Worth nothing is PecanPi only has a 48kHz oscillator. There is a volume control chip on the board that enables use of a volume knob (on pecanpi Rev.2 at least, original had no knob), and it also does SRC on 44k rates. Everything is reclocked.
Not that I have a problem with the design, but I think it will sound best when feeding it 48k multiples of sampling rate via software, bypassing the hardware resampler. Then it will be reclocked for lowest jitter, but not resampled.
Volt+ D measurements by Amir
https://www.audiosciencereview.com/forum/index.php?threads/allo-volt-d-amplifier-review.15539/
He seems to like it
New AMP first measurement at 10W , 1khz 8R -102 noise dominating
We are fine tuning.
https://www.audiosciencereview.com/forum/index.php?threads/allo-volt-d-amplifier-review.15539/
He seems to like it
New AMP first measurement at 10W , 1khz 8R -102 noise dominating
We are fine tuning.
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Speaking of Allo Volt + D, while Amir is a very performance-oriented person and appreciated the said amp, I was surprised by a mixed response of many site members. The actual complaints are quite valid though and likely to overweight the positives when making the buying decision. Hopefully, the new amp will improve in some of these areas:
- no PSU provided, so an additional shopping research and $ needed with no guarantee to have a well-paired PSU
- the amp takes a lot of desk space
- the above point is worsened by its irregular, non-cuboid shape that increases the space occupied and makes it harder to stack it with other devices
- transparent case, the sales statistics of similar audio devices clearly show the preference for black cases followed by silver ones, I would be surprised if a fully-transparent case would be preferred by more than 5% of the potential buyers and would not be surprised if for a much more significant share it would be a dealbreaker
- stiff and small knob
- no PSU provided, so an additional shopping research and $ needed with no guarantee to have a well-paired PSU
- the amp takes a lot of desk space
- the above point is worsened by its irregular, non-cuboid shape that increases the space occupied and makes it harder to stack it with other devices
- transparent case, the sales statistics of similar audio devices clearly show the preference for black cases followed by silver ones, I would be surprised if a fully-transparent case would be preferred by more than 5% of the potential buyers and would not be surprised if for a much more significant share it would be a dealbreaker
- stiff and small knob
Shanti and JCAT(Bakoon) Lithium PS.
I want to rewire the very long, thin DC cable on Shanti to something better. Any proven (sound-wise) wire for DIY DC cable?
ShantiBakoon by drjlo2, on Flickr
I want to rewire the very long, thin DC cable on Shanti to something better. Any proven (sound-wise) wire for DIY DC cable?
ShantiBakoon by drjlo2, on FlickrIf you wish to change the cable , I would recommend a thicker gauge .
Regarding Volt+D this is a rather old design and not everyone will like the casing or the stepped attenuator . However for 129$ its a very good amp (price/quality). Please note that I am working on a new gen amp that should be better.
I am working on a new firmware (Rev Dac) and hopefully we will have it out in about 2 weeks.
Regarding Volt+D this is a rather old design and not everyone will like the casing or the stepped attenuator . However for 129$ its a very good amp (price/quality). Please note that I am working on a new gen amp that should be better.
I am working on a new firmware (Rev Dac) and hopefully we will have it out in about 2 weeks.
I am attaching the first FFT of the new AMP
Taken at 8R/1Khz 5W *15db gain
No optimization whatsoever .
Please note H2 and H3 and...nothing at all
. Also note that at 10W we see the same pattern (slightly increased H2 and H3)
Generally speaking gently decaying harmonics (h2-h5 max) and no harmonic after , is a sign of good sound (but its only one parameter)
Taken at 8R/1Khz 5W *15db gain
No optimization whatsoever .
Please note H2 and H3 and...nothing at all
. Also note that at 10W we see the same pattern (slightly increased H2 and H3)Generally speaking gently decaying harmonics (h2-h5 max) and no harmonic after , is a sign of good sound (but its only one parameter)
6.67khz is not dependant on amp ic. Tommorow our office will be closed but I am very excited to do the rest of testing. I think we will reduce h by around 6db. We already beat Ti evm. Our new llc zero voltage switching ( half bridge) smps is delayed 2 weeks so we are testing with mediocre psu.
I expect h3 ( thus 6.67khz hump) to be much lower than datasheet of ti. Note also that unlike hypex or orchard amps, we do not rely on feedback to reduce harmonics. While feedback gives good thd, some literature point to the fact that transient intermodulation distortion is worst using a lot of feedback. At 5db negative feedback, Tim should have no issue.
This amp will be a true contender to the best.
I expect h3 ( thus 6.67khz hump) to be much lower than datasheet of ti. Note also that unlike hypex or orchard amps, we do not rely on feedback to reduce harmonics. While feedback gives good thd, some literature point to the fact that transient intermodulation distortion is worst using a lot of feedback. At 5db negative feedback, Tim should have no issue.
This amp will be a true contender to the best.
@cdsgames Food for thought Does negative feedback cause TIM? - PURIFI with a lot more technical explanation in the link at the end.
This is worth trying without getting into "exotic" cables. I personally use cotton-insulated silver chassis wires from VH Audio.
DIY DC power cables - UpTone Audio (Sponsored) - Audiophile Style
You are wasting your money... having said that, have fun!!
//
Imagine using a 6 ft tube to drink your beverage out of a container instead of a 10” straw of the same diameter.
Now swap out that plastic straw for a glass one. For a steel one. For a paper one. Is there a difference in the taste of your beverage? Probably not. But you can’t deny that the experience is different.
Lots of similarities between fluids and current!
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I’m a big fan of Neotech OCC. Pure silver starts getting quite pricey for anything but short signal runs. Plus solid core wires aren’t easy to manipulate around; damage it and you have to re-wire the whole thing. May I recommend adding a DC barrel jack (Switchcraft or CUI make good stuff) and then making short DC cables with connectors and wires of your choosing? Lots more flexibility, and low barrier to entry that way. You also don’t have to think of strain relief
Yes I am aware of it and I think Mr Bruno Putzeys is the leading designer of claa d amp. In fact , most class D designs today are based on his feedback white paper..
Now that being said .. global feedback is something that makes sense from a mathematical point of view . Note that many things make sense in math but SQ does not agree directly . Global feedback will lower THD / IMD and look great on graphs .
Note also that Hypex and Bosc amps pursue this approach . They also have switching noise on the output that barely attenuated compared with fundamental .
By using the TPA3255 , I have no choice but not to rely on feedback for great graphs . Instead I turn to the old school of analog design . If I have very little feedback , I should have no distortion in the first place.. What approach will sound better in your opinion ? ( I understand my opinion is biased)
So I am designing with a few parameters in mind. Great PSU (plenty of power , ultra low noise to start , great dynamic load response) , no noise on output (from SW or PSU ) , reducing magnetic hysteresis by making my own core , (jury is still out on that one) , hi input impedance , good CMRR. As you can see on this project I am considering a multitude of factors .
All this yes but in the same time DC blocking caps and all other safety incorporated . (they all increase harmonics)
Dear cdgames,
I own an usbridge signature+digione signature. I read on Audiophonics about the usbridge signature that anything that works with a Raspberry Pi will work with the USBridge Signature. My question now is if it's possible to use together the Terra-Berry2 board and the usbridge signature with their own psu: 5V for the usbridge and 5V for the RCA pin jack adaptor 2 (feeding only psu DAC input).
I own an usbridge signature+digione signature. I read on Audiophonics about the usbridge signature that anything that works with a Raspberry Pi will work with the USBridge Signature. My question now is if it's possible to use together the Terra-Berry2 board and the usbridge signature with their own psu: 5V for the usbridge and 5V for the RCA pin jack adaptor 2 (feeding only psu DAC input).