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WHOA! 304Tls

75.128.188.58
Posted on February 25, 2015 at 22:02:43
Michael Samra
Dealer

Posts: 36118
Location: saginaw michigan
Joined: January 30, 2005
 This is an AM modulator which I would love to have but the 304TL only has a MU of 12 and loads at 6.6k in PP at 2500v. A pair of these and you can build a nice 1500 watt PP tube amp if someone could wind an output transformer the size of Vermont.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken

 

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304TL has a following, posted on February 26, 2015 at 05:33:33
Chip647
Audiophile

Posts: 2653
Location: The South
Joined: December 24, 2012

Guitar amps as well.

 

RE: WHOA! 304Tls, posted on February 26, 2015 at 05:50:45
sony6060
Audiophile

Posts: 1465
Location: USA
Joined: August 8, 2014
 I found ten of these 304TL tubes at a garage sale a few years ago. I suspect a problem with ultra high power audio transformers is producing a full range and flat high frequency response. The stray capacitance and insulation spacing in between the windings would be huge.

What would a 2.5KW audio transformer weigh? 75lbs?

 

RE: WHOA! 304Tls, posted on February 26, 2015 at 06:07:55
PakProtector
Audiophile

Posts: 12366
Joined: May 14, 2002
 The smaller tantalum anode stuff is quite enough to run well up to the limits of good OPT performance. The big stuff needs enough dissipation to run the anodes up to gettering temperature. Even two of those in Class A is huge by OPT capability. Dave and Jeffrey have found a few ways around this to good effect though...:) and SE no less...

Their plate resistance is quite low thanks to the gm afforded by what is basically 4 75TL's in parallel...mu of 12 is quite adequate.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

Some guys showed up at RMAF in Denver a few year ago..., posted on February 26, 2015 at 07:24:10
Ivan303
Audiophile

Posts: 48887
Location: Cadiere d'azur FRANCE - Santa Fe, NM
Joined: February 26, 2001

with a PP 304TL amp that filled(and warmed) up most of the room.

One of THE best sounding systems is pictured above, 5 way Ale compression driver horns driven by a custom made SE 304tl mono-blocks.

Seem to recall that a lower voltages (1000-1200) the plate resistance of this tube would be pretty low requiring only a 2.5K to 3.5K output transformer. Likely work fine with something designed for an 845 or GM70.

I've go about a dozen of them somewhere in storage, was thinking of using 'half' of one for a SE amp build, kind of a poor man's 152tl amp.




First they came for the dumb-asses
And I did not speak out
Because I was not a dumb-ass

 

Insanity! (but fun too)! (nt), posted on February 26, 2015 at 16:22:47
gusser
Audiophile

Posts: 3649
Location: So. California
Joined: September 6, 2006
 x

 

At first glance... I thought that those were woodstoves!, posted on February 26, 2015 at 17:08:35
richardl
Audiophile

Posts: 3555
Joined: September 5, 2002
 too big for me

 

RE: Some guys showed up at RMAF in Denver a few year ago..., posted on February 26, 2015 at 19:51:54
Michael Samra
Dealer

Posts: 36118
Location: saginaw michigan
Joined: January 30, 2005
 Are those your Western Electric speakers?
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken

 

RE: WHOA! 304Tls, posted on February 26, 2015 at 20:03:25
Michael Samra
Dealer

Posts: 36118
Location: saginaw michigan
Joined: January 30, 2005
 The 12 mu is fine..Not everyone agrees but even 6L6gc running in triode have a mu of about 6 as I recall.
You have to love to two anodes and two grids. Just keep the Tantalum hot enough to getter by pretty much running it to red.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken

 

Five way ALE Acoustics system..., posted on February 26, 2015 at 20:05:44
Ivan303
Audiophile

Posts: 48887
Location: Cadiere d'azur FRANCE - Santa Fe, NM
Joined: February 26, 2001

Former and possibly current ALE distributor Kevin Brook's home system from about a decade or so ago.

Some of the best sound in a home system I've ever heard!






First they came for the dumb-asses
And I did not speak out
Because I was not a dumb-ass

 

Four anodes...., posted on February 27, 2015 at 07:32:29
Ivan303
Audiophile

Posts: 48887
Location: Cadiere d'azur FRANCE - Santa Fe, NM
Joined: February 26, 2001
 It's four 75tl in parallel.

Cathodes/filaments can be wire as all four in series at 10V or series/parallel at 5V.

This would allow, if one so chooses, to run HALF the tube, with 5V at 12.5A filaments.

At about 1000V and 100ma, this might be somewhere between an 845 and a 211 in plate resistance.


First they came for the dumb-asses
And I did not speak out
Because I was not a dumb-ass

 

RE: WHOA! 304Tls, posted on February 27, 2015 at 08:59:51
Alpha Al
Industry Professional

Posts: 2958
Location: N. Carolina
Joined: February 16, 2004
Contributor
  Since: December 3, 2015
 304TL is an interesting tube. It has four plates in parallel. Supposedly, it is four 100TL's in one envelope. And the filaments are divided into circuits, so you can run them at 5V/25A or 10V/12.5A.

There's also a 304TH, same but with a MU of 20.

 

It's four 75tl or better yet..., posted on February 27, 2015 at 09:24:09
Ivan303
Audiophile

Posts: 48887
Location: Cadiere d'azur FRANCE - Santa Fe, NM
Joined: February 26, 2001
 two 152tl in parallel.

Link below:




First they came for the dumb-asses
And I did not speak out
Because I was not a dumb-ass

 

RE: WHOA! 304Tls, posted on February 27, 2015 at 20:00:01
Michael Samra
Dealer

Posts: 36118
Location: saginaw michigan
Joined: January 30, 2005
 Jim
The audio transformers we use in the AM modulators handle the HV well but we also have a much higher impedance secondary. I would guess it's in the 75lb to 125lb range.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken

 

it is better than that...:), posted on February 28, 2015 at 04:49:55
PakProtector
Audiophile

Posts: 12366
Joined: May 14, 2002
 it is proof that the Religious Fanatic prohibitions against paralleling tubes is BS!
cheers,
Douglas

Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

RE: it is better than that...:), posted on February 28, 2015 at 05:54:47
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 Worse yet... if you run the filaments in series you also have 2 of those parallel plates at 5V less bias than the other two.

dave

 

RE: WHOA! 304Tls, posted on February 28, 2015 at 06:45:49
sony6060
Audiophile

Posts: 1465
Location: USA
Joined: August 8, 2014
 I do like the efficiency of class C RF plate modulated finals.

 

RE: it is better than that...:), posted on February 28, 2015 at 16:58:40
tube wrangler
Manufacturer

Posts: 2484
Location: USA
Joined: January 29, 2007
 Did you know that simply running only the filament will melt solder?

Now, add the plate current to that.

I once built a good sounding S.E. amp out of one-- until I realized that a good 2A3 or 45 outperforms it. It made a nice transmitting tube-- I've replaced a lot of them in Mil.Spec. transmitters.

Guess what? Dull Cherry-Red is what the plates like. Run an old one at the same temperature, and you'll get nothing! (In a transmitter). They have to be "sharp".

For practical purposes, it's another outdated antique. Today, we have 100% solid-state transmitters with autotune.

---Dennis---

 

RE: Some guys showed up at RMAF in Denver a few year ago..., posted on February 28, 2015 at 17:22:10
tube wrangler
Manufacturer

Posts: 2484
Location: USA
Joined: January 29, 2007
 Run 600 VDC across the tube. Decide your loading and plate current, and drive requirements based on that.

The 304TL is plenty linear-- so what is practical works just fine-- no need to morph this thing into a monster. Use a LOT of forced-air cooling.

I was in the room you show at RMAF. This system sounded good, warm, friendly, with low distortion.

Compared to the "ultimate"-- whoever that was-- it scored maybe a 9.3-- of a possible "10".

It's best quality was an effortless ease. What little it lacked was not enough extended highs, and it was slightly euphonic-- not in a necessarily bad way. A good feature which it had was bass that was real--not bloated, and not recessive or peaky.., but which underlaid the music in a positive way-- not overbearing. This shows good woofer cone-control and good execution of speakers in the demo room..

Could one live with this system over a period of years? YES, I think you would keep it.

The Von Gaylord room sounded good also, with their oil-cooled ceramic-triode amps. Von Gaylord demo rooms should always be attended at an audio show, no matter who you are or what you represent. I always make it a point to visit them as well as most others.

---Dennis---



 

RE: Five way ALE Acoustics system..., posted on February 28, 2015 at 19:50:42
Wojciech
Audiophile

Posts: 4131
Joined: June 23, 2009
 I heard he now likes Lowther based system more than the monster horn installation on the picture.

 

WAF?, posted on March 1, 2015 at 08:34:00
Ivan303
Audiophile

Posts: 48887
Location: Cadiere d'azur FRANCE - Santa Fe, NM
Joined: February 26, 2001
 That horn system sure too up a lot of room in the parlor!

Just guessing that Kevin is no longer an ALE dealer, which might explain it as well.

Sure did sound good!




First they came for the dumb-asses
And I did not speak out
Because I was not a dumb-ass

 

RE: WAF?, posted on March 1, 2015 at 09:20:43
Wojciech
Audiophile

Posts: 4131
Joined: June 23, 2009
 My friend who has his Lowther honeymoon (Don't we all at some point in this hobby? Mine was ~5 years ago..;) talks frequently with Kevin.
Surely , well integrated Lowther system is almost maintenance free which can't be said about huge 5 way Ale system.
Rgrds. W

 

RE: did you hear these guys?, posted on March 1, 2015 at 13:01:04
deathtube 667
 Were these guys at RMAF?

Looks like he was influenced by the old Altec/WE single driver technology.

There is a thread started on High EF forum about them.

 

RE: "maintenance free"..., posted on March 1, 2015 at 13:54:16
Ivan303
Audiophile

Posts: 48887
Location: Cadiere d'azur FRANCE - Santa Fe, NM
Joined: February 26, 2001
 What's the maintenance on a 5-way ALE horn system?

OK, once it's set up properly.

Those magnets are pretty stable as long as you don't drop them.




First they came for the dumb-asses
And I did not speak out
Because I was not a dumb-ass

 

Don't recall, but PHY-HP drivers have been around for a while. /n, posted on March 1, 2015 at 13:57:22
Ivan303
Audiophile

Posts: 48887
Location: Cadiere d'azur FRANCE - Santa Fe, NM
Joined: February 26, 2001
 n


First they came for the dumb-asses
And I did not speak out
Because I was not a dumb-ass

 

Isn't the GM-70 the same problem?, posted on March 1, 2015 at 19:55:42
Ivan303
Audiophile

Posts: 48887
Location: Cadiere d'azur FRANCE - Santa Fe, NM
Joined: February 26, 2001
 one end of the cathode is biased at 10V from the other?

And the venerable RCA 10? Biased 7.5V different, one end of the cathode to the other?


And yet...






First they came for the dumb-asses
And I did not speak out
Because I was not a dumb-ass

 

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