41Hz AMP3

[Pano]

My AMP3 boards arrived today all the way from far away Sweden-land. Hurray!
The PCBs look very nice. Those SMDs are tiny. Will start building tomorrow. Will measure and listen ASAP.
Wish me luck! SMDs - Yikes!

Anyone else start building theirs?

[BWRX]

Good Luck! and enjoy the solder fumes

[ohenry]

Originally posted by panomaniac
My AMP3 boards arrived today all the way from far away Sweden-land. Hurray!
The PCBs look very nice. Those SMDs are tiny. Will start building tomorrow. Will measure and listen ASAP.
Wish me luck! SMDs - Yikes!

Anyone else start building theirs?

I have only wound the toroids. The other will have to wait until the weekend. Those SMD's are intimidating me already.

Good luck with it, I hope it has the magic of the TA 2024 (and I hope I can put the damn thing together!).

[heresie]

hello
Do you have a T amp to compare with? or a ucd?

Best regard
Avi

[cdwitmer]

I just ordered a pair of AMP3 boards . . . I'm a total newbie to SMT DIY, but it should be fun!

[dgo]

Can't wait to read your experiences!!

I've put one together as well. I'm just waiting for two toroids and
than I can complete it (hopefully they arrive in the post today)

Although *very* tiny, I found the surface mounting actually to be
easier than hole through soldering, once you're used to the
dimensions (and have good eyesight).

I did it using a cheap 0.5 mm tip on a very cheap 12v Weller mini
iron which made it harder than it had to be. Also, I didn't have
magnification which made soldering the chip quite 'thrilling'
I guess if I pulled it off with my little diy experience,
anyone can a soldering station, 3rd hand and magnifier are
on my shopping list though..

Excellent support by jan by the way. Two thumbs up for that guy!

I can't wait to listen to it and compare it to the SI. I hope it's as
good sounding with hopefully slightly better clipping behaviour and
bass response due to better components and power. Also, the
2021B chip has slightly better specs on paper (80 to 55 dB channel
separation for instance)

hope I didn't screw thing up and it plays when I fire it up

[mb]

I just finished winding and installing the 4 inductors, and began testing with a 12V SLA and small safety resistor.

No smoke, no offset voltage... connected a source and one speaker... no sound . Oops... still in sleep mode. Closed jumper J2, and voila, music! Other channel works ok too.

Too early to make any conclusions on sound but I have very high expectations. Put the pcb side by side with the SI 5066, and the difference in quality (and components) is pretty obvious.

Will be taking my time to build a moderate sized p/s and little chassis, but so far, so good.

[joensd]

Hi,
just finished a 41Hz-AMP3-board.
Soldering was easier than I thought.
Definitely useful to have tweezers around if you know what I mean.
My fingers never seemed bigger than today.

After some sound out of one channel and short loud noise out of the other I listened to music for like 2minutes until the second channel again did that loud noise. Switched off and checked everything.
The amp seems to work from 10-60seconds from switch on (~40mA draw) and then starts drawing more from the supply than it should. (200-300mA without load; haven´t dared to connect any speakers until stability is given).
At the same time DC-offset is going up (~0.6V).

Anybody experienced anything similar or any ideas what that might be? Lose contacts causing oscillations or rather the input stage?
Defect chip?

greets&happy building

[mb]

Perhaps you may try to clean off any excess flux, especially around the TA2021B, then go over every pin with the iron to ensure good solder contact, and clean again. This worked for me when I had no output from one channel.

In your case the problem seems less likely to be on the input side. Perhaps the power or control pins?

[dgo]

Originally posted by joensd


..
After some sound out of one channel and short loud noise out of the other I listened to music for like 2minutes until the second channel again did that loud noise. Switched off and checked everything.
The amp seems to work from 10-60seconds from switch on (~40mA draw) and then starts drawing more from the supply than it should. (200-300mA without load; haven´t dared to connect any speakers until stability is given).
At the same time DC-offset is going up (~0.6V).

greets&happy building

My board draw too much current and make a loud noise too. Apart from wiring the jumper wrong, something else shorted.. After rewiring input/output and recheking and clearing between the pins of the chip with a hobby knife, this problem is now gone.

I do have a problem with the right channel though preventing more listening. This channel pops quite loud everytime when the source mutes/unmutes (like changing a cd track) and also I can hear some sissling in the background. The other channel only pops acceptably on power on/off and doesn't have a sizzle but is clear. Beats me...