A7 plus Amp. Power/Headroom

[mah]

[Listening test / DIY design] Altec A7 Clone

[Elitopus1]

IMG_9311.JPG


Little pic, but maybe you get the point

[LowOhms]

I think this information is misleading and bone-headed.

Especially IF you are looking for highest possible quality sound reproduction through ALTEC speakers. We have proven this, time and time again, over the past 15 years.

To use INSTANTANEOUS PEAK requirements, and design a SYSTEM around that, is designing it for maybe 0.001% of the music material you will ever hear. What about the other 99.999 % of the time, you spend listening critically, or casually, to your speakers ??

IF an ALTEC A7 speaker is wired correctly ( most are NOT optimally wired ) we use an average of 1/10th to 1/12th of a Watt in our normal listening, be it casual or critical.

A well-designed Serious Stereo single ended 2A3 amp, about 3 Watts, with no feedback, will do the job FAR better than anything " I " have ever heard - any ALTEC speaker ever play. It will be nicer sounding, more natural sounding, and play FAR more dynamic, than ANY 200 Watt solid State amp you put on a A7 !!! Easily. ( This is why I DIY build clones, of such amp circuits )

Raising your eyebrows?? No problem !!!

Let me explain WHY this is so.

To get an ALTEC to play at "normal to high" listening levels, it is paramount that the amp plays the FIRST WATT and BELOW in as pristine a manner as possible. This is the exclusive area where triode tubes are employed, and it will be Single Ended, never ever Push Pull.

IF you seek highest quality reproduction. It requires, to my ears, ( and other CRITICAL listeners ), that the amps have ZERO forms of negative feedback, so as to reproduce the music in the MUSIC's time, and not the AMP's ( any kind of feedback, even a little bit ) feedback time. ( Sorry Nelson, it disqualifies years of your "First Watt" work .) These amps will be monoblocks also, if you want the best possible...I sure do, in 2017 !!

Now, boys and girls, let me explain to you what happens when you put a 200 Watt solid state amp on a ALTEC A7 type of speaker. First of all, 99.9% of the time, the high power amp is being operated at its WORST possible operating points, as far as voltage swing across the devices. Big solid state amps don't "throttle-down" well at ALL, when playing on a ALTEC, well wired, and at our TYPICAL listening levels.

I am talking about amps that the Klipsch boys may use, stuff like the Ashleys, etc. A solid state amp typically requires SOME feedback, if high powered, a LOT of feedback, and that 200 Watt amp is ( a) ALL OUT OF TIME and ( b) can't accelerate from, and get-off dead center. A Typical 200 Watt rated solid state amp, say an Ashley, etc will do 200 Watts into a 1 Kilohertz SINE wave, but if you feed it a MUSIC signals, it is likely only produce 66 Watts. My first audio mentor, showed this to a highly respected Audio Engineer designer, back in the 1980s.

I can tell you this, on my home system, the SET Type 46 stereo amp I built for my friends's Valencia system, 1.3 Watts, will ABSOLUTELY TROUNCE any high-powered amp you put on my system, on DYNAMIC RESOLUTION AND IN DYNAMIC CONTRASTING, except MAYBE a new Spectral DMA-200 as a guess.

For my own use, later this year, I am doing a pair of 3 Watt 2A3 monoblock builds, DIY, precisely the way " I " want it to be executed.

The low powered Triode SET, when WELL done, has itself operating using the best possible voltage swings, at its most linear operating points, and so lovely - with ZERO feedback, for it to match to the ALTEC speaker.

I can offer proof to my post as follws... not in a graph or a table. But by YOU listening.

A well set up ALTEC system will be playing at this year's RMAF audio show, in Denver. in the Serious Stereo room, #3017. I have volunteered to help with the Demos, as I want to hear it more myself, and the Designer is a three-decades audio friend of mine. if you want to hear ALTECS as you never have before, spend some time with us, October 6-7-8th Friday through Sunday. GPA 604s in big MLTL enclosures. Disclaimer, I am NOT an employee of Serious Stereo. There will be about 200 other Audio Manufacturers there at the Denver show, also for you to visit and hear. I hope I can meet some of you.

Have fun. I do ! I am !!


Low Ohms......Jeff Medwin

[Elitopus1]

Jeff
Are you saying the instruments in that chart will not produce the sound levels given?

Being a drummer, I assure you a snare drum can produce a 130db level. My speakers can reproduce that

[LowOhms]

Jeff
Are you saying the instruments in that chart will not produce the sound levels given?

Being a drummer, I assure you a snare drum can produce a 130db level. My speakers can reproduce

EP1,

No, not at all. I say designing for Instantaneous PEAK levels is bone headed, because it forces you into using the WORST sounding amps possible on your ALTEC speakers.

Also, the big amps will often MISS the instantaneous peaks, and much other subtle information, because they (1) playing non linearly and (b) are ALL OUT OF TIME, due to their multiple negative feedback loops. You always hear the ALTEC playback the music in the AMPS time, NOT in the MUSIC's time.

When you HEAR what I am discussing, this is very easy to grasp.

But as I also pointed out, it is easy to " lose it " if ANY part of the system ( wiring, source, etc ) is overlooked and not fully optimized.

Jeff Medwin..... Lpw Ohms

PS OT, Lovely day today for me, so far, in the stock market !

[Old Guy]

I think this information is misleading and bone-headed.


A Typical 200 Watt rated solid state amp, say an Ashley, etc will do 200 Watts into a 1 Kilohertz SINE wave, but if you feed it a MUSIC signals, it is likely only produce 66 Watts. My first audio mentor, showed this to a highly respected Audio Engineer designer, back in the 1980s.


Low Ohms......Jeff Medwin

I think your analysis of amps is misleading and boneheaded. You probably saw a test on an el cheapo amp back in the 80's then you apply what you saw on ONE amp to apply to all amps. It's just not true. Having owned multiple Altec 9440 amps I assure you a 400 watt rated channel can produce substantially more than 132 watts full range, and can reach transients in the over 1000 watt range.

You also likely tried exactly ONE type of musical signal and assumed the same for all musical signals, which is bull.

This is the problem I have with your generalizations, is that you just do not do enough research to back up what you say.

And sorry but your tiny little amp will be distorting on the peaks of the music I listen to. I've actually tested with my music, which you obviously have not.

Use your little amp that you have bragged about at least what, 20 times so far? Your rights end when you start demanding others do it.

And you seriously need to do more work before posting the incredible inaccuracies that you do.

[LowOhms]

I think your analysis of amps is misleading and boneheaded. You probably saw a test on an el cheapo amp back in the 80's then you apply what you saw on ONE amp to apply to all amps. It's just not true. Having owned multiple Altec 9440 amps I assure you a 400 watt rated channel can produce substantially more than 132 watts full range, and can reach transients in the over 1000 watt range.

You also likely tried exactly ONE type of musical signal and assumed the same for all musical signals, which is bull.

This is the problem I have with your generalizations, is that you just do not do enough research to back up what you say.

And sorry but your tiny little amp will be distorting on the peaks of the music I listen to. I've actually tested with my music, which you obviously have not.

Use your little amp that you have bragged about at least what, 20 times so far? Your rights end when you start demanding others do it.

And you seriously need to do more work before posting the incredible inaccuracies that you do.

Hey Old Guy,

My goodness, ALTEC 9440 is ALL you really needed to say!!!

You really don't get it at all, sorry.

I explained it, very well explained, above.

I did not design and do that test. I was told about it only one week ago, from my first audio mentor's Vice President of Manufacturing. My first audio mentor, Robert W. Fulton, who was in the William Z Johnson era, a contemporary, friend and - neighbors to each other, in Minneapolis. They attended the same Church . Robert did the test with an EE.

Ever hear of William Z. Johnson? Ever own any of his gear ?? He, and his wife Nancy, and Robert, we four all knew each other, we were very friendly to each other back then.

Jeff Medwin

[Old Guy]

Hey Old Guy,

My goodness, ALTEC 9440 is ALL you really needed to say!!!

You really don't get it at all, sorry.

I explained it, very well explained, above.

I did not design and do that test. I was told about it only one week ago, from my first audio mentor's Vice President of Manufacturing. My first audio mentor, Robert W. Fulton, who was in the William Z Johnson era, a contemporary, friend and - neighbors to each other, in Minneapolis. They attended the same Church . Robert did the test with an EE.

Ever hear of William Z. Johnson? Ever own any of his gear ?? He, and his wife Nancy, and Robert, we four all knew each other, we were very friendly to each other back then.

Jeff Medwin

Nope- you continually insult other members of the forum while making grossly misleading posts. It's you that doesn't get it. What you want is to come in here and post nonsense while having everyone else agree with you. If you post bullcrap it will be called out as such. Your little flea power amp is not going to work for everyone yet you keep bragging about it over and over while insisting it does.

The same size does not fit all, Jeff. Quit insisting that it does. Since you refuse to quit making misleading posts at least quit posting your misleading info works for everybody.

[LowOhms]

Nope- you continually insult other members of the forum while making grossly misleading posts. It's you that doesn't get it. What you want is to come in here and post nonsense while having everyone else agree with you. If you post bullcrap it will be called out as such. Your little flea power amp is not going to work for everyone yet you keep bragging about it over and over while insisting it does.

The same size does not fit all, Jeff. Quit insisting that it does. Since you refuse to quit making misleading posts at least quit posting your misleading info works for everybody.

Hey Old Guy,

You are severely misquoting me. I never said " one size fits all " ................nor did I say " everyone should do what I do."

EVER !!!

I just very CLEARLY stated that amps, not ALTEC speakers are the problem, and that the best sonics, in HI FI terms, ( not pro sound terms ) will come from only 0.02% of the commercial amps made.

And one choice is solid state and one is tube.

I also said 99.98 percent of the amps " I " have heard, are unacceptable to me.

If my opinion offends you, or Wojo, or ???, I can't help that. I am not here to brown nose a group, be a good ole boy, but only to share HONESTLY my opinions and listening experiences.

My posted inferences are that people should HEAR what I discuss, for themselves, to discover what is possible, at least to my way of hearing things.

Its certainly not criminal, nor done with ill intent. I may be helping some others, opening their eyes, ears, minds, to get them to HEAR and UNDERSTAND what is possible to obtain, sonically, with ALTEC speakers.

Thats it !!

Jeff Medwin.... Low Ohms

[Old Guy]

If that is all you are saying why do you feel the need to repeatedly brag about your amp?

Should I go back through your posts and count how many times you have done so?

And sorry to bruise your ego but what is acceptable to you means nothing to others.

You have for some reason a need to make grandiose and insulting posts not borne out by facts.

And it's very important to you to state your information is valuable. If it's valuable people will recognize it. You shouldn't have to crow about it.

Frankly, 90% of what you post is either useless or flat out wrong.