Thanks Nelson

[nzlowie]

Hi Nelson

I know you're a very busy man and won't have time to answer lots of msg's so I understand if you just take the thanks part of this message!

First of all, I like countless others offer thanks and gratitude for the unselfish work you do for the diy audio community, too many times we see people with your skills just take and take, for me this is refreshing so thanks for being you.

I've just been watching a couple of your video seminars and realized you must have tried hundreds of amp configurations...... I've made a few amps over the years that have been in the diy arena, even though I could probably afford some of the really good gear I enjoy building and trying to optimize my system.
My current system uses 4 ACA's driven with minidsp for my mid/hf horns, a DSP bass amp drives the bass. I think it was zenmod who suggested I could replace the output caps for something better than electrolytic as we only needed FR down to 500hz, this improved things further.

Now comes the questions.....
I know the ACA was meant as a starter project, do you have any better designs you could share in the <5w range? My horn's are around 115db so very little power required.
I'd also like to replace the minidsp with your new xover, I realize it won't have DSP capability but will there be any way to tweak the FR for a non linear driver? Or in your opinion is it better to leave a few peaks and dips rather than eq the hell out of the signal? I like the minimalist approach, the less we interfere the better right?

Sorry msg got a bit longer than planned! Anyway keep up the good work we appreciate your support.

Regards Dave

 

[Nelson Pass]

Flattery will get you anywhere.....

Perhaps a nice single-ended version of a follower? Very easy to do.

Maybe ZM or Mike will put one up.

The first crossover coming does have EQ on top and bottom, as it was set
up for the LXmini. On the top, there is a notch to take out a peak in the
driver, and on the bottom there is boost at the lowest frequency, and
both of these are variable with choice of resistors and capacitors. This
one has fixed values, but I will have another one which is variable,
pretty much delivering the performance of the B5.

 

[Zen Mod]

look no further than Mr. MR's MoFo

 

[woofertester]

Flattery will get you anywhere.....

Perhaps a nice single-ended version of a follower? Very easy to do.

Maybe ZM or Mike will put one up.

The first crossover coming does have EQ on top and bottom, as it was set
up for the LXmini. On the top, there is a notch to take out a peak in the
driver, and on the bottom there is boost at the lowest frequency, and
both of these are variable with choice of resistors and capacitors. This
one has fixed values, but I will have another one which is variable,
pretty much delivering the performance of the B5.

This was the answer to my question the other day.

 

[Michael Rothacher]

Wow! With that sort of efficiency, you could get away with a 12V MoFo, maybe even battery powered. With a nice tube pre, Bob's your uncle.

 

[Zen Mod]

as I said , look no further

 

[Vix]

Or, try F2 lite. Just like an ordinary F2, just replace the CSS withh the lightbulbs. With 19v or 24 v supply, maybe you could get a 2-3 w one. Super simple, has some gain, and it has magic
And yes, thank you Nelson for all amps and bright ideas

 

[Michael Rothacher]

 

[Zen Mod]

for bass duty , increase C1 to 10mF

for squawker duty , leave it as is ..... or use adequately calculated solid cap

 

[nzlowie]

Flattery will get you anywhere.....

Perhaps a nice single-ended version of a follower? Very easy to do.

Maybe ZM or Mike will put one up.

The first crossover coming does have EQ on top and bottom, as it was set
up for the LXmini. On the top, there is a notch to take out a peak in the
driver, and on the bottom there is boost at the lowest frequency, and
both of these are variable with choice of resistors and capacitors. This
one has fixed values, but I will have another one which is variable,
pretty much delivering the performance of the B5.

Nothing wrong with giving credit or thanks where it's due. Too many of us just take without giving a thought to the work that happens in the background. This goes for many aspects of life.

Ok, will keep watching with interest.

Cheers

 

[koja]

I believe that the great majority here understands that Papa must have fried, in his time, bags of transistors to get to know these critters so well to get a single piece (or a pair) to do magic.

 

[Zen Mod]

yup

giving necklace of these to every acquaintance

 

[Nelson Pass]

Actually I have fried very few devices, probably less than a hundred.

 

[res07njc]

The takeaway being... if you understand the physical properties of the things being experimented with, there's no need to break them. Only to determine if they meet your goal. Of course, who doesn't want to witness its limit.

 

[dewdrop]

Actually I have fried very few devices, probably less than a hundred.

And you fry them so that we don't have to. Thanks again for all your contribution.

 

[marconi118]

for high efficiency compression horns from 500Hz (in my case 115db JBL 2360 + 2446j) the small MoFo seems ideal.

I would not go below 15V Psu to avoid stray capacitance of the mosfet? Have read here on this forum.

And loaded with small air core inductor (3mH) or light bulb (800mA bias)?

 

[Zen Mod]

for bulb - at least twice voltage rail , vs. choke iteration

 

[marconi118]

speaking about the B1 buffer as a base to build high pass filter for the active rossover, could it be possible to use the MoFo as the buffer for the high pass filter?

using 2 capacitors in series with the input of hte MoFo and the resistor tapped in the middle of the 2 capacitors to the output of the MoFo?

 

[Zen Mod]

yup

everything is possible , even wooden stove

 

[marconi118]

my question is serious, the answer is maybe no it will introduce distortion sound bad etc...

a schema of what I propose: the MoFo with integrated igh pass filter 12db/oct