Alright
Sonically, 5AR4 or 5U4GB as the rectifier? I seem to find that 5U4 is directly heated, and 5AR is indirectly, isn't directly heated supposed to be sonically better? I can use either with the transformer..
Power supply is rectifier into 15H choke, 10uf cap into 10H choke, 200uf cap for the B+
Thanks,
Aaron
Sonically, 5AR4 or 5U4GB as the rectifier? I seem to find that 5U4 is directly heated, and 5AR is indirectly, isn't directly heated supposed to be sonically better? I can use either with the transformer..
Power supply is rectifier into 15H choke, 10uf cap into 10H choke, 200uf cap for the B+
Thanks,
Aaron
This week I took delivery of Sovtek 2A3 tubes 
Now I am ordering a Tango MX-175 power transformer, Tango LC-15-150 and Tango LC-10-200 chokes, and Tango NC-14 interstages.
Wish me the luck to carry out this project
Thanks to all! ultranalog, fdegrove, brett, dice45, and john! thanks again..
-- Aaron
Now I am ordering a Tango MX-175 power transformer, Tango LC-15-150 and Tango LC-10-200 chokes, and Tango NC-14 interstages.
Wish me the luck to carry out this project
Thanks to all! ultranalog, fdegrove, brett, dice45, and john! thanks again..
-- Aaron
Re: Re: psu
All you will accomplish by doing this is making a less effective filter.
Maximum filtering is obtained by using identical LC or RC stages, and basically any more than two isn't going to accomplish much (or enough to justify the expense), except put additional strain on your power transformer as it tries to keep all that capacitance charged up. The math to justify that statement can be found in the Radiotron manual.
Any ringing in this circuit would be caused by the transformers, and motorboating is a non issue with only a single voltage amplifier per stage.
You only get motorboating when three or more stages couple through a common supply.
I would remove everything after the second 100MF cap.
ultranalog said:
All you will accomplish by doing this is making a less effective filter.
Maximum filtering is obtained by using identical LC or RC stages, and basically any more than two isn't going to accomplish much (or enough to justify the expense), except put additional strain on your power transformer as it tries to keep all that capacitance charged up. The math to justify that statement can be found in the Radiotron manual.
Any ringing in this circuit would be caused by the transformers, and motorboating is a non issue with only a single voltage amplifier per stage.
You only get motorboating when three or more stages couple through a common supply.
I would remove everything after the second 100MF cap.
Re: I detect a note of sarcasm...
Just a bit, more tongue in cheek than anything. As you posted, after the second cap there is really only the circuit in the first PSU layout
Just a bit, more tongue in cheek than anything. As you posted, after the second cap there is really only the circuit in the first PSU layout
With a good shunt reg, I would say the second stage is unneccessary, but in an unregulated SE amp, the second LC stage would be of benefit sonically. I can hear the improvement in a good PP diff amp, so in a SE, which is about two orders of magnitude more sensitive to PSU irregularities I would expect it to be even more audible. Providing the capacitors are of good quality, and the PSU can charge them quickly enough, why would it be overkill?Joel said:
Brett said:
See my comment in my 71A post to fdegrove. This is a class A single ended amp - you don't need a reulated power supply. Yes, you would hear a difference (maybe) in a PP amp.
And, last time I checked chokes and big caps cost money ($100 for a 100MF Black Gate???, etc.) - so why spend the money if he doesn't have to? A very simple PS in this amp will be quite effective.
I disagree with all of what you posted here. A SE amp is FAR more sensitive to PSU, than an equivalent Class A PP amp, especially one with a differential topology. If any sort of amp <i>needs</i> a good shunt reg, it's a SET.Joel said:
I don't use BG caps, thay sound awful, PP in oil motor runs are far cheaper and better sounding. As to cost of chokes, good quality surplus can be found easily and cheaply on eBay.
PSU REG
Hi Joel,
Man, you type faster then I can read.
I must say that I still have to see a tube design that didn't benefit from separate HT rails and good regulation,be that PP,SE
or preamp.
No matter the wattage of amp and even in Class A1.
To give an example of what most people would call overkill:
I use a phono preamp where every stage has its' own transformer for B+ and heaters.
It has a very good shunt reg per stage,decoupled with 660 mF/300VDC.
(don't care about he Joule content but I'm sure the figures are impressive)
If you take the basic circuitry and just give it a textbook PSU it doesn't come close sonically.
It is still miles ahead of any competition since 1986.
Then I guess if a standard high-end manufacturer would build like that it would probably be their last design ever.
No offense Joel,if you got some time on your hands one day just give it a try.
Regards,
Hi Joel,
Man, you type faster then I can read.
I must say that I still have to see a tube design that didn't benefit from separate HT rails and good regulation,be that PP,SE
or preamp.
No matter the wattage of amp and even in Class A1.
To give an example of what most people would call overkill:
I use a phono preamp where every stage has its' own transformer for B+ and heaters.
It has a very good shunt reg per stage,decoupled with 660 mF/300VDC.
(don't care about he Joule content but I'm sure the figures are impressive)
If you take the basic circuitry and just give it a textbook PSU it doesn't come close sonically.
It is still miles ahead of any competition since 1986.
Then I guess if a standard high-end manufacturer would build like that it would probably be their last design ever.
No offense Joel,if you got some time on your hands one day just give it a try.
Regards,
diminishing returns
Brett, I was not talking about hum filtering, only regulation. They are not the same thing. A class A power output stage does not require a high level of regulation - it does not have the current swing. It is not going to suck down your PS at full load (assuming you have enough capacitance, and can charge it) A push-pull AB stage, having a greatly varying current demand, benefits from regulation (chokes). Are you going to disagree with that statement?
Hum: yes, single-ended amps do not cancel out power supply noise like a PP amp - but, as I said before, 200MF is more than enough to drop the ripple to a couple millivolts.
Fedgrove - yes, I suppose you could put 100 punds of iron, and 20,000MF of capacitance in a powersupply also - but I don't see why you would waste your time and money. I'm not condeming you, just saying I don't choose to build that way, and I don't think my amps are sonically deficient.
Brett said:
Brett, I was not talking about hum filtering, only regulation. They are not the same thing. A class A power output stage does not require a high level of regulation - it does not have the current swing. It is not going to suck down your PS at full load (assuming you have enough capacitance, and can charge it) A push-pull AB stage, having a greatly varying current demand, benefits from regulation (chokes). Are you going to disagree with that statement?
Hum: yes, single-ended amps do not cancel out power supply noise like a PP amp - but, as I said before, 200MF is more than enough to drop the ripple to a couple millivolts.
Fedgrove - yes, I suppose you could put 100 punds of iron, and 20,000MF of capacitance in a powersupply also - but I don't see why you would waste your time and money. I'm not condeming you, just saying I don't choose to build that way, and I don't think my amps are sonically deficient.
NO OFFENSE.
Joel,
I undestand you completely.
Still,in the context of DIY we're at liberty to advance a bit on the current state of the art?
Diminishing returns?
Well my ears keep on telling me different and apparantly other people, even though they sit at the other end of the world feel likewise.
I always felt it money well spent.
No one is saying your amps are deficient.
I think when we see a good design we just want to make it better still.
(there should be a name for a disease like that)
See you,
Joel,
I undestand you completely.
Still,in the context of DIY we're at liberty to advance a bit on the current state of the art?
Diminishing returns?
Well my ears keep on telling me different and apparantly other people, even though they sit at the other end of the world feel likewise.
I always felt it money well spent.
No one is saying your amps are deficient.
I think when we see a good design we just want to make it better still.
(there should be a name for a disease like that)
See you,
subjective results cannot be repeated
Well, yes, that is what everyone seems to fall back on - "I can hear a difference - if you can't, don't do it". That really shuts down the learning process though, doesn't it?
And, yes I do advocate a certain minimalist apporach - but isn't that the essence of what makes a tube amp sound better than a Sony? Everyone always asks "why do tube amps sound different than SS amps"??? Look at the topologies! A williamson sounds a lot more like my 150W Soundcraftsmen MOSFET amplifier, than a single ended triode with 9 parts in it.
So, I think active regulation, OTL designs, current sources, and complex PSU's are heading in the wrong direction. Dunno, maybe I'm nuts.
Well, yes, that is what everyone seems to fall back on - "I can hear a difference - if you can't, don't do it". That really shuts down the learning process though, doesn't it?
And, yes I do advocate a certain minimalist apporach - but isn't that the essence of what makes a tube amp sound better than a Sony? Everyone always asks "why do tube amps sound different than SS amps"??? Look at the topologies! A williamson sounds a lot more like my 150W Soundcraftsmen MOSFET amplifier, than a single ended triode with 9 parts in it.
So, I think active regulation, OTL designs, current sources, and complex PSU's are heading in the wrong direction. Dunno, maybe I'm nuts.
AUDIBLE AND MEASURABLE.
Joel,
Things like this can be measured as well.
I don't think that designing using a dedicated PSU for all stages is all that farfetched anyway.
These kind of upgrades I did for years in a row,every single time the amp or preamp sounded a lot better to everyone that heard it.
When you have repeated results that are so consistent I stop calling that subjective.
Hell,I don't even bother to measure after a while.
If you really want to advance I'ld keep an open mind,won't you?
Circuit
,PSU
.
Cheers,
Joel,
Things like this can be measured as well.
I don't think that designing using a dedicated PSU for all stages is all that farfetched anyway.
These kind of upgrades I did for years in a row,every single time the amp or preamp sounded a lot better to everyone that heard it.
When you have repeated results that are so consistent I stop calling that subjective.
Hell,I don't even bother to measure after a while.
If you really want to advance I'ld keep an open mind,won't you?
Circuit
,PSU .Cheers,
frank, I do try to keep an open mind - to sensible things. But when somebody makes a statement that you should "avoid identical power supply filter sections", it just smacks of audio magazine BS, I have to try to defend good practice... A statement like that flies in the face of 60 years of audio engineering. That is not advancement, it's a step back.
There was a guy in another section of the forum that claims he hears a difference when he places 3 cd's on top of his player, as opposed to only 2 cd's.
I'm not kidding. I will not keep an open mind about that.
There was a guy in another section of the forum that claims he hears a difference when he places 3 cd's on top of his player, as opposed to only 2 cd's.
I'm not kidding. I will not keep an open mind about that.- Status
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