While waiting for my gmarsh Wiener TDA3118, I put a mildly hot-rodded TDA7297 to use to audition some Klipsch Kg4s from Craigslist in Troy, MI. The small amp, battery booster and Pono player make it easy to listen to speakers that are not in a system.
Dave Brubeck's Take Five and Eric Clapton Unplugged sounded very good from the Kg4s.
I didn't buy them. They were too nice, almost mint. I'm not looking for furniture. The seller is asking $300 OBO and should not accept much less, which is more than I was willing to pay.
Dave Brubeck's Take Five and Eric Clapton Unplugged sounded very good from the Kg4s.
I didn't buy them. They were too nice, almost mint. I'm not looking for furniture. The seller is asking $300 OBO and should not accept much less, which is more than I was willing to pay.
Attachments
Hey guys, since the kits don't go, I thought some of you might be interested in just the PCB's. There's the PSU, too, that I use.
I am a happy owner of this PCB and now is full working. It provides a different level to audition than the Chinese 3USD module which is already a best buy for their sound/price.
I have also plans to build in the future the Antipole PSU to match with it and I will report the results here.
I intend to build two Antipole PSU the second one for my DUG PBTL TPA3116D2 modules that I also enjoyed a lot.
Literally.
That common mode choke on the AC side of the rectifier. That will lower the noise floor. It is especially effective at HF where the majority of active devices (such as regulators) are especially ineffective. HF, if it gets close to the audio band, will also affect imaging/realism practical concerns. For a great many audio tasks the practices of "Throw a transformer at the problem" is an unnecessarily expensive way of getting highly effective, very quickly. Basically, transformer solutions cost a little more (as well as indicate lack of brainpower for getting less expensive actives to do a similar job) but reward with an easily applied and sure means to work.
However, if you had one thing to buy and it had to work then a transformer-based filter is highly recommendable for getting the job done on the first try. In this case, even though transformer-based filters cost more upfront, the one and only purchase for it, can be far less expensive than many of something else.
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The CMC also has the naked EPCOS MKT capacitors to decouple any extra noise right there in between the CMC and diodes. I've found this to do a much better job at creating pleasurable music than bypassing diodes with capacitors; which has a moderately if not poor rating for being a good idea here on DIYa. After that the copper pours reduce the inductance a lot so the large capacitors on the DC side will have a better affect than typical with small traces, on remaining noise in that local area.
The amplifier itself uses a copper pour and when used with the high end OSCON capacitors (SEPF, and FP: panasonic/nichicon) the ESR/ESL is crazy low since the capacitors already outperform the capacitor multiplier at 14mohm, but are about 1-1.5mohm with 12x of them. Then the capacitor multiplier takes over for remaining needed power, as it acts like an infinitely size capacitor regulated to 17.8-18v for safety (not the Chinese reject chips don't often work at this voltage, where as ones from Mouser can play for an unknown time well above it). The capacitor multiplier has decent PSRR qualities, and itself is also lower ESR than the typical capacitor (which the SEPF/FP's are not).
Both boards feature CFC, which is just capacitor orientation to cancel their fields. It adds no cost to it, too.
The chips is current limited so the higher and more controlled the voltage is, the better the device operates.
How does it sound? Well here's my potentially biased opinion... It has really good impact in the higher registers for things like cymbals, voice, etc. It's somewhat unique in those areas and this I love. Even on my 8ohm 87/db speakers playing Nirvana's Unplugged last 4 tracks can give you some chills. I play them load. My buddies girl wanted to listen to several sound when I was playing it; she otherwise doesn't really pay attention or care about Nirvana. The bass is actually rather good, at least it's musically fulfilling as it sounds louder than it even is, but on higher efficiency speakers it's loud like it sounds. A friend told me it sounds like it has at least 30w. I think that's partly because it has balanced outputs.
The chip responds to everything. The custom amp I made for my buddy used all copper connectors and it made it sound much more grainless and smooth where it should be. Don't get my wrong, Jack White's awful sounding instruments played with some talented still sounded fun like they should; and like bad instruments being played near explosion. Also the input capacitors are very important. I tell everyone to bypass the recommended PHE426 1.5uf with a MKP1837 .022uf because it adds the capability for speed that most amplifiers just don't have. With that comes greatly improved micro detail, tone, which creates not only better imaging but an ambiance around the instruments/singer that is pretty interesting to hear. Basically this information is just too smeared typically for it to come across as anything, but the speed of this amp and the small bypass caps give you something awesome.
I don't think it's possible to make something that sounds better for the money, currently. I mean... How often can a couple hundred bucks worth of parts be just what you're looking for with $27K speakers? The chassis alone for a class A unit with at least 15w costs more than one of these even with some fancy connectors.
For some other opinions
The amplifier itself uses a copper pour and when used with the high end OSCON capacitors (SEPF, and FP: panasonic/nichicon) the ESR/ESL is crazy low since the capacitors already outperform the capacitor multiplier at 14mohm, but are about 1-1.5mohm with 12x of them. Then the capacitor multiplier takes over for remaining needed power, as it acts like an infinitely size capacitor regulated to 17.8-18v for safety (not the Chinese reject chips don't often work at this voltage, where as ones from Mouser can play for an unknown time well above it). The capacitor multiplier has decent PSRR qualities, and itself is also lower ESR than the typical capacitor (which the SEPF/FP's are not).
Both boards feature CFC, which is just capacitor orientation to cancel their fields. It adds no cost to it, too.
The chips is current limited so the higher and more controlled the voltage is, the better the device operates.
How does it sound? Well here's my potentially biased opinion... It has really good impact in the higher registers for things like cymbals, voice, etc. It's somewhat unique in those areas and this I love. Even on my 8ohm 87/db speakers playing Nirvana's Unplugged last 4 tracks can give you some chills. I play them load. My buddies girl wanted to listen to several sound when I was playing it; she otherwise doesn't really pay attention or care about Nirvana. The bass is actually rather good, at least it's musically fulfilling as it sounds louder than it even is, but on higher efficiency speakers it's loud like it sounds. A friend told me it sounds like it has at least 30w. I think that's partly because it has balanced outputs.
The chip responds to everything. The custom amp I made for my buddy used all copper connectors and it made it sound much more grainless and smooth where it should be. Don't get my wrong, Jack White's awful sounding instruments played with some talented still sounded fun like they should; and like bad instruments being played near explosion. Also the input capacitors are very important. I tell everyone to bypass the recommended PHE426 1.5uf with a MKP1837 .022uf because it adds the capability for speed that most amplifiers just don't have. With that comes greatly improved micro detail, tone, which creates not only better imaging but an ambiance around the instruments/singer that is pretty interesting to hear. Basically this information is just too smeared typically for it to come across as anything, but the speed of this amp and the small bypass caps give you something awesome.
I don't think it's possible to make something that sounds better for the money, currently. I mean... How often can a couple hundred bucks worth of parts be just what you're looking for with $27K speakers? The chassis alone for a class A unit with at least 15w costs more than one of these even with some fancy connectors.
For some other opinions
What short-circuit protection? What if the 3$ chip failsnfor whatever reason with DC on the outputs?
You would trust a pair of super speakers without a protection circuit with your version?
Everyone with a Pass Labs amplifier does (people who own $27k speakers). In fact speaker protection circuits aren't that common. BTW Pass says in all his years, failures that don't trip a fuse or such, are extremely rare and he just wouldn't bother with speaker protection.
One should see a chip with some measure that clearly aren't hurting the sound as a blessing. Read the datasheet, I'm not your mother.
And lastly yes I'd trust it. I can't imagine any reason not to. Have you noticed the chip is in between your speakers and the rest of the circuit? There's no ground for the speakers. This should tell you it's nearly impossible to make a circuit that could cause anymore harm than the one you're familiar with (while having an working amplifier). The chip has the most basic of basic inputs and outputs for pins.
One should see a chip with some measure that clearly aren't hurting the sound as a blessing. Read the datasheet, I'm not your mother.
And lastly yes I'd trust it. I can't imagine any reason not to. Have you noticed the chip is in between your speakers and the rest of the circuit? There's no ground for the speakers. This should tell you it's nearly impossible to make a circuit that could cause anymore harm than the one you're familiar with (while having an working amplifier). The chip has the most basic of basic inputs and outputs for pins.
I was not asking about the short-circuit protection as if I didn't knew about it, I was merely pointing out that there are other ways the chip could fail.
I feel you are a little tense.
I just finished my Dallas II enclosures and I am actively looking to diy a protection circuit.
Again, I wouldn't trust anything on my speakers without a protection circuit. I repaired a few amps with DC on the outputs, and almost wept looking at blown speakers.
So yes, someone that is putting a diy amp on $27K speakers without a protection circuit is taking a hell of a chance.
I don't care how many have $27K speakers that use them without protection, I'm just saying it's risky. Even more risky with a diy amp.
I feel you are a little tense.
I just finished my Dallas II enclosures and I am actively looking to diy a protection circuit.
Again, I wouldn't trust anything on my speakers without a protection circuit. I repaired a few amps with DC on the outputs, and almost wept looking at blown speakers.
So yes, someone that is putting a diy amp on $27K speakers without a protection circuit is taking a hell of a chance.
I don't care how many have $27K speakers that use them without protection, I'm just saying it's risky. Even more risky with a diy amp.
Well this is all very simple then, you can put a protection circuit on your amps.
You're wrong to say it's more risky with a DIY amplifier in this situation. There's no truth to that. The chip is between the "DIY" circuit and the speakers because of the balanced nature. What you're saying could be true of untested, unproven, experimental designs of say 3875,3886,1875,7293 chips or transistor based amps because the speakers share a ground with the circuit, and the feedback is user controlled. With the 7297 it's physically impossible to stimulate a response other than factory out of it the chip be changing the circuit design. So again to be redundant, no you can't. The best effort you could make is to attach a speaker cable to the enclosure.
I might feel a bit tense, when I'm trying to offer PCB boards that are perfectly good with no danger invoked and you keep repeating inapplicable concern. It's probably the safest amp kit out there. But to those whom don't understand circuits full-well see someone talking all about how risky the amplifier is, it's hard to explain to them it's not.
You're wrong to say it's more risky with a DIY amplifier in this situation. There's no truth to that. The chip is between the "DIY" circuit and the speakers because of the balanced nature. What you're saying could be true of untested, unproven, experimental designs of say 3875,3886,1875,7293 chips or transistor based amps because the speakers share a ground with the circuit, and the feedback is user controlled. With the 7297 it's physically impossible to stimulate a response other than factory out of it the chip be changing the circuit design. So again to be redundant, no you can't. The best effort you could make is to attach a speaker cable to the enclosure.
I might feel a bit tense, when I'm trying to offer PCB boards that are perfectly good with no danger invoked and you keep repeating inapplicable concern. It's probably the safest amp kit out there. But to those whom don't understand circuits full-well see someone talking all about how risky the amplifier is, it's hard to explain to them it's not.
Just for argument's sake, it's not fair comparing off the shelf product with your pcb. It's not just the cable that you attach. You need a heatsink, with airflow designed into the case etc.
If anything, you should be happy that you have a chance to explain some stuff. Maybe there are potential clients that have these concerns. You shouldn't be so expeditive with this kind of info.
Wish you all the luck with selling the board. I don't see how much I could get out of this chip, that would justify the extra cost on components. Also I don't know what speakers must one have to be able to sense the improvement.
If anything, you should be happy that you have a chance to explain some stuff. Maybe there are potential clients that have these concerns. You shouldn't be so expeditive with this kind of info.
Wish you all the luck with selling the board. I don't see how much I could get out of this chip, that would justify the extra cost on components. Also I don't know what speakers must one have to be able to sense the improvement.
I find it strange that you are not prepared to use your own money but are relying on some sort of crowd funding scheme.
After reading your own glowing product write up, I think the best proof is to put yer own money where your mouth is?
I'd gladly fund it with my own money, but I don't have it at the moment. At the moment I just moved because I found out I had a landlord that lied repeatedly, as I was living in a registered meth house (unannounced to me until a letter came in the mail that started the whole thing). Behind I left all my furniture, bed, bedding, etc... all contaminated. So it's out of my control to fund the PCB's atm. I'll get them out any which way I can because I have people asking about them all the time.
Trileru, you're right it isn't fair, because mine is better than most people can afford.
Trileru, you're right it isn't fair, because mine is better than most people can afford.
You've got a good point there. Indeed you should put your efforts and expense into parts capable of higher resolution as well as more marketable specs.
In comparison, what Trileru and I did with his board, has accomplished the majority of the features as your board, yet at far lower costs. That's got to be inconvenient!
The cause of this problem, is the specs of the chip itself, which has held you back and that has made your price point look disproportionate. It probably isn't off. But, to keep it from looking that way, you'll just have to use higher quality actives prior to charging so much for them. See how that works?
Basically, to get wallets loosened from their regular position, you'd be in need of some rather wallet-loosening specs to accomplish it. Otherwise, an error may be present. It was the puny actives--those cheap car chips just don't go as high as the price point needed to cover your costs.
I suppose that's a matter of opinion Dan. Depends on what you think of it being good or not. If it's just wattage, well, that's one thing. But since neither of you have heard it, maybe it'd helpful to compare to some words from someone that has, and has heard a lot (Tyson has done some RMAF coverage for years now, him and Pez actually have changed RMAF in ways over the years).
BTW the two VCC pins are not separate channels. Keantoken helped me figure that out.
Dan I'm not sure what "actives" means?
Personally I haven't been exposed to other amps with much higher resolution to speak about... Including but not limited to, McIntosh, Crown XLS, ICEpower, and Bryston - a few just off the top of my head from the last few months.
BTW the two VCC pins are not separate channels. Keantoken helped me figure that out.
Dan I'm not sure what "actives" means?
Personally I haven't been exposed to other amps with much higher resolution to speak about... Including but not limited to, McIntosh, Crown XLS, ICEpower, and Bryston - a few just off the top of my head from the last few months.