New Solid State Amplifier - Indian Build

[maurawkela]

Around a year ago, i posted my attempt to build a SS Amp. I got lots of help. That one didn't materialize due to time constraint. Now, i'm embarking on a new one. Last time, Mr. Fahey has asked me to post how i put my amplifier together. I'm putting it here and the cost. It might be boring for some, but, its also to show that SS rocks even in India.

The Amp is based on TDA2030. I'm using Eminince Legend 121A. (i know its a small amp for a big speaker, but this is my first SS Amp, so i'm starting small  ) I got the PCB layout from General Guitar gadgets and etch it myself.

Cost of Components:
1. TDA2030A (i piece)          Rs. 10.
2. PCB                              Rs. 5. (approx) I cut a small size from the Copper Clad PCB of 12x10 which cost Rs. 50.
3. Resistor (3)                    Rs. 1.50.
3. Capacitor (7)                  Rs. 10.
4. Diode (2)                       Rs.2.
5. Heatsink                        Rs. 10.
                            Total    Rs.38.50  0r US $ 0.74  :dbtu:

Am planning to construct it soon. I have already etch the PCB. I'll be happy if you can suggest a very simple preamp for it. I'm planning to use it mainly as a guitar amp. (I'll put the pics as soon as i finish it, but compared to some of the very accomplished ones posted here, it will be a simple affair)

[joecool85]

I look forward to seeing the pics of this build.  No problem with it being simple, most of my builds are too  :tu:

As for the preamp, it depends on what you are looking for.  Do you want a nice crisp clean sound or a crunchy distortion?  You can run most any pedal in front of the amp and use it as a preamp but if you want it to be clean you will probably want to build a dedicated TL072 or similar based one.

[J M Fahey]

Congratulations!!
Will you run it on batteries?
If you build a Power Supply you can get up to very respectable 15W, which coupled to your efficient speaker will mean a LOUD amp.
Just ask your neighbours !! They´ll agree !
Out of curiosity: how much did you pay for your Eminence?
Could you buy it in a shop or had to order it from USA?
Any Customs problems or taxes?
As of the preamp: the simplest one is the MXR Dist+ , put a switch in series with the clipping diodes.
With them it distorts; without them it becomes the MXR MicroAmp *clean* preamp.
The switch should be a 6 leg micro SPDT; one half opens the diodes path ,  the other one puts a 100K or 68K resistor in parallel with the 1M feedback resistor (R8 in their Dist+ schematic) to tame the gain.
The rest of the schematic is basically the same.
Very simple, no tone controls, but a good starter.

[maurawkela]

Thanks for the kind responses.

I looked at the MXR Dist+ and it looks fine. I'll try to incorporate it with the required modification. I just need a cleadn sound with minimum control.

I got the Eminence 121A from their India distributor, so there was no need for hassles. I placed the order and i expect to get it within the next week. They stock only two speaker here, Legend 121A and Guvnor. I choose 121 as i'm into country music and this is their suggestion (on eminence website). I paid Rs. 3380 or US $ 67. Its the costliest part of my present project.

[J M Fahey]

Well, it´s an investment.
In the future, you will build more complex amps, and already have a good speaker.

[joecool85]

Well, it´s an investment.
In the future, you will build more complex amps, and already have a good speaker.

I agree with this entirely.  Assuming you don't over power your speaker and damage it, it will last through many decades of use  :tu: