??nice 20-30w class a amp solid st. project?

[elviukai]

hello, I am thinking for building this kind of amp. have found some projects, but not detailed. thanks for any sugestions.. email me.

[jmateus]

It's a very ambitious project specially because it requires a huge
heat sink.
The amp per se is not difficult to build if you build it from a
reputable design like the JLH original design or subsequent
upgrades.
This one is close to the original:
http://diyaudio.8m.com/Bebet/bebet.html
Or this one which is a newer version:
http://www.gmweb.btinternet.co.uk/jlhesl.htm

In any case special care should be taken to the power supply
For this particular matter you should check the Rod Elliot web
site, there is a link on the latest URL for his site. I'm talking
about the capacitance multiplier power supply that most
class A gurus advocate for this amplifier.

My amplifier that I just finished last week is a big heat factory
and despite the humangus heat sink, runs VERY,VERY HOT....*
Good luck!...

[Mattyo5]

I'm actually building Rod Elliot's Death of Zen amp only I'm building it to run at close to 30wpc rather than Rod's 10wpc. Yeah, it'll be biased for 150 watts of heat per channel. If you have the heatsinks for it...go for it! I know of a GREAT place you can get big heatsinks. I'm not quite done w/ the project...but as soon as I am, I'll post it here. It uses 8! 2sc5200 transistors per channel and 2sc5200 transistors as the drivers! Should be sweet once I get it running. I had one channel biased...but I changed toroids. I'll post stuff soon...within a week hopefully.

www.sound.westhost.com project 36

-Matthew K. Olson

[ultrachrome]

Originally posted by jmateus
It's a very ambitious project specially because it requires a huge
heat sink.
The amp per se is not difficult to build if you build it from a
reputable design like the JLH original design or subsequent
upgrades.
This one is close to the original:
http://diyaudio.8m.com/Bebet/bebet.html

Actually, the Bebe T is based on Rod Elliot's DoZ. I've got the PCBs and parts for a DoZ but I need to gain a little more experience before I attempt the capacitance multiplier power supply.

I'm going to build a chip amp as soon as I finish my AKSA 55 and then I'll build the DoZ.

[jmateus]

By the way, speaking about AKSA, I'm very curious to know how
is this amplifier as far as the quality.
I've got the boards - bought from Ron Elliot - and the rest of the parts but I never built it. More than a year ago I was anxious
to buid it but something came up and I'm still wandering about
its quality. Is it as good as many people say it is?

I'd appreciate some feedback.

[paulb]

Originally posted by jmateus
By the way, speaking about AKSA, I'm very curious to know how
is this amplifier as far as the quality.
I've got the boards - bought from Ron Elliot - and the rest of the parts but I never built it. More than a year ago I was anxious
to buid it but something came up and I'm still wandering about
its quality. Is it as good as many people say it is?

I'd appreciate some feedback.

Do you mean Rod Elliot?
I don't think he sold boards for AKSA. He accidentally posted the schematic there once.
Just do a search for AKSA and you'll find testimonies.

[Mattyo5]

Rod Elliot sells boards for his projects, the closest to the AKSA being the Project 3a. The circuitry is similar. I have not built the p3a (I have 4! boards sitting waiting) yet but I have heard the AKSA. We have tried the AKSA side by side w/ a Zen4...and the Zen 4 sounded much better. The difference was quite obvious. Instruments sounded much clearer and less mushy. Another plus to the Zen4 is that it is cheaper. The AKSA is quite expensive, but the one good thing about the AKSA that I will say is that the project is very complete and its quite easy to do from what I hear. There are very few parts to source out. (power supply, case, and wire is all you need to source I think). My friend built the Zen 4 and we figured about $350 in parts, and for a AKSA...almost $600. Up to you. Rod Elliots projects are great too, so go check out his project 3a if you are in the market for building a nice amp. www.sound.westhost.com

later

-Matthew K. Olson

[AKSA]

Hi Matthew,

Interesting comment about the AKSA; may I ask the version? It's now at Version 2.0, with updates, and has moved on a little.

I did sell some boards through Rod Elliott a couple of years ago, but eventually withdrew them because with pcbs only it was impossible to control component selection, which is VERY important, and if done badly can affect the sonics.

Someone here commented on quality, and another mentioned it was very expensive. I'd refute that; you don't get anything good for nothing in this world, and I spent years getting this design correct, and feel these responses a little uncharitable. AKSAs are routinely compared to amps costing five times as much.

I now sell the basic amp kit, which includes everything except the case, power switch and transformers - the heavy, bulky parts - and it's very comprehensive with ultra-detailed instructions. I also sell a Nirvana upgrade which takes it up a notch further.

The AKSA was developed alongside some very good amps, including the 15W Class A Sugden A21, and my own design, a tube/mosfet hybrid called the Glass Harmony, single ended, of 28wpc. It's hallmark is not mushy sound at all, but beguiling midrange and strong bass control. I'd suggest something is wrong if the bass is mushy, that's never a criticism of the amp that I've heard!

Hope this clears things up,


Cheers,

Hugh

[Mattyo5]

Hugh, thanks for the post. My comments were not to downplay or insult the AKSA at all. I'm just giving what I think is a fair evaluation. Is the amp good, yes. I have a friend that builds amps all the time and he built one w/ the nirvanna kit, the right transformers, caps etc and it cost him about $600 (and thats built without an expensive case). Will it beat the pants off of a lot of commercial amps at $3k...probably. Its almost a complete kit...with very little sourcing of components...so in that regard, it gets rid of a LOT of headaches and makes the AKSA a GREAT GREAT GREAT beginners and even midlevel project. I know many many people have built it and are very happy. However, a friend has also built the Zenv4 which we had side by side. In that amp, everything seems more cohesive (not that the AKSA isn't...especially compared to some other amps) but the Zen 4 is that extra little bit of refinement (albeit at lower power). Never said the bass was mushy, i'm sorry that one might have taken that out of my comment. The soundstage was not as cohesive as the Zen4. On the Zen4, instruments were more easily localized. The difference in price $350 for Zen4.

Now, as far as the circuitry between the project 3a and the AKSA, I just build amps, and unfortunately never had the chance to take any EE classes, so circuitry (by in large) is a little beyond me. I have a general idea of what everything does, opamps, voltage dividers, caps/resistors/ crossovernetworks, transistors, but i'm quite lacking in the ability to take ones design appart and critisize it. In general, the circuit that I saw looked similar to the p3a. If the AKSA is now on a 2.0 version, that I probably have not seen. I'll look at that when i have some more time (dental school takes up most of it).

I hope these comments were not uncharitable. Kudo's to all your work Hugh. These kits have been fantastic for a lot of people. I really didn't mean to step on toes here, just to give an eval of what i heard and what I thought. I have no doubt that the AKSA beats many amps way higher priced. Thats the beauty of DIY.

-Matthew K. Olson

[AKSA]

Hi Matthew,

Thank you for your gracious response! I appreciate the time you took to explain the assessment.

I must have a gander at the Zen4. Is it a single ended design? What sort of power?

No problem; I'll visit the Pass site and investigate. The original Zen started me off about ten years ago, so I'm always fascinated by Nelson's creativity.

Cheers,

Hugh