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Author Topic: Oh the Humanity! 304 Abuse!  (Read 11606 times)
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Patrick J. / KD5OEI
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« on: June 08, 2008, 02:05:10 PM »

Wasting 304's in class A !!  And fer playin the dang phonograph!

Oh the humanity!!


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This ham got his ticket the old fashioned way.


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« Reply #1 on: June 08, 2008, 02:22:42 PM »

Is that the portable amplifier for your ipod, or do you use it in your sports car?
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Rick / W8KHK  ex WB2HKX, WB4GNR
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« Reply #2 on: June 08, 2008, 02:33:04 PM »

Build another one of those, dress them up in a fancy enclosure, and put them on e-Pay with a $50,000 reserve.  You might make it to $100K before bidding ends.  A lot easier and more fun than doing honest but shitty work on a day job for a living.  A phool and his money are soon pharted.

Then use some of the profit to buy up one or more retired tube-type 1-kw broadcast transmitters to convert to the ham bands.
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Don, K4KYV                                       AMI#5
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« Reply #3 on: June 08, 2008, 02:47:41 PM »

even tho ... I'll bet it sounds good ... 73  John
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« Reply #4 on: June 08, 2008, 02:54:20 PM »

Oh no.. it's not mine.. I'm a push-pull beam tube man, myself. Not that I don't like to modulate with the 3-500Z twins now and then. I don't have an ipod, but I use a notebook for playing MP3's, and here is my 6146 tube car stereo power amp I built and used when I had a van. It won't fit in my truck:
http://www.montagar.com/~patj/tubeart.htm

There is a commercial phool version of this thing somewhere with a glass top and an obscene price. I think it's rated 100 watts and I bet it goes though 304's like gas through an H2.

I will allow it probably sounds real good. It's probably the poor man's version of the big phool 304 amp. Getting into the ieea of "perfect amps" like this, the listener/engineer/audioplile/audiophool had best own a very good pair of speakers, or the work is for nothing.

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« Reply #5 on: June 08, 2008, 03:09:12 PM »

As Don says, they go for a Phoolish price:

http://www.alumrocktech.com/amplifier.shtml

http://www.alumrocktech.com/prices.shtml


STEREO 304TL AMPLIFIER  $85,000 
(Includes demonstration at and delivery to your location within the continental U.S. upon payment of a deposit to cover time and travel expenses.)
 
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Rick / W8KHK  ex WB2HKX, WB4GNR
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« Reply #6 on: June 08, 2008, 04:08:12 PM »

I wonder if it is due to the 304 or just the huge class A function?
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« Reply #7 on: June 09, 2008, 07:11:56 AM »

As Don says, they go for a Phoolish price:

http://www.alumrocktech.com/amplifier.shtml

http://www.alumrocktech.com/prices.shtml


STEREO 304TL AMPLIFIER  $85,000 
(Includes demonstration at and delivery to your location within the continental U.S. upon payment of a deposit to cover time and travel expenses.)
 


What a piece of junk!  Puts out 30 whole watts (yes, 30 watts) with (according to their specs) 5% distortion !!!!!!  That's a lot of distortion.  30 watts?

I bet they have not sold one.  Who would be that stupid (maybe I shouldn't ask the question - that's why they're called Phools) enough to buy one of these at $85,000.

If they sold 3 of those in a year, I'll start a company producing tube amps that put out 100 watts using big transmitting triodes.  And I won't even charge more than the 30 watt 5% distortion model these yoyos sell.  You heard it here first!

Regards,

Steve
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« Reply #8 on: June 09, 2008, 09:34:31 AM »

I have resisted entering a discussion of euphony for several months now ... I think hearing is one of our more difficult senses to quantify ... It seems to exist in people in highly varying degrees ... think of it ... it has to be logarithmic in amplitude response to handle the many orders of magnitude of acoustic power levels ... if you buy into the theory of evolutionary development  of human hearing, this would tend to explain why we have the Fletcher-Munson syndrome in amplitude vs freqency response as a survival aid (the peak at 3 kHz is adaptive to twigs snapping, etc)

This can go on a long time....I used to have very good hearing until I started using a  cpap
and my right ear is now functioning poorly ... I can no longer hear the audio hologram of soundstage width, depth, and height .... I can't hear it now BUT I USED TO .... I guess this is what I'm trying to get across ...BEAR has heard it .... I can remember hearing it .... euphony does exist for some and not for others ... how nonegalitarian and unfair ... but the point is ... If some are willing to vote with their $, there just might be something to it .... 73 John
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« Reply #9 on: June 09, 2008, 09:47:13 AM »



Puts out 30 whole watts (yes, 30 watts) with (according to their specs) 5% distortion !!!!!!  That's a lot of distortion.  30 watts?



It takes 100 watts to just light up a 304's filaments..
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« Reply #10 on: June 09, 2008, 10:00:31 AM »

OK , FB OM.
And  nice rug too.

What rug merchant did ya pick that up from? Grin

Better throw it in to on epay.
Increased microphonic suppression of the floor plane acoustics.

Less midrange feedback.
About the bass? ...  well I don't know.
Maybe some foam from a mattress?
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« Reply #11 on: June 09, 2008, 11:33:58 AM »

What a piece of junk!  Puts out 30 whole watts (yes, 30 watts) with (according to their specs) 5% distortion !!!!!!  That's a lot of distortion.  30 watts?

My Gates BC1-T 833A modulators with the shitty 807 direct-coupled cathode follower driver stage is rated at only 2-3% THD at more than 500 watts audio output.

But I get the impression that audiophools love the sound of even harmonic distortion (it adds "tessitura" to the sound of the music).  Even harmonic distortion is what you get bundles of when you run a tube in single ended class-A service.  No tube charts I have ever seen have ever shown a power tube with a perfectly straight line characteristic curve, or even a close approximation to it.  They all have a substantial curvature, particularly at the bottom end.  That's why serious audiophiles run their output tubes in push-pull.  The non-linearities in each side of the balanced cancel out, making it possible to achieve total harmonic distortion levels at below 1%, even without feedback.  With negative feedback, the distortion can be reduced to a fraction of a per cent.

It would be a lot cheaper to simply take a 30-watt amplifier, maybe something running pushpull-parallel 6L6's, and put a resistor in series with a diode across the audio output.  That would give plenty of even-harmonic distortion, just as it does with "negative cycle loading" and "ultramodulation" in a ham transmitter.
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Don, K4KYV                                       AMI#5
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« Reply #12 on: June 09, 2008, 12:48:46 PM »

"tessitura"

I had that once. A week on Penicillin took care of it.

 Grin

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« Reply #13 on: June 09, 2008, 02:40:23 PM »

Quote
Quote from: k4kyv on Today at 11:33:58 AM
"tessitura"


Quote
I had that once. A week on Penicillin took care of it.

 

No Bill.... I think he's talking about that stuff in us that gives us scrote !!
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« Reply #14 on: June 09, 2008, 04:16:36 PM »

I knew I'd seen that rug before.

Found it!   You sly fox. Who'd ever thought you'd build a rig on it.

(Farfest 2003, Howard Co.)


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« Reply #15 on: June 09, 2008, 10:27:23 PM »

Euphony? I looked that one up. I have heard of a eupohonium, the brass instrument.

eu·pho·ny - agreeableness of sound; pleasing effect to the ear, ..

I don't care, I can tell if an amp sounds good to me or not. Euphony is in the ear of the listener. Sure, you can tell a rotten amp! Or a broken one.

I did go back to that costly Phool amp and look at the awful frequency response. For that money, I'd expect it to be flat past 20Hz, not Vout=0.9 at 20Hz. Output transformers way too dinky for 30 watts class A. I bet they never sell any except maybe one to a rich Japanese guy, and he's pissed off, but can't admit it or would lose face!
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« Reply #16 on: June 10, 2008, 09:27:17 AM »

exactly right Patrick ....  I own a Marantz 8 pp amp .... unity coupling output xfmr and measures very well on the test equipment ... the sound is truly excellent and was the first amp that I heard soundstage width on .... I was satisfied untill I heard a single ended directly heated triode amp .... The advantge I heard was at partial power say 25% of full rated outpoot .... Don, it is true that single ended output generates even order harmonics in abundance when overdriven ... the art for hi-fi is not to do that ...73 ...John
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« Reply #17 on: June 10, 2008, 11:51:46 PM »

The only thing I do not care for with class A single ended triode amps is the low efficiency and generally low power output. I like to turn up the sound to an obscene level when the imperial cruiser is firing at the millenium falcon.

Maybe I need two sets of speakers and amps. One for listening to the euponiums and one for listening to the carnage. different tools for different applications.

What, if any, modern, cheap ($120), Pd=300W+ triodes can run class A1 like a 304 though? a 3-500Z is very close to zero bias, complicating drive matters. Would a tetrode like an 4-400 sound as good? Audiophiles seem to say no.
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« Reply #18 on: June 11, 2008, 07:59:17 AM »

What, if any, modern, cheap ($120), Pd=300W+ triodes can run class A1 like a 304 though? a 3-500Z is very close to zero bias, complicating drive matters. Would a tetrode like an 4-400 sound as good? Audiophiles seem to say no.

I guess this calls for a "Double Blind Taste Test"  Roll Eyes Grin Roll Eyes Grin Roll Eyes Grin
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