australian gainclone newbie

[sparehead1]

Hi all, I've decided to have some fun with diy audio and was going to start by making some speakers then started looking at amps to drive some kit speakers and decided to start with a gainclone kit from chipamp.com and build it while teaching myself electronics and looking speakers to match. My dad's a retired electrical engineer so i figure this will also give us fun projects (he's now going to build a point to point gainclone) and things to talk about. I can solder and have repaired an amp but it just had some blown caps and dry joints and I have made a cmoy headphone amp that i like but i'm keen to get into something more meaty while I teach myself.

I was thinking that I would build some monoblock's for the living room using the LM3886 kit and then look at making a passive pre-amp if it needed it, even if it was just a pot with some connectors in a pretty box. Then I realised I'm sat in front of my computer most of the time and I've got cheap logitech's and this is where I do most of my listening at the moment! So I thought I'd build up a LM1875 kit for my room and get some bookshelf speakers to go in the desk. I have one complete LM3886 kit, the bonus LM1875 PCB kit and an extra LM3886 PCB kit on the way. Fun time's ahead!

I do have some questions though (bonus points to anyone who saw that coming) as I understand it bookshelf speakers need to be driven harder than floorstanders, I'm assuming this is a general rule and/or given the same drivers in each enclosure. Would I be better of with another LM3886 for what ever bookshelf speakers I make for my room or will the LM1875's drive bookshelf speakers ok? I have a strong feeling this is probably a stupid question but thought it best to ask anyway. I've been reading that these amps need fairly sensitive speakers also, what should I be looking for to match these amps? My mate has some acoustic energy AE one's that I really like and I liked the old wharfedale's my dad gave me when I moved out 10 years ago but I've got no idea what sort of figures or configuration's I need to be looking at on speakers to get good sound and not drive the amp's into clipping. I listen to all sorts, from Bon Iver and Camille through to Pendulum and Lamb of God. I'm not a big fan of booming bass for the sake of booming base and cant help but think of the neighbour's. I will be using both amps for music, movies and games and both with be driven by asus xonar STX sound cards. Any and all advice welcome and I hope this isn't too long winded for a first post

[Nuuk]

it is true that the easier load the speakers present to a GC, the better it can sound.

If I were you, I would do some research on the speakers that you want first, looking for those that are small enough but still easy to drive. When you have those sorted, you can choose your chip. LM1875 will do for near-field listening, LM3886 if you want to 'fill' a room.

[pacificblue]

Originally posted by Nuuk
it is true that the easier load the speakers present to a GC, the better it can sound.

Which is of course true for any amplifier.

Originally posted by sparehead1
I'm not a big fan of booming bass for the sake of booming base and cant help but think of the neighbour's.

In that case you should not worry too much. Build it and try it.

Originally posted by sparehead1
as I understand it bookshelf speakers need to be driven harder than floorstanders, I'm assuming this is a general rule and/or given the same drivers in each enclosure.

The same driver in different enclosure sizes, will usually have less maximum SPL at the low end. You won't get more out of it, by driving it harder. In many cases the sensitivity will go down in a smaller enclosure. In others, where the driver parameters are better suited to the smaller enclosure, the opposite can be the case. In either case the difference is small and will not be the deciding factor for or against a chipamp.

[sparehead1]

Thanks guys, I'll keep reading and will stick to the LM1875 for near field and LM3886 for the living room plan

I've been doing alot of reading over at your site Nuuk, very helpful, thanks for putting all the effort into writing it up and putting it on the net

I'm reading through your power supply guide at the moment.

Cheers pacificblue, a little peace of mind is a great help when getting set on a new project

Looks like I need to do a lot more reading on speakers

[ZirconiumZephyr]

what an interesting thread. I'm pretty much in the same situation as you, rather basic knowledge of audio electronics from fixing an amplifier and I'm now tossing up whether to buy a GC kit just to power some speakers for my computer.

Shall keep an eye on this thread.

[sparehead1]

Originally posted by ZirconiumZephyr
what an interesting thread. I'm pretty much in the same situation as you, rather basic knowledge of audio electronics from fixing an amplifier and I'm now tossing up whether to buy a GC kit just to power some speakers for my computer.

Shall keep an eye on this thread.

If your keeping an eye on it then I'll keep you posted

If you were looking at a kit for use with your computer this may help, there are some LM1875 chipamp.com kits for sale in Oz by another forum member:

FS: LM1875 Stereo Kits (x3) FREE Shipping in Australia!

for my first set of computer speakers I thought I'd make some of these Hi-Vi B3S single driver from zaph but using the B3N's just because I like the look.

You can get the drivers here as well:

http://darcheraudio.com.au/shop/inde...index&cPath=31

I figure they will be about as straight forward to make as a first set of speakers can be and the drivers are only $20!

Biggest thing for me at the moment is figuring out what transformers to use in the amp's.

[sivrat]

Hi,

though I would way in here as I have just finnished my first build.
I built a tda2050 (what i could get localy) and it sounds great.

This is after going round and round in circles trying to find the best way and changing my mind at least 40 times as to the how to do it.

In the end, I used what I had at hand and built it as a learning experience. I can say, I am not disapointed.

I had 2 old PC swithching supplies on hand, so I followed Nuuks instructions on decibel dungeon and did the ground modifaction on one and wired them up into a +12 0 -12 config. The smps are running at 10 amps so it has plenty of grunt for the volume I listen at.

As for the ciruit, I used the data sheet and went with that, I can alsways change it later if I feel the need.

I guess the main factor that made me decide was a pearl of wisdom from decibel dungeon, who said, dont get caught up in the planning, and just build it

[sparehead1]

Originally posted by sivrat
Hi,

though I would way in here as I have just finnished my first build.
I built a tda2050 (what i could get localy) and it sounds great.

This is after going round and round in circles trying to find the best way and changing my mind at least 40 times as to the how to do it.

In the end, I used what I had at hand and built it as a learning experience. I can say, I am not disapointed.

I had 2 old PC swithching supplies on hand, so I followed Nuuks instructions on decibel dungeon and did the ground modifaction on one and wired them up into a +12 0 -12 config. The smps are running at 10 amps so it has plenty of grunt for the volume I listen at.

As for the ciruit, I used the data sheet and went with that, I can alsways change it later if I feel the need.

I guess the main factor that made me decide was a pearl of wisdom from decibel dungeon, who said, dont get caught up in the planning, and just build it

Thanks sivrat Good advice from decibel dungeon. I'd hate to think of amount of time I've spent going over and over things in the planning of projects. Funny enough this all started with me going round and round looking at speakers. Atleast now I'm pulling the trigger and have chipamp.com kits on the way and am ordering some little fullrange drivers for my first attempt and this kit:

http://www.madisound.com/catalog/pro...oducts_id=8525

for the next

On the hunt now for encolsures for amps

Interesting about using pc psu's. I'll have to look at decibel dungeon again and have a read about that

[sivrat]

Ya, the PC switch supplies worked a treat.

they are under the SMPS section in db dungeon. well worth a look if you have them spare.

[sparehead1]

my old flat mate left 2 psu's from a rack mount dell server behind when he moved out I'll show them to my dad when I see him next, my dad is interested in using smps to power gainclones now and will know what he's doing when he open's one up unlike me.

I should get my dad onto these forums since he's making a ptp gainclone and is an electrical engineer.