Building the ultimate DIY power amp

[LRRockBox]

I guess that, just like a great many enthousiasts, I would like to own a pair of Krell MRA's, Levenson 33's or big Pass monoblocks.
Unfortunately, I was swapped as a baby and now some poor mum's kid now has my very rich parents, so I have to work for a living and it's not in the cards.
So what would you good folks consider to be the best power amp achievable the diy route ?
I've been waiting a great many years to start building my own, and it seems now I have the time and funds to make a go of it.

Suggestions please !

Many thanks,

Peter R.

[Damon Hill]

How much power do you want, and how much
are you willing to spend in getting there? Any
other specific features that grab your interest?
Prior experience in electronics and building things?

Myself, I'm rather happy with my Leach amplifier;
does about 120 watts/8 ohms, 200 watts/4 ohms.
Very well documented, though maybe a bit
complex for a first-timer.

Others are happy with the AKSA amps, Sloans
MOSFET amps, various other projects such as the
Pass Zen class A amps and Gainclones. The
GainClones are about as simple a first time project
as you could hope for.

Which one is 'best' is largely a matter of opinion.
Do a tour of the Solid State and Chip Amplifier
threads and see what you can learn.

[LRRockBox]

Err, I may need to add a few comments,so...

I'm not exactly a first timer. To building an amp, yes, However, I do have a masters in electronics, and a VERY goo soldering iron
Power : yes please. I mesioned a threesome by the big US boys. I DO like the sound of 'em. Given the money, I'd seriously look into the X600 or the FPB's.
However, a substantial budget is available to me, furthermor, I don't have to spend it in one go, so funds can be 'slushed' without my better half (may the peace be upon her) being alerted.
I now have Infinity Kappa 80 speakers, rated 250W at 6 Ohms nominal, efficiency about 89 db/w/m. One day, I WILL get a pair of Nautili, though.

Oh, darn shame I only found out about the Levinson 38S printboards yesterday. I would have loved to get my hands on one of those for 400 S$, however much that is in real money

Peter R.

[traderbam]

Not exactly sure what you are asking. Are you asking which existing kit is the best or are you asking what the best possible sound a diy'er can achieve?

The exisiting amp kits I've seen on or refered to in this forum are not going to be anything near the sound of the brands you've mentioned. I estimate the best will give you a sound comparable to commercial products in the sub US$1000 area for a stereo amp.

This is not to say that you cannot build something better yourself. I think audio is one of the great levellers in that neither high levels of education nor years of making products seem to correlate strongly with sound quality. Nor is material cost strongly correlated. It is more a matter of how you think about the problem, what assumptions you make and how you test whether something sounds better than something else.

In principle, you you can make something that sounds as good or better than a Krell at under $300 parts cost. But you need to be wickedly cunning.

One bit of platinum advice from one engineer to another. You will have been taught a number of things in your masters course which will get in the way of you designing great audio, if designing is what you have in mind. A number of simplifying assumptions are made in electronics which work very well except in audio. Be very, very careful about this because this is what separates the Krells from the Leaches.

[tcpip]

Originally posted by traderbam
The exisiting amp kits I've seen on or refered to in this forum are not going to be anything near the sound of the brands you've mentioned. I estimate the best will give you a sound comparable to commercial products in the sub US$1000 area for a stereo amp.

In principle, you you can make something that sounds as good or better than a Krell at under $300 parts cost. But you need to be wickedly cunning.

Your comments were very interesting to say the least. Let me make my motivation clear: I'm not trying to pick an argument with anyone, or show you how much I know. If you see my posts elsewhere, you'll know I'm quite new to the game.

However, based on my dabblings, I was getting the impression that a carefully constructed DIY amp, say a Randy Slone OptiMOS, could match the quality of a good $10K commercial amp. Am I wrong?

And... here's the part that I find really interesting: if I'm wrong, then what's the difference between something carefully designed by a Doug Self or a Randy Slone with decades of experience, and the really famous commercial brands like the Mark Levinsons or Krells or whatever? (I know that famous does not mean good... see Microsoft software quality, but for starters this is the best I could ask.)

I'm seriously really curious to know... how do the more sophisticated DIY Class B power amps compare with the more expensive, high-end, well-regarded commercial products? And if there is a difference, why is it there?

Remember, I'm not arguing, only asking.

[analog_sa]

I would like to own a pair of Krell MRA's, Levenson 33's or big Pass monoblocks.

I would be very suspicious of most diy designs, especially those developed by 'experienced engineers' who believe all good amps sound the same. The few exceptions - Pass, JLH, Hiraga are all power deficient if otherwise exceptional.

You best bet will be to clone a commercial design - not a popular with this forum approach, but one more likely to fulfill your requirements.

[rif]

Originally posted by LRRockBox
I guess that, just like a great many enthousiasts, I would like to own a pair of Krell MRA's, Levenson 33's or big Pass monoblocks.

Just an FYI: Nelson Pass frequently replies to posts on these boards, but I think he's probably biased towards those posts on the Pass Labs forum

[traderbam]

tcpip wrote:

I was getting the impression that a carefully constructed DIY amp, say a Randy Slone OptiMOS, could match the quality of a good $10K commercial amp. Am I wrong?

I think you are. I haven't heard any Slone designs. I have seen the schematics of a few and heard comments about his book 2nd hand. IMO the info I have does not bode well for an audiophile result. If anyone has got a bona-fide review or direct comparison with any commercial products I would really like to know. Usually this key data is missing!

And... here's the part that I find really interesting: if I'm wrong, then what's the difference between something carefully designed by a Doug Self or a Randy Slone with decades of experience, and the really famous commercial brands like the Mark Levinsons or Krells or whatever?

Because they don't really want to or aren't able to.

I'm seriously really curious to know... how do the more sophisticated DIY Class B power amps compare with the more expensive, high-end, well-regarded commercial products? And if there is a difference, why is it there?

It isn't a matter of class. The reason the differences are there are superior engineering by the high-end companies compared to most DIY'ers. Superior engineering comes from a better evaluation process, better understanding of components, sheer cleverness and time and money to support them.

How does a DIY'er beat Ferrari?

[johnnyx]

Originally posted by traderbam
tcpip wrote: The reason the differences are there are superior engineering by the high-end companies compared to most DIY'ers.

How does a DIY'er beat Ferrari?

So it's the CNC machine tools they use then?

[millwood]

Originally posted by traderbam
How does a DIY'er beat Ferrari?

I think it is quite possible and probably to modify a vehicle to beat a Ferrari (or any other car you may wish) on certain parameters.

It is very hard to produce (modify or not) a vehicle that will better a ferrari in all parameters, like performance, comfort, luxury, reliability, cost, etc.

that pretty much holds true for diy electronics as well.