pal1972 Posted December 10, 2009 Share Posted December 10, 2009 Ive considered tis for a while now, but have no idea of how/what to do!! Ive got an ashdown MAG600 head at the minute and I never use the eq at all! so basically i'm just using input and output volumes! I did have a little giant1000 before as i wanted a compact head but found it was lacking somewhat. I'd still really like a really small head so was wondering about building one myself!? Ideally it would be around the same size as the LG1000 but i'd only need input, output and DI - no eq. How easy/difficult wuld it be to make one? Ideally 500w would do and it would need to be 4ohm. Anyone on here ever built themselves an amp head?? or know where i can go for help on internet?? Quote Link to comment Share on other sites More sharing options...
Stylon Pilson Posted December 10, 2009 Share Posted December 10, 2009 [url="http://basschat.co.uk/index.php?showtopic=28057"]This thread might be relevant to your interests.[/url] S.P. Quote Link to comment Share on other sites More sharing options...
trent900 Posted December 10, 2009 Share Posted December 10, 2009 My limited understanding is that it is possible to build an amp head DIY, but not with a good power-to-weight ratio. Lightweight amps tend to be Class D, as this amplification method is much more efficient enabling smaller components, less heat generation, smaller transformers etc. However, the downside is that Class D is also the least linear amplification method. It is a sort-of 'digital' amp, in that it compares your input signal to a fixed-frequency carrier wave. When the input signal is within the amplitude range of the carrier, the power stage is 'on', otherwise it's off. In this way, the amplified output signal is effectively constructed from a superimposed set of time periods where the power stage is on or off. It's more complicated than this, but that gives you a flavour, and I don't really understand it well enough to go into any more detail! There is also a low-pass filter in the output signal to remove the carrier wave frequency. So, there are lots of sources of distortion in a lightweight Class D amplifier: from memory, the worst are errors in the timing of the on/off switches for the power stage, resonances from other components when the power stage switches on and off giving weird extra harmonics, and non-linearity in the low pass filter. I don't believe it's possible to create a high-power, low-weight Class A or Class AB (nice, linear, full sounding) amplifier, simply because the inefficiencies involved mean you have to draw so much mains power that the transformers required become huge and heavy. The only way I could think would be to attack the transformer design - for example, transformers get much more efficient if you increase the AC frequency - but then you're into a whole world of complex design way beyond my ken and you would probably flood the amp with RF interference and resonance anyway. You might try a [url="http://www.diyaudio.com/forums/solid-state/68415-class-h-amplifier.html"]Class H[/url] amp, but I don't really know anything about that... In short, it is my understand that a DIY build will not match the sound quality, power and weight balance already achieved by mass manufacturers (like the LG1000). But it might be fun to try. Cheers Jon Quote Link to comment Share on other sites More sharing options...
Mr. Foxen Posted December 12, 2009 Share Posted December 12, 2009 Build a valve preamp first, and use in into a power amp. See how you get on with that. Quote Link to comment Share on other sites More sharing options...
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