WD Class D Amps?

[Black Stuart]

Leo,
that is the amp but I think that is not a complete schematic.

Thanks for posting that site. That it only draws 88W is very interesting indeed. The class A Mosfet designs do work and work well.

I thought your comments about different class D amps very interesting and that your opinion of the Nu-Force very telling indeed.

What Macura says is very, very important re. mosfets - they do need very good heatsinking and/or as Tourmaline has done use near silent Papst fans.

For E60 he now has a h/amp that is cool, both valves and mosfets. I think his idea could be used for lots of amps, this will of course mean adopting a different approach to chassis design or in the case of the Bada of removing the bottom plate.

I wonder also now that all the components are operating at low temperatures and therefore well within specs if this is helping to create the 'wonderful sound' that Tourmaline is hearing.

I've always felt that heat is something that has never been properly dealt with in class A designs, probably because it means designing a totally different kind of chassis.

[S-Man]

If they add some cases etc as Leo suggested then WD distributing Hypex modules should be worthwhile. If thay just add a fat margin onto the very reasonable Hypex prices then I see this as a negative move.

Seas drive units seem to be rather pricey via Arena!

[petercom]

At present we are planning to introduce the Hypex modules as a complete kit to build your own amplifier.

SEAS drive units are priced as they always have been in the UK (e.g. Wilmslow etc). You can't compare our tiny market to the States market (which I presume is what you are alluding to) which is huge in comparison and allows manufacturers and distributors to sell at reduced prices.

However if you add on shipping and import duty you will probably find, for most items, that the UK price is equivalent or cheaper.

Selling to N. America is always the holy grail for most UK manufacturers because of the size of the market there.

[leo:)]

Nice one Peter! hope you'll be stocking the latest ones with LM4562 and the option to add the discrete regulation

[S-Man]

Originally Posted by petercom

SEAS drive units are priced as they always have been in the UK (e.g. Wilmslow etc).

Maybe inflation has been rampant in the last 3 years. According to my receipt I paid £30.64 + VAT each for 2 CA15RLY drive units at Wilmslow Audio in April 2004. Arena is selling them for £53 inc VAT.

[petercom]

It is not so much inflation as the cost of raw materials. The average increase from most major drive unit manufacturers over the last three years has been between 10 and 15% per year. For example DST increased prices by 20% this year alone.

The cost of steel and alloy baskets and magnet structures is a major source of concern to drive unit manufacturers at the moment as the vast consumption by China is driving prices for metals up on the world market.

[S-Man]

Fair comment, Peter, and I accept I may have been hasty in my judgement in my earlier post. The cost of copper has also gone through the roof, just look at the price of transformers nowadays.

OTOH we do seem to pay a lot more for most things than in most other countries, particularly the US, but also Germany, France etc. It's either tax or profit that makes the difference because most items are not made in the UK anymore.

[Stratmangler]

Originally Posted by S-Man

OTOH we do seem to pay a lot more for most things than in most other countries, particularly the US, but also Germany, France etc. It's either tax or profit that makes the difference because most items are not made in the UK anymore.

It's usually some form of exise duty or the other.
Let's face it, Britain has become a very expensive place to live, courtesy of our current incumbent at No.10's budgetary policies when he lived next door.

I'm going to stop before this becomes a rant.

Chris

[Stratmangler]

Originally Posted by petercom

It is not so much inflation as the cost of raw materials. The average increase from most major drive unit manufacturers over the last three years has been between 10 and 15% per year. For example DST increased prices by 20% this year alone.

The cost of steel and alloy baskets and magnet structures is a major source of concern to drive unit manufacturers at the moment as the vast consumption by China is driving prices for metals up on the world market.

The cost of cable has hit everyone hard in the communications industry as prices have doubled for cable.

This has, I believe, largely because of Chinese demand for raw materials. This is the flip side of the £3.00 pair of jeans from Tesco situation - you pay for the low cost in certain other ways.

Chris

[charly]

I believe the necessary parts can be had from Hypex for about £500.