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Post by PinkFloyd on Oct 28, 2010 22:04:34 GMT
98F? Do you measure in the nude? If it "ever" gets up to 98F here there is NO WAY I will be sitting measuring "FET's".... I'll be laying down somewhere cool panting like a dog OR swimming in the sea with a mermaid..... more likely panting like a dog unable to function due to the heat It's all bollocks, at the end of the day, there are so many variables involved. I've "always" said that matching is a waste of time and it "all sounds the same".... probably OK if you live in a constant temperature type climate and your ambient room temperature is the same from day to day.... but if you make amps in Australia for use in the UK you're pretty much fuucked. We "all" know how good it "could" be but most of us live in the real world and can only go on what we have been blessed with.... look back a few posts, I asked Ian what his "ambient room temperature" was I set the amp up for his operating conditions.... IMPOSSIBLE to be accurate with anything (taking thermal drift into consideration) and even if you "are" meticulous with your settings in Iceland they will deviate by a considerable margin once they go into operation in FIJI! Panda is ideal for the DIY'er as it can be set up to local ambient conditions (and "ideally" checked every three months to re-calibrate) but is not the type of thing you'd calibrate in the antarctic and ship to Tahiti I feel that regional variations are something that should be discussed more. Mike.
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Post by PinkFloyd on Oct 28, 2010 22:10:05 GMT
And if Frans gives you a hard time, aim it in his direction ? No No..... I wouldn't do anything so nasty to Frans I''d just "ass" fekk him without margarine
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Post by Deleted on Oct 28, 2010 22:32:15 GMT
Mike A properly matched pair of FETS or BJTs if thermally bonded together, will track each other whether in Scotland , Fiji, or the Snowy Mountains of Australia all year round. You are lucky that you don't have temperatures going as high as 45C, but we have quite a few summer days in Sydney with 40C. On the plus side, itis rare to get below 0C in Sydney metrop area . Alex
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Post by PinkFloyd on Oct 28, 2010 22:39:11 GMT
Alex,
I am talking "actual" operating conditions.... all bollocks in the real world... case closed.
Enjoy your kebab.
Mike.
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Post by Deleted on Oct 28, 2010 22:56:55 GMT
Alex, I am talking "actual" operating conditions.... all bollocks in the real world... case closed. Enjoy your kebab. Mike. Tell that to the guys in the UK who have built my Class A HA , or modified 15W Class A amplifier ! Case closed. ,
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Post by clausdk on Oct 28, 2010 23:15:20 GMT
And if Frans gives you a hard time, aim it in his direction ? No No..... I wouldn't do anything so nasty to Frans I''d just "ass" fekk him without margarine ' If you are going that extreeme, I could help getting some margarine
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Post by Deleted on Oct 29, 2010 5:19:56 GMT
Mike is actually pretty close there in stating at which temperature to match the parts and more importantly adjust the DC offset in the Panda at the operating temperatures.
You would have to realise that the Panda heats up the (closed) casing quite high as inside there is about 13 Watts being dissipated. 2*28Vdc * 0.2Adc = 11W + losses (heat) by the transformer about 1-2 Watts. The ambient temperature is just 'added' on top of that. I suppose when left on for a few hours the temperatures in the cabinet easily reach 40 to maybe 50oC !
Mike should be able to confirm this by taking temp measurements immediatly after the hood has been popped when left on for minimal 1hr.
No I won't mention switches, wires and other parts because I feel I have said enough about this in other threads and this is about the Panda and hate to get into 'Alex like' discussions as these are pointless and only lead to agrevation (where the pictured gun comes in handy)
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Post by PinkFloyd on Oct 29, 2010 6:38:04 GMT
Mike is actually pretty close there in stating at which temperature to match the parts and more importantly adjust the DC offset in the Panda at the operating temperatures. You would have to realise that the Panda heats up the (closed) casing quite high as inside there is about 13 Watts being dissipated. 2*28Vdc * 0.2Adc = 11W + losses (heat) by the transformer about 1-2 Watts. The ambient temperature is just 'added' on top of that. I suppose when left on for a few hours the temperatures in the cabinet easily reach 40 to maybe 50oC ! Mike should be able to confirm this by taking temp measurements immediatly after the hood has been popped when left on for minimal 1hr. No I won't mention switches, wires and other parts because I feel I have said enough about this in other threads and this is about the Panda and hate to get into 'Alex like' discussions as these are pointless and only lead to agrevation (where the pictured gun comes in handy) Frans, I will stick my Fluke temperature probe in one of the spare holes later on and see what the weather is like inside the Panda.
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Post by Deleted on Oct 29, 2010 7:03:56 GMT
Frans The main reason you don't enter into many of these discussions these days, is that you know that the vast majority of RG members hear changes with various components, including I.C.s ,valves of the same designation, headphone cables, capacitors and different types of resistors, that you insist are impossible. I wasn't referring to the Panda in particular but Mike's general comment. My Class A preamp is good from switch on, and sounds at it's best after only a couple of minutes. Because of lack of space it sits directly on top of my Class A amplifier, which dissipates approximately 100W of heat, so you can imagine the temperature range inside that cabinet during the seasons, and the temperature range inside the preamp, as well as the 15W/Ch Class A itself. Yet, it still stays balanced within close limits at the front end, and output stage bias only increases by a few percent before stabilising. The only concession I make is leaving the perspex cabinet doors ajar on hot days. However, the transformers are external to the preamp and Power amplifier, and in a separate 2U rack case. Alex P.S. Was it REALLY necessary to use the phrase " 'Alex like' discussions ?
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Post by Deleted on Oct 29, 2010 7:08:17 GMT
Don't forget the margerine! There's nothing worse than ab aggravated bear.
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Post by Deleted on Oct 29, 2010 8:11:23 GMT
Frans The main reason you don't enter into many of these discussions these days, is that you know that the vast majority of RG members hear changes with various components, including I.C.s ,valves of the same designation, headphone cables, capacitors and different types of resistors, that you insist are impossible. Alex P.S. Was it REALLY necessary to use the phrase " 'Alex like' discussions ? My answer is: NOPE not the reason ! The reason is because I lived in the Grotto for a year now and come to understand that you do not preach the Koran to Christians nor the Bible to Muslims... pointless nobody listens and both think they are right. Your P.S. proved my point I will stick my Fluke temperature probe in one of the spare holes later on and see what the weather is like inside the Panda. Better in there then the other place that might require margarine !
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Post by Deleted on Oct 29, 2010 8:36:14 GMT
Sorry Alex, I didn't see your post on my poxy screen and made a daft joke! EE's puzzle me because they are open to ideas and then kind of closed without measured proof. I still don't understand why the guys at work don't hear things until they see the proof.
It kind of makes you feel that it's better to say nothing until you're 'told' what you're supposed to hear. I sometimes hear a version of something that to me, sounds quite different but I have to'water down' what I'm saying because I know that they can't hear what I'm describing. For instance, if someone asks me whether it's better to buy this or that, I feel a bit uncomfortable because I know that they won't hear perhaps what I hear!
The thing is that it starts problems so it's best imo to leave it alone because measurements and ears don't alwyas like each other!
Actually Mike wrote a very interesting reply somewhere ina thread to you about 'what sounds real' which was very telling. He's happy to accept that if it sounds correct and is a good representation of the music he's listening to,then he's happy ... and who's right in any case? I agreed with what he was saying since that's what works for me.
If you ask what is the best headphone, there's no real answer. However, you feel that given measurements, e could all be put right so that we are all listening to the same sound. That's not the case so I get tired of being told I'm making it up because some probe informs me that it can't hear any difference.
I suspect that Frans is equally tired of statements concerning sounds that aren't backed up by a probe.
I quite like Mike's approach of 'suck it and see.' Otherwise we'd all be listening to the same gear because it's technically more correct than something else.
Oh for perfect sound reproduction. That'swhat Philips' EE's thought they had all yhose years ago!
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Post by Deleted on Oct 29, 2010 9:23:49 GMT
Ian Actually, they weren't that far off the mark. If they had made it 16 bits 48KHZ, many more people would have been happier with it. However, although a well mastered CD can sound very good indeed with the right gear, I think that they weren't far enough advanced in the area of extracting all that information properly off the CD back then (still aren't ?). The original CD players had trouble even resolving 14 bits , let alone 16 bits. Let me know when you are ready to DL another rip of the same material.I think it sounds quite different,(far better low end especially) despite what the numbers say.This time you will have the Panda advantage. Regards Alex
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Post by Deleted on Oct 29, 2010 9:29:38 GMT
No it didn't That part came across as bitchy, which may not have been your intention. Without that bit, I wouldn't have bitten back in the manner that I did.
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Post by Deleted on Oct 29, 2010 10:41:55 GMT
Ian Actually, they weren't that far off the mark. If they had made it 16 bits 48KHZ, many more people would have been happier with it. However, although a well mastered CD can sound very good indeed with the right gear, I think that they weren't far enough advanced in the area of extracting all that information properly off the CD back then (still aren't ?). The original CD players had trouble even resolving 14 bits , let alone 16 bits. Let me know when you are ready to DL another rip of the same material.I think it sounds quite different,(far better low end especially) despite what the numbers say.This time you will have the Panda advantage. Regards Alex O.K.... I 'll bite. 44.1 to 48 khz is less then 10% in increase in bandwith while you state 96 and preferably 192kHz gives much better sound so no 48kHz would NOT have been satisfactory for those. 44.1 kHz gives in practice about 20kHz (and not very accurate at that) while 48 kHz would extend the FR to about 22kHz. Hardly something worth mentioning/hearing as a 20kHz sine wave can only be 'described' as a squarewave and is 'converted' back to a sine wave by analog filtering (in case of first generation Japanese players) or by calculation (oversampling) in the first generation Philips and all other oversampling gear nowadays. It was not that a CD's info could not be retreived back then. All 16 bits are ALWAYS retreived and processed. It was then and it is now, also the processing of these signals is no problem as the speeds in audio signals, compared to what was and is technically possible, relates to a lamborghini that drives at the speed of a normal bike. What you are referring to is the DAC in those days. Philips was not able to manufacture a DAC that could resolve 16 bits but could make a 14 bit version. Smart as they were they used over sampling to create a similar resolution as a linear 16 bit would (like the Japanese made) This has to do with the fact that the largerst bit could not be made to the tolerarance needed (within 0.002% !). You would have to understand that 0 Volt (no sound) output in a PCM signal is 'between' value 01111111111111111 and 1000000000000000 and the last one is actually 1 current from 1 'current source' and needs to have the same value as the added currents of the lower 15 bits added together + 1 LSB (least significant bit, the digit on the far right). That's where the technical difficulty lies. Later there appeared 18 bit and even 24 bit DAC's. You would think that these could at least dissolve 17.5 and 23 bits, alas the 18 bit version could barely resolve more then 16 bits and the 24 bits about 18bits. To resolve 24 bits you would have to be able to create current sources with an accuracy of better then 0.000005%. That's where the problems lie in the digital to analog domain. Not in the 'retrieval' of bits from a disc or HD or whatever medium. Not in the processing of bits and bytes. Not in the speeds needed for accurate production. Now back to the Panda..
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Post by Deleted on Oct 29, 2010 11:26:25 GMT
Solderdude That was a very simplified ánswer for Ian's benefit, and was addressed to Ian. It was not posted to start another pointless discussion that nobody else gives a damn about. SandyK
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Post by Deleted on Oct 29, 2010 12:26:32 GMT
It was posted as a general explanation regarding a very small but most important part of digital audio (DAC) and was not adressed to anyone specific.
In reply to Ian I would say:
Musicians focus on different aspects in music and reproduction then most others do. Studio technicians are interested in headroom, mic placement, needed effects and technical aspects regarding the recording of (individual) instruments and (mostly) in second place to the other, also important, matters that matter more to musicians. They FOCUS on different aspects of music/recordings. a good cooperation (synergy) between the people involved in the recording and proper knowledge of their 'things' will always result in excellent recordings, regardless of the media it is on.
Ask a total noob if they can hear differences between a cheap headphone and an expensive one and they probably would say they can hear slight differnces if any. Do the same with 2 expensive ones and they cannot tell the difference at all. Yet... ask a tech and musician (and other hifi interested people) and they CAN hear (obvious) differences. a matter of training the brains and knowing what to look for. Nothing strange or magical about that.
For some musicians this comes naturally but know a LOT of musicians that cannot tell the differences between 2 good headphones or can't even notice certain amounts of distortion where I can hear them very clearly already (differnt aspect of sound). So... yes.. someone can hear a difference while others can't I do not doubt that NOR dispute that nor is that strange or weird in any way.... merely a fact.
Totally agree on headphones and they differ greatly (which is VERY visible in graphs b.t.w.) the differences between the best are huge. There are even differences between 2 HP's of the same type ! I can happily report I am perfectly able to hear those and validate by reading graphs.
Also completely agree that advising people on which is 'best' and the old K701 vs HD650 debate is very personal and hard to give proper advice if you don't know what the asker is looking for and if they can even tell the difference between an HD201 and LCD2.
I too was a big member of the I can hear a difference between certain parts group for a long time and tried to prove it with equipment. Thing is need you need to look at the whole picture not just a FR graph or distortion figures. So I built differntial amps and own test equipment. Switching boxes that switch fast (without a glitch in the sound revealing a switch was thrown) and with certain simple FR measurement things and level adjustment capabilities (VERY important must be correct within 0.1 dB). This would prove the differences are there and are repeatable, quantifyable.
Well.. the outcome of all these years of testing, debating, listening (with others, not alone), building special equipment, switching between certain parts and ONLY these parts e.t.c. led me to certain , in hifi circles, unpopular conclusions.
What I found (talking about amps specific here not playback equipment) is that when there were differences heard n AB-x comparisons and subjective tests these are always visible in FR or other figures (and certainly detected with the differential amp) i.
Now what's the most interesting part.. If there were differences heard in subjective tests ...yes, also by this EE with bad hearing and un-open mind, and certain aspects were within certain parameters (FR 20Hz-20kHz - 0.5dB) phase shift was non existant or very small, distortion was below 0.1% and the level is the same (within 0.1 dB) and AB and blind AB tests were performed no one .. and I literally mean NO one, also the ones that can clearly hear the differences (I did too) were unable to tell which amp was under which switch. This bugged me to no end and tried everything. I am not stupid I heard these things but as soon as conditions are equal they are not detectable. Sometimes I left a switch in one position thinking I heard A and was lisitening to B without knowing and could clearly hear the signature of A ... while B was actually playing. I was kidding myself... but that was only me... Can anyone here honoustly blame me for trying and leading me to this conclusion ?
These kind of experiments have been done by many people all over the world with always the same outcome. yes AB and blind AB MUST be flawed because of this.
This can only lead to one conclusion if you 'believe' in science.. It can lead to opposite conclusions if you believe in other things.
So YES it is a matter of 'religion' after all because even though everybody that joins these tests and have to acknowledge at that specific time/place that they do not understand WHY they can't hear the differences (blame it on switches, equipment, .. whatever, everything but their own hearing) all continued to say they can hear differences (nobody fell of their belief, like I did) .. only not at that particular test. That's a choice and everyone is free to make such decisions.
For me personally it's not (anymore) about retreiving the absolute eargasm but about enjoying music. Every new artist I discover or new album that is well recorded and sounds good to me does it for me. a lot of people can do that with cheap buds and 128kB MP3 I prefer better quality but excellent is good enough.
What sortof annoys me is certain statements being made with regards to certain parts and technigues that have NO truth (or only parts of it) in there. Just as Ian is probably annoyed when stupid remarks are made about instruments or recordings by musical noobs that do not know or know only a tiny bit about his expertise.
So there you have it.. I explained myself and HOW I got to my statements and respect Ian and Israel and other musicians for their specific knowledge.. I just would not draw similar conclusions based on technical aspects.
I too can hear (big) subjective differences but since they seem to dissappear in AB-x tests I have come to dismiss them in general. THAT's why I am 'skeptic' not because of any other reasons... my mistake probably..
In short.. nobody is absolutely right and vent their own opinions based on the experiences/knowledge/insight they have.
yes... you can hear things I can't and hope it's not a burdon but only enhances you enjoying music.
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Post by Deleted on Oct 29, 2010 13:19:50 GMT
Thanks Alex! ;-)
I'll be home tomorrow! Yay!!! I'm defintely a home person. Feel like I'm just in the wrong place. A flight path has been booked!!!
What is surprising is the same numbers give a different sound. I took the Mahler rip with me along with the cd. I found some believers ....... in Germany!!! They can hear differences so it's not just me and my imagination.
I suspect that the added depth of the Panda will show it even more. First impressions here were same recording, different master. One guy felt that the cd must have been made from a poor master and the rip was the 'orrected' version.
That means that some of the deaf aids at work need to go eh? ;-)
So the sound is there on the cd all along but the reason it doesn't match my impression of the master is in the conversion to analogue.
The other device I'm getting good results from is the buffer, whether it's adding colouration or doing omething else electrically I have no clue, but the amount of change is variable, depending on the player. It improves an Ipod outpuy big time. I'm really surprised that the Ipod market haven't got stuck into that idea yet, although I see a niche market exists for tube amps for them - the Fatman.
At the moment, most amp makers ignore the Ipod market so you rarely find amps dedicated to them but ou know, with files like the ones you make and hard drives getting bigger, I can see the whole market going that way in the future. It's strange that a copy sounds better than the original that it came from and a source with this kind of quality going through a decent amp would be stunning.
I was quite interested in the Brennan devices for digital files but it seems that cost cuttimg has meant that it's notas good as it could be. If it were really good quality and could produce rips like the ones you've ben doing, I'd take one away with me when I'm away from home.
I'm really looking forward to connecting the K701 to the Panda now it has more drive capabilty. It's the best sound I've ever heard from the AKG and seems much more controlled and better behaved in the treble region. The Panda has real authority in the way it pushed headphones and has totally sold me on the K701 for really clean, analytical listening. The HD250is pure entertainment and it even drived the Beyer 770 well,somehow bringing the mids more into focus.
Home tomorrow!!!!
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Post by Deleted on Oct 29, 2010 13:54:06 GMT
Sorry Frans. We crossed over. It takes me forever to type on this.
I do agree, musos listen for something different and are often perfectly happy listening on earbuds. I suppose that's because they kind of reproduce it in their heads based on what they hear in buds!!
It comes as one helluva shock when they hear equipment that gets close to what they imagine. When they hear something that is, they are so overcome by the sound, they can become blind to other aspects of the sound. That's quite common, I think with musi people.
What always surprises me with good equipment is how clean it sounds and the large dynamic range that it produces. That for me can make me forgive other terrible faults or problems.
BTW - your English is amazing. It'svery easy to forget that it's not your first language. I think that you'reable to communicate better than the English guys I have to work with!
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Post by clausdk on Oct 29, 2010 18:36:12 GMT
OK now I am confused, I just got my packet today from Mick, Thank you very much Mick, you are the best..
I or rather we (koolind and I) have ordered some toroids, but they say 115 volts and have 4 wires to mains ??
Can I use them anyway and if, how do I do that ??
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Will
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Post by Will on Oct 29, 2010 18:48:09 GMT
Take a photo of the label on the traffo, clear enough that we can read it, and we'll tell you how to wire it.
Four wires on the primary side makes me think it can be wired for 110V or 240V.
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Post by PinkFloyd on Oct 29, 2010 19:42:03 GMT
Claus,
Blue is neutral, brown live.... Connect the two other wires together for 230v duty.
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Post by clausdk on Oct 29, 2010 23:01:13 GMT
Claus, Blue is neutral, brown live.... Connect the two other wires together for 230v duty. Ahh thanks, so blue and and brown for 230 and the two other soldered toogether, easy done..
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Post by Deleted on Oct 29, 2010 23:08:25 GMT
Claus, Blue is neutral, brown live.... Connect the two other wires together for 230v duty. Ahh thanks, so blue and and brown for 230 and the two other soldered toogether, easy done.. Claus Don't forget to insulate the joined leads with a piece of heatshrink tubing or similar.Heatshrink tubing is recommended, as if it is properly done, it will not fall off. Alex.
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Post by PinkFloyd on Oct 29, 2010 23:49:58 GMT
Or just twist the two central leads together, flood some solder into them and clamp with 5a connector strip
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