Hi, I can't quite see from you photos, but it doesn't look like yor ground connection goes to the case. If it does please ignore the following.
For a DIY project it is entirely up to you but if it was a comercial product you would require a direct connection from the ground tag on the inlet to a min size of 4mm screw or stud on the case with a shake proof washer. Its good practice to do this as it ensures if any mains leads come loose or if the switch mode lets go the box won't become live.
I'd also recomend a fused inlet if you haven't alread used one so if a mains cable does touch the box the fuse will blow in the box rather than taking out you house fuse (Which will take longer to react)
Regards,
Andrew
For a DIY project it is entirely up to you but if it was a comercial product you would require a direct connection from the ground tag on the inlet to a min size of 4mm screw or stud on the case with a shake proof washer. Its good practice to do this as it ensures if any mains leads come loose or if the switch mode lets go the box won't become live.
I'd also recomend a fused inlet if you haven't alread used one so if a mains cable does touch the box the fuse will blow in the box rather than taking out you house fuse (Which will take longer to react)
Regards,
Andrew
Hi
The case is grounded via the psu casing bolted in two places, also the mains inlet is a fused one with both poles fused (twin fuses).
Rgds BITF
Hi Iter
The capacitor is a 3900uf 85v, I have a box of these so just used what is to hand (seems to do the job). The Arjen modules are pretty good out of the box, my only tip when building is keep the signal interconnects as short as possible!
Used good quality phono sockets (neutrik) and the amp is silent with no signal connected. Building these amps as been my first dabble with electronics for 20 years, so pretty impressed with the results.
Attached a picture of my first attempt using a TA2024 enclosed in an old 2Wire outer case, nice sound but not enough output for me!
I would like to build an amp in a wooden case but my woodwork skills are not great!
Rgds BITF
Attachments
Hey Borninthefifties,
I'm using this TA2020 too and love the sound. I've switched out the input caps for Audiocap thetas 2uf from Partsexpress and love it even better. Have you tried it with and without the tube buffer? I have the buffer but havent hooked it up yet and was wonding about the sound? What are you using as a preamp or volume control on general? I used the Alps that came with it but at lower volumes it's not evenly balanced with the left channel being alittle too low. At higher volumes the alps in fine.
I guess I'm asking you this because I was researching passive preamps today and thought you may have already figured this out concering the TA2020.
I'm using this TA2020 too and love the sound. I've switched out the input caps for Audiocap thetas 2uf from Partsexpress and love it even better. Have you tried it with and without the tube buffer? I have the buffer but havent hooked it up yet and was wonding about the sound? What are you using as a preamp or volume control on general? I used the Alps that came with it but at lower volumes it's not evenly balanced with the left channel being alittle too low. At higher volumes the alps in fine.
I guess I'm asking you this because I was researching passive preamps today and thought you may have already figured this out concering the TA2020.
Hi ashevillebob, I am using the valve buffer/TA2020 amp combo with an iPod connected directly, so the output from the player is ample and a pre-amp is not needed.
Volume is controlled by the iPod so a volume pot is also not needed (like to keep things simple, hav'nt even got a on/off swith). I did notice that the gain pot on the buffer suffers from the same problem of uneven levels at a low setting?
I prefer the sound with the buffer, trying alternative 12AU7's at the moment(does make a lot of difference). Might like you,play around with some different input caps though!
Rgds BITF
I'm using Arjen's Ta2020 and tube buffer together. As is, I found the combo picky with music. Wonderful with some CDs, okay with others.
I just swapped in a NOS Raytheon 12AU7A / ECC82 I picked up for almost nothing, and it is transformed. This is the usual audio thing of, "I thought it sounded good before". It seems to be more "efficient"? I'm not up on tube terminology, but its like the difference between an 87db and 92db sensitivity driver. This cheap tube change really opened things up, particularly on the high end and bass guitar. Before this, I was preferring TA2020 alone for about 1/2 the music I listen to. I expect improvements as I get more time on the tube.
Anyway, I highly recommend the Raytheon 12AU7A for guys with the Arjen Tube Buffer.
I just swapped in a NOS Raytheon 12AU7A / ECC82 I picked up for almost nothing, and it is transformed. This is the usual audio thing of, "I thought it sounded good before". It seems to be more "efficient"? I'm not up on tube terminology, but its like the difference between an 87db and 92db sensitivity driver. This cheap tube change really opened things up, particularly on the high end and bass guitar. Before this, I was preferring TA2020 alone for about 1/2 the music I listen to. I expect improvements as I get more time on the tube.
Anyway, I highly recommend the Raytheon 12AU7A for guys with the Arjen Tube Buffer.
I ordered a Helder 3020 V3 off ebay about 6 days ago and it came today to country OZ! Despite the info on the site saying it would take 5 weeks or so, how's that for under promising and over delivering!
The really impressive thing is the build quality, very thick board, beautifully laid out and built, definitely a whole grade higher than the alternatives and parts selection looks very good to for the price point with the right selection of thru hole caps and SMDs where they are most appropriate. I look forward to firing it up and burning it in. Oh and the packaging was also very good, no chance of damage.
The really impressive thing is the build quality, very thick board, beautifully laid out and built, definitely a whole grade higher than the alternatives and parts selection looks very good to for the price point with the right selection of thru hole caps and SMDs where they are most appropriate. I look forward to firing it up and burning it in. Oh and the packaging was also very good, no chance of damage.
Arjen's 2020 always surprises me. I go back and forth between it and my Hlly t-90 (2022) and the Sure board (2050). The Helder very much holds its own on a variety of systems. It brings out the texture and the richness in recordings that often leads me to think that it's as good an amp as I need. The single ended 12 volt aspect also makes it very flexible. I have it plugged into my laptop at work (low output generic sound card) with a pair of Radio Shack Lx5's (50 dollars for the pair when they closed them out) , I've used it in my car with a nimh battery pack ( I have a plug for the cigarette lighter, but don't have the right connector), and I've run it in my living room system (tubed pre-amp, big speakers). I've also used a linear regulated power supply, an SMPS from a laptop, and batteries. Believe it or not, I liked the SMPS best (12 volt 2.5 amps) though I haven't tried an SLA battery yet.
Other than the fact that there are situations where the power limitations of the chip come into play, I seldom think "Geez, I need something better than this." In fact, I still seriously wonder if there are things the 2020 does that are more "right" than the 2050 or 2022. For one, with acoustic music it's easier to forget that there's an amplifier involved. One of my quirky notions about amplifiers is that with really good equipment if you play it at a level dramatically louder than the actual performance, things don't sound quite right. It was something I always found interesting about the 300B, even when I was staying within the power limits of that tube there was a volume setting for particular music that was "more right".
Other than the fact that there are situations where the power limitations of the chip come into play, I seldom think "Geez, I need something better than this." In fact, I still seriously wonder if there are things the 2020 does that are more "right" than the 2050 or 2022. For one, with acoustic music it's easier to forget that there's an amplifier involved. One of my quirky notions about amplifiers is that with really good equipment if you play it at a level dramatically louder than the actual performance, things don't sound quite right. It was something I always found interesting about the 300B, even when I was staying within the power limits of that tube there was a volume setting for particular music that was "more right".
I fired up the little beasty last night and from the very first minute it sounded right. it has almost holographic clarity on good gear running of a big SLA.
It has now been burning in for about 8 hrs and sounds wonderful this morning.
I am going to go out on a limb here and say this amp is probably about the best amp I have ever heard and I don't say that lightly I have heard a huge array of amps expensive and cheap and built a lot myself.
Sure the power is limited but when you have efficient speakers that is hardly an issue. The noise level is non existent, though I did add a copper ground plane right under the board so that might come into it.
I am very impressed.
It has now been burning in for about 8 hrs and sounds wonderful this morning.
I am going to go out on a limb here and say this amp is probably about the best amp I have ever heard and I don't say that lightly I have heard a huge array of amps expensive and cheap and built a lot myself.
Sure the power is limited but when you have efficient speakers that is hardly an issue. The noise level is non existent, though I did add a copper ground plane right under the board so that might come into it.
I am very impressed.
No, this excerpt from the Tripath data sheet shows that it is already bridged;
T E C H N I CAL I N F O RMA T I O N
1 of 13 TA2020-020, Rev. 4.0, 09.00
Stereo 20W (4Ω) Class-T Digital Audio Amplifier using
Digital Power ProcessingTM Technology TA2020-020
September, 2000
General Description
The TA2020-020 is a 20W continuous average two-channel Class-T Digital Audio Power
Amplifier IC using Tripath’s proprietary Digital Power ProcessingTM technology. Class-T
amplifiers offer both the audio fidelity of Class-AB and the power efficiency of Class-D
amplifiers.
Applications
DVD Players
Mini/Micro Component Systems
Automotive Audio
Computer / PC Multimedia
Cable Set-Top Products
Televisions
Battery Powered Systems
Benefits
Fully integrated solution with FETs
Easier to design-in than Class-D
Reduced system cost with no heat sink
Dramatically improves efficiency versus
Class-AB
Signal fidelity equal to high quality linear
amplifiers
High dynamic range compatible with
digital media such as CD, DVD, and
internet audio
Features
Class-T architecture
Single Supply Operation
“Audiophile” Quality Sound
0.03% THD+N @ 10W 4Ω
0.1% THD+N @12W 4Ω
0.18% IHF-IM @ 1W 4Ω
High Power
13W @ 8Ω, 10% THD+N
23W @ 4Ω, 10% THD+N
38W EIAJ* VDD=14.4V @ 4Ω
*saturated square wave output
High Efficiency
88% @ 12W 8Ω
81% @ 20W 4Ω
Dynamic Range = 103 dB
Up to 2X25Wrms @ 4Ω, VDD=14.6V
Mute and Sleep inputs
Turn-on & turn-off pop suppression
Over-current protection
Over-temperature protection
Bridged outputs
32-pin SSIP package
An update on the Helder 2020 mk 3. I have now had the amp runnig for about 60hrs and can only say this is a truly impressive amp, vocal, stringed instruments, piano are all great. The amp has air in spades and digs out detail that none of the other tripaths, gainclones or trannie amps I have ever tried have managed. In fact I would say it sounds pretty much like a really good tube amp within its power limitations of course, as it sure doesn't clip like a tube amp.
The bass is tight and much better than I expected. I have ordered 4 more boards to finish of my OB system.
I have also ordered the new Helder tube buffer, has anyone tried this one. Certainly looking forward to it, I was lucky enough to have 4 NOS Phillips minwatt tubes for it and picked the buffer up on ebay for $27.00 so a bit of bargain I think.
The bass is tight and much better than I expected. I have ordered 4 more boards to finish of my OB system.
I have also ordered the new Helder tube buffer, has anyone tried this one. Certainly looking forward to it, I was lucky enough to have 4 NOS Phillips minwatt tubes for it and picked the buffer up on ebay for $27.00 so a bit of bargain I think.
My Helder has now passed 120 hrs and I can say with total conviction that in standard form this is an exceptional little amp.
I have noticed as the hours built up the amp smoothed out and seems to cope better with a greater range of source materials, in other words music that initially sounded a little harsh now doesn't. I have had several people come in an listen to the amp, the first comment all of them has made is just how clear and detailed the music sounds.
There is really very little I think you would do to the amp, the input caps are fine once burnt in, the amp remains utterly quite noise wise. Overall perhaps the only things I might touch are the diode bridge, I will never use AC with these amps or stuff up the polarity (I hope), perhaps shielding the torroids from the rest of the board though overall I think that is well executed as it is.
Basically I feel this amp simply amplifies whatever goes into it so the best results will be gained from getting a better input and perhaps PS optimisation.
I have noticed as the hours built up the amp smoothed out and seems to cope better with a greater range of source materials, in other words music that initially sounded a little harsh now doesn't. I have had several people come in an listen to the amp, the first comment all of them has made is just how clear and detailed the music sounds.
There is really very little I think you would do to the amp, the input caps are fine once burnt in, the amp remains utterly quite noise wise. Overall perhaps the only things I might touch are the diode bridge, I will never use AC with these amps or stuff up the polarity (I hope), perhaps shielding the torroids from the rest of the board though overall I think that is well executed as it is.
Basically I feel this amp simply amplifies whatever goes into it so the best results will be gained from getting a better input and perhaps PS optimisation.
Hi Zero One,
You shouldn't be short of current with a 16Ah beasty! Do you run any capacitors with the battery?
I use a 7.2Ah with a couple of 6800uf caps, I find this works fine.
I'm not sure that the very heavy cable would make a significant improvement to the amplifier performance considering the size of the PCB track that it feeds
Hi audi0, there is certainly no lack of current, at present I have no caps across the battery, though I have used them in the past on other amps. I will be running some test later to determine the optimum caps to add to the battery to reduce the noise floor but frankly the noise is so low at present it is hardly an issue.
Caps may of course improve the bass further though this amp is well served by the onboard tank cap, basically this is my thinking behind the heavy wire and short power route, when the amp needs current the cable is basically a non issue, it will have no negative effect upon the supply situation.
The amp can run a very long time on the battery without lowering the voltage, seems to be at least 14 hrs before it gets to about 12.6V at moderate listening levels through 86 db speakers. I suspect there may be some difference in sound depending on the size and type of battery used, I am planning to compare a few soon including a very large automotive one.
Caps may of course improve the bass further though this amp is well served by the onboard tank cap, basically this is my thinking behind the heavy wire and short power route, when the amp needs current the cable is basically a non issue, it will have no negative effect upon the supply situation.
The amp can run a very long time on the battery without lowering the voltage, seems to be at least 14 hrs before it gets to about 12.6V at moderate listening levels through 86 db speakers. I suspect there may be some difference in sound depending on the size and type of battery used, I am planning to compare a few soon including a very large automotive one.
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