Sunday, 14 February 2010

Ruby Amp

26 comments:

  1. Is this designed to work with an external speaker or is the "out" line meant to go directly to a speaker? Also, there are two "9V" lines in this design but where do each of those go. I have seen other Ruby amp designs but they always have just one 9V line from the board.

    Thanks in advance for any advice.

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  2. Yes, the output from the 220uF cap goes to the speaker as per the scheme at runoffgroove, http://www.runoffgroove.com/ruby.html.

    There is only 1 x 9V line in but the relative positions of the components on the tagboard made it difficult to take the supply to the jfet and the IC to the same tag. But they will both need connected to the same supply so you can just daisy chain the two required connections.

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  3. Thanks so much for the help. I was also curious. Where do you buy boards like this? Or the other kind that are featured prominently on this site? I've looked at every major electronics supplier I can think of and not found any.

    Thanks again!

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  4. You can buy this kind of tagboard from a number of sellers, such as:

    http://www.ampmaker.com/tag-board-1275-0.html

    and Musikding sells similar:

    http://www.musikding.de/index.php/cat/c105_Termnal-Strips.html

    as well as the stripboard which you should also be able to find at a number of electronic retailers:

    http://www.musikding.de/index.php/cat/c91_Circuit-board-material.html

    http://www.banzaimusic.com/PC-Boards/

    http://www.rapidonline.com/Tools-Fasteners-Production-Equipment/PCB-Equipment/Prototyping-Boards/Stripboard/29453/kw/stripboard

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  5. Wow, thank you for all of your help. I really appreciate it. I have one last question, how can I add a Power switch to this circuit. I'm assuming it would attach somehow to the 9V adaptor but I have no idea how. Thanks again!

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  6. I'm sorry I thought I was done with the stupid questions, but as I'm sure you can tell by now, I'm new to this.

    So anyway, I tried to build this amp w/ a small 4" speaker. All I'm getting out of it is hum. The gain knob doesn't really effect the hum, but the volume know definitely does. So the only questions that I have left are 1) where is that ground wire coming in on the left side of the diagram coming from? and 2) where do the ground wires for the speaker, the 9V Jack and the input jack go? Do I just pick an empty spot on the tag board for all of them? I'm sorry for all the dumb questions. Thanks again for all of your assistance.

    - Adam

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  7. All the grounds should be connected to a central point so you know they're all connected together. The sleeve of one of the sockets is a good idea, or as you suggest, a free tag would be fine.

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  8. Hi,

    I've build this amp, but there is nothing coming out of the speaker. I thought maybe the ic was broken, but that doesn't seem to be the problem. I've noticed that you didnt put a 100 uf cap at the 9v point and on the original layout, the 220 uf cap is reversed, with the negative side going to the speaker. So maybe that could be it. But i'm a little confused too about the offboard wiring. Where does the neg side of the battery go to? I think it's to the ring of the input jack, but i'm not sure.

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  9. Agree with JonasL, the 220uF is definately the wrong way... The 100uF cap from +9V to ground shouldn't be too hard to fit... I guess it could just sit between 9V lug (top left corner) straight down to the ground lug where the 1M5 resistor is grounded.
    Awesome work IvIark! Will definately build this thing on tagboard.

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  10. Thanks for the heads up guys

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  11. The 100u cap is to smooth the supply and is optional. If you have a dubious or noisy supply and want to include it, you could put a small radial cap on the bottom row between the 3rd and 4th from right tabs or as perkabrod suggested, from top to bottom left. Layout is updated.

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  12. i don't suppose that you have a vero version of this laying around that you could post? or the little jem, noisy cricket, or any of the 386 mini amp circuits?

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    Replies
    1. I don't, but I could do one. Which one would you prefer?

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  13. i guess the noisy cricket would be my first choice. it seems to have a bit more control. but, whatever one you post, i will build. thanks, that is very cool of you to do.

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  14. Believe me. 100µF filter cap is not optional. Or maybe i would be, if i haven't done what i threatened earlier.

    Missus is out of town, so no photos right now, but...

    I built this with Boob Tube 1.5 with ECC82 as a preamp in a single BB box.

    Output of the Boob Tube is so high, that i had to do a little low volume/gain mods :) - I used B1K for volume and added 8K2 resistor in series with vol 2 lug. Then i set the gain with 1K2 resistor between IC pins 1 and 8. Also i think it's worth noting that i'm running this with 12V.

    One more thing to note in addition to power filter. MPF102 pinout is DSG, so to use it, one has to twist the pins. I tried that, but got it to sound great with BF244A that has DGS pinout.

    But that's about it. This layout works, but pinout of MPF102 is twisted and power filtering is required. Tag it.

    This is truly great little practise amp :)
    +m

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    Replies
    1. Nice one mate, corrections made! :o)

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    2. And here's a few shots:
      http://mirosol.kapsi.fi/varasto/boxes_other/gemstone2_1.JPG
      http://mirosol.kapsi.fi/varasto/boxes_other/gemstone2_2.JPG

      Knobs come in the way, but the texts are from left to right, Tone, Gain, Level and Master.

      Input, 12V DC and 8ohm Out are on the back.

      Sounds pretty f*n good. Half watt hybrid. I'm pretty proud of myself at the moment :)
      +m

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    3. Awesome. Do you know, one of these would be really useful for me, a little amp that I can keep in my workshop so I don't have to come in the house to test something, it'd be ideal. But as usual I procrastinate wondering about what to build, forget what I was thinking of and decide to do a new layout instead. I need to sort my shit out.

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    4. Well.. It's not that hard of a build and doesn't need anything special, except the tubes. Banzai has them for decent prices (JJ/Tesla ECC83 for more drive and ECC82 for more fat) and i bet you have the tagboard and all the other parts at hand.

      Lowering the main volume and gain may be in order, but with those i've done, the level is still enough to be Loud!

      Nice project. :)
      +m

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  15. Wat type of speaker could be used? No matter about ohm value?

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    Replies
    1. I just built the Noisy Cricket (based on the Ruby Amp) and wired it straight into a strandard 8ohm 8" midrange speaker and it worked just fine. I don't think it's too fussy about what you use, I've seen people use the tiny 1" mylar speakers or hook them up to 4 x 12" Marshall cabinets.

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  16. Looks interesting :) could you put up a vero layout of this too? And what modifications would need to be made if I want to use this as a full range amp (ie for bass and for guitar) ?

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  17. Hello. I have built this amp and I would like to put it inside a BB box. Usually with stompboxes I ground the enclosure via the input and output jacks. I am not sure if this still applies to an amp. At least to the output jack to speaker. Or to both jacks. Can I still connect all grounds to the enclosure here?

    thanks

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  18. I'd like to make the same amp that Mirosol built (ruby amp and boob tube in the same box)
    But how do you do with the pots: you'll have two volumes and two gains. Which ones do you remove: the amp ones or the boob tube ones? and how ?
    thanks

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  19. Any suggestions on power supplies? Has anyone used a boss or a onespot? Just want to make sure I don't blow it with too much current.

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  20. So anyway, I tried to build this amp w/ a small 4" speaker. ... mguitaramp.blogspot.com

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