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
Hi Trent:
Welcome to the board.
May i suggest you to go straight forward to the Ruby amp.
It is ideal for begginers. It is easy, very cheap, the parts are very common, and best of all, if you make every step reasonably well, it work pretty good. It´s only disadvantage is very low power (about 1 W), but is ok for a practice bedroom little amp.
Here the link www.runoffgroove.com/ruby.html (http://www.runoffgroove.com/ruby.html)
Basicaly this circuit use an LM386 chip, which is an operational amp. Here you got the datasheet of him. LM 386 Datasheet (http://www.datasheetcatalog.org/datasheet/nationalsemiconductor/DS006976.PDF)
Ruby has an improvement of the suggested circuit at the datasheet, and use a FET as buffer stage, it really worth it.
By my little experience with this amp, it will sound as good as good be the speaker that you use with him. Maybe you can try several til you get one that you like.
Any question, don´t hesitate to make it.
I agree the Ruby is a good one to start on, although I have a personal preference to the more simplistic Little Gem circuit myself: http://runoffgroove.com/littlegem.html
And it's true about the speaker. I've had mine running on a 10" Dean Markley speaker cab and it was loud enough my wife told me to turn it down lol. But on a small 2-3" non-guitar speaker that is much less efficient it's real quiet, just enough to practice on.
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 (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
Try to build Project27 preamp which fits what you need, and a TDA2030 or TDA2050 power amp, which is much simpler than the 100W one suggested by Rodd Elliott.
You'll have the equivalent of a commercial 15W practice amplifier.
You can design a board for the preamp in Veroboard using Bancika's excellent DIY Layout Creator, available online for free.
It already has an example with a 15W TDA2030 amp.
A car subwoofer is about the worst guitar speaker you can find, but it will do nicely at a school classroom level.
I already mounted an about 15 W amp stage using TDA2005 datasheet circuit (bridge one). It work pretty good too.
Simple, few commons components and it work with 12V.
It is another option that you could choose for use with Projet 27 preamp...
About your speaker, i think that the main bad think it has is it´s frecuency response (31hz-700hz), because guitar´s frecuencies goes from few hertz til around 6 Khz. Probably your guitar will sound very bass, and without any bright.
I used a satellite speaker from my home theather in a try with Ruby Amp and it sounded really good.
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
Hi Trent,
Re speakers;
Use the *search box here* or google some words you obviously have not heard of. :tu:
As complex as it maybe portrayed by never ending supply of over tecky types,,,There are in fact only 2 types of speakers you need to understand.
*High complience and Low compliance*
A Woofer is a high compliance driver as it needs to *Comply* to a certain dimension box to work effectively.
most stuff is HC,, which is intended for HiFi or for monitoring pre-recorded sound.
With LC (as hopefully you have already caught on) it matters little whether its inside a box or bolted to a flat board.
As long as there is some panel or open back box to seperate the phase to some extent they deliver close to the same sound,, in or out of a box.
these do not need to *Comply* to any particular size box (within reason)
In years gone by these LC drivers where often the only type used whether it be Hifi or vocal PA use.
Back In the 40's a rolled edge long throw woofer would have been very rare.
Most HiFi/Car stereo type speakers are *Woofers of very limited bandwidth* and often have shocking SPL figures (hence they need 10 times the power to be as loud as a guitar speaker)
So yes an *LC* or *full range* or now called *MI speaker* is what you need.
(MI = Musical Instrument)
Dead easy to pick the difference between LC and HC;
Just look for the rolled edge on a woofer with a loose easy to move cone.
An LC speaker has a *spider rippled edge* and the cone will be very tight and hard to move. (they only ever move about a 1/4 inch)
Teemu and a few other savvy folk have written some good explanations about all this right here at SS guitar,,, but I can't seem to find it? :o
Joe cool,, might know where that went?
Phil.
I would look two main characteristics for a speaker (behind of its size, of course).
First: Bandwidth ( from around 30-50 hz to 5800-6000 hz ).
Second: SPL (the higher value, the better) SPL is how much sound pressure produces the speaker with 1W of signal, measured at 1 mts of distance. The unit for this are [db] so a difference of 3 db means twice the sound pressure. You actual Alpine speaker push 84 db. If you find the same speaker model but with 87db, it pushes twice. Figure that with the same ruby you produce a lot more of noise :trouble
As a basic seat of the pants rule, what Phatt said can be translated into:
1) thick cardboard cone, foam/rubber edge (sometimes black cloth "wet" with a sticky liquid), if ypu look closely you can see the cloth thread, easy to move cone (more than 1/4" back and forth with slight finger pressure, low resonance (you tap the cone with your middle finger and it sounds with a low note, similar to a bass drum)= high compliance/Hi Fi woofer/car audio (that Alpine you have)
They have no highs, no attack, (your strings sound as if made of putty), and low efficiency, they need *lots* of watts to make some sound.
2) thin cardboard cone, cardboard edge (sometimes "wet" with a sticky liquid), if you look closely you can see it's still "painted" cardboard, hard to move cone (no more than 1/8" back and forth with stronger finger pressure, high resonance (you tap the cone with your middle finger and it sounds with a higher note, similar to a tambourine)= low compliance/guitar/TV speaker (not Home Theater but the cheap junk they use in the TV itself)
They have lots of highs, good attack, (your strings sound as if made of metal), and high efficiency, they need only a couple of watts to become obnoxious.
They look cheap, are cheap, great!
Can be reclaimed from TVs, car radios, etc; where a couple watts must count.
EDIT: google "Jensen Mod Speakers" and look at the pictures of MOD 6" , 8" and 10" , that's what you want.
Compare these to the Alpines or any other audio/car speakers.
The alpine is 84 dB ; the worst Mod (6") is 90db; the 8" 92 or 94; the 10" around 95dB; ten times as loud as the Alpine, go figure !!!
Did I mention they are cheap?
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 just got my Tiny Giant kit and started identifying and dry fitting the componants in place and I'm having some trouble. Some of the rectangular caps don't physically fit next to each other. Also there is one rectangle printed on the board with no info inside, and 2 more holes on either side of that marked 1uF. If I could see a photo of the componant side of the board that would be helpful. Also there are 2 solder pads under were the tl072 sits. Connections there? Any help would be great
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
Is this the schematic you used fro the vero layout Joe?
(http://www.ssguitar.com/index.php?action=dlattach;topic=1885.0;attach=1452;image)
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: Hayden on February 23, 2011, 03:00:59 PM
I just got my Tiny Giant kit and started identifying and dry fitting the componants in place and I'm having some trouble. Some of the rectangular caps don't physically fit next to each other. Also there is one rectangle printed on the board with no info inside, and 2 more holes on either side of that marked 1uF. If I could see a photo of the componant side of the board that would be helpful. Also there are 2 solder pads under were the tl072 sits. Connections there? Any help would be great
This link might help: http://www.diystompboxes.com/smfforum/index.php?topic=89687.0
Quote from: Trent on February 23, 2011, 09:06:08 PM
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
I used the original schematic from Dean Markley: http://deanmarkley.com/Info/LegacyAmps/Schematics/D1515.pdf
I stopped at the output of the treble pot. If you build it I would add R11, R12 and C11 between the preamp and poweramp as in the original schematic.
The buffer would be only if you were using it as a stomp box so that if you put it in front of another box it won't cause crazyness. If you are using it strictly as a preamp in front of a poweramp it is totally unnecessary and I would build it as in my vero.
As for the switch, it is easiest to just use a DPDT switch on the amp as you suggested. This is how Dean Markley built it as well.
That link was perfect. Had the photo and lots of other good info. Thank you so much.
Quote from: Hayden on February 24, 2011, 08:45:19 AM
That link was perfect. Had the photo and lots of other good info. Thank you so much.
No problem. Taylor, the fellow who designed this circuit, is a more frequent poster on diystompboxes than here and that is where he has the build thread.
With that link I finished the build and am very pleased with the result. Trying different speakers and I'm impressed with the volume and tone. Hooked it up to my EMC bass cab and it drove that 15 inch speaker with no problem. I want to use a smaller speaker and build a nice wooden cabinet with a black plastic faceplater for the control and jack. Thanks again.
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 (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
Quote from: Trent on March 01, 2011, 03:28:00 AM
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 (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
I've heard great things about those "vintage" Jensens. I'd say go for it.
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
Jensens are very good.
As for a cabinet, I'd search for a classic amp that used a 10" speaker, say a Fender , Laney, etc. and use its size as a guide.
Or you can use a 1x12" combo as a guide.
You can still use a 10" there but the somewhat larger cabinet will give you more body/bass.
You can also buy a Jensen MOD 12 50 for about the same price, and will have a beefier, "better" speaker.
USA prices:
C10Q U$47
MOD 1250 U$49.50
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 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.
(http://i214.photobucket.com/albums/cc88/Wrxus/077.jpg)
Speaker cab
(http://i214.photobucket.com/albums/cc88/Wrxus/001.jpg)
(http://i214.photobucket.com/albums/cc88/Wrxus/004.jpg)
(http://i214.photobucket.com/albums/cc88/Wrxus/006.jpg)
(http://i214.photobucket.com/albums/cc88/Wrxus/005.jpg)
(http://i214.photobucket.com/albums/cc88/Wrxus/089.jpg)
(http://i214.photobucket.com/albums/cc88/Wrxus/090.jpg)
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
Looks good so far. What size speaker are you using?
10 inch. I have to cut a hole in the backing board, it doesn't sound that good as a sealed cab.
Congratulations.
Excellent build. :tu:
Quote from: Trent on May 18, 2011, 07:26:22 PM
10 inch. I have to cut a hole in the backing board, it doesn't sound that good as a sealed cab.
I've not really heard any sealed cab situations that I like better than open back. Personal preference I guess.
Having mess with speakers for many years.
That box is miles to big for that sized speaker to work with a sealed back. 8|
Get the dimensions right and sealed back can be rewarding.
Generally open backs sound bigger at first hearing but start gigging at high SPL and sealboxes will deliver better reproduction.
my 2 cents worth.
Phil.
Hi guys,
I am a german amp hobbyist. This is a very intersting site and I want to share my projects with you. Actuall I build a 50Watt SS-Guitaramp. It contains a Poweramp, a preamp and a equalizer. Mayby some of this modules are interessting for you, or they push on your own inventions :)
This is the Amp in the test phase:
(http://hostarea.de/out.php/i173703_gimos50-proto.jpg)
I have a own site where I publish the development. There are also some sound samples.
http://xipix.de/elektro/gimos50.html (http://xipix.de/elektro/gimos50.html)
The next days i will start with the case and a DC-protect.
Nice, keep posting, an keep contributing.
Welcome to the board.
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
(http://i214.photobucket.com/albums/cc88/Wrxus/Amp2.jpg)
(http://i214.photobucket.com/albums/cc88/Wrxus/Amp3.jpg)
Holes I cut in the cab because as a sealed cab it sounded like poo.
(http://i214.photobucket.com/albums/cc88/Wrxus/Amp5.jpg)
Inside the K20-X - Sorry its not the best but I cbf undoing the pots to get the lid off.
(http://i214.photobucket.com/albums/cc88/Wrxus/Amp8.jpg)
Inside the tiny giant
(http://i214.photobucket.com/albums/cc88/Wrxus/Amp7.jpg)
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!
COOL !!!!!! :dbtu: :dbtu: :tu:
Sounds like for the K-20X you used linear pots instead of logarithmic.
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?
It may make little difference what pots are used.
(I hope Joe cool understands I'm just trying to help build a better mouse trap. winky.)
I've taken some time to test the KX20 preamp concept and thought I'd share my findings.
There is substantial loss with this idea and this maybe some of the reason it did not work.
Note the 3 traces which should need little explanation.
The output of the opamp has 20Db gain but is lost by the diode clamping.
But then the signal gets an even bigger kick in the teeth.
So without another gain stage I doubt it will be worth the effort.
Overall loss is down 25 Db at 1kHz.
This (Tone after diode clippers) idea may work in some situations but without help it will be hit and miss when shoehorned into any circuit.
Phil.
I wonder if the original K-20X does that or if it is just my rendition.
Hi Joe,,, Yep hard to know without setting the whole thing up to test it.
Here is another shot this time focus on the tone curves.
Note that most of the bass boosting is below 100 Hz.
Which tells me that unless the next thing in the signal path has MASSIVE bass cut it will sound like mud.
You could raise the treble cap too 5nF (Even 10nF) and see if that helps but as is,,, it's a hit an miss tone.
The screen shot shows all the extreme tone control positions.
Note; the drawing I have is rather blurred so I may have read the values wrong.
Lowering the value of coupling caps may help wipe excessive Bass response.
Cheers,,,Phil.
Phil, here is a link to the original schematic: http://deanmarkley.com/Info/LegacyAmps/Schematics/D1515.pdf
As for it sounding muddy, I don't think my K-20X does and with it driving the stock 8" speaker you'd think it certainly would by what you are describing. Maybe you do have the values wrong? I didn't have time to check what you had.
Agree that simulation, a *very* useful tool, tells only half the story.
The often forgotten speaker is the other 50% of the sound.
*NO* guitsar speaker I know is flat, all show some huge mid/high frequency peak.
This certaomly colors the sound a lot.
Quote from: J M Fahey on February 10, 2012, 08:48:44 AM
Agree that simulation, a *very* useful tool, tells only half the story.
The often forgotten speaker is the other 50% of the sound.
*NO* guitsar speaker I know is flat, all show some huge mid/high frequency peak.
This certaomly colors the sound a lot.
Agreed, and regardless of what any simulation says, I know that my K-20X has a nice dynamic EQ and isn't muddy at all unless I crank the bass full and turn the mids and treble all the way down...which is what you would expect (and want).
Hi Joe,
Great thanks for the link to the schematic.
Arrh HUH :police:
Lets see how good My detective skills are working? 8|
Yes C12 is only 1uF and this to my understanding dramatically wipes low frequency from the signal. Hence it all balances out but as I mentioned it may not work so well when used with another power stage.
Most SS poweramps I've seen don't bother much and just let it run flat from about 10Hz BUT This is ONE place you can make a big impact on bass response. Below 5uF it really cuts deep,,, 10uF seems to be the most common for the average SSpower chip.
HiFi power stage might use 50uF or higher.
A point of interest that some might like to know;
If you care to research the response curves in some famous Valve Amps you might notice that the preamp stages have almost DC response (massive bass) BUT the power stages being cap coupled do wipe off a lot of lows. So the whole thing balances out as one.
Whereas most SS circuits the opposite is almost the norm ,,all the eqing is done in the preamps and the power stages tend to run hi fi flat response.
Some quality SS gear does play around with the power stage response but with most cheap guitar amps this would be very Rare.
LOL,, so you either have a rare quality unit or just a lucky mistake at the factory.
I agree with Mr Fahey's speaker comment but in this case my money is on C12.
Change that back to 10uF and you WILL instantly understand. winky.
Cheers,, Phil.