Hi-end Pro Amplifier to dream about

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barefoot

barefoot

barefootsound.com
Wow!

I just did a quick search and found that Threshold has resurfaced as a pro amplifier manufacturer. They used to be a very hi-end/hi-fi company. For a mere $7000 here's something to drool over. http://www.threshold-audio.com/Stasis7.html

Cool Lesson in No Compromise Amplifier Design

Warning: The following is very geek/techy.

Threshold uses a completely brute force method of amplification. Bipolar transistors have an optimal collector current (Iopt ) where noise and distortion are minimum. They also have a current gain versus collector current curve. This means the gain versus input level is not flat over the working range of the transistor. What Threshold does is run a whole bunch of high current output transistors in parallel class-A with the idle current in each equal to Iopt . In the case of this amp it's 16 output transistors.

A 100W amp delivers a maximum current of 5A (Ispkr ) into an 8 Ohm speaker at full output. Each of the 16 transistors shares the current (Ishare ) equally.

Ishare = Ispkr /16 = 5A/16 = 0.3125A

If you make Ishare small compared to Iopt (about one 10th) then each transistor stays very close to its optimal current regardless of the current delivered to the speaker. The speaker drive current is only a small perturbation of the idle current. And since the output current of each transistor changes very little, the input current gain versus collector current curve is essentially flat over the small range it covers. This results in very linear gain from the lowest level signals to the highest.

Iopt ± Ishare = Iopt (approximately)

So each transistor idles at

Iopt = 10*Ishare = 3.125A

And the total idle current of each cannel of the amp is

Itotal = 16*Iopt = 50A

50 Amps! From 40V supplies this translates to 2000 Watts!

A 100W stereo amp built on this design principle would dissipate 4000W just sitting there!

I doubt Threshold has gone to such extremes in this pro amp design, but in the past they actually have built amps like I've described. The $7000 price tag of this new model is relatively cheap compared to their old stuff.

barefoot
 

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Yo Shoeless One:]

If you get one these amps, don't drop it on your foot! OUCH, 72 pounds will get your bunions yelling.

Green Hornet:D :p
 
SHUT UP BAREFOOT !

Don't you know that most members here HATE, HATE, HATE, audiophiles like the likes of you & me.

Keep your Hi END thoughts to your self or suffer the terrible
fate that is in store for you.


Didn't you know that all mics, speakers, soundcards, multi-tracks, & cassette decks are created equal ?

FOOL !


LOVE,

SEAN
 
smellyfuzz,

when are you going to post an mp3 so that we can hear your stuff that is so cool.

Hey, mabe we should call you a fool too for buying a bunch of crappy mics. I looked at your list and I did not see a neumann or a BLUE or akg or any tube mic. Your recordings are surely doomed
 
Actually, what we don't like are mystics who spout green-marker bullshit.

True audiophiles that look at specs and can rationalize and quantify their opinions are ok though!

;)

Bruce
 
Blue Bear Sound said:
Actually, what we don't like are mystics who spout green-marker bullshit.
Click to expand...
Couldn't have said it better Bruce. :)

I get very nervous when anyone refers to me as an audiophile. So many who call themselves audiophiles tend to have ridiculous superstitions and completely buy into very expensive placebo effects.
True audiophiles that look at specs and can rationalize and quantify their opinions are ok though!
Click to expand...
Now if you could just adopt this philosophy when it comes to monitors.;)

barefoot
 
I think what the whole thing boils down to is that there are no perfect speakers, they don't exist, and so what you have to do is pick the monitor whose deficiencies you find easiest to compensate for, granted a nearly perfect speaker should be easier to 'correct' for in your head than a horribly innacurate one, but the fact that a lot of pro engineers pick less than perfect monitors seems to contradict this.
Who knows, got me stumped.
:)
 
vox said:
I think what the whole thing boils down to is that there are no perfect speakers, and so what you have to do is pick the monitor whose deficiencies you find easiest to compensate for...
Click to expand...

Well, you definitely have a point when it comes to Mackies, Events, Yorkvilles and the like. These are all VERY far from perfect, and choosing one is almost like picking your favorite shade of mud.;)

It's an involved subject, but one of these days I need to write a long post explaining the major factors in monitor designs - what sets them apart and what they generally have in common. Everyone seems to think it's so mysterious, but in fact, just looking at the basic design of a speaker can tell you quite a lot. Size, materials, crossover frequency, port placement, etc., are all good predictors of a monitors behavior, especially with respect to how the sound spreads in a room. What is more difficult to determine is a monitors distortion characteristics. These have a lot to do with the internal driver design. Of course, price is sometimes an indicator.

Anyhow, every time I start to write about this stuff I get the feeling it's going to turn into a book. Maybe I'll try doing it in installments in a single thread.

barefoot
 
when are you going to post an mp3 so that we can hear your stuff that is so cool.
Click to expand...

CYAN,

Many, many times members like the likes of you have stated that to me.

I ask you, have I ever stated that I was a recording engineer, that I worked in a studio, that I knew how to master an album ?

I sit at a perspective of having a semi flat, some what accurate stereo system,
in a fairly good sounding room that allows compact disks to be reproduced
reveling their dynamics & flaws.

I have spent countless hours JUST listening & analyzing my favorite music.

AND although, one could spend far more money for a system then I did mine,
I'm confident that my setup is far more ear pleasing and reveling then say 90%
of the current members' stereos at HR.com.

For me to start advertising that I have some song for all to tear down the
musical quality would serve only to let members be vindictive.

Plus, I have no desire to prove to plastic speaker recording artist, that the time I'm spending LEARNING recording & mixing, is well spent.

My problem with many members here, & why I make such statements is that too
many members have not spent any time listening to even a remotely ACCURATE
music systems, nor do they accept the fact that recording on a CPU with a Soundblaster & plastic speakers will NOT give them a million dollar sounding song.


Hey, mabe we should call you a fool too for buying a bunch of crappy mics. I looked at your list and I did not see a neumann or a BLUE or akg or any tube mic. Your recordings are surely doomed
Click to expand...

Missed my point completely,

I do not claim to have any "state of the art equipment".

Nor do I buy into The Marshall mics sound just a good as a Neumann.

You have been around here a long time Cyan,
doesn't bother you a little that just because Harvey (who I respect) states
that a certain mic is good, every one seems to run out & buy one
Then that person thinks he/she has a studio full of $200-300 state of the art wonders?

Barefoot put this piece of equipment up, & it looks cool, but I'm sure he
would be the first to recommend giving it a listen before you buy.

I'm sure he wouldn't expect anyone to just take his word for it.

Anyway, how often do we post about amps & their effects on sound ?
We are to busy talking about micing & compression.
How often do ever talk even about accuracy of sound going to tape or hard disk.

I do not expect anyone here to even consider buying a Threshold,
I understand all about being poor or on a budget, but should we not at least
discuss why it sells for $7000.00 & how it would effect our mix-downs ?


BAREFOOT,

Carful when you are agreeing with Blue Bear on this subject,
He is an advocate for dismissing the importance of cabling, speaker stands,
room treatment placement, absorption feet & spending too much on equipment.
 
If you preach to a 13 yr old girl that nsync is bad, do you get surprised when you get scorn in return?

Smellyfuzz,
you by now know my view on audiophilia. It is exciting. If I had the money, I would have an audiophile system. And I am not talking a wannabe audiophile system. I am talking $50,000 or more. The fact is that you think you are in a vantage position because you have a measly(i dont know how much it cost) system. Maybe you are, but I am also sure that some higher audiophiles will think that your system and room are for amateurs. Dont worry, you will understand what a real audiophile is talking about when youre big

You are right-if you post music on this board, it will get torn apart pretty bad. I am almost sure that you will produce something so substandard as to be embarassing. You critisize a person for thinking highly of his sblive . If everybody got critisized for having less than perfect gear, then nobody would have gear, because for every piece of gear, there is a better one out there. Remember, music is not all about sound. You should be ashamed of listening to crappy music just because it was recorded on audiphile gear.

By the way, I think that you should be ashamed for buying crappy gear. You should be penalized for buying all those fake mics. How do you expect an audiophile to listen to your work. It will be completely substandard. No tube warmth, no rich midrange, harsh highend.

As far as people buying gear on another person's opinion, it is a matter or respect for the person and having no other choice.

If you think your system is not better than 100% of members at hr system, then something is wrong. I spent $500 on my system, you probably $7500. What do you expect. DUH

Hey, if you insist that you are not into recording, or mastering, then leave us be and let us make music.

Btw, everybody on this board has spent countless hours just studying and analyzing our favorite music.
 
smellyfuzz originally wrote:
Barefoot put this piece of equipment up, & it looks cool, but I'm sure he would be the first to recommend giving it a listen before you buy.

I'm sure he wouldn't expect anyone to just take his word for it.
Click to expand...
I say don't trust my opinion, trust the (real) numbers.

I build speakers, so I'm intimately familiar with their problems, which are many and far more significant than those of electronics. And since amps drive speakers, I've also spent a fair amount of time investigating them as well. Personally, I don't want my amp to "sound" like anything. What I want in an amplifier is a perfect linear gain voltage source capable of driving complex low impedance loads without perturbation. In this regard I trust my instruments more than I do my ears.

Since audio systems, most especially speakers, are fought with nonlinearities I can't say I know exactly what perfect reproduction sounds like. As I design better systems, or hear other's designs, I continually learn what accuracy sounds like. I love to listen to music through beautiful equipment, but as far as accuracy goes, I trust the numbers most.
BAREFOOT,

Carful when you are agreeing with Blue Bear on this subject, He is an advocate for dismissing the importance of cabling, speaker stands, room treatment placement, absorption feet & spending too much on equipment.
Click to expand...
I won't speak for Bruce, but here's my brief opinion on these topics:

Cabling - Significant when connected to very low voltage, low current sources such as a microphones. Insignificant for line level and speaker level signals unless they have bad connections (cold solder joints or such) or very long runs. Once I was trying to sell my speakers to a hi-end shop. The owner told me the quality of the speaker cables was more important than the quality of the speakers. I laughed at him. Obviously I didn't make the sale.

Speaker Stands and Feet - Unless your floor is made of stretched tin foil or something these make very little difference. Better to throw your money into a more inert speaker cabinet than into fancy stands and spikes.

Room Treatment Placement - Depending on the frequency and the type of treatment, placement can definitely matter. Mid and high frequency absorption or diffusion at first refection points can have a significant impact on imaging. Low frequency absorption tends to be more effective in corners due to the nature of standing wave modes.

Spending Too Much on Equipment - My wife thinks any amount I spend on equipment is too much, while no amount she spends on shoes is ever too much .;)

barefoot
 
SORRY GUYS

CYAN,

I seem to keep making you angry.

In all honesty, not my intentions here.

Nor do I mean to preach, but only to offer a different point of view.

LET FACE IT CYAN.....

That does not ever go over well here, in this very, very gang mentality
web-site.

It is obvious that I'm not a very good writer,
so my opinions might be miss understood.

BUT Sonusman, seems to be more eloquent in his posts &
points out basically points of views that I agree with:

https://homerecording.com/bbs/showthread.php?s=&threadid=13758


https://homerecording.com/bbs/showthread.php?s=&threadid=28755&perpage=25&pagenumber=2


Barefoot,

That man was absolutely a fool.

And yes, in audiophile land, just as recording engineer land,
just as many speaker & electronics land, many fools show up.

Never the less, I do respect your knowledge of speakers.

I like that you posted an amp that few can afford, so we can marvel at
its construction.

And I completely disagree with your views on stands & cabling.



LOVE,

SEAN
 
lay off sean...


there's no need for all this, this is a cool community, no need for any angry comments.
 
Ah, say what you will, but paying $7000 for a power amp just seems sick & wrong. Of course, I feel the same way about nsync....
 
Yeah, it's probably overkill even for a pro studio. Really it's designed like a true "reference" amp for laboratory work. It makes sense, and I'd love to have one, for testing loudspeakers though. :)

barefoot
 
That's a cool amp! All you need now is a pair of killer speakers - and then of cause some cheapass thin copper wire to hook'em up :rolleyes:
 
Tired of fighting lightweights

For those of you who may not know, sjoko is referring to a "debate" we got into in another thread. https://homerecording.com/bbs/showthread.php?threadid=13758&perpage=25&pagenumber=1
I use quotes around "debate" because it's pretty one sided with respect to thoughtful arguments.

sjoko,

Until you can reply with an informed response that shows:

1. You actually understand the principles behind the arguments I have put forward.
2. Specific counter arguments with supporting data to refute my arguments.

Then I'll take you seriously. Until then, all I can see you have to offer are your unsubstantiated superstitions, insults, and rolled eyes - very compelling arguments indeed.

Oh and tell me, where do you buy all your electronics with those special "transmission line" copper wrapped silver PC board traces? Or, how about those copper wrapped silver voice coils in your speakers? Certainly you need these to match your hyperphysical Zaolla wire.

Come on sjoko. Give me some intelligent thoughts on this subject, or step off.

barefoot
 
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Thanks for posting that link - I prefer fact over "science"
Here's an other one for you :rolleyes: :D
 
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