MOSFET amp thump.
 

On 5/05/2016 4:44 PM, Eiron wrote:
On 05/05/2016 07:17, Don Pearce wrote:
On Thu, 5 May 2016 15:12:49 +1000, Trevor Wilson
wrote:


http://me-au.com/me850data2.jpg

It will even survive the crowbar protection system (until that
protection system is destroyed).

Why would anyone design that amplifier and say it is for music? One of
the most pointless specs I've ever read. You're just ****ing your
money away if you buy that.

Because of the Australian fashion for designing speakers with impedances
that drop to zero at the crossover frequencies.


**I should also mention the (in)famous Gale 401 speaker. UK designed and
built, with an impedance curve dipping to around 1.8 Ohms in the
mid-bass region. In fact, the designer of the above-mentioned amplifier
owned a pair of Gale 401s back when they were first released and was
part of the reason why he designed his amplifiers with such prodigious
current ability.

--
Trevor Wilson
www.rageaudio.com.au

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MOSFET amp thump.
 

On Fri, 6 May 2016 06:48:59 +1000, Trevor Wilson
wrote:

On 5/05/2016 4:44 PM, Eiron wrote:
On 05/05/2016 07:17, Don Pearce wrote:
On Thu, 5 May 2016 15:12:49 +1000, Trevor Wilson
wrote:


http://me-au.com/me850data2.jpg

It will even survive the crowbar protection system (until that
protection system is destroyed).

Why would anyone design that amplifier and say it is for music? One of
the most pointless specs I've ever read. You're just ****ing your
money away if you buy that.

Because of the Australian fashion for designing speakers with impedances
that drop to zero at the crossover frequencies.


**I should also mention the (in)famous Gale 401 speaker. UK designed and
built, with an impedance curve dipping to around 1.8 Ohms in the
mid-bass region. In fact, the designer of the above-mentioned amplifier
owned a pair of Gale 401s back when they were first released and was
part of the reason why he designed his amplifiers with such prodigious
current ability.

Gale never made much of a mark here. They pretty quickly got taken
over and became an own-brand label for Richer Sounds.

d

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MOSFET amp thump.
 

On 6/05/2016 8:05 AM, Don Pearce wrote:
On Fri, 6 May 2016 06:48:59 +1000, Trevor Wilson
wrote:

On 5/05/2016 4:44 PM, Eiron wrote:
On 05/05/2016 07:17, Don Pearce wrote:
On Thu, 5 May 2016 15:12:49 +1000, Trevor Wilson
wrote:


http://me-au.com/me850data2.jpg

It will even survive the crowbar protection system (until that
protection system is destroyed).

Why would anyone design that amplifier and say it is for music? One of
the most pointless specs I've ever read. You're just ****ing your
money away if you buy that.

Because of the Australian fashion for designing speakers with impedances
that drop to zero at the crossover frequencies.


**I should also mention the (in)famous Gale 401 speaker. UK designed and
built, with an impedance curve dipping to around 1.8 Ohms in the
mid-bass region. In fact, the designer of the above-mentioned amplifier
owned a pair of Gale 401s back when they were first released and was
part of the reason why he designed his amplifiers with such prodigious
current ability.

Gale never made much of a mark here. They pretty quickly got taken
over and became an own-brand label for Richer Sounds.


**Funny about that. The Gales have acquired something of a cult status
over here. 40 year old examples command quite respectable prices.


--
Trevor Wilson
www.rageaudio.com.au

---
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MOSFET amp thump.
 

On 5/05/2016 4:44 PM, Eiron wrote:
On 05/05/2016 07:17, Don Pearce wrote:
On Thu, 5 May 2016 15:12:49 +1000, Trevor Wilson
wrote:


http://me-au.com/me850data2.jpg

It will even survive the crowbar protection system (until that
protection system is destroyed).

Why would anyone design that amplifier and say it is for music? One of
the most pointless specs I've ever read. You're just ****ing your
money away if you buy that.

Because of the Australian fashion for designing speakers with impedances
that drop to zero at the crossover frequencies.


**I have scanned and uploaded three crossover diagrams from several
Infinity models:

Quantum Line Source (QLS):

The QLS used a VERY heavy, mica coated, clay loaded, 30cm paper cone
'Watkins' bass driver in a large, sealed enclosure. The driver employed
two voice coils. VC1 is a 4 Ohm rated coil and VC2 is a 2 Ohm rated
coil. Very tough to drive, but fabulous sounding system, with, arguably
the best bass of any Infinity speaker.

RS2.5:

The RS2.5 used a single polypropylene, 30cm 'Watkins' bass driver in a
large, sealed enclosure. A ******* of a speaker to driver, with a flabby
bottom end, likely due to the poor piston properties of the bass driver.

RS4.5:

The RS4.5 used two 'Watkins' bass drivers in a very large, sealed
enclosure. Possibly the worst speaker load I've ever encountered. Just
horrible. Destroyer of amplifiers and requiring HUGE gobs of current in
the bottom end. Prodigious, if quite flabby and ill-defined bass. The
mids and highs were easier, being substantially resistive in nature, but
still hovered around 3 Ohms for most of the range.

Crossover schematics:

http://postimg.org/gallery/29r95sbwy/


--
Trevor Wilson
www.rageaudio.com.au

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MOSFET amp thump.
 

On 6/05/2016 9:25 AM, Trevor Wilson wrote:


Crossover schematics:


**Let's try again:

http://www.pdf-archive.com/2016/05/06/infinity-xovers/




--
Trevor Wilson
www.rageaudio.com.au

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MOSFET amp thump.
 

Trevor Wilson wrote:



**I should also mention the (in)famous Gale 401 speaker. UK designed and
built, with an impedance curve dipping to around 1.8 Ohms in the
mid-bass region.

** Not true at all.

The Gale 401 used two nominal 8 ohm woofers ( 5.6ohms DC ) in parallel, with a 3.3mH inductor in series. The box was sealed so the impedance of the woofers rose to a maximum at resonance and fell to a minimum around 250Hz.

http://0339436.netsolhost.com/WordPr...chematic-4.jpg

The minimum *possible* impedance at 250 Hz calculates to 6.3 ohms.

Warm the voice coils up a bit with bass and you will see 8 ohms or more.

Reviews said the speaker's impedance averaged 8 ohms - as claimed.


In fact, the designer of the above-mentioned amplifier
owned a pair of Gale 401s back when they were first released and was
part of the reason why he designed his amplifiers with such prodigious
current ability.


** Really ??

That would have been a big mistake for Mr Stein.



...... Phil