DIY Amplifier

Discussion in 'Home Theater Projects' started by Mike_Mo, Mar 18, 2004.

  1. Mike_Mo

    Mike_Mo Auditioning

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    I'm thinking about building my own multichannel amplifier. Can anyone give me any recommendations? I found some links to designs but I'm wondering if the sound quality can match that of the retail world? I recently started building my own speakers with great success. It's a shocking discovery that a DIYer can build great speakers for $500 that can compare to speakers selling for $1500 plus. I wonder if the same holds true for amplifiers?
     
  2. George W

    George W Stunt Coordinator

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    Seems that it does Mike, I would take a look at Aspen amplifiers. You can find their forum here: http://www.audiocircle.com/circles/v...b7e8f82386f468
    I can not vouch for them directly as I have not yet had time to build my kit, but I have yet to hear any negative comments about them. You might also look at pass labs as I believe they might have some amps that would work as well. Good luck!

    George
     
  3. Bob K

    Bob K Stunt Coordinator

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  4. Stephen Weller

    Stephen Weller Stunt Coordinator

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    If you don't need massive amounts of power, check this out

    S1554kit $19.95 2 x 22 WATT STEREO

    Here: http://www.dckits.com/audio.htm

    I built three of these for my temporary 5.1 amp until I could convince the spouse that an integrated amp was worth it. I'm still using one in my DVC sub.

    All these approaches have two limitations:

    1) You'll still need a decoder, but you can use it as a preamp.

    2) You'll need a clean, hefty power supply. PC switchers are cheap and work well, but there are very few that don't produce obnoxious noise from the fan.

    And if you think 22 watts isn't very much/not enough, consider that drivers are spec'd at "N dB @ 1W/1M." Think about it for a minute.
     
  5. Mike_Mo

    Mike_Mo Auditioning

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    Thank you for the good information. I'm glad to hear the DYIer can build a quality amp. With Outlaw Audio selling good 7 channel - 100watt/ch amplifiers for $800 I wanted to make sure what I can build would be far superior and come close to the high end stuff.
    Aspen amps, Audiokit amps, and Pass Labs seem to all have very good amps. Now I just need to do some more homework and find the best back for the buck.
     
  6. Adam Demuth

    Adam Demuth Agent

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    Stephen: Nice, I've been looking for a ready to go kit with some decent wattage behind it. When you refer to noise from a PC power supply, are you referring to electrical noise (that affects the amps performance/that you can hear through the speakers), or audible (not through the speakers) noise?
     
  7. Craig Treusdell

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    Mike -
    I built a 6 channel Leach amp (Dr. Marshall Leach, GaTech) and they sound excellent. 120W @ 8Ohm, 240W @ 4Ohm (with 2 more transformers), and it is stable to 2Ohms.
    He also has a design for the Leach Super amp that will put out 300W @ 8Ohm, stable to 2Ohm as well.

    I wish I had added auto signal-sensing turn-on and indicators for clipping and power.

    I spent about $1200 on the entire unit and do not see it as all that cost effective when compared to decent quality amps with similar specs today. I could have cut corners on some of the cost, but I wanted a quality unit. This was 10 years ago, so I'm sure the price is not accurate.

    The front and back are 1/4" Lexan and two fans are on the bottom blowing air up through the heat sinks. Even when driven hard the amp stays very cool. I should have added temperature controls and used variable speed fans.... The caps will play two channels driven hard for about 5 seconds after the unit is unplugged. [​IMG]

    Here are some pics:
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
     
  8. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    I built a 50wpc inverted GainKlone Amplifier (Thorsten's Design). Not only is it only 9 working parts making it the most simplified DIY chip amplifier on the market, but it's a signiture part of its sound since it costs about $150 for the quality parts to make it sound good. (Such as BlackGate Capacitors)

    It's a clone of the GainCard Amplifier which retails for $2,500 (without power supply) which has the same general design.

    It hands down beats my 100WPC Rotel amplifier in detail and doesn't sound as muffled.

    The GainKlone is probably the most popular DIY amp that exists today and is very common on the DIYaudio forums.

    Highly recommend looking into this one if your a bit new to DIY amplifiers.
     
  9. Michael R Price

    Michael R Price Screenwriter

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    I also built amplifiers designed by others but not available as kits. For each of them the circuit is publicly available, and you can purchase blank PCBs. These aren't so hard to assemble if you know what you're doing and there are usually a lot of people willing to help you if you have problems.

    Firstly, I built the fourth variation of the "Zen" amplifier by Nelson Pass. In my configuration it is about 15 watts, single-ended. It's really weak of course but the treble is amazing. Especially at low volumes you can tell it's a sort of "special" sound. If you'd like to avoid tubes this is the right kind of amplifier for high efficiency speakers.

    Then I built Anthony Holton's symmetrical amplifiers... I had a lot of expensive failures but eventually figured it out and got these working after a few months. I used high quality power components (large, good toroids, capacitors, and heatsinks). These gave my Kit 281s a *surprising* dynamic quality compared to the 100 watt amp I had. Of course the sound is really clean and clear, probably like a good big solid state amp. It doesn't get the treble to sound so "right" like the Zen, however.

    Thus, I will use both in active bi-amping. [​IMG] This level of amplification quality would not have been possible given my budget. These two amplifiers cost me about $700 total to build and I learned quite a bit in doing so.
     
  10. Joe Hsu

    Joe Hsu Supporting Actor

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    I second the idea to check out DIYaudio.com, and look under the "chip amps" section...I too will be building my own amp in the near future, and they have a couple of kits (one for the PCB and all resistors, caps, etc., and another for a high-quality chassis...there's talk about a complete kit soon), in addition to a lot of PASSlabs talk.
     

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