Humble Beginnings - My first DIY Amp!

[spy king]

Hey!

While trying to decide what amp/speaker combo to get, I also decided to play around with some attempts at a small amp too!

Stumbled upon couple of threads here, and was hooked!

So headed of and looked at various circuits, picked one and was off to get components!

The ckt I found, listed a 25.2v CT transformer. The silly me had to go through three iterations of transformers and revised my basic rectification knowledge after I finally realised that I needed a 12-0-12 xformer!

Anyway, long story short, It worked first time I hooked it all up! (Yes, just now! )
It's a little messy (just twisted wires together to test) but I need help with the final wiring.


I noticed a faint hum at full volume, and a small crackle when I touch the input. Could it be cause I have just twisted all the ground wires and not soldered it properly?

What wires should I use to connect the input & output jacks to the pcb?

 

[Kannan_madhu]

Congrats, Hows it sound ?

 

[sachu888]

Congrats Spy king.

Regards,
Sachin

 

[captrajesh]

Congrats.

Hmm, the plan of buying a Marantz has been shelved I guess.

 

[Thad E Ginathom]

What? No explosions? I'm going back to Kannan_madhu's thread! :lol: I guess you'll have to call yours The Hummer!

But seriously... well done, and it is nice to know that his thread has been your inspiration

 

[spy king]

Hey all!

I hooked the amp up again this morning and ensured that none of the signal and power wires were intertwined.

Was pleasantly surprised to get absolutely NO hum even at full volume! There is no thump when I switch on the amp as well!

I proceeded to listen to some flac files from my fuze and was very satisfied! I had set the fuze eq to flat.

I found that the highs were a bit shriller than what I enjoy. What would be the best way to tone it down a bit? Currently have used a 20k feed back.

Otherwise, I am really happy and pleased with the outcome of this DIY. Now just need to tidy it all up.Can I use CAT5/6 cable for leads to the jacks from the PCB? Need inputs for this..

Congrats.

Hmm, the plan of buying a Marantz has been shelved I guess.

Nope! Getting the PM5004 This was just to see how it would turn out! shall now use this in my room or something..

 

[sachu888]

Hi,
Great to see your amp is working.You can use twisted pair of Cat5 cable for input/output jacks.

Regards,
Sachin

 

[iaudio]

Sorry for the noon question, but which amp/chip/design is this based on?

 

[Kannan_madhu]

Take some coal place the amp above it and burn for some hours the shrills will go.. as per sound gurus amp advice ( adding coal is my suggestion ). seriously i think it will sound good after some usage .

 

[spy king]

Hi,
Great to see your amp is working.You can use twisted pair of Cat5 cable for input/output jacks.

Regards,
Sachin

Alright! Shall read up as to number of wires for each and stuff!

Will 18guage do for the power wires? I am not going to be drawing more than 1.5-2 amps..

Sorry for the noon question, but which amp/chip/design is this based on?

The amp has two LM1875's, one for each channel.

 

[Thad E Ginathom]

cat-5 (etc) cable is very specifically designed and built for ethernet networking. The specification is very exact: even the angle of the twist matters! This gives people the idea that is has sort of inherent superiority. Outside of its designed application, I don't think it has any superiority at all.

But hey, have to admit that I don't know anything about building amplifiers!