A-40 or another diy amp recommendation please.

[elizard]

Hey, I'm new here, as well as new to the diy scene, so bear with me please.

I'm planning on building a pre-amp and a poweramp for use at home, and so far I've selected the bottlehead foreplay for the preamp.
The whole day I've been reading the stuff on building an A-40, and seems to be close to painless with good results.

My question is, how good will the combination sound first of all. Second off, I'm driving 91dB @ 1w/1m speakers, so I think the 40wpc will be LOTS, considering the room is approx 10'x15'.
The second question is if I should go ahead, acquire all parts and build the a40 (approx $500 US), or if I should look into another amp. Also any recommendations on what I should look into if A-40 isn't suitable.

Thank You lots in advance!

[grataku]

It's up to you. If you want a classic project what you have in mind will be fine, if you want the latest cutting edge design, the Pass camp has LOTS of much better offerings.

[elizard]

well I'm not really concerned if its a "classic" or "cutting edge"
all i care for is that i get warm and clean sound
i don't need something SUPER loud, i know 40wpc should be sufficient, at least for now
also i don't need extreme precision for the audio ..

what sort of characteristics does the a-40 exhibit? warmer? cleaner?

also does anyone have experience building one, and if so, will it be hard for my first project?

the price i'm gonna pay for the pre-amp/amp is probably close to, or just over $1000 .. so for that type of money, i really hope i get something sweet sounding
that's why i want to do lots of research on what will sound the best

also i will be upgrading my speakers
Latest ones i was looking at are the monitor audio silver 6's, which sounded very good, clean, and tight .. what i was going for
i might change my mind by the time i get the money for them
my top priority now is the amp/preamp

[grataku]

The current state of the art in audio that I am referring to is the topology that gives the best sound, irrespective of tubes or solid state or power requirements. By the way, 40W is already a very high power for class A. You should be able to build a very good pre- power amp pair with the budget you have.
If you look at the gallery in the passdiy site you'll probably find people that built the A40 and then jumped to a newer design.
For example, if I remember correctly, Peter Daniel built the A75 then built the Aleph and liked it more.

[elizard]

Well, thank you very much

now .. my next questions (newbies are like little kids .. never stop with the questions)
is A-40 a good first amp for me to make? or would you suggest i go another route?

[Peter Daniel]

Go with Alephs. Those are more recent designs and they sound better. They are probably easier to built as well. If you need 40 W, Aleph 5 should be fine.

Since you started talking about Pass amps, I will not mention Gainclone, but this is probably the easiest one to built and provides 40W as well.

[elizard]

just as i spent 2 hours working out the price, and making a pricelist/order for all the stuff for the a-40!!!
heh .. i worked out around $500US, which is a lot more than i was going to spend on the amp to begin with (a month ago i wanted to get a nad 320bee .. $350US i think, and that's integrated!)

but .. i appreciate, and value the suggestion! especially from you, and yeah i figured you'd suggest a gainclone

hmm .. i guess tomorrow its back to the drawing board to figure out the price and difficulty of building an aleph 5

btw, what is the price to make a 40wpc gainclone? i looked at the one you built (very beautiful indeed) and it looks like a very few inexpensive parts .. maybe i'll build one as a prequel to the aleph 5, just to get myself in working order

[Eric]

When I started looking for an amp to build, I too selected the a40 mostly because I had no experience and there are circuit boards readily availble from Audio Express. I have recently completed my a40 and enjoy it very much - I will compare it to my Marantz MA500 monoblocks shortly.

The Aleph designs that are floating around here were not available when I began my a40. For ease of construction, its basically a toss-up right now.

I have kept a pretty detailed log of my a40 building experience on my web page if you are interested. Your price of $500 is right on the money.

Eric

[elizard]

I actually used your webpage to find some parts from a few suppliers.
I ordered most from digikey though, and they charge $8 shipping, no handling to canada. Which isn't bad, but isn't great. Still, no complaints.

I'm still curious on how much the gainclone would cost. I guess i'll wait till i get to school to find out, no time now.

[Eric]

I have finally had an opportunity to compare my newly constructed a40 to my Marantz MA500 monoblock amps (Class B, 125wpc) that I've been using for about 5 years. The Marantz amps are so much better than the inexpensive integrated amp that they replaced I was wondering how much of a difference I would notice. Both amps were compared using my Atlantic Technology System 350 speakers.

I spent a few hours listening to Dire Straits "Brothers in Arms" disk, switching back and forth between the two amps. This is one of my favorite disks and happens to be well recorded to boot. The difference between the two amps was pretty clear.

Compared the to Marantz amps, the instruments sounded much more "diffuse" and spread out with the a40. Mark Knopfler's voice also sound much more clear, much more focused in the center between the speakers, and much louder (despite matching the levels of the amps with my SPL meter beforehand) - interestingly, the music itself did not sound louder. There seemed to be a greater depth separation between the singing and the music. Switching back to the Marantz amps, it seemed as if the soundstage was compressed both front to back and side to side. Mark's voice sounded "flat" and less distinguished in point of origin from the music. Moving back to the a40, it was as if the music had just popped back into 3-D: Mark's voice was much more prominent, much more clear, and was projected at a location several feet in front of the speakers and directly between them. The music was more perceptibly originating from behind the speakers and sounded more spread out to the left and right than the physical spacing of the speakers. Overall, it sounded as if the a40 amp was also "cleaner" and more realistic sounding than the MA500s. Listening to more of the Dire Straits CD, it sounded as if the music through the a40 had more midrange and more "warmth" than the same music through the MA500s. This may have been what contributed to Mark's voice sounding louder through the a40, while the music appeared to be at the same level.

I was really surprised at the perceived warmth of the a40 amp when it was compared to the MA500s. Nelson recently described the sound of his amps: ".. if you listen to the amps representing my progression as a designer, you will find a trend from accurate and analytical to warm and romantic." Since this design is from 1978, I had expected it to lean toward the "accurate and analytical" end of the spectrum. Since the MA500s have been described by many as being warm and smooth sounding amps, I was expecting the a40 to sound "thin" in comparison. In reality, the a40 made the MA500s sound thin and flat.

What an excellent contribution Nelson has made to the DIY community! Thank you Nelson!