My DIY Stereo Amp Thread

[Family_Dog]

Just make very sure they are insulated from the metal chassis when you mount them!


-F_D

[Crafty]

Made the power link wires, and hooked up the power amp to the psu. I almost expected smoke to escape...
Made me smile a bit when the LEDs came on in stead :p

[Crafty]

Okey, i could not help my self. I ran my iphone directly in to the power amp. Works perfectly! Plays a little soft i think. Will try and fine rune that with the pre amp. On the other hand, i have no ide what the iphone output is. Might be less than 1v

[tangmonster]

Okey, i could not help my self. I ran my iphone directly in to the power amp. Works perfectly! Plays a little soft i think. Will try and fine rune that with the pre amp. On the other hand, i have no ide what the iphone output is. Might be less than 1v

handheld devices and pc soundcards is normally between 0.7V and 1V peak. It varies between devices. I am also sure you will get devices that has lower peak voltages. with a 3.3V battery thhre isn't much you can do except for expensive charge pump switch mode power supply circuits but there won't be enough space and it will push up cost too much and it won't be able to drive the higher current into 32ohm headphones.

[Crafty]

Well if all goes well, I will hook up the pre-amp tonight.  I somehow want to mount the pre-amp to the face plate 1st.
So the scary part will happen tonight. Drilling the face plate. If it goes wrong.... I know I took the last one from you  :-p. There is no ordering another one.
So I will measure 6 times, and drill once.
Do you have the dimentions with you of the face plate? Perhaps I can do a drawing at work, print it, then stick it on with all the markings in place...
In the front, there are 4 tone controls. Bass, Trebble, balance, and volume. One blue LED light with chrome housing, and a power switch 20mm x 15mm push button.

[Crafty]

Quick Update

Played Pink Floyd - Shine On you Crazy diamond on the amp. Part 1 - n( the whole album)
It works....
I think the tone control trimmers needs some fine tuning.
Also I need to remove the Pots from the pcb, since they then cannot go through the front panel. They were mounted to deep.
Will run small wires from the front panel to the pcb then.

Do do:
remove pots from PCB
Drill 4 holes in front panel for tone control pots, and link with wires.
Drill Speaker Connection holes in chassis
Connect Speaker connections to power amp.
Drill Power Light Hole in front pannel.
Remove LED from pre-amp PSU, and run wires to Blue LED on Front Panel.
Toggle Switch on Front Panel

Close her up, hook her up to source, and Kenwoods and enjoy :-)

[Crafty]

Final Order placed. +/- R300

Some aluminium knobs for the volume and tone controls.
Gold plated binding posts.
New switch

So after this, it's home free! Will update with pictures soon!

[Abu]

Sweet!  cant wait to see pics... What's the final cost then.. ballpark?

[Crafty]

Roughly R2K
Could have done it for a lot cheaper, but I got a very nice chassis, aluminium knobs and metal switches. All connectors at the back are 24k gold plated. 1 set of RCA inputs, and stereo binding post output. Contains fairly interesting pre-amp that controls the volume and tones by changing the DC (made by philips). So you have no potentiometers directly in line with the actual audio signal. the TDA IC controls the audio signal depending on the DC.  The output of the pre-amp is matched 100% to the input of the power amp. Exactly at 1v
I would like to build in some speaker protection still. That will work out somewhere between R100 and R200 and another small pc board to build up. Will use it without protection in the mean time. Another future adition might me a mm/mc pre-pre-amp ;-p
That way I have a phono input, and will fine tune the current input for a cd player. Just need to get a selector swtich then as well.
this was a lot of fun. and did a lot of learning as well.
Next is some of Rudi's designs...

[Crafty]

SEXY!!!!

[Spuds]

SEXY!!!!

Those look familiar. 

When can we expect pics of the fully assembled unit?

[Crafty]

Those look familiar. 

When can we expect pics of the fully assembled unit?

Well tonight I'm installing SQL 2008 and installing the new server at work for our finance application. We've been pushing hard for this.
Once I get home, I need to install my wive's new head unit in her car with some 6x9's
After that, I will perhaps tacle something easy such as replacing the grounded RCA's with the new insulated ones, and then bed.
By this weekend I want to demo the whole setup. Turn table configured, phone stages in place, amp finished, and some vinyls cleaned :-)

[Atjan]

Busy guy!
Where did you source those saxy knobs?

[audiomuze]

Well tonight I'm installing SQL 2008 and installing the new server at work for our finance application. <snip> ...and then bed.

bwahahahahahaha 

[Spuds]

bwahahahahahaha 

Yeah, that sound a bit more how I'd see things going as well.