Re: Re: Re: Caps
My rails are 36V and I believe 680 BG NX don't come in 50V. Anyway, I want to try those 1000u N types to see what the hype is all about😉
protos said:
My rails are 36V and I believe 680 BG NX don't come in 50V. Anyway, I want to try those 1000u N types to see what the hype is all about😉
Re: Caps & batteries
I thought I need two per channel to get 24V. And car batteries are not recommended. I would use Panasonic 12V rechargable, I already have 4 of them at my disposal, but no charger yet😉
carlosfm said:
I thought I need two per channel to get 24V. And car batteries are not recommended. I would use Panasonic 12V rechargable, I already have 4 of them at my disposal, but no charger yet😉
Peter I thought I've read somewhere on this forum that you said the 18V version sounded better than the higher voltage versions. Was this in the bass region? If so, do you think this could be related to the cap size, because logically to me it seems that the higher voltage version just put more stress on the caps especially in the bass region, no?
I was planning to do some comparisons myself, between inverted non-inverted, added dc-servo to get some feeling on the impacts on the sound. And the idea was to do this for my bi-amped system so i could also experiment a little with low capsizes for the highs and highs for the low, but for now i still have murphy to deal with (see other thread)
I was planning to do some comparisons myself, between inverted non-inverted, added dc-servo to get some feeling on the impacts on the sound. And the idea was to do this for my bi-amped system so i could also experiment a little with low capsizes for the highs and highs for the low, but for now i still have murphy to deal with (see other thread)
I never said it sounded better, I only said it makes more bass and in some systems the bass overpowers the rest of the frquencies and the tonal balance is not right. I'm not bass freak anymore and to me 22V sounds the best, with proper dynamics. Of course it all will be dependant on choice of transformes, diodes and caps. So you should also understand that it's best sounding only in my setup, others may differ.
Regarding the caps size, I don't know what the rest of you is using, but my 1000u per rail BG caps, produce subjectively the same amount of bass slamm as Aleph X (with 150,000u). I don't know how it would be if I push the gainclone to the limits, but so far I didn't have that need😉
Re: Re: Caps & batteries
Peter, I didn't explain myself well.
I meant this:
2*24v transformer * 1.41 = 33.84 volts.
3*12volts battery (in series) = 36 volts.
So, this is a value close to what you get with a 24 volt transformer, after the bridges and caps.
Peter Daniel said:
Peter, I didn't explain myself well.
I meant this:
2*24v transformer * 1.41 = 33.84 volts.
3*12volts battery (in series) = 36 volts.
So, this is a value close to what you get with a 24 volt transformer, after the bridges and caps.
nania said:
Thanks... I think I'm starting to understand it now. I will have to build one and see what all the fuss is about.
PSU with input inductors
Has anyone tested GC PSU's with input inductors? Say some 15 mH each?
I have now 4 LM3875 and I will be seaching for parts to build 2 channels.
Has anyone tested GC PSU's with input inductors? Say some 15 mH each?
I have now 4 LM3875 and I will be seaching for parts to build 2 channels.
Why would you need inductors? This is not an Aleph😉
First, they are not needed, second, they won't work in this application, tere are no steady current draw.
First, they are not needed, second, they won't work in this application, tere are no steady current draw.
Of course I'm not sure of the result because these are not tested yet but think they could contribute to:
Clean the grunges from the diode bridge
Better regulatuion for the rails and
Fast acting for power demand which could be good when using small value capacitance.
If idle quisent current is to low for this application I would add some shunt resistance.
I would need though a higher voltage secondary winding to compensate for the voltage loss with the input inductors and provide some 300VA tranies.
Are inductors not applicable for class AB amps?
Clean the grunges from the diode bridge
Better regulatuion for the rails and
Fast acting for power demand which could be good when using small value capacitance.
If idle quisent current is to low for this application I would add some shunt resistance.
I would need though a higher voltage secondary winding to compensate for the voltage loss with the input inductors and provide some 300VA tranies.
Are inductors not applicable for class AB amps?
apassgear said:
At idle there is practically no current draw, so ther is no reason to increase voltage to compensate, when there is no voltage loss. As the current is being drawn the supplies will fluctuate.
As PD says, just plonking an inductor in there for good measure will make regulation somewhat worse.
I don't think that placing inductors in a gainclone power supply would be a good idea (also true for every class B and AB amp)
No inductors, no resistors, ni pi filters. Just caps!
Since you have a class B amp, the drawn current isn't constant at all; so the voltage drop across the inductor (or resistor) will vary, and so will your supply voltage do
If you want to regulate more, try active regulation.
A class B amp's PS can't be designed as a class A's one
No inductors, no resistors, ni pi filters. Just caps!
Since you have a class B amp, the drawn current isn't constant at all; so the voltage drop across the inductor (or resistor) will vary, and so will your supply voltage do
If you want to regulate more, try active regulation.
A class B amp's PS can't be designed as a class A's one
Actually, the same can probably be argued with the Aleph amps with their highly variable instantaneous current draw during operation. The Aleph-X on the other hand is perfect for inductor based power supplies as it has a true constant current draw.
bg alternatif
try 8 different brand 220 microfarad paralleled.
Gives you a wider range of different ESR, kind of low-Q ESR cap. Never tried it myself, but could work, since in the discharge cycle, current availability would by more evenly spread, since not all caps will discharge at the same pace. (Also reason total capacity should be a bit higher compared to the unique bg).
Load cycle will also be more spread-out in time.
try 8 different brand 220 microfarad paralleled.
Gives you a wider range of different ESR, kind of low-Q ESR cap. Never tried it myself, but could work, since in the discharge cycle, current availability would by more evenly spread, since not all caps will discharge at the same pace. (Also reason total capacity should be a bit higher compared to the unique bg).
Load cycle will also be more spread-out in time.
PSU with inductors
Hi all,
I just signed up after following some of the threads for a while.
My current amp started with a few ideas from Thorston i.e. "try batteries with just a 1u cap across this pins" & "try inverting mode"
This gave quite a good result but slightly lacking in detail so I put in some DNM slit foil T network 10,000uf caps that I had.
🙂
This gave a result that ( along with more recent mods including removing the + input resistor ) I am VERY happy with and I regard as my current reference.
When building another amp for a friend I tried to emulate the same very smooth, detailed and natural sound that I have with batteries using a transformer & bridge.
After much experimentation & listening I ended up with schottkys, 2,200uf, choke, 4700uf, choke 10,000uf T network and then the 1uf across the pins. the result was almost indisinguishable from the batteries.
So I say if you feel like trying chokes go ahead and give them a try you might like what you hear
cheers
mike
Hi all,
I just signed up after following some of the threads for a while.
My current amp started with a few ideas from Thorston i.e. "try batteries with just a 1u cap across this pins" & "try inverting mode"
This gave quite a good result but slightly lacking in detail so I put in some DNM slit foil T network 10,000uf caps that I had.
🙂
This gave a result that ( along with more recent mods including removing the + input resistor ) I am VERY happy with and I regard as my current reference.
When building another amp for a friend I tried to emulate the same very smooth, detailed and natural sound that I have with batteries using a transformer & bridge.
After much experimentation & listening I ended up with schottkys, 2,200uf, choke, 4700uf, choke 10,000uf T network and then the 1uf across the pins. the result was almost indisinguishable from the batteries.
So I say if you feel like trying chokes go ahead and give them a try you might like what you hear
cheers
mike
Hi Mike and welcome to the forum.
Before somebody else asks, can you give us more details of your battery set up please? What type of batteries, voltages and do you use one set for both channels?
Again, if you could ellaborate - was this using a PSU in a separate case? If so did all the caps (except the 1.0ufd) go in the PSU with the chokes? And did you use one PSU for both channels or one for each?
Before somebody else asks, can you give us more details of your battery set up please? What type of batteries, voltages and do you use one set for both channels?
Again, if you could ellaborate - was this using a PSU in a separate case? If so did all the caps (except the 1.0ufd) go in the PSU with the chokes? And did you use one PSU for both channels or one for each?
You're reading too fast
Have you read what I said??!
To have a voltage similar to what you get with a 2x24 volts transformer you need 3 12 volt batteries in series per rail.
And that's a fact.
Of cource you don't need the bridges with batteries.
The 1.41 ratio applies to the transformer with the bridges and caps.
That's why you need 3 batteries in series per rail.
Not 4.
Nuuk said:
Have you read what I said??!
To have a voltage similar to what you get with a 2x24 volts transformer you need 3 12 volt batteries in series per rail.
And that's a fact.
Of cource you don't need the bridges with batteries.
The 1.41 ratio applies to the transformer with the bridges and caps.
That's why you need 3 batteries in series per rail.
Not 4.
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