Any good DIY poweramp projects?

Dec 7, 2004 at 3:05 AM Post #16 of 25
Quote:

But good luck to fit one in a 300$ budget.


It can be done but not without some thrifty shopping at the electronics surplus sites.Big heat sinks are not cheap.

If this is an amp of interest then i suggest buying the zen boards from audio express,about $12 and building the basic "building block" that all the other pass amps are close to in design.Once this is up and running you can decide how far to take the design in the zen series of articles which can and do go all the way to an aleph design .
each level of improvement is simply changes in the active current source and the addition of an input buffer.The REAL Aleph amp adds a true differential input stage which if you look at the schematics is identical to the Balzen balanced line stage with different operating points so that board.also available from audio express ,can be used with a pair of zen amp boards to build a full aleph amp with a minimum fuss.

My zens are run in parallel (a single stereo board for each channel) so they are mono blocks.BIG HEATERS and that si fine this time of year.I use the mosfet input buffer from V4 and not a full on gain stage and i beleive mine run at 8W or so,plenty for my speakers to crank out volume.Being a simple design it is no problem for me to open them up and "fiddle" with the current source,current load and input topology (from parallel to driven balkanced with a balanced-to-single ended 1:2 transformer).Great fun amps to play with.

But if bang for the buck is considered then the gainclone wins hands down over any other amp i know of on the planet !

It really is a nice sounding amp and will not shame you.Add to that the documentation available ALL OVER the internet,the low parts count and ease of assembly and it is a no brainer for me .

I have built several and they work great and even if you go all out and buy only the best "perceived" parts available the count in R/C is so low you will not go broke.

go for it man
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Dec 7, 2004 at 5:03 AM Post #17 of 25
hey rick or anyone else, do you guys have any experience with the passdiy phono boards? im looking at getting a really nice phono pre to match whatever headamp i build next. their stuff looks good but pricey when i factor in ITL shipping. jim hagermans bugle pre or cornet may be better options for me.

edit: i basically want an affordable phono pre pcb.....
 
Dec 7, 2004 at 5:47 AM Post #18 of 25
Quote:

Originally Posted by bg4533
Are there any good DIY poweramp projects around? I am open to tubes and SS and enjoy a tubey sound.


I agree with the options people are giving you. The P3A, BrianGT GCs and and AKSA 55 I've built are all good amps but the AKSA is in a class of its own IMHO. It also has a reputation of being a bit tubey. You may have to do a little creative accounting to fit your budget.
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Have a look here: http://www.audiocircle.com/circles/viewforum.php?f=19

I imagine the Leach and any Passlab amps would also be excellent projects, but I haven't any personal experience with these.

Thanks
Greg
 
Dec 7, 2004 at 8:38 AM Post #19 of 25
Quote:

hey rick or anyone else, do you guys have any experience with the passdiy phono boards? im looking at getting a really nice phono pre to match whatever headamp i build next. their stuff looks good but pricey when i factor in ITL shipping. jim hagermans bugle pre or cornet may be better options for me.

edit: i basically want an affordable phono pre pcb.....


I have studied the pass diy phono stage and if not already set pretty much set in that department would maybe consider building one.Jfets are a fav with me anyway.but the build will be an expensive one and if i personally was choosing at that price point i would go with the bottlehead tube stage kit.something about tubes and vinyl just sounds correct and once you have a good tube phono stage there is no going back,unless it is a noisy one and that is something common at this high in gain.

does it have to be a kit ? If not then try thr "pacific" jfet phono stage and power it up with a jung or other super regulator.pretty straighforward build even without a pcb since there are no chips to worry about .four jfets handle the duty.
grab an aos regulator board, set it to 24 volts then slap it to the phono stage,put it all in a "box" ,plug it in and enjoy man !

My "backup" phono stage is the pacific and sometimes i use it even though i have the tube monster availble.Way less heat is generated,my electrical bills are not as high and not the least-it sounds damn good to my ears .
 
Dec 7, 2004 at 6:34 PM Post #20 of 25
ta. i will look in to the pacific. i built on perf board a urei 1620 card based on the original schematic. its a pig and i can't debug it. too unstable, even off battery power.
 
Dec 7, 2004 at 7:59 PM Post #22 of 25
Quote:

Originally Posted by 00940
The other usual amp in this price range is the Leach amp. .


I didn't realize it was realistic to build a Leach amp for < $300.00. I'd have guessed that the price using decent (not audiophile crazy expensive) parts would be closer to double that.



First time I head one was about 1977 or 8. At the time it just blew everything else out of the water. Parts cost was way beyond my high school budget so I didn't attempt it then.

.
 
Dec 7, 2004 at 11:16 PM Post #23 of 25
Quote:

First time I head one was about 1977 or 8. At the time it just blew everything else out of the water. Parts cost was way beyond my high school budget so I didn't attempt it then.


the original Audio Magazine article was in 1976 and it was the first time i ever seen the mag in my life.The "Build A Low T.I.M. Amplifier" was the cover story and is what drew me to the magazine.never built it but the design is mostly still valid.
No way you build it for $300 though ! This is no simple design and the parts count is very high.


Pacific pre phono stage :

cake to build and not easy to screw up unless you use a noisy power source :

http://www.diyaudio.com/forums/showt...223&highlight=


attachment.php



optimised version,a little more difficult to build but reported to sound better.i woul;dn't know myself but low inpedace drivers at the beginning of the EQ network and at the output are not a bad dthing in my experience :

http://www.diyaudio.com/forums/showt...?postid=252211

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Dec 8, 2004 at 4:55 AM Post #24 of 25
rick, cheers. it took a bit of hunting but i did find the schematics for those yesterday.
 
Dec 9, 2004 at 1:28 AM Post #25 of 25
BTW-if you need the original pacific schematic send me an email so I have an address to send it.I scan everything going out so i am virus free and it is safe to open an attachment.

rickcr42@xxxsbcglobal.net

remove the "xxx" from the email addy or it will not reach me

spammers dammit ! Gotta watch the spammers !
 
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