Quote from: joecool85 on February 06, 2012, 04:15:47 PM
Sounds like for the K-20X you used linear pots instead of logarithmic.

I believe I did. That would be the problem then aye?

Hi,

Been a while since I posted but I thought i'd let you guys know how my project went. Needless to say my teacher was impressed, I think he was glad to see someone actually build something with a bit of passion as opposed to everyone else who just wanted to do as little as possible to get a pass.

If you remember when I started the project I didn't even have an electric guitar. It was a good excuse to get one, so I ended up getting an Ibanez RG and just had the tremolo blocked (don't ask).

Anyway, to the amp, the tiny giant I built for the power amp worked really well. did everything it was supposed to and sounded pretty cool. However the K20-X preamp didn't work that well (managed to hide that from the TAFE teacher quite well  8|) in that the treble and mid adjustments don't do anything at all and the bass does nothing until right up the top when the sound suddenly changes to mud. I checked the schematics for ages but can't find what I did wrong :embarassed:

Anyway after TAFE I kinda just threw it in the wardrobe for a few months and was actually thinking about giving it away for the space, until Christmas where my soon-to-be-wife bought me a big muff pi (she has good taste), and out of curiousity I hooked it up the the tiny giant through the 10in cab I built and WOW! I'm impressed. Sounds fantastic!! So good infact that if I have to get rid of one, it won't be the one I built.

So here are some pics I took the other day.


Tiny Giant on the left, K20-X on the right





Holes I cut in the cab because as a sealed cab it sounded like poo.




Inside the K20-X - Sorry its not the best but I cbf undoing the pots to get the lid off.




Inside the tiny giant





I'm still not finished yet as I am going to have the cab and tiny giant painted. Then it will be complete!

Anyway thanks to all you guys for your help and advice. It has been a very educational build and well worth it. The next project is to take a 1/5 scale baja rc car and convert it from petrol to electric  :tu:

Thanks again!

10 inch. I have to cut a hole in the backing board, it doesn't sound that good as a sealed cab.

Hey Hey People! I'm still kicking!

Have been plodding along, breadboarded the power amp and pre amp circuits, and have built the speaker cab. I have designed the pcb and will make it up tomorrow night. All that is left is to find some enclosures for them  both. Anyway here are some pics.

Breadboarding the tiny giant.



Speaker cab









Still a bit to do but i'm happy. I must say i'm rather impressed with my woodworking skills.
Anyway i'll post up pics of the final product.

Cheers

Hi all,

Well i've been pretty busy lately but my amp is moving along nicely. I bought the wood for the cab and i'll put that together this weekend. I have been heaps slow with my circuit however I have a question about the preamp grounding.

As I plan to use the same single 14v supply for the preamp and power amp, I have had a crack at making a dual P/S for the preamp but I'm unsure what grounds become the VGND and what will be V-(or 0V) So a little help there would be much appriciated.

Also As the preamp will be permanently coneected to the power amp is there really any need for the op amp right in front of the TDA7240A? Or does the preamp circuit take care of that?

I have attached an overall drawing I did.

Thanks for your help.

Trent

Hey, Still here,

I have ordered the speaker and it should arrive today so i'll be building a cab for it in the next week or so.

Can someone give me some advice on cab design for this speaker? I have done a bit of reading and all I have a chieved is a sound feeling of futility. I have a feeling that an open back design would not suit this speaker at all so i'm going to go for a sealed cab. But yeah, any help would be awesome.

And thanks for everything so far, you guys have helped heaps.

Cheers,

Trent

Hey all,

I'm still around, just been busy and sick so haven't been in front of computer much.

I'm going to build myself a single speaker cab and found this Jensen speaker that I can get to my door for around $110. http://www.jensentone.com/c10q.php

I don't know much about this sort of thing (as previously stated), so is this a decent speaker for the price? Keep in mind i'm in Australia and we pay more for everything for some reason.

Cheers,

Trent

Is this the schematic you used fro the vero layout Joe?



There are a few schematics in that thread and I dont know which one you used  I like the idea of having a clean and overdrive channel. But instead of a stompbox I might just put a switch in the amp.

Cheers,

Trent

Quote from: joecool85 on February 23, 2011, 08:40:30 AM
If you want to build a real amp, may I recommend building a K20-X.  I already have the preamp all vero-ed out here: http://www.ssguitar.com/index.php?topic=1885.msg12904#msg12904

For the power amp you could use most anything, in stock form it uses a TDA2030 poweramp circuit.  You could hook it up to a Velleman kit, chipamp.com kit or anything else similar.  For the price I would recommend using the Tiny Giant for the power amp: http://musicpcb.com/pcbs/tiny-giant-amp/

I had a read through the thread for the K20-X preamp and that looks promising. But what would this output buffer that is referred to entail? Seems you guys think its necessary but I need some elaboration on the details of how and why.

And that tiny giant amp looks good too. I like the idea of using an old laptop power supply.

Thanks again for the help,

Trent

Thanks for all the help guys.  :tu:

You know i'm actually finding this kind of interesting  To the point that I might even attempt a proper amp once I get my guitar.

Anyway im quite impressed and confused at the amount of info out there.  So after alot of looking I thought I might build a ruby amp, but also attempt some sort of preamp to go in front of it, maybe the umble that I saw on runoffgroove.com.

Also if the sub I have is a bad idea, what is a good cheap speaker? If the amp is run off a 9v battery then something small yes? about 6in? Will anything with a frequency response up to about 6khz do?


Once again sorry for all the questions.  And feel free to tell me anything else you may think I need to know.

Thanks heaps,

Trent

Hey guys,

Thanks for the input but unfortunately I don't think that one will be complex enough for the class. It needs to have a few adjustments (tone bass etc) and have a preamp stage and power amp stage. So is there anything you know of that you could reccommend? I found the project 27 amp that another guy on this forum said he was building and that one looks ok if a little complicated. But I reckon I could pull it off. But a liitle simpler amp would be good to.

Also I have a 10in sub I had for my car that never got put in so I was going to use that. Here is the link to the spec sheet http://www.alpine.com.au/files/current_owners_manuals/SWS-1043D.pdf Its the SWS-1043D. Will it work ok? It only has to be decent and if this project turns out any good I will possibly replace it with a better speaker later on.

Thanks for all your help,

Trent

Hey all.

Just joined up for the knowledge. I am doing a TAFE class that requires me to build something rather technical, and because Ijust started learning how to play the guitar I picked an amplifier. I figured it would sufficiently test my skill to learn in a reasonably short timeframe (4 months). I have a basic understanding of electronics, have fairly high soldering skill but I know next to nothing about guitars and music. So i'll be learning on all fronts.

Anyway, I will be sure to do the obliged n00b thing and ask many questions and whatnot. I intend to keep this amp so would like to do a resonable job on it. Ideally something that sounds decent to just practice on at home when I eventually get an electric. And potentially build myself another even better amp in the future.

I will poke around the forum when I get time but i'm at work now so I gots to go.

Cheers