"I am looking for musical, warm but detailed sound."
It might help if you added some details about the query and further define the OP?
56v @ 14A is about 780va (+/- 28V rails?) - what do you need it for? What sort of amp? (ClassA, AB, D, etc)
What are the speakers (mains, surround, subs, etc) and how efficient are they (70, 80, 90 dB/W) and how loud do you play them? And what sort of music (Classical, Jazz, R & R, musac, etc) - and so on ...
Eric's report was carried out on smaller sized caps (about 100uF) using his preamplifier and they don't automatically 'scale up' to drive an amplifier/speakers and parallelling a couple of dozen of them doesn't guarantee to produce the expected results either, sorry.
It might help if you added some details about the query and further define the OP?
56v @ 14A is about 780va (+/- 28V rails?) - what do you need it for? What sort of amp? (ClassA, AB, D, etc)
What are the speakers (mains, surround, subs, etc) and how efficient are they (70, 80, 90 dB/W) and how loud do you play them? And what sort of music (Classical, Jazz, R & R, musac, etc) - and so on ...
Eric's report was carried out on smaller sized caps (about 100uF) using his preamplifier and they don't automatically 'scale up' to drive an amplifier/speakers and parallelling a couple of dozen of them doesn't guarantee to produce the expected results either, sorry.
Thanks for your answers and thanks for the nye "toy" 
I found an comment from Ron AKA: Ripple current in input capacitor too high?
Is that a good rule and when "pr rail" does he mean that value for phase and the same value for neutral on left channel and again phase and neutra on the right channel or 4 times in total?
I found an comment from Ron AKA: Ripple current in input capacitor too high?
Is that a good rule and when "pr rail" does he mean that value for phase and the same value for neutral on left channel and again phase and neutra on the right channel or 4 times in total?
Sorry for not including that is a schematic fine?
It is a class A/B amp.
I have some great errors in my calculations, so here are the new:
100W 8Ohm = 28ppV
600VA / 28ppV = 10A
28-0-0-28 10A transformer
My speakers, right now are som old 88dB home build stereo speakers from a former friend that I will change in the future.
I mostly listens to classic, love the sound of a church organ but also Eric Clapton so my style are wide spread.
Lol nothing are so easy
But taking out from specification, does it looks like that those on the schematic are good enough?
EDIT: forgot, I do normally play a bit louder then speak level, up to maybe 80dB
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Ah, that's the thread with the query about the extra bridge for the 'front end' - the diagram is a bit confusing the way it's drawn.
Okay, some comments that are mostly my opinions but looking at your "musical, warm but detailed sound"part for the expected low volume of about 80dB, I think you will be looking to optimise the sound for medium power use, except maybe for the demands of the organ music low frequency response - that can be a bit tricky - the Silmic will give you a softer sound, so don't discount it, but you might find it loses bass definition - I'd be a bit inclined to just 'suck it and see' with this cap and keep a Panasonic FC in your box
I would use the 4,700uF/63 Nichicon KG (Fine Gold) for the rails on the front end gain stage, and the bypass to be polyester (MKC) instead of polypropylene (MKP) for a clear midrange - if your budget will stand it, you could really get better mids/tops with using the BHC SlitFoil caps (Kemet ALC20s, for example - actually made by Supertec)
For the output stage, I think I'd steer clear of the old Phillips BC caps, particularly the bigger sized ones - you would possibly be better off using a pair of the 10,000uF Nichicon 'Super Through' for this - it's more than big enough) to give that 'more musical' feel for the expected large transients - another one you could try here is the Epcos caps - now with TDK website but the numbers are still the same - the new snapin version of the famous B41550s are the pick (used to be called 'Sikorels') but again, not kind to the budget (not sure about this but B41560 - there's a few different ones)
The MUR860 diodes are a well-recognised diode - I suggest you look at the MSR 860 or the bigger 1560s as soft recovery diodes - the Phillips BYV 29s are similar - I recently tried some MBR 1045 that have a lower Vf and excellent (they also come in 80 volts, mbr1080)
Just a final thing - those output 0.15R emitter resistors - if you ask at Elfa, you might be still able to get those Isabellenhutte Manganin power resistors - they're definitely a softer/smoother power resistor than currently available - just a small thing but they all add up
No doubt, there'll be some differing opinions about some of the component choices and it is a bit of a guessing game without hearing any of the other bits in your system, but I used a very similar combination of components on a recent class A amplifier with excellent results, so I think this class AB one will work in a similar way.
Okay, some comments that are mostly my opinions but looking at your "musical, warm but detailed sound"part for the expected low volume of about 80dB, I think you will be looking to optimise the sound for medium power use, except maybe for the demands of the organ music low frequency response - that can be a bit tricky - the Silmic will give you a softer sound, so don't discount it, but you might find it loses bass definition - I'd be a bit inclined to just 'suck it and see' with this cap and keep a Panasonic FC in your box
I would use the 4,700uF/63 Nichicon KG (Fine Gold) for the rails on the front end gain stage, and the bypass to be polyester (MKC) instead of polypropylene (MKP) for a clear midrange - if your budget will stand it, you could really get better mids/tops with using the BHC SlitFoil caps (Kemet ALC20s, for example - actually made by Supertec)
For the output stage, I think I'd steer clear of the old Phillips BC caps, particularly the bigger sized ones - you would possibly be better off using a pair of the 10,000uF Nichicon 'Super Through' for this - it's more than big enough) to give that 'more musical' feel for the expected large transients - another one you could try here is the Epcos caps - now with TDK website but the numbers are still the same - the new snapin version of the famous B41550s are the pick (used to be called 'Sikorels') but again, not kind to the budget (not sure about this but B41560 - there's a few different ones)
The MUR860 diodes are a well-recognised diode - I suggest you look at the MSR 860 or the bigger 1560s as soft recovery diodes - the Phillips BYV 29s are similar - I recently tried some MBR 1045 that have a lower Vf and excellent (they also come in 80 volts, mbr1080)
Just a final thing - those output 0.15R emitter resistors - if you ask at Elfa, you might be still able to get those Isabellenhutte Manganin power resistors - they're definitely a softer/smoother power resistor than currently available - just a small thing but they all add up
No doubt, there'll be some differing opinions about some of the component choices and it is a bit of a guessing game without hearing any of the other bits in your system, but I used a very similar combination of components on a recent class A amplifier with excellent results, so I think this class AB one will work in a similar way.
Nothing good: the circuit is worthless crap, designed by people thinking that useless complication automatically results in better performance.
The reality is that such "elaborate" schemes do in fact the opposite.
First of all, there is no need for two different bridges for the main rectification purpose: one is sufficient, and brings advantages in terms of efficiency and perturbations control. The subject has already been discussed at length.
Adding the third bridge compounds these disadvantages: because it is tributary of the conduction of diodes in the main bridges for its supply, it will be a half wave rectifier, with all the additional ripple it implies.
In short, this silly arrangement does the opposite of what it is supposed to do, and it does so at great expense, with no less than three rectifier bridges when one should be enough, plus two isolation diodes, maybe schottky for the other supplies.
At most, a second bridge could be added to generate the aux. supplies.
Both of these "normal" solutions are superior to the fancy one proposed.
Let me guess: this scheme has been designed by some true audiophile?
This plan has the odd feature that if signal frequency is below line freq, only one of the two 26V secondaries handles each half-cycle of signal. Sag is somewhat higher. The "3rd rectifier" takes AC from both windings, and in this situation will not sag as much, supplying ample headroom voltage to driver stages.
While the load on the 3rd rect is small, the caps are large enough that _I_ would size this 3rd rect for the available surge from the transformer. >6A steady rating should be ample. OTOH I would not be shocked if a 1N4002 bridge lasted years.
I think it is over-wrought.
While the load on the 3rd rect is small, the caps are large enough that _I_ would size this 3rd rect for the available surge from the transformer. >6A steady rating should be ample. OTOH I would not be shocked if a 1N4002 bridge lasted years.
I think it is over-wrought.
jameshillj Wow thanks a heap, I'll follow all your advices and do the changes!
About the base, is it not possible to add a bass-buffer in the circuit, that can compensate for the lack of deepness without making everything boomy? (there are nothing like when the organ in "Toccata and Fugue in D Minor" are scaring the moles under the house or the treble scratching tiles of my roof!
About the base, is it not possible to add a bass-buffer in the circuit, that can compensate for the lack of deepness without making everything boomy? (there are nothing like when the organ in "Toccata and Fugue in D Minor" are scaring the moles under the house or the treble scratching tiles of my roof!
a separate power trafo for the input stage?
how about a separate trafo windings?
i have seen this done on some Japanese amps ...
i wish a study can be done wrt to benefits of using this aside from added parts...
I have not enough knowledge to know what are bull or not, but no matter what, it cant hurt to follow his advice. I need some components and if he means they are better and they are of good quality, maybe the result surprises me!
Help are helples stuck in selecting the right components to an amplifier PSU!
I know that I keep asking the same thing over and over but my brain do not want to understand!
All my confusion comes from a lot of great info from you, that I know are true but are hard for me to combine and maybe I have misunderstood.
Hope that you can help me
I know that the gain in the amplifier are the important number, when trying to ovoid clipping, that (for easy numbers sake) line output to RCA are 1Vpp and that gain x line input = minimum voltage to avoid clipping.
On the other hand do I know that amplifiers rated output wattage depends on the transformers secondary voltage so that 21V would be a 50W 8Ohm and 28V would be a 100W 8Ohm amplifier.
I guess what I am asking, is it possible to look at a schematic and calculate the gain and then calculate the transformers minimum voltage, its needed ampere and in the end how many uF I need?
I know that I keep asking the same thing over and over but my brain do not want to understand!
All my confusion comes from a lot of great info from you, that I know are true but are hard for me to combine and maybe I have misunderstood.
Hope that you can help me
I know that the gain in the amplifier are the important number, when trying to ovoid clipping, that (for easy numbers sake) line output to RCA are 1Vpp and that gain x line input = minimum voltage to avoid clipping.
On the other hand do I know that amplifiers rated output wattage depends on the transformers secondary voltage so that 21V would be a 50W 8Ohm and 28V would be a 100W 8Ohm amplifier.
I guess what I am asking, is it possible to look at a schematic and calculate the gain and then calculate the transformers minimum voltage, its needed ampere and in the end how many uF I need?
The power you want depends on the speaker... the sensitivity of the speaker, and how loud you want to have it. You choose an amplifier that will give you that power.
If you choose your own amplifier rail Voltage, you need to use a design that is OK with it or you might cause damage. Also it might not work properly.
You might be focusing on the sensitivity of the amplifier a little prematurely. It is important enough, if you have everything else worked out.
If you choose your own amplifier rail Voltage, you need to use a design that is OK with it or you might cause damage. Also it might not work properly.
You might be focusing on the sensitivity of the amplifier a little prematurely. It is important enough, if you have everything else worked out.
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