[Martin Schöön]

Anyone here with firsthand experience of amplifiers
based on Tripath's ICs?

For example:
http://www.41hz.com/

--
Martin Schöön "Problems worthy of attack
show their worth by hitting back."
Piet Hein

[Arny Krueger]

"Martin "Schöön"" wrote in
message
Anyone here with firsthand experience of amplifiers
based on Tripath's ICs?

Yes. IME, worse then mediocre.

[Eeyore]

Martin Schöön wrote:

Anyone here with firsthand experience of amplifiers based on Tripath's
ICs?

Sort of ages back. I was considering using them for our products.

Why do you ask ?

Graham

[Trevor Wilson[_2_]]

"Martin "Schöön"" wrote in message
...
Anyone here with firsthand experience of amplifiers
based on Tripath's ICs?

**Yep. They're expensive, REALLY poor performing, unreliable POS. They were
a con-job from day one.

Trevor Wilson

[Geoff]

Martin "Schöön" wrote:
Anyone here with firsthand experience of amplifiers
based on Tripath's ICs?

For example:
http://www.41hz.com/

Yes - I purchased one from www.cadaudio.dk that didn't work, and have had
years of coresspondence (pretty much one-sided, not many replies) and no
resolution. But that's not Tripath's fault !


geoff

[Kevin McMurtrie]

In article ,
(Martin Schöön) wrote:

Anyone here with firsthand experience of amplifiers
based on Tripath's ICs?

For example:
http://www.41hz.com/

I haven't used them personally but I read their sample schematics and
docs. They're not audiophile but they're nothing to worry about for the
MP3 generation. Their primary feature is enabling ultra-compact
amplifiers with low complexity and cost.

The corporate web site appears to have been abandoned in late 2006.
Most of the products that have documentation are marked as obsolete.
The last PR entries are about lawsuit settlements.

--
I don't read Google's spam. Reply with another service.

[Arny Krueger]

"Kevin McMurtrie" wrote in
message

In article ,
(Martin Schöön) wrote:

Anyone here with firsthand experience of amplifiers
based on Tripath's ICs?

For example:
http://www.41hz.com/

I haven't used them personally but I read their sample
schematics and docs. They're not audiophile but they're
nothing to worry about for the MP3 generation. Their
primary feature is enabling ultra-compact amplifiers with
low complexity and cost.

The irony is that the Tripath amp I have, which is based on their TA2020
chip and a few discrete transistors, is neither smaller nor cheaper, nor
simpler than a comparable linear amp would be. The parts count and size is
inflated by the low pass filter on the outputs. The heat sinks are tiny, but
everything else is pretty much regular-sized. The output filter network is
almost half the amp, and is loaded with inductors that were no doubt not
free.

[Eeyore]

Arny Krueger wrote:

"Kevin McMurtrie" wrote
(Martin Schöön) wrote:

Anyone here with firsthand experience of amplifiers
based on Tripath's ICs?

For example:
http://www.41hz.com/

I haven't used them personally but I read their sample
schematics and docs. They're not audiophile but they're
nothing to worry about for the MP3 generation. Their
primary feature is enabling ultra-compact amplifiers with
low complexity and cost.

The irony is that the Tripath amp I have, which is based on their TA2020
chip and a few discrete transistors, is neither smaller nor cheaper, nor
simpler than a comparable linear amp would be. The parts count and size is
inflated by the low pass filter on the outputs. The heat sinks are tiny, but
everything else is pretty much regular-sized. The output filter network is
almost half the amp, and is loaded with inductors that were no doubt not
free.

Sure, but it'll use less power than a linear amp. That's a main reason why
switching amps have become popular, although I note that the supposed popularity
seems to have waned recently.

I was SERIOUSLY considering Tripath for a new product back around 2000 but I
wasn't impressed by the demonstration where I wanted to run it at its full
power sine wave rating but the rep said the demo amp wasn't designed to cope
with that ! What the hell were they thinking of ?

Graham

[Arny Krueger]

"Eeyore" wrote in
message
Arny Krueger wrote:

"Kevin McMurtrie" wrote
(Martin Schöön) wrote:

Anyone here with firsthand experience of amplifiers
based on Tripath's ICs?

For example:
http://www.41hz.com/

I haven't used them personally but I read their sample
schematics and docs. They're not audiophile but they're
nothing to worry about for the MP3 generation. Their
primary feature is enabling ultra-compact amplifiers
with low complexity and cost.

The irony is that the Tripath amp I have, which is based
on their TA2020 chip and a few discrete transistors, is
neither smaller nor cheaper, nor simpler than a
comparable linear amp would be. The parts count and
size is inflated by the low pass filter on the outputs.
The heat sinks are tiny, but everything else is pretty
much regular-sized. The output filter network is almost
half the amp, and is loaded with inductors that were no
doubt not free.

Sure, but it'll use less power than a linear amp.

In most office and home applications that's not an issue. Even in mobile
applications like a car, there's plenty of power available.

That's
a main reason why switching amps have become popular,
although I note that the supposed popularity seems to
have waned recently.

I see using them in cell phones. I don't think they have gone anywhere with
portable music players.

I was SERIOUSLY considering Tripath for a new product
back around 2000 but I wasn't impressed by the
demonstration where I wanted to run it at its full power
sine wave rating

The Tripath module I have was rated well optimistically.

but the rep said the demo amp wasn't
designed to cope with that ! What the hell were they
thinking of ?

The problem I saw was that ignoring your first nasty bit of news, the amps
had a lot of nonlinear distortion related to the switching, well below
clipping. I mean like 2-3 dB below clipping. They also had a relatively
high output impedance in the top half of the audio band.

[Chris Morriss]

In message , Arny Krueger
writes

Snipped...

The problem I saw was that ignoring your first nasty bit of news, the amps
had a lot of nonlinear distortion related to the switching, well below
clipping. I mean like 2-3 dB below clipping. They also had a relatively
high output impedance in the top half of the audio band.



The Tripath design took its NFB from before the output filter, so the
rising impedance of the output inductor became important.

The UCD design is one of the few that take the NFB after the output
filter and use the phase shift of the filter (together with other
components) to set the self-oscillating frequency.

For those who are interested, it's worth reading the paper that Bruno
Putzeys (then of Philips) presented at an AES conference a few years
ago. It details the background behind the UCD design.
--
Chris Morriss

[Kevin McMurtrie]

In article ,
"Arny Krueger" wrote:

"Eeyore" wrote in
message
[ snip ]

Sure, but it'll use less power than a linear amp.

In most office and home applications that's not an issue. Even in mobile
applications like a car, there's plenty of power available.

There's never enough power and cooling available! Car audio is
especially problematic because 12V wiring is expensive and there's no
room for cooling. My Roku Radio uses a Class D amp so the entire
enclosure can be a tuned woofer cabinet without overheating. Small
electronics use Class D so that the audio amp fits on the main PCB
without extra copper layers for cooling.

Home theater also seems to have reached the point where the Class D
electronics are cheaper than the bulk. Half of the new models I saw
this Christmas were Class D.

--
I don't read Google's spam. Reply with another service.

[Eeyore]

Arny Krueger wrote:

The problem I saw was that ...... the amps
had a lot of nonlinear distortion related to the switching, well below
clipping. I mean like 2-3 dB below clipping.

Yes. For a while they had an application note that explained that. It looked
like 'fuzz' on the output waveform that's reminiscent of instability in linear
designs. It wasn't a disaster from a spec viewepoint since it was all beyond
the audio range but it didn't give one confidence.

Graham

[Chris Morriss]

In message , Kevin
McMurtrie writes
In article ,
(Martin Schöön) wrote:

Anyone here with firsthand experience of amplifiers
based on Tripath's ICs?

For example:
http://www.41hz.com/

I haven't used them personally but I read their sample schematics and
docs. They're not audiophile but they're nothing to worry about for the
MP3 generation. Their primary feature is enabling ultra-compact
amplifiers with low complexity and cost.

The corporate web site appears to have been abandoned in late 2006.
Most of the products that have documentation are marked as obsolete.
The last PR entries are about lawsuit settlements.


They weren't really anything new in the Class-D world.

If you want to buy Class-D modules with real quality performance I
suggest you have a look at the UCD range on the Hypex website.
--
Chris Morriss