Want to build my first amp

[still4given]

Hi guys,

Well, I have been busy fixing a few of my amps lately with the help of a few of you guys here. I am really getting ancious to build something. I am looking for suggestiong as to how to get started. I would like to build something that is better than the amps I currently have but realize that may not be the best place to start. I currently have Hafler DH-200, Hafler Pro230 and Soundcraftsmen PCR800. Is this a realistic pursuit?

These amps seem only ample for my needs and I'm not sure I would have use for someting less powerful unless it was far, far superior sonically.

I have searched through the threads, but end up reading for hours and still don't have a good idea where to start. I have very limited knowledge about electronics but have a huge desire to learn.

Thanks for any help you can give me.

Blessings, Terry

[demogorgon]

Hi Terry!

While i'm not familiar with building "solid state" from scratch, I have on the other hand built a couple of IC amps referd to as GainClones, and those can be hard enough for a "newbee", not using kits.

Etching the boards, making layouts ect.

and so my tip would be to perhaps start there.
though not having heard of the amps you spoke of, I personally am a beliver in theese litle GC's.. very nice indeed.

wish you the best of luck with diy regardless.

Marius

[skyraider]

I agree that GC is an excellent project for a beginer. It never gets better than this.

However, if budget is no objection for you, you may want to try listening to tube amps. Some single ended tube projects are not much harder than a GC, and its a new listening experience.

[Jennice]

Terry,

Welcome to the DIYaudio forum.

Yes, there's tone of material and inspiration here, but it's not a site which is good as a collection of pre-planned DIY kits.

You're not ensured to make it cheaper by DIY than the companies do. Let's make that clear to start with.
One of the reasons (apart from the benefit of mas production) is that the large companies have to make compromises that DIY'ers don't. A frequent compromise can be found in the power supplies of commercial products, and their (lack of) heat sinking calculations. They have some internal heat sinks, and while they're usually adequate, they usually don't stand up to long term high-level listening with demanding speakers. They have their (thermal) safety circuits, which I personally don't believe in. I prefer to design on the safe side, and avoid the need for this safety stuff by design.

Secondly I like BIG power supplies.
Something way too costly for most affordable commercial stuff.

Sonically, there's no guarantee that your DIY stuff will sound better than the commercual stuff, but there's a decent chance.
Remember that part of the fun of DIY'ing is in the "D".
Then again, my amp design has created requests from both my brother and some colleagues. I'm currently in the tarting phase of building a set of amp's for my brother, but you're too early for copying along, as I don't have correct schematics, and I will have to do a wire change to my PCB's (didn't bother to have new ones made - too expensive).
So, sonically, I'd never change my current 80W @ 8ohm amp back to my Onkyo Integra with the same rating. There's a lot more "whomp" when called for in my DIY thing. (Then again, there's a lot more juice in the power supply than the Onkyo ever had. The transformers in this one weigh about the same (in total) as the complete Onkyo amp.)

Since you're not that experienced with the electronics, you can have a look at the GainClones (CG for short, if you search for them), although I fear that they are not powerful enough for your needs. Alternatively, visit the web page of an Australian guy called Rod Elliot, who has taken his doings to the level of offering printed circuit boards. This would probably make life somewhat easier for you. A popular sedign seems to be:
http://sound.westhost.com/project3a.htm

Ob, my... what a lot of stuff in one post (y'all can wake up now... I'm about done )
Just keep in mind: High power and high quality don't mix with low budget, but you've probably realised that by now.

Jennice

[acenovelty]

Hello still4given,

Check out these pages:

http://users.ece.gatech.edu/~mleach/lowtim/

http://users.ece.gatech.edu/~mleach/superamp/

http://sound.westhost.com/project101.htm

Good documentation from the authors, proven design, sounds as good as the amps you have now. Not kits, so you get to learn something also.

For the power supply read up here:

http://www.tnt-audio.com/clinica/ssps1_e.html
http://zero-distortion.com/start.htm

Prosit

[still4given]

Hey folks, thanks for the quick replies.

demogorgon,

I have read a little about the Gainclone amp. I believe they are in the Chip Amp forum, am I right? They look very simple to build. How is the fidelity? The amps I have right now range from the Haflers at about 100WPC to 205WPC for the Soundcraftsmen. They are all MOSFET amps.

It seemed like the GC's were quite a bit less, though I know that there is more to loudness than just watts. I am driving JBL 4412 Studio Moitors and 4425 Studio Monitors. They are fairly efficient so I may not need the power I am currently running.

skyraider,

I wouldn't say budget is no option but I have been tinking about tube as well. Could you offer some links for some, at least kit type tube amps?

Jennice,

Thanks for the informative post. I will keep an eye out for you progress on you design.

acenovelty,

Thanks for the links. tThose Leach amps look pretty good.

Blessings, Terry

[Jennice]

Still4given,

Like some ESP projects (Rod Elliot, aka. Elliot Sound Products), my own is fairly straight-forward. I build my power transistors (I'm a BJT guy) and rpower resistors directly on the heat sink (hard-wired), and mount the small signal part on a 9x11 cm PCB.
I found this to be the easiest way to use whatever heat sinks I can get my hands on, with the same small-signal circuit.

Oh yeah.. and let's not forget the PSU. (Can such a thing ever get big eough? I don't believe so... (This hurts on the budget)

Before we get any further, you'll have to decide on budget limits. Also, your project plans depend on availaibility of places that can make PCB's for you (unless you can DIY). This aspect may be cruicial on deciding for a finished design with PCB, or which route to take.

How extensive is your knowledge on electronics, and which tools / measuring devices do you have at hand?

Jennice

[still4given]

Hi Jennice,

Thanks for the reply.

I have very little experience except for the little bit I've learned by working on my present amps. Right now all I have for test equipment is a multi meter. As I go along I will be adding to that for sure.

I guess my plan is to start with someting fairly simple so I can learn. I just thought it would be best to build something that I can actually use rather than just building something that will sit on a shelf.

I have a couple of Hafler power transformers that I bought to fix my Haflers and then found I didn't need them. I'm not sure it they will be useful for a DIY project. They put out 63V per side. Heavy things as well. It seems most of the amps I see being built here use toroid trannies.


I have zero experience making PCBs so I should probably start with an amp design for which I could obtain a PCB.

As I said, I am open for suggestions.

Blessings, Terry

[Jennice]

Originally posted by still4given
Hi Jennice,

Thanks for the reply.

I have very little experience except for the little bit I've learned by working on my present amps. Right now all I have for test equipment is a multi meter. As I go along I will be adding to that for sure.

An oscilloscope (2 channels preferrably) will certainly be a nice addition. Older ones with 10 - 20 MHz are fine for audio use (even for seeing possible oscillations).

I guess my plan is to start with someting fairly simple so I can learn. I just thought it would be best to build something that I can actually use rather than just building something that will sit on a shelf.

I fully understand your point of view. This should be possible with some of the proven designs from (amongst others) ESP.

I have a couple of Hafler power transformers that I bought to fix my Haflers and then found I didn't need them. I'm not sure it they will be useful for a DIY project. They put out 63V per side. Heavy things as well. It seems most of the amps I see being built here use toroid trannies.

63V will give you quite some output power. Is it 63V AC or rectified DC? Even if it's 63V DC, you'll probably want 100V electrolytic caps.
If I recall correctly, you're in the states with 110V outlet voltage. If your transformers are with two primaries (spare parts that could be used in europe with 230V, then you could leave it at that and use it at half the rated voltage. Remember that current capability will not double, so your useable power is decreased.

I have zero experience making PCBs so I should probably start with an amp design for which I could obtain a PCB.

If you are daring enough to use a schematic program, or can find pictures of layouts, then there is the option of finding a place that can make them for you. Most places are for business customers who (gladly?) pay a LOT but get the PCB's made very quickly. DIY'ers usually have other priorities.

Chip amps are probably the easiest thing to start with, although you're not likely to find 100W chip amps. The GainClones are said to sound very good indeed (unlike some power chips).
Some are so easy that they can be hard-wired without the need for PCB's. Some ESP projects have PCB's available. I'd say there are plenty of options. By the sound of your electronics knowledge, I'd go for chip amp or a kit.


Jennice

[demogorgon]

Terry!

To tell someone how good an amp sounds is like discussing, well, audio.. there is just no factbook answer offcourse *** how we like sound and how we weight differen parameters!

but if i do have to say something about the sound of the gc at least i have made, thn i would say that they sond like they could have cost aboute 500-600 dollars and be a hell of a bargain

they do like easy to drive speakers, så those monitors of yours might wel be a very good match for a GC.
And they do put out 68w per chip, if treated right :P
(there is no reason why you could not bridge or paralell them though)

oh, and did i forgett? there are PLENTY of pcb layotes to study for Gainclones. just search for "kostasthegrate" and you should find his pcb layoute wich i use.

(btw, those trannys of yourse may prove a bit to violent for a GC as trhey dont like more than 2*42v dc into them..)