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
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
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.
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.
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
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
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?
In your case the problem seems less likely to be on the input side. Perhaps the power or control pins?
joensd said:
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...
Yes there is one.
Schematic used is more or less the one from the TA2021B datasheet.
Found a lose solder joint of one of the feedback resistors.
Must have been the noise on one of the channels when no contact.
Don´t know what happened but now it really seems the amp is shot.
Puts out DC of about -6V and 5V generator inside the chip seems to work just when it feels like...
OK, where was the other chip?
greets
Well, I finally got it right after rechecking (and -soldering mind you) all connections! My new soldering station and magnifier sure did help a lot!
I've also built a nice alu casing for it (my first diy casing ) and I've been listening to it all day.
(the protection foil is still on the front panel, a switch + led will be added plus a larger knob).
anyway:
No more strange pops (other than switch on), no more noises, no over current drawing, no excessive heat. It plays, and it plays damn fine.
Appearantly, it needs a burnin just like the 2024. After a day, it's already getting better (esp. highs/mids are getting more natural now, less harsh/shrill (same like the 2024 when it's factory fresh).
I didn't make a direct comparison with the SI 2024 yet, but my first impressions are as follows. Basically, the characteristics are like the 2024 in the SI. Lots of detail, great high & mids, great stereo image.
The bass response is way better that the factory SI, due to the larger input caps. You have to mod the SI to get bass like this.
Also, I've got the impression the stereo image of the amp3 (or 2021b) is a litte different than the 2024. width is about the same (maybe a litte wider) but I've got a feeling there is more depth.
(listening to my favorite chesky recordings)
It sounds a little different than my SI's, but they are burnt in so I cannot draw any conclusions right now about that being permanent.
I didn't really push it's limits, but it seems to have a litte more breath than the SI (on 8 ohm that is)
Over all, I think it's very good sounding and this seems definately a very good starting point for diy projects. I'm building a few more of these for my interested friends and relatives !
I've also built a nice alu casing for it (my first diy casing
) and I've been listening to it all day. (the protection foil is still on the front panel, a switch + led will be added plus a larger knob).
An externally hosted image should be here but it was not working when we last tested it.
anyway:
No more strange pops (other than switch on), no more noises, no over current drawing, no excessive heat. It plays, and it plays damn fine.
Appearantly, it needs a burnin just like the 2024. After a day, it's already getting better (esp. highs/mids are getting more natural now, less harsh/shrill (same like the 2024 when it's factory fresh).
I didn't make a direct comparison with the SI 2024 yet, but my first impressions are as follows. Basically, the characteristics are like the 2024 in the SI. Lots of detail, great high & mids, great stereo image.
The bass response is way better that the factory SI, due to the larger input caps. You have to mod the SI to get bass like this.
Also, I've got the impression the stereo image of the amp3 (or 2021b) is a litte different than the 2024. width is about the same (maybe a litte wider) but I've got a feeling there is more depth.
(listening to my favorite chesky recordings)
It sounds a little different than my SI's, but they are burnt in so I cannot draw any conclusions right now about that being permanent.
I didn't really push it's limits, but it seems to have a litte more breath than the SI (on 8 ohm that is)
Over all, I think it's very good sounding and this seems definately a very good starting point for diy projects. I'm building a few more of these for my interested friends and relatives !
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