My wife's family are from the Netherlands. I used to love hearing her grandfathers (RIP) stories about how he hid in a secret room to avoid getting carted off somewhere horrible. He survived and made it in the early 1950's to South Africa. Blues skies and 280 days a year sunshine - and a new beginning.
You want it , because its there and available ...how are you getting 90db, whats your measured noise floor ..?
I don't know, say 120dB max loud, room at 30dB quiet? Sounds like in the ballpark?
Jan
Last edited:
Jan,
The issue is not the overall noise level vs the peak level. It is how much or little masking the noise presents. JJ tells me that if he gets to pick the tones 100db of masking can be useless.
Dick,
To me getting up every day and doing his job, knowing what lies ahead is what made those airmen heroic. That is different to me than using the term hero
Also I assume the spell correct turn Mao-ist into moist.
When you save a soul you redeem all...
ES
Ahh , a Noble is highly overrated after seeing how they give them away and anyone telling me there is no sonic difference between amplifiers are either deaf or dead ..
Two amplfiers from the same designer and manufacturer can sound different much less , it really makes me wonder the intent of those involved in such "scientific" endeavors. Poor program material and speakers can mask the difference , so if you wanted to skew things anything is possible , not so in the real world .
This reminds me of an incident years ago with an associate who sold Bose wave radios , he had a demo disc from Bose which was part of his presentation, anyway he would pop this disc in after careful placement of the radio and damn it , if it wasnt impressive. He did give me a copy and lol , its was , well , artistic and carefully EQ'ed for the bose radio, raised level and squashed dynamics to boot.
I think you missed the point. Subjective judgments are great but are not verifiable or repeatable if the external biases are removed. I know I have made the best amplifiers ever made. Others have discarded them as not good or deeply flawed. Neither judgement has any useful quality to it. Just saying "I hear a difference" may be traceable to a completly benign characteristic. There was a period where Quad ESL grilles were considered to have big effects on the sound. The difference (in a perforated aluminium sheet) was the color. And its a difference that had no measurable impact except for the subjective.
A means where the sonic differences can be verified without the biases that affect traditional sighted AB tests would be great. I don't like ABX testing because its very hard work and pretty tedious. I do think other blind test regimens can be done that may provide useful results. There is little economic incentive to go down the road so its not happening soon.
However tuning a demo to sound good on your product is very traditional practice. If you are making small 2 way speakers you don't demo them with HipHop. Large organizations need to deal with poor training and skills at the bottom of the chain so they find ways to reduce the need for those skills.
What is the equivalent A weighted noise level that is 130 dB below 100W/8 Ohms? Its roughly 8.9 uV. If the amp has 29 dB of gain that would be an input referred noise of 300 nV. That translates into an input noise resistance equivalent of 800 Ohms or 3 nV/RtHz. Its good performance but not too difficult to achieve with available components. No need for heroic efforts. Probably a number of power amps from the last 20-30 years have been capable of that performance.
I think the performance envelope of the amp is a valid target in light of what is possible with high resolution digital recordings. There are very valid issues about whether microphones can capture anything like that range, or that it can really exist in nature as something humans can perceive.
I think the performance envelope of the amp is a valid target in light of what is possible with high resolution digital recordings. There are very valid issues about whether microphones can capture anything like that range, or that it can really exist in nature as something humans can perceive.
There certainly is a large over-lapping grey area. And, in consumer electronics vs - say - military contracts - specs and data/measurement is a completely different ball game. Consumer electronics gets to "market' with celebs and glitter and flash and models, life style, adverts,propaganda etc to sell their 'spec'. here we keep acting like we can separate the two. Not going to happen in the real world which extists here and now. I like the intellectual part of design and not the consumer retail part. I liked the pure R&D that was the core of my career... no marketing. The arguments about listening and all are important but not when it gets mixed between the pure designing..... they are really separate issues and disciplines. Though they are about/apply to the same subject.
We keep falling back on a single product's spec.... but it is the result of the whole recording/playback chain that we are hearing and therefore we need very low distortion for each piece of that chain from end to end to keep below the audible thresholds for the chain. We haven't done that, yet.
Thx-RNMarsh
We keep falling back on a single product's spec.... but it is the result of the whole recording/playback chain that we are hearing and therefore we need very low distortion for each piece of that chain from end to end to keep below the audible thresholds for the chain. We haven't done that, yet.
Thx-RNMarsh
Last edited:
Everyone go out and save a soul... you might find its your own in the process.
[btw - lived in Germany and married a German... no prejudices about Germans here)
Thx-RNMarsh
30db Is very low , recording studios and custom environments get down that low and below. Most domestic environments are in the 48-52 db range ..
Agree Richard ,
Hifi in itself is fantastic , the business of hifi is what i hated , you have to join their little club and it has nothing to do with quality of product , they will create that image for for you , science and all ...
Even Sy had to revert to custom silver cables .....
Or you can join the team ...
I'm in there as the last reference.
Tomorrow I'm going to rejoin the discrete op-amp thread, I was inspired by the folks at Linear Systems and Nelson at BA to do an all FET op-amp. It's looking good so far and has only 12 FET's, that's more than 2 but hey.
More :
Few people in the audio business would deny that John Curl is an audio design genius—arguably the greatest one of our generation.
Bring it on John ....
I have complimented John on his achievements numerous times, the knee-jerk support for the likes of Peter Belt, Geoff Kait, and Bybee detract from my feelings toward John.
I'm in there as the last reference.
BTW we have several patents on low quiescent current high output amplifiers, I have posted some schematics here and there, the ratios can get quite extreme like 250uA bias and 500mA out maintaining -90dB distortion.
Tomorrow I'm going to rejoin the discrete op-amp thread, I was inspired by the folks at Linear Systems and Nelson at BA to do an all FET op-amp. It's looking good so far and has only 12 FET's, that's more than 2 but hey.
I get the impression of a less restrained, slightly more dynamic sound from decent transistor designs than I do from chips. Chips do give a very detailed sound but just don't involve me in the music quite as much. This is only my impression so far so please don't torch me for it
No problem with that, though those chips are full of transistors.
- Status
- Not open for further replies.