A7 plus Amp. Power/Headroom

[tomt]

"Perfect" only exists in the associated personalities.

I like that.

[Old Guy]

On a 288 or 291 high pass filtered at 400-500hz with an appropriate acoustic load in front of it, 3 to 5 watts can take you a good ways down that road, certainly you should be able to expect clean ~120db peaks. That's nothing to sneeze at.

Much of the magic is happening above that kneepoint anyway.

For me, hifi and most aspects of audio in general are a giant balancing act of compromise at nearly all levels. "Perfect" only exists in the associated personalities.

If you figure a 110 dB/w driver- bear in mind this is at 1 meter usually...then in theory 1/10 watt will generate 100 dB. 1 watt would generate 110 Db since 10 dB is ten times power.

Here's where the flea power amp begins to lose it. The next 10 dB to reach 120 is again ten times power, or 10 watts. All amps can put out transients far beyond continuous ratings, so let's say the 2 or 3 watt amp can get us there. If you are willing to sit 3 feet from the driver a small amp can get you to 120 dB IF you are listening at 1/10 of a watt average level. The amp is reproducing a 10 watt transient.

The next 10 dB to get to 130 is again 10 times power. That flea power amp would be called upon to generate 100 watt transients cleanly. If you believe that I have some bottom land in the Everglades for sale.

This is all assuming the listener is one meter from the speaker with a 110 dB/watt speaker. Get realistic, and start thinking about a 100 dB/watt woofer and you soon realize that you need a 100 watt amp that can reproduce 1 kilowatt transients. Surprisingly not difficult to find. But it is absolutely impossible that the small amp can reach a 130 dB transient cleanly with any woofer on the market.

If listening to recordings with limited dynamic range you will likely be OK with the small amp. But if listening at a higher average level than 100 dB, or to wide range recordings, the little amp is, as Monty Python would say, right out.

[LowOhms]

Again, you are mostly looking to design a system that plays 0.01 percent of the recorded audio information, while neglecting the possibility of hearing the highest QUALITY reproduction, for all the rest of the audio reproduction, the remaining 99.99 percent of recorded material, which plays back in our homes 99.99 percent of the time. That makes absolutely very LITTLE sense to me.

There are HUGE differences in sonics, between amps, but to judge audio AMPS, and get a great one, TAKES a high quality ALTEC speaker ( or WW2 Klangfilm, or Ale drivers ) of 100 db plus efficiency, to hear and tell whats going on.

Some, over the years, (only a few ), have worked this amplifier requirement out beautifully, using ALTEC drivers, or JBL, and taken it to " as close as possible " to perfection. Perfection is an unobtainable goal.

I have been DIY building, usually from-scratch designing DHTs, ( directly heated triode amps ), since 1982, which was my first 2A3 amp build. No negative feedback loop, in ALL of these designs. What a PLEASURE it is to me, to hear an ALTEC VOTT or 604 speaker with an amp with ZERO negative feedback. You hear all the music in the time of the music, and NOT in the out-of-time overlay of a typical audio amp.

Everything is important if you want the system to fly, and I have found MANY things that will cause loss of " the musical experience", IF the detail is not thought of, or properly attended to..

AS I have often asserted, I find VERY few know how to get the amp as good as possible, for the optimal ALTEC listening experience. Its a lot of fun for me, thinking and working on this one aspect... the audio amplifier. Late 2017 will see me DIYing for myself, new 2A3 monoblocks for my VOTTS, with all I know and have learned to date, incorporated into it.

No one in this world has yet heard a directly coupled, two stage, SE 2A3 mono amp with two SIX ohm power supply chokes per channel. That's only twelve ohms ( total ) DC resistance in the B+ Supply. Additionally, employing new supply caps capable of doing 1.500 Amperes Peak Instantaneous. ( in-time Rim-shots anyone :-) ? And a system wired internally ...for efficient energy transfer, to support it linearly ??? Need a couple of months and I will get it built, 'waiting on my chassis welder presently.

The DC SE Type 46 stereo amp I designed and built May 2017 was for Greg B.'s Valencias. It really was a "warm up", for this upcoming mono 2A3 build - something for my own use, long-term.

To be continued... my friends.

Have FUN, I sure do.

Low Ohms,...... Jeff Medwin

[Phil-G]

To be continued... Jeff Medwin

Ad Nauseam

[mah]

The 'best way' repetition in this thread alone is obvious.

[LowOhms]

The 'best way' repetition in this thread alone is obvious.

Absolutely. About 3,500 people have accessed this Thread. Maybe some will learn about this new capacitor type, my original intent is to share with all, and advantageously be able to employ them.

The best....

In audio, if you don't try to do it the best way you can, I always find, it isn't worth doing !!!

Others may have different values, but what I say is precisely my own values and goals, since I was 20 years old.


Low Ohms..... Jeff Medwin

[Phil-G]

Maybe some will learn about this new capacitor type,

that's a different thread

[mah]

LowOhms: "Absolutely. About 3,500 people have accessed this Thread. Maybe some will learn about this new capacitor type, my original intent is to share with all, and advantageously be able to employ them".

Given the frequent repetition and thread-jacking, I'd say that is proselytizing - adding little to this forum. IMHOOC.

Considering that this forum is basically about Vintage Altec Products I am surprised that your obvious and repetitious pushing of your personal hobby fringe views(with little respect for the preferences and choices of other members) has not been moderated here, especially in light of members objections.

[magnarc]

If you figure a 110 dB/w driver- bear in mind this is at 1 meter usually...then in theory 1/10 watt will generate 100 dB. 1 watt would generate 110 Db since 10 dB is ten times power.

Here's where the flea power amp begins to lose it. The next 10 dB to reach 120 is again ten times power, or 10 watts. All amps can put out transients far beyond continuous ratings, so let's say the 2 or 3 watt amp can get us there. If you are willing to sit 3 feet from the driver a small amp can get you to 120 dB IF you are listening at 1/10 of a watt average level. The amp is reproducing a 10 watt transient.

The next 10 dB to get to 130 is again 10 times power. That flea power amp would be called upon to generate 100 watt transients cleanly. If you believe that I have some bottom land in the Everglades for sale.

This is all assuming the listener is one meter from the speaker with a 110 dB/watt speaker. Get realistic, and start thinking about a 100 dB/watt woofer and you soon realize that you need a 100 watt amp that can reproduce 1 kilowatt transients. Surprisingly not difficult to find. But it is absolutely impossible that the small amp can reach a 130 dB transient cleanly with any woofer on the market.

If listening to recordings with limited dynamic range you will likely be OK with the small amp. But if listening at a higher average level than 100 dB, or to wide range recordings, the little amp is, as Monty Python would say, right out.

Again, thank you Old Guy for reiterating concisely what most of us on this board know!
You need clean amplifier power to cover ALL aspects of the program material, ever for one split second.
I'd rather my clean power than blown voice coils from an amp that clips.

[LowOhms]

LowOhms: "Absolutely. About 3,500 people have accessed this Thread. Maybe some will learn about this new capacitor type, my original intent is to share with all, and advantageously be able to employ them".

Given the frequent repetition and thread-jacking, I'd say that is proselytizing - adding little to this forum. IMHOOC.

Considering that this forum is basically about Vintage Altec Products I am surprised that your obvious and repetitious pushing of your personal hobby fringe views(with little respect for the preferences and choices of other members) has not been moderated here, especially in light of members objections.

YOU should be moderated here, for constantly picking on me.

WE were both warned about bad behavior this week mah. Remember??

This is not the "good ole boy" Forum for you to spend all your retirement time, posting upon.

New ideas, relating to audio, and directly to ALTEC applications, are a positive, not a negative.

I am discussing best possible caps, ( the ONLY ones, I find, that DYNAMICALLY get the leading edge of transients, bass on up .... 1,500 Amperes Peak ) to use as bypasses in key positions, in the other thread.

In this thread, I shed light on the sonic trade-offs of designing for "headroom" in amplifiers powering 100 + dB speakers. I suggested the latest and best possible power amps, to play an ALTEC in the home, and have it sound like the real thing. Amps that can play back material in-time of the music, and easily provide a serious listener with the beat possible dynamics for home-use ALTECs, ....by FAR.

I gave GREAT engineering reasons as to WHY this is so, ( which NO one denies ), and why it will sound better in a home than your complex setup - two biamped, digitally EQed NAD amps, or any older Ashley FET amps, throttled down.

It is a well-reviewed amplifier I refer to, and a proven ( 1929 Loftin-White variant ) circuit, superbly implemented to perfection, never really outdone when operating properly, since its inception, in 1989.

This gets demoed on GPA 604s / MLTLs, GM inspired, each year since 2005 at RMAF's October shows, and in Montana it can be heard. "I " use the circuit, DIYed, as my favorite, for my VOTT A5-800 hybrids.

I suggest, this is entirely related and pertains to ALTEC speakers, old and new GPAs, and this " headroom " thread.. :-)

Jeff Medwin .... Low Ohms.