logic in SET power amps.. well I have 3 amps and the one I love the most is a 300B set so go figure.
The world is mad on measurements but thats not the whole picture now is it.
i will however report on using the bulk foil resistors in the places recommended and see what transpires.
I would like to thank all for the help, 33dot in particular.
Onwards and upwards
Hi Nick,
Don’t go nuts with all the recommendations from this thread. I used all those exotic parts because they were in my parts box from years of packratting. The first priority is to determine if you have a circuit fault that is causing the treble fatigue and address that problem. If there is a fault and you’ve fixed it then you can address tone and distortion at your leisure and have fun doing so.
Before you source all the components I used in my phono, dig into the parts box. Network with other audio hobbyist in your area and see if they have interesting caps or resistors you can borrow and try out in your circuit. In the end of the day it is only your opinion that counts. I like the tone of the Russian caps but you may prefer something else. The foil resistor is good for me (but I got it cheap @ a surplus store) but something else may work for you.
Regarding voltage rating of available caps for me as long as the rating is higher than specified it’s ok. One of the limiting factors is higher voltage rating usually means larger physical cap. Some folks will argue that you should use the voltage specified only otherwise the amp won’t sound right of good. I believe for example C5: a 47nf 500V Teflon will sound superior to a 47nf 250V Mylar. If you can find a 47nf 250V Teflon great it will cost less. For C8 I can see your problem the most common rating for a K40Y9 is 400V and the spec is 630. There are 630V K40Y9 but not so common and the K72 is rated @ 500V…. what to do?
In many designs there are factors of safety. If you notice max B+ for the follower is 325V far below the 630V spec (I measure around 160V @ the output of the follower). There are two things to keep in mind depending on your PS design. In my phono it’s unregulated CLCRC. First when B+ is turned on there is no significant load and B+ will spike then settle down as the tubes warm and the circuit applies a load to the PS. Second depending of the PS design you want to protect the circuit from a rise in B+ in the event of a fault in the PS.
In my case I use a small value cap off the rectifier to get the ball park B+ voltage. If this cap fails (short) I’m left with a choke input. In this case B+ will be lowered and I will have no over voltage problem with the rest of the circuit. You would need to calculate what will happen to your PS in the event of a capacitor or choke short (no idea what happens to a regulated PS). I can feel comfortable using a 400V K40Y9 parallel with a 500V K72 in my case.
I’m with you 300b SET is the way to go! You may get more bass slam with a tube PP or high current transistor but that’s what a powered sub woofer is all about.
Cheers
33dot33rpm
Don’t go nuts with all the recommendations from this thread. I used all those exotic parts because they were in my parts box from years of packratting. The first priority is to determine if you have a circuit fault that is causing the treble fatigue and address that problem. If there is a fault and you’ve fixed it then you can address tone and distortion at your leisure and have fun doing so.
Before you source all the components I used in my phono, dig into the parts box. Network with other audio hobbyist in your area and see if they have interesting caps or resistors you can borrow and try out in your circuit. In the end of the day it is only your opinion that counts. I like the tone of the Russian caps but you may prefer something else. The foil resistor is good for me (but I got it cheap @ a surplus store) but something else may work for you.
Regarding voltage rating of available caps for me as long as the rating is higher than specified it’s ok. One of the limiting factors is higher voltage rating usually means larger physical cap. Some folks will argue that you should use the voltage specified only otherwise the amp won’t sound right of good. I believe for example C5: a 47nf 500V Teflon will sound superior to a 47nf 250V Mylar. If you can find a 47nf 250V Teflon great it will cost less. For C8 I can see your problem the most common rating for a K40Y9 is 400V and the spec is 630. There are 630V K40Y9 but not so common and the K72 is rated @ 500V…. what to do?
In many designs there are factors of safety. If you notice max B+ for the follower is 325V far below the 630V spec (I measure around 160V @ the output of the follower). There are two things to keep in mind depending on your PS design. In my phono it’s unregulated CLCRC. First when B+ is turned on there is no significant load and B+ will spike then settle down as the tubes warm and the circuit applies a load to the PS. Second depending of the PS design you want to protect the circuit from a rise in B+ in the event of a fault in the PS.
In my case I use a small value cap off the rectifier to get the ball park B+ voltage. If this cap fails (short) I’m left with a choke input. In this case B+ will be lowered and I will have no over voltage problem with the rest of the circuit. You would need to calculate what will happen to your PS in the event of a capacitor or choke short (no idea what happens to a regulated PS). I can feel comfortable using a 400V K40Y9 parallel with a 500V K72 in my case.
I’m with you 300b SET is the way to go! You may get more bass slam with a tube PP or high current transistor but that’s what a powered sub woofer is all about.
Cheers
33dot33rpm
Thanks for your encouragement
You are illuminating 33 dot. I appreciate your good and timely advice.
Will sort out the itch first before. I go gettin' exotic In the interim I will keep looking for the specified caps. I never would have thought the makers of the cossack motorcycle and other mechanical delights would end up making audiophile caps!!! Good heavens only knows how much the russian stuff would cost if mundorf or auricap produced them.
One other question...
I am probably going to use polypropylene caps in my psu for my monoblocs.. say 5 to 10uf for the first after the rectifier then a choke, then 47uf and maybe a crc for the 300b b+. I am debating wether to use regulated b+ for the 6 sn7/6ca7 driver stage..For this i would have to reduce the b+ down from 480V from the first stage of filtration via a voltage divider. I will probably run the 6sn 7 and 6ca7 at 250v.
I have an amp at home which runs 12at7 into a 6ca7 driving the 300b and it sounds magnificent to me so I thought i would just kind of use this circuit (monobloc parallel 300bs though).
The ppropylene caps i have in mind for power supply have a dc rating of between 700V to 1000V really low esr, high current surge ability blah blah... they are just kind of big. your thoughts on this?
Thanks again
Nick
You are illuminating 33 dot. I appreciate your good and timely advice.
Will sort out the itch first before. I go gettin' exotic In the interim I will keep looking for the specified caps. I never would have thought the makers of the cossack motorcycle and other mechanical delights would end up making audiophile caps!!! Good heavens only knows how much the russian stuff would cost if mundorf or auricap produced them.
One other question...
I am probably going to use polypropylene caps in my psu for my monoblocs.. say 5 to 10uf for the first after the rectifier then a choke, then 47uf and maybe a crc for the 300b b+. I am debating wether to use regulated b+ for the 6 sn7/6ca7 driver stage..For this i would have to reduce the b+ down from 480V from the first stage of filtration via a voltage divider. I will probably run the 6sn 7 and 6ca7 at 250v.
I have an amp at home which runs 12at7 into a 6ca7 driving the 300b and it sounds magnificent to me so I thought i would just kind of use this circuit (monobloc parallel 300bs though).
The ppropylene caps i have in mind for power supply have a dc rating of between 700V to 1000V really low esr, high current surge ability blah blah... they are just kind of big. your thoughts on this?
Thanks again
Nick
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