Help a newbie choose a DIY amp and cd source for cheap

Hi Guys,
I am a very serious audiophile, i have a successfull award winning sound quality competition car already.
I want to do a cheap DIY home stereo.
I have already picked out the speakers that i will build. They will have 150W RMS power handling, [email protected] sensitivity and a frequency response of 39Hz-20Khz and are fairly flat with ±3dB over that range. The speakers have 2 8" drivers and 1 tweet each, they are vented.

Anyway, my question is not about the speakers.

I need to amp them somehow. All i need is an amp with volume control.

To give you an idea of my price range and what i would probably buy if i cant work out the DIY stuff:
http://www.cambridgeaudio.com/index2_f.htm
I would get the A300 Integrated Amp and the D300 CD transport.
Together I could get them both for around $700 shipped or tax included.

So, i need an amp of similar power, it does not have to be integrated, just has to have a volume control. I will also need a very good cd transport with around 2V preouts (if the amp is not integrated).

I am toying with the idea of a lesser power tube amp too.

I simply dont know where to start. I am in no big rush. I am very willing to get books if you suggest. Kits would be nice, but not totally necessary.

I am an electrical and computer engineer in training. I have some circuits experience and learn fast. I can definitly solder and read schematics.

So, to sum up,
With no more than $700, what amp and cd source would you choose?
 

SuppersReady

Member
Paid Member
2002-10-03 10:26 am
UK
I can't help you with the CD source, but I would definitely consider the smaller Aleph amplifiers www.passlabs.com/aleph.htm.

This could be put together with one of the Zen pre-amp stages www.passdiy.com/legacy.htm along with a suitable PSU.

These are relatively simple circuits with an excellent reputation for sound quality. Use a search engine with the Aleph amps and you will see what I mean. Try these for starters:www.stereophile.com/showarchives.cgi?674 & www.stereophile.com/shownews.cgi?318

If you need any further encouragement look here.
www.passdiy.com/gallery.htm

Regards

Paul
 
i am a little confused about what you are suggesting.

are you saying i should buy the aleph amps and build the preamp? where can i find the specs of each amp and where can i buy them? which preamp and psu are you referring to? is this in my price range? say $400-500 for ALL PARTS including PSU and chasis, for the preamp and 2 amp channels.

btw, i do have access to a very nice shop with cnc routers, lathes, laser cutters, rapid prototypers, and the usual manual milling machines, lathes, drill presses, table saw...
 
I believe that Paul was suggesting that you build an Aleph/zen pre integrated. I think that you would blow your entire budget on only the heatsinks, transformers, and power supply caps doing it this way, unless you are an outstanding shopper with exceptionally good luck. I would think a class A is out of the question.
I wish I could recommend something, but your budget is fairly low. What about finding something used and modifying it? Dynaco ST70?
 
i am fine with class AB, i dont know how much more complex the circuits are, i dont need that much power, just 15-50W.

how much would the zen v4 cost to build for 2 channels?

what about "the bride of zen" as a preamp?

if i dont get a source with balanced outputs, is there any need for a balanced preamp?
 
Equilibrium said:
Have a look at this amp.

It is on my short list. It will take me some time to work myself up to building an Aleph.


Happy trails.

that looks very doable, how much would the supplies cost to build this be (approximately, chasis not included, but psu included)? of course i would want to build 2. no need for a preamp with stated sensitivities.

i have access to bench dc power supplies, oscilliscopes, you name it. but they are not at my home.
 

SuppersReady

Member
Paid Member
2002-10-03 10:26 am
UK
Hi Miasma,

Just looking at some prices:
Example of Aleph 3.
Aleph boards (via Harvardian?) $45
Harvardian free Q pack of zeners and smaller transistors
BOSOZ board-stereo (via Old Colony) $20
4*26000uF 75V Caps (ApexJr) for Aleph PSU $28
Output mosfets $15-20
Transformers (Don't know US prices) $?40-50
Caps for BOSOZ $???

No need to populate the boards with the most expensive resistors, etc at this point. If you like the sound, you could upgrade parts later on. Heatsinks from ebay or ApexJr perhaps?
Might push the budget, might not. Having access to all the equipment mentioned will save loads on chassis.

I'll admit I am biased as I've just started ordering parts for an Aleph 5. Whichever route you decide I hope you'll enjoy the journey and the destination (Oops, I'm waxing a little metaphorical).

Have fun,:cool:

Paul
 
Miasma said:


that looks very doable, how much would the supplies cost to build this be (approximately, chasis not included, but psu included)? of course i would want to build 2. no need for a preamp with stated sensitivities.

$10 for resistors
$25 for capacitors
$50 for a xfmr
$30 for transistors
$5 for a bridge
$18 for a psb
heatsinks ???? I lean towards salvage $20 ???? your call
maybe $40 for wire, solder, diodes, beer, fuses, switches

totals about $200 plus 25% just cause chaos rules
and your looking at $250 easy as key lime pie.
Do you like key lime pie?
I like key lime pie.
A girlie girl is in my kitchen as I type
making key lime pie.
Life is good.
 
paulb said:
You won't find a DIY amp in your price range that is cheaper than a commercial unit. Don't do this to save money. Especially if your time is worth anything.
"wire, solder, diodes, beer, fuses, switches" all add up. Beer? Sounds like a great idea.

time is of little importance here. i want the satisfaction that i built my own amp. it seems i simply cant afford an aleph, knowing that, are there any other designs in the same price range ($700) as the design that i mentioned i lied, that will work any better?