Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Build Your Own Professional-Grade Audio Amp on the Sort-Of Cheap

spectrum.ieee.org

Post reply on HN
Print view View original

81–90 of 270 posts

Re: Build Your Own Professional-Grade Audio Amp on the Sort-Of Cheap

#81

Post by W-_-D »

aidenn0 wrote: post #73
comboy wrote: post #18

Any DAC chip and some usb interface for it that you could recommend to go with this? And slightly OT, but does anybody know any ABX test of balanced input/output signal? I find it hard to believe that there is a single person who can hear the difference.

There are cases where the difference is huge; particularly when you have very long runs between the preamp and the amp. This is on reason why you usually see XLR inputs to monitors. Any noise induced is amplified and a long unbalanced wire is a big antenna. I've heard of cases where you could receive AM radio stations from such a setup; I lean towards "urban legend" for that though. While it seems theoretically possi…

It's actually pretty common on older guitar amps. I've got a Marshall TMB replica which has this issue when the guitar isn't plugged in. If you turn it up loud enough, you can make out sentences clearly. I thought I was going crazy when I first noticed it.

Re: Build Your Own Professional-Grade Audio Amp on the Sort-Of Cheap

#82

Post by kazinator »

irrational wrote: post #26
Matsta wrote: post #10

The majority of all active speakers produced nowadays are Class-D, it's nothing really new (and the fact they are super cheap). No idea how this guy wrote this article and didn't come across DIY Audio (or he just didn't mention it in the article). There is a tonne of information here: https://www.diyaudio.com/forums/class-d/

I have some questions. My son has been taking guitar lessons using a classic guitar. Using the advice of his instructor we are getting him a begginer's electric guitar for christmas. We also need to get him an amp. Is the amp in this article the same kind of amp that you could plug an electric guitar into? I know nothing about music or instruments, but I do know about electronics so I was thinking it might be fun to…

You can absolutely use stand-alone "hi-fi" amplifiers for guitar; that's what I do. You just can't plug your guitar straight into that; you need some pre-amplifier gear. My gear is old-school in a big rack, described below.

Nowadays, there exist units that provide complete signal processing for guitar: simulating guitar pre-amplifiers, amplifiers and speaker cabinets digitally. You plug your guitar into this, and then it can go straight into a PA system, or your recording console. Something like that can be used with an amplifier like the one being built here.

My rig consists of a 6U portable rack case with a few pieces of gear. The guitar goes into an ADA MP-1 MIDI-programmable tube pre-amp (built in 1987, revamped by me). This goes into a splitter-mixer (called the SMF-1 that I built myself) which bifurcates the signal through a digital effect unit that provides reverb, and then mixes it again. The dry signal remains analog. Then it goes into a 31 band equalizer, and from there to the power amplifier, an Alesis RA-100, which feeds a guitar "4x12" speaker cabinet (four 12" speakers). I could take out the amplifier and drop-in replace it with any rack-mountable amp, provided it doesn't require more than 3U spaces. QSC, Yamaha, Yorkville, whatever.

There also exist dedicated rack-mounted power amplifiers intended for guitar, like the Rocktron Velocity or Marshall Valvestate 8008 (both of these examples are stereo). Many of these kinds of ampls have been produced. These are just power amps; they can't produce any overdrive tones and have only minimal tone control or none at all. The 8008 has a switch on the back for "tube like" behavior, which just means current feedback. That will give it more of a mid-scooped frequency response, induced by the reactive speaker load. I can do something like that with my equalizer.

The amplifier project we see here could be turned into a guitar amp by adding a preamp circuit board into the chassis, fed by a guitar input jack, and exposing some tone and gain controls. The stereo function of the amp could be useful if we add jacks for an external effect loop and make it stereo (mono out, stereo in). Then we need a stereo guitar cabinet: minimally a 2x10 or 2x12 wired for stereo.

Re: Build Your Own Professional-Grade Audio Amp on the Sort-Of Cheap

#84

Post by brokenmachine »

MrTonyD wrote: post #56

I'm probably the only one with this opinion...but I sure miss the old days of tube amps that weren't able to be highly accurate. They would roll-off the on the high end, distort a bit all over, and gave a very warm and relaxing feel to the albums I played obsessively. Now I've owned high-end tube and solid-state gear, and the music hasn't sounded good for decades. Combine that with the very limited bits provided by C…

You can get tube preamps that are supposedly good, which might give you the distortion you crave even when paired with a low-distortion Class-D power amplifier.

CDs are still 1000x better than records with all their hiss and distortion in my humble opinion.

Not saying you're one of these people, but I think lots of old-timers who complain about the quality of CD's or anything digital don't really understand how they work - Even though the bits are "limited", they do not actually output a staircase as shown in the explanations, the signal is interpolated between samples by analog filtering on the output. So it's actually outputting a smooth line that goes through the sample points.

Also lots of stuff is available in 96k and above FLAC now if the limited bits are a problem. I get any music I care about in that quality but it's often because the mastering is better on those releases than the actual quality of the reproduction.

Sometimes there's a SACD, Bluray or DVDA release if there's no hi-res digital download available.

Anecdotally I'm happy if I can get anything at 48k 24bit or more.

It's really the loudness war that has ruined music. That's the only thing about records that I consider better than digital - because of the limitations of the medium, they can't brickwall compress everything or the needle will physically jump off the record.

Genuine question: what was so good about music before that is missing in your opinion now?

Also, do you enjoy digital re-releases of records you previously enjoyed as much as before? Why or why not?

Re: Build Your Own Professional-Grade Audio Amp on the Sort-Of Cheap

#85

Post by mbell »

willtim wrote: post #36
fermienrico wrote: post #16

It is refreshing to see these types of articles. Of all disciplines of human interests and hobbies, Audiophiles are one of the most stubborn, misinformed, anecdotal and delusional bunch. Of course I am generalizing, but every time I engage in a discussion about audio quality, it is a losing battle. Not because of lack of data or supporting evidence, but because of the fundamental dissent for data driven arguments. Yo…

Your generalisation is unfair. Most Audiophiles just want to listen to music the way the artists intended. This is not easy in a industry where colouring the sound is even celebrated, e.g. 'Beats by Dre'. I recently tried the latest noise cancelling headphones by Sony (1000XM3). The noise cancelling was excellent, but the bass was +5db overblown, boomy and drowned out most of the mids, the treble was dark to hide the…

> Your generalisation is unfair. Most Audiophiles just want to listen to music the way the artists intended.

That is not my experience at all. Audio gear that is 'flat', in that it outputs as close a representation to the recording as possible is largely shunned in audiophile circles. They mostly want to listen to something that 'sounds good', with all the psychoacoustic baggage that comes with such a statement. As an example if the end goal is accurate reproduction then a tube amp is objectively worse than almost any other amp built in the last 30 years, yet they sell!

Re: Build Your Own Professional-Grade Audio Amp on the Sort-Of Cheap

#86

Post by deltron3030 »

88 wrote: post #61
Karunamon wrote: post #44

Earlier quoted context omitted.

Of course they’re anecdotal - listening to music is a subjective experience. If someone really thinks their music sounds better after adding $100 cable lifters and taping $50 bags of rocks to their $10,000 system, they are automatically correct . Their ears, their hobby. It would be like saying that something can’t work because it’s a placebo - even if all they’re getting is a sugar pill, if the symptoms went away, t…

Placebo effects are real.

Ears are easy too fool by visuals. https://www.youtube.com/watch?v=G-lN8vWm3m0

Re: Build Your Own Professional-Grade Audio Amp on the Sort-Of Cheap

#87

Post by randomfinn »

dharma1 wrote: post #59
willtim wrote: post #36

Earlier quoted context omitted.

Your generalisation is unfair. Most Audiophiles just want to listen to music the way the artists intended. This is not easy in a industry where colouring the sound is even celebrated, e.g. 'Beats by Dre'. I recently tried the latest noise cancelling headphones by Sony (1000XM3). The noise cancelling was excellent, but the bass was +5db overblown, boomy and drowned out most of the mids, the treble was dark to hide the…

As far a noise sound quality for cancelling wireless closed headphones go, the Sony's are the best along with Sennheiser Momentum 2.0 on-ear. There are of course much better headphones, and I wouldn't call them audiophile headphones, but I haven't found other wireless ones that do noise-cancelling and isolation as well and still manage to sound acceptable.

If in-ear headphones work for you, you can find both very good isolation and excellent sound quality. I like my Shure SE530's for some peace and quiet on airplanes, and often find myself just enjoying the sound of them (or rather the original recording).

Re: Build Your Own Professional-Grade Audio Amp on the Sort-Of Cheap

#89

Post by mbell »

fermienrico wrote: post #29
albertgoeswoof wrote: post #27

Earlier quoted context omitted.

Nothing wrong with vinyl, that’s more about physically handling the media, reading the sleeves, listening to an album the whole way through etc. Than the audio quality. No vinyl enthusiast would say the quality is objectively better, but the experience arguably is

Yea, I removed the Vinyl argument. That's for another time. Nothing wrong with Records but I've had the same issue talking to people about Records wrt to audio quality. I own Records and like you, I enjoy the experience. There is something amazing about listening to the entire album without distractions and in the sequence that the artist intended. You could do this with mp3/CD, but Records get me in the right mood :…

There are objective reasons to favor vinyl even today. The 'audio quality' if measured in terms of SNR is objectively much worse than any modern medium, however the mixes used for vinyl tend to not be compressed to death so the dynamic range can offset this shortcoming.

Re: Build Your Own Professional-Grade Audio Amp on the Sort-Of Cheap

#90

Post by sneak »

TylerE wrote: post #78
Karunamon wrote: post #44

Earlier quoted context omitted.

Of course they’re anecdotal - listening to music is a subjective experience. If someone really thinks their music sounds better after adding $100 cable lifters and taping $50 bags of rocks to their $10,000 system, they are automatically correct . Their ears, their hobby. It would be like saying that something can’t work because it’s a placebo - even if all they’re getting is a sugar pill, if the symptoms went away, t…

Please don't lump all audiophiles in with some sort of distorted (irony...) stereotype. I don't have a $10k system, or anything close to it, but yes, my system that I put together for about $1000 is way way way way better than what you're listening onm because I care enough to have a good external DAC, and feed that into a good amp paired with either a set of decent used speakers or one of a couple of sets of good he…

Your external dac is indistinguishable to your ears from the internal one in whatever device you are using to supply it with bits. This is precisely what OP is talking about.
Post reply on HN