Post your Solid State pics here

Transpow PR-240..

Bought one of these amps a couple of months ago.
I'd like to (know if it's worthwhile to) repair this little beast. I'll find out soon how cleaning affects the sound anyway. :)
Unafortunately I cannot find anything about it. I'd greatly appreciate it if anyone can help me to find info. I suspect it might be a kit build?

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Hi! this is my first post in DIY Audio!

Here I share my first project, it's MOSFET amplifier (1 channel shown in the photo), supply is +/- 30 VDC, power output about 30W at 8 ohm (that's what I'm using now).

I made two of these stages, the transformer is rated at 100VA, the capacitors values of the power supply are 4700uF (I will add more caps to it soon).
I made it few months ago and it works pretty fine (begginners luck?) jaja. This stage is from PCP Audio (spanish web if you look for it).

I also made a 24db/octave crossover (from ESP Audio) and the voltage regulator from the same author (yes, I'm thinking about bi-amplifing). I tested them (not for a long time, as I don't have another amp yet) and worked well.

Now I'm going for the woofer amp, I decided S-Sub from PCP Audio too.

The speakers consist on 8" woofer, 5" mid and 1" dome tweeter.

I Didn't make a chassis for it yet... because I haven't decided what I'm going to include inside it yet...

So I still experimenting and enjoying!

Salute!
 

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Hi! this is my first post in DIY Audio!

Here I share my first project, it's MOSFET amplifier (1 channel shown in the photo), supply is +/- 30 VDC, power output about 30W at 8 ohm (that's what I'm using now).

I made two of these stages, the transformer is rated at 100VA, the capacitors values of the power supply are 4700uF (I will add more caps to it soon).
I made it few months ago and it works pretty fine (begginners luck?) jaja. This stage is from PCP Audio (spanish web if you look for it).

I also made a 24db/octave crossover (from ESP Audio) and the voltage regulator from the same author (yes, I'm thinking about bi-amplifing). I tested them (not for a long time, as I don't have another amp yet) and worked well.

Now I'm going for the woofer amp, I decided S-Sub from PCP Audio too.

The speakers consist on 8" woofer, 5" mid and 1" dome tweeter.

I Didn't make a chassis for it yet... because I haven't decided what I'm going to include inside it yet...

So I still experimenting and enjoying!

Salute!

Hi Fedess, congrats and welcome :)

I like the build of yours, i were using google translate to read the spanish ( thanks to google translate for this fine tool ). I find PCP's site very informative, it seems to be the right place for people, who are new into DIY projects, all in all a great site.

The project of yours: DIY AMP PUBLIC - PCPfiles en www.pcpaudio.com
 
Voltcontrol: " I'd like to (know if it's worthwhile to) repair this little beast. ..."

ostripper: " ... Looks like a high current dual 55-0-55 Vdc setup. good for a 120W amp. "

Here is what I would do (and have done): Keep all the cool hardware, trannies, caps, gauges, switches ... and strip the old audio circuits out and add modular amplifiers ... Example: HPA-nxV200 180 watt MOSFET Audio Amplifier Module ... or ...
 
Hi, thanks everybody!


KrammeAcoustics: Thank you! I can help with some translation from spanish to english if you find something interesting

Mooly: thank you! what do you mean with correcting grounding?

regiregi22: It sounds much clearer than a commercial (gainclone) soundsytem!! The difference is very noticeable. =) The response is flatter than commercial but it still needs some eq (or maybe my speakers need it...!)
 
Thnx Ostripper, do you have an axample of a nice design?

I was thinking in the lines of a dual mono Firstwatt F5 diy.
But honestly, I don't know enough about electronics to develop that (yet..).

I don't do those 25w amps , for a 53-0-53VDC setup like yours an AX1.0 with a PB-120 powerboard will do fine. (attached below) Dual mono with these would be sweet.

Just a tweaked Doug Self blameless. At a hundred mA bias it is in class A anyways, (firstwatt??) with .0002%THD.

With the PB120 (120w powerboard) or PB-200 you can add any voltage board you like :

AX1 - Blameless
BX1 - RCA bootstrap amp (like aksa55)
CX1.1 - balanced VAS (symasym style) my favorite.
no DX1 - copyright issue. :D :D :D
EX1 - Complimentary balanced amp (leach style)
FX1 - A Harmon-Kardon clone , very highly acclaimed.

What is nice all the voltage boards will work with any of the powerboards seamlessly. If you want to try something new , plug it in.
OS
 

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Who cares about...

This is the last discrete operational amplifier that i designed 6 months ago. The reason was to make something that can surpass the problem of performance variation according to the level of power supply. An annoying problem that i had encountered with Burson's discrete. This module, it has the same performance with any symmetrical power supply from +/-12V up to +/-30V. It is implemented at whole with BJTs (BC550C - BC560C, MJE172 - MJE182) but it has a very good bandwidth, up to 650KHz. Connected in non-inverting mode for Av=2, with Zin=5KΩ and RL=500Ω, it has a rise time of 600nsec thus a bandwidth = 0.34 / 600nsec = 560KHz. Later i decided to make a further improvement. To eliminate the need for voltage regulators in power supply. I removed any current mirror, and i added constant current sources in all stages. The result is very good. This module supplied with +/-30Vdc from unregulated power supply it presents in output a ripple noise of just 50μV. The use of voltage regulators is only an option. During a test with voltage regulators with BJTs connected in common base mode in their outputs, the ripple noise wasn't reduced further. Later i started a new drawing with SMD parts to reduce the PCB size as much as possible. I have finished the new SMD PCB but i had never the chance or the mood to assemble it ... six months ago.
 

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