To amplify an audio amplifyer

[mtbolha]

Hi, I'm new to this forum and also to electronics. Thanks to Dave and EEVBlog that i love to watch It got me interested in how things work. And now I'm allways looking how to mod or fix things.

I have maybe a silly question, but I think that maybe not...and you can help me work it out.

I'm interested to amplify and amp.

I have an old Dynacord Amp (i will look-up for model if needed) that has 150watt RMS. Is there any small easy thing to build, to amplify the amp to 300watt RMS make it 2x power or double the power in a simple way? Maybe in beetween speakers or directly in amp circuit, to change some transistor or some resistor that limits the power?

I'm not realy good in this, but sound is also an electrical signal?

[sanjin]

Hi mtbolha,

unfortunately there is no simple way of increasing the output power of a power amp as you will have to modify the output stage.

Sanjin

[tehmeme]

I have an old Dynacord Amp (i will look-up for model if needed) that has 150watt RMS. Is there any small easy thing to build, to amplify the amp to 300watt RMS make it 2x power or double the power in a simple way? Maybe in beetween speakers or directly in amp circuit, to change some transistor or some resistor that limits the power?

The quick answer is no.
You can build/buy a pre-amp (which amplifies the input signal) but this may deteriorate the overall output (the amplifier may end up clipping the signal) and causing distortion / overdrive. The total output will still be 150W.

I guess what you are looking for is to modify the output stage and this would depend on the specific amp.

It would also help to know the model and year, since Dynocord have been around since the 40s or 50s and have many different amps for many different uses, utilizing different technologies.

[tehmeme]

You can build/buy a pre-amp (which amplifies the input signal) but this may deteriorate the overall output (the amplifier may end up clipping the signal) and causing distortion / overdrive. The total output will still be 150W.

oh and by the way if you are using the amp as a guitar amp, this overdrive effect won't be the acoustically warm and pleasant type.   

[Lightages]

If you want to double the sound pressure or volume or loudness of the the amp, you need 10X the power instead of just double the power. The modifications to the amp to double the power is a lot of work for little gain in loudness.

[mtbolha]

Hi thanks for responce. I will look for a model and will let you know tomorow, its in a basement, need to dig it out. Its over 30 years old i'm sure of that. Maybe it has some older technology in it that can be subsituted by some new chip or some kind of override that was not yet invented in the days that it was build.

I remember it puts out very good sound clear sound, and quality bass, when pluged into laptop or some other kind or "finished music" (mp3, audio cd...) But when pluged into mixer or directly to instrument (Korg Pa800 Keyboard) for live performance or "karaoke night" it is very low on power, bass is too high not clear, high sounds are disorted.. and its unusable. For normal music its 10/10 for 150watt rms, nobody belives it has only that much power. But when I try to use it for Live performance.. it is bad.. So maybe somehow modify it, because I know It can sound good, maybe this preamplify version is not bad.

[Zbig]

Are you sure the problem is the amp you're using? Have you achieved live performance results you're happy with using different amp? What I mean is there's great amount of work and experience going into mixing and mastering the commercially available music, it's kind of an art by itself. I'm sorry if I'm stating the obvious, but are you familiar with compression, equalization, etc?

[tehmeme]

Hi thanks for responce. I will look for a model and will let you know tomorow, its in a basement, need to dig it out. Its over 30 years old i'm sure of that. Maybe it has some older technology in it that can be subsituted by some new chip or some kind of override that was not yet invented in the days that it was build.

It would be interesting to find out the model, but again, it is very unlikely there is anything that could be done.

As Lightages also mentioned, the ear works in a logarithmic way, so to make the sound perceptively twice as "loud" you would need to have it a multiple of times more powerful.

I remember it puts out very good sound clear sound, and quality bass, when pluged into laptop or some other kind or "finished music" (mp3, audio cd...) But when pluged into mixer or directly to instrument (Korg Pa800 Keyboard) for live performance or "karaoke night" it is very low on power, bass is too high not clear, high sounds are disorted.. and its unusable. For normal music its 10/10 for 150watt rms, nobody belives it has only that much power. But when I try to use it for Live performance.. it is bad.. So maybe somehow modify it, because I know It can sound good, maybe this preamplify version is not bad.

bass is too high not clear, high sounds are disorted

From what you're describing, the input signal is already adequate, and the amplifier when maxed out is already starting to clip the signal, therefore adding a pre-amp would only make things much worse.

Are you also sure you are not cranking your Korg's output to 11? and causing the sound to deteriorate there?

Just out of curiosity, what type of music and/or events are you into?

[tehmeme]

Are you sure the problem is the amp you're using? Have you achieved live performance results you're happy with using different amp? What I mean is there's great amount of work and experience going into mixing and mastering the commercially available music, it's kind of an art by itself. I'm sorry if I'm stating the obvious, but are you familiar with compression, equalization, etc?

+1

[mtbolha]

Here is the model of my Dynacord amp, its: Dynacord A1001
Its an old thing, but as said before, sounds really great when pluged into radio, laptop or simmilar. Very loud and clear, with good bass even if used outside, its hard to belive how loud it can get for its power raiting.

I know a thing or two about music. All my channels are mastered, compressed and equalised before going into an amp (if not used thru mixer, connected directly thru Korg Pa800 - the Korg keyboard provides mastering, equalising and so on automaticly on its output channel). If I use another amp with same settings on mixer it sounds great, my other amp is Behringer (with lower power rating than dynacord) - its known that is not so good, but it sounds decent I whould give it 6-7/10.

I have a hunch that I need to modyfe something inside Dynacord A1001 to let it sound good. I have a feeling that I can make it sound good for live music just as its good for radio, mp3s and other kind of non-live music and audio. I think it has some limiters inside that needs to by bypassed or modyfied... I dont know...