That's great news meanman1964. 😀
We are talking about the BAKSA this time?
regards
Yes! Greg we do.
For the drivers I used the BD139-140 combo,C3503 for the VAS and the C5200/A1943 as output trannies
For the drivers I used the BD139-140 combo,C3503 for the VAS and the C5200/A1943 as output trannies
2SC3503 have high Early Voltage (Bob Cordell model) and low Cob. It will give low THD in the range of audio frequency.
For drivers I will choose high hFE like 2SC5171/2SA1930 or 2SC4793/2SA1837.
For 75W/4Ohm, I think 300W is enough for 2 channels.
Hi meanman1964,
The bobbins I use come from here:
Jaycar Electronics - Search Results for bobbin
Jaycar are also in the UK (and cheaper)
Jaycar Electronics - Search results bobbin
Also, I have seen then available from the large electronic suppliers as well.
regards
The bobbins I use come from here:
Jaycar Electronics - Search Results for bobbin
Jaycar are also in the UK (and cheaper)
Jaycar Electronics - Search results bobbin
Also, I have seen then available from the large electronic suppliers as well.
regards
D
Deleted member 148505
I find the baksa lacking in details on the top end of percussion instruments.
Also the bass is very punchy, as if there's a "loudness button" that's activated. 🙂
Also the bass is very punchy, as if there's a "loudness button" that's activated. 🙂
Go back to my post #589.
You MUST use top quality polypropylene for the "base charge suck out" cap. This affects the top end detail (I used a Relcap polypropylene), a Polypheylene Sulphide (PPS) cap would probably work well too.
The Vbe bypass cap should be a non-polarised electrolytic (or a Blackgate NX if you can find them and have plenty of cash).
The +ve rail cap on the input diffamp is also critical to good top end detail. Rubycon ZL worked well but the latter ZLH lost top end detail and I did'nt like them.
The bottom end can be manipulated to some degree by varying the bootstrap cap. Since a very large part of the gain of the amp is in that VAS (Voltage Amplifying Stage) with the bootstrapped load, then the quality/size of the bootstrap cap has a large influence.
The simplicity of the circuit means that component quality (particularly capacitors) has a large influence.
Hope this is of some interest/benefit to you.
I've dissappeared onto the "hollow state" (tubes) audio forums these days but my AKSA 55 Nivarna + is still one of my favourite amps and I put it back into the system every 6 months or so just to check that my tube amps are up to standard.
Cheers,
Ian
You MUST use top quality polypropylene for the "base charge suck out" cap. This affects the top end detail (I used a Relcap polypropylene), a Polypheylene Sulphide (PPS) cap would probably work well too.
The Vbe bypass cap should be a non-polarised electrolytic (or a Blackgate NX if you can find them and have plenty of cash).
The +ve rail cap on the input diffamp is also critical to good top end detail. Rubycon ZL worked well but the latter ZLH lost top end detail and I did'nt like them.
The bottom end can be manipulated to some degree by varying the bootstrap cap. Since a very large part of the gain of the amp is in that VAS (Voltage Amplifying Stage) with the bootstrapped load, then the quality/size of the bootstrap cap has a large influence.
The simplicity of the circuit means that component quality (particularly capacitors) has a large influence.
Hope this is of some interest/benefit to you.
I've dissappeared onto the "hollow state" (tubes) audio forums these days but my AKSA 55 Nivarna + is still one of my favourite amps and I put it back into the system every 6 months or so just to check that my tube amps are up to standard.
Cheers,
Ian
mongrel Aksa 55N+
To rabbitz.
I've been reading the thread "Baksa". In his post 272, you say:
I have built a lot of amps such as the AKSA 55, AKSA 55N, AKSA 55N+, AKSA 55N+ (mongrel), DX HRII, GB150, LF55, LM3875, LM4780, NX150, NXV200, P3A, P101 and some SC amps. There is a theme here as I'm sucked in by the presentation of Hugh's amps and my main amp for the last couple of years has been the mongrel AKSA 55N+. That's not going to change any time soon... or ever.
My question is: what is the mongrel aksa 55N+? It refers to a circuit Frugalamp of the Ostripper, Frugalamp 1A, 1B ?. Thank you very much.
GEirin
To rabbitz.
I've been reading the thread "Baksa". In his post 272, you say:
I have built a lot of amps such as the AKSA 55, AKSA 55N, AKSA 55N+, AKSA 55N+ (mongrel), DX HRII, GB150, LF55, LM3875, LM4780, NX150, NXV200, P3A, P101 and some SC amps. There is a theme here as I'm sucked in by the presentation of Hugh's amps and my main amp for the last couple of years has been the mongrel AKSA 55N+. That's not going to change any time soon... or ever.
My question is: what is the mongrel aksa 55N+? It refers to a circuit Frugalamp of the Ostripper, Frugalamp 1A, 1B ?. Thank you very much.
GEirin
Beginners and students - Should you want to understand more of the BAKSA then I would recommend Douglas Self's "Blameless Amplifier" paper. This amp and many more were based upon this amplifier topology.
ALL of the various circuit options in the paper were explored by Hugh and it is interesting to note which of the "advanced options" went into the final design and which were "left on the test bench" as maybe being technically superior but not sounding as good. The paper also gives you the basic math to examine the design yourself.
So for your possible education:
Distortion In Power Amplifiers
Cheers,
Ian (AKSA 55N+ Owner).
ALL of the various circuit options in the paper were explored by Hugh and it is interesting to note which of the "advanced options" went into the final design and which were "left on the test bench" as maybe being technically superior but not sounding as good. The paper also gives you the basic math to examine the design yourself.
So for your possible education:
Distortion In Power Amplifiers
Cheers,
Ian (AKSA 55N+ Owner).
Geirin, Rabbitz doesn't post here very often anymore. But I have chatted with him in the past, and the Mongrel that he refers to is based on an original AKSA 55N+ but with Rabbitz's own modifications and component changes 🙂
Tony.
Tony.
Hi Ian, Geirin, Tony,
Thanks for the comments. I'm watching the Self thread with amusement; I KNOW what measurements better but sounds worse, and I do have my own views about this. But my views are so off the wall, and so absurd to the objectivists, that I do not comment - I'm saving my energies for further amp design, I know how tightly some of these beliefs are held by the intelligensia and I prefer to leave these debates to others. Since illness a couple of years back I do not argue so well now, although I realise now that you cannot convince people if they do not want to be turned. OTOH, I might be wrong, I have known many people who think the AKSAs were poor performing amplifiers, so what would I know?
I come to the conclusion that good results are created by empirical testing rather more than by mathematical analysis, and these approaches cannot be reconciled in 'reasoned' posts. People believe what they belief, and nothing ever changes. A lot of education makes a lot of hubris!
Hugh
Thanks for the comments. I'm watching the Self thread with amusement; I KNOW what measurements better but sounds worse, and I do have my own views about this. But my views are so off the wall, and so absurd to the objectivists, that I do not comment - I'm saving my energies for further amp design, I know how tightly some of these beliefs are held by the intelligensia and I prefer to leave these debates to others. Since illness a couple of years back I do not argue so well now, although I realise now that you cannot convince people if they do not want to be turned. OTOH, I might be wrong, I have known many people who think the AKSAs were poor performing amplifiers, so what would I know?
I come to the conclusion that good results are created by empirical testing rather more than by mathematical analysis, and these approaches cannot be reconciled in 'reasoned' posts. People believe what they belief, and nothing ever changes. A lot of education makes a lot of hubris!
Hugh
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