homer09 said:
It's difficult to say if a speaker is hard to drive just by the specs. You will need impedance curves.
Though if you see a speaker that is speced at 4 ohms, you should be aware that it might go lower, and if that dip down is in the lower frequencies it will demand a lot of current from your amp.
Carlos
Thanks and congratulations
Hi Carlos!
I have built my last chip amp (after many others of various configurations), following exactly your last schematics, for the amp itself as well as for the psu (18-0-18 230Va, 4x4700 uf each rail). It has been singing since last night : its sound is wonderful. It's obviously the best I'have made. I'm the happiest diyer ever!
Thanks, Carlos, to share your schematics, ideas, suggestions on this forum : it's been such a great help for me.
Merci beaucoup!
A bientôt.
Jack
Hi Carlos!
I have built my last chip amp (after many others of various configurations), following exactly your last schematics, for the amp itself as well as for the psu (18-0-18 230Va, 4x4700 uf each rail). It has been singing since last night : its sound is wonderful. It's obviously the best I'have made. I'm the happiest diyer ever!
Thanks, Carlos, to share your schematics, ideas, suggestions on this forum : it's been such a great help for me.
Merci beaucoup!
A bientôt.
Jack
Re: Re: Improving the Non-Inverting chipamp
Hi Carlos,
I having some Kiwame of 2.2K / 100, and all parts for unreguated snubberized PS. Now thinking of it's worth trying this.
Rin 10K, Cin 1UF, Rf 2.2K/100 Kiwame, 25W (or 50W version, undecided yet).
How about using "Figure 4 - Second Gain Stage" as buffer with x2 gain using NE5532 ?
Also,
Which one is your preferences for LM3875 using latest 0.1R + 3.3nf snubberized at chip ( I have all parts but undecided yet?
A) 18-0-18 (180VA) or 25-0-25 (240 VA)
B) Unsubberized PS with 10,000 per rail, or 4,700x3 per rail, or 4,700x2 + 2200 + 1000 per rail
C). Standard 2,200 or 1,000 at chip.
??
loong said:
Hi Carlos,
I having some Kiwame of 2.2K / 100, and all parts for unreguated snubberized PS. Now thinking of it's worth trying this.
Rin 10K, Cin 1UF, Rf 2.2K/100 Kiwame, 25W (or 50W version, undecided yet).
How about using "Figure 4 - Second Gain Stage" as buffer with x2 gain using NE5532 ?
Also,
Which one is your preferences for LM3875 using latest 0.1R + 3.3nf snubberized at chip ( I have all parts but undecided yet?
A) 18-0-18 (180VA) or 25-0-25 (240 VA)
B) Unsubberized PS with 10,000 per rail, or 4,700x3 per rail, or 4,700x2 + 2200 + 1000 per rail
C). Standard 2,200 or 1,000 at chip.
??
Nuuk said:
Yes, I have always found the NE5532 to sound unnatural, it is not bad at all but there's some lack of midbass.
Most manufacturers use them on CDPs because it produces a somewhat tighter presentation, 'tighter' bass.
But the problem is before the analog stage. The NEs are just hiding it.
Most CDPs suffer from high jitter and bass is untight. That bad bass is immediately revealed by a good op-amp on the analog stage.
Put there a good clock and PSU and the NE5532 sounds exactly as it does: thin.
One major secret of good amp ...
After had built 6-8 versions of chip amp since 2 years ago, ....
After playing around (including blow many caps /amps and throwing them away) ....
I now realized that ..
- Choice of (good) chips doesn't much matter among LM series, OPA series, STK 404x series
- Exotic components may sound different but not better (subjectively)
However, what I admitted and relaized is that one major secret of a good sounding amp. A chip amp with proper PS can outperform many commercial & expensive amps because of....
the Good Power Supply .....
Amen.
PS: Now, I am having so many chip amps surrounding, and plan to build the final one, the ultimate & best possible LM3875 chip amp, ....
After had built 6-8 versions of chip amp since 2 years ago, ....
After playing around (including blow many caps /amps and throwing them away) ....
I now realized that ..
- Choice of (good) chips doesn't much matter among LM series, OPA series, STK 404x series
- Exotic components may sound different but not better (subjectively)
However, what I admitted and relaized is that one major secret of a good sounding amp. A chip amp with proper PS can outperform many commercial & expensive amps because of....
the Good Power Supply .....
Amen.
PS: Now, I am having so many chip amps surrounding, and plan to build the final one, the ultimate & best possible LM3875 chip amp, ....
Re: Re: One major secret of good amp ...
Ha ha ha,
It is because I have too many chip amps around and my GF want me to have only "one", then do some other hobbies. --_--""
PS: Your GC web site is very informative.
Vikash said:
Haha. You're very disillusioned to think you will ever make a *final* one
Ha ha ha,
It is because I have too many chip amps around and my GF want me to have only "one", then do some other hobbies. --_--""
PS: Your GC web site is very informative.
As it is for some people, including myself, very difficult to locate sources for low-ohmic resistors as needed e.g. in Carlos' design, I ended up in making my own ones.
The procedure is very simple - you just have to crack a wirewound resistor, take out the wire, calculate the resistivity per length relation and cut it down to the appropriate length.
Some more words and pictures on my website.
Mick
The procedure is very simple - you just have to crack a wirewound resistor, take out the wire, calculate the resistivity per length relation and cut it down to the appropriate length.
Some more words and pictures on my website.
Mick
carlosfm said:
How yes! I liked that Setup
The Vivid speakers were also quite good, nice treble but lack of deep bass.
I also liked the Prima Luna Setup and another one that I can’t remember. ( It was in a small room near Bel Canto)
Major disappointment, Krell evolution with Wilson Alexandria….
I could not stay there the full 25m ! It was to dull for my beloved hears! heheheheh
