XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
|
Post by XTRProf on Mar 28, 2012 14:13:34 GMT
KT88 or 6550 or EL34 Power Amp?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 28, 2012 15:24:30 GMT
You want the truth and nothing but the truth ?
You will have to listen for yourself as. a: it's highly subjective. b: it's dependent on the used trafo c: it's dependent on the topology
|
|
XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
|
Post by XTRProf on Mar 28, 2012 15:29:19 GMT
You want the truth and nothing but the truth ? You will have to listen for yourself as. a: it's highly subjective. b: it's dependent on the used trafo c: it's dependent on the topology You are right! You are turning subjectivist sooner than I thought.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 28, 2012 16:56:49 GMT
I WAS a subjectivist before I became a non-subjectivist. Right up to the point when I became interested in perception and started testing while eliminating the 'knowing' part.
I also was a devoted catholic (parents were) before I became an atheïst, caused by looking at religion from another angle.
These events were not related nor happening in the same time frame. Has little to do with powertubes and transformers though.
Give me a good SS over those cumbersome tubes anytime. Sounding different (better ?) does not equal better quality.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 28, 2012 18:24:56 GMT
Give me a good SS over those cumbersome tubes anytime. Sounding different (better ?) does not equal better quality. Frans, after a long journey I ended up with valves because I preferred them over solid state. So to me , valves do sound different and better, therefore, to me , have better sound quality. As you said yourself "it's highly subjective". Jeff
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 28, 2012 19:21:27 GMT
Yup,
The (added) harmonics are liked by many people. The sound is different because it has changed. For tube lovers it is changed for the better. Technically the SS amps perform arguably and measurably better and more stable over time, the last bit is why I prefer SS. Especially with pushpull designs tubes have to be matched and you can do that but are they still matched a month later ? No such probs with SS.
It's the same argument between vinyl and digital. vinyl is arguably and measurably vastly inferior to even 16/44 (except for FR but those that can provably hear above 20kHz I still have to meet). the reason vinyl is preferred over digital by many is because of the compression (to get it to 'fit' on the vinyl) and the changes you can 'control' in FR/impulse depending on cartridge, the background noise e.t.c. all add to the original signal. The 'added' things may sound better to many... technically better it is not.
But you are absolutely right... it's all about personal enjoyment and who cares what other people think/feel/hear/prefer.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 28, 2012 19:28:28 GMT
Not forgetting the RIAA curve that is kind of superimposed onto the sound of the music. In the bad old days, each studio had their own signature sound that was stamped into the sound of the album!!
The compression is there to stop distortion and also help stop the bleedover to the next groove on high peaks. The sound is actually lower but averages higher overall so we think it's loud.
There used to be some excellent recordings from the Suisse Romande Orchestra which were recorded so low in volume that surface noise became a problem on lesser equipment, but the dynamics were better.
They also made matters worse by putting nearly 30 minutes on each side as well so it had to be quieter to stop the horrible groove bleedover. Quite funny when you hear a loud sound before it happens!!
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 28, 2012 19:35:25 GMT
Indeed.
let's also not forget the tapes and the 'compatibility' issues that it had. Dolby-A-B-C-DBX, bias adjustment, tape materials, recording levels, head azimuth, tape speed, wow and flutter (now jitter).
Strange thing is I could easily enjoy music back then and listen past the faults and can still do so now. Old records on old equipment (tube or SS) can still sound amazingly good.
Those that are bothered by shortcomings probably have a harder time enjoying music as those that don't care or listen 'past it'.
I don't worry about jitter, distortion, wow and flutter, channel separation and what not. I can hear it... but it doesn't bother me anymore. It did for quite some time but realized it's part of the experience.
Some things became better and some things worse. Loudness wars and commercial/target group decisions now are the things that are wrong. Since the majority doesn't care this is not going to change, perhaps only get worse.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 28, 2012 20:35:27 GMT
They also made matters worse by putting nearly 30 minutes on each side as well so it had to be quieter to stop the horrible groove bleedover. Quite funny when you hear a loud sound before it happens!! Ian , is this the same thing as the term I used to hear - "Pre-echo"? Jeff
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 28, 2012 21:11:02 GMT
The pre-echo was formed on the mastertape that was used to record the master before it was pressed.
This was caused by too thin magnetic tape that was stored too long. The signal is stored by magnetic particles on the tape that are set in a certain position by the recording head. To give it enough 'power' to be magnetised a bias current was needed that overcomes the hysteresis in every magnetic particle. When a magnetic field is placed near particles that can be magnetised for a longer period the particles on the layer exactly over (or under) the magnetic soundsignature also get slightly magnetised by the signals lying a few micrometers next to it (the tape thickness). Sometimes with older tapes you can sometimes hear 2 pre-echo's preceding a crescendo (increasing in amplitude) when there was total silence.
pre-echo does not exist in digital audio, also not with DAT tape.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 28, 2012 21:14:53 GMT
thanks for explaining Frans
|
|
XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
|
Post by XTRProf on Mar 29, 2012 0:48:47 GMT
I WAS a subjectivist before I became a non-subjectivist. Right up to the point when I became interested in perception and started Well, welcome back! Sounding different (better ?) does not equal better quality. Oh, did we Audiofools say it's technically better quality? Better sound quality, yes, yes, yes ........ There are 2 kind of qualities here - TECHNICAL and SOUND Qualities. There's always where the confusion and unhappiness comes in between the subjectivists and the objectivists as the terms of "endearment" are different. We subjectivists reference is Live music. Even the studio engineers' rice bowls go on a subjectivist path for their clients. Proof here: It must Sound Better For Sure after that video for studio engineers and technicians. Well, for those good engineers that care about sound quality. I got nothing against technical as I graduated from a technical college, btw. But my reference for any hifi equipment is Live music and analog and tube / hybrid sound more like Live? Don't all agree, no matter what the technical specs are?
|
|
|
Post by ozelui on Apr 3, 2012 6:24:45 GMT
Hello there!
As far as I can remember, regarding the two best stereo set-ups I have heard, one used tubes (Audio Research with 6H30/6550 tubes) and the other one was Solid State(Dartzeel pre/power combo)....I would like to have BOTH! But if pushed, I would say "give me tubes everytime". Now returning to the subject of this thread: I like KT88´s sound a lot (Primaluna Prologue Two). Cannot give opinion about 6550´s but they should be more or less the same (I like them a lot in an Audio Research VSI 55 on in a Reference 210T for instance). As far as I know, I would recommend EL34´s if you want to get that "old school" "tubey" warmth in the midrange. Again, it depends on the circuit topology and tubes used...When it comes to vinyl...LP´s + KT88´s a combination which needs to be heard if not yet.... Now there are also those KT120 which have been used by now on several equipment. In my setup, KT88´s push "all the buttons" with different music styles. I have also noticed that the front-end tube complement (preamp+driver tubes) can really make a difference even using the same KT88´s...so you can actually adjust the "voice" of the amp to your own system/preferences. Not an easy question! ;-)
|
|
XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
|
Post by XTRProf on Apr 3, 2012 6:57:30 GMT
I like KT88´s sound a lot (Primaluna Prologue Two). Cannot give opinion about 6550´s but they should be more or less the same (I like them a lot in an Audio Research VSI 55 on in a Reference 210T for instance). As far as I know, I would recommend EL34´s if you want to get that "old school" "tubey" warmth in the midrange. Again, it depends on the circuit topology and tubes used...When it comes to vinyl...LP´s + KT88´s a combination which needs to be heard if not yet.... Now there are also those KT120 which have been used by now on several equipment. In my setup, KT88´s push "all the buttons" with different music styles. I have also noticed that the front-end tube complement (preamp+driver tubes) can really make a difference even using the same KT88´s...so you can actually adjust the "voice" of the amp to your own system/preferences. Not an easy question! ;-) Hi there, Can I infer that the KT66, 77, 88, 90 and even the 120 and the 6550 will be your vote if overall sound is important? The EL34 if the old school mid centric beguil us more? Then I will go with what you like, the first fews. But the EL34 amps are usually cheaper though maybe because of what you had mentioned - only mid centric. Anyway, the KTs seemed to be interchangeable with the 6550, right? Thanks.
|
|
|
Post by ozelui on Apr 3, 2012 7:31:30 GMT
Hi again! Yep, they would get my vote. EL34´s based amps I have heard had a little more "romance" in the midrange. Great for some classical music and vocal jazz. I would recommend you take a look at this EL34 shootout, really interesting: thetubestore.com/el34review.htmlIf I were to buy an EL34-only based amp, I would give a try to those Gold Lion KT77´s. In fact, my next tube quad is going to be a matched quad of Gold Lion KT88s. When I bought my amp, there was little difference between Prologue One (EL34s only) and Prologue Two (KT88s and EL34s)...when funds permit, I would like to try an EL34 set... Regarding the 6550/KT88, yes, they tend to be interchangeable (always check with vendor first) provided they are biased accordingly. Also worth mentioning that I find rather useful the "Maximatcher" I got to check/match power tubes. Like the glow of tubes in the dark....
|
|
XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
|
Post by XTRProf on Apr 5, 2012 3:08:35 GMT
I would recommend you take a look at this EL34 shootout, really interesting: thetubestore.com/el34review.htmlIf I were to buy an EL34-only based amp, I would give a try to those Gold Lion KT77´s. In fact, my next tube quad is going to be a matched quad of Gold Lion KT88s. Thanks very much! I only have some time to read that today as boss is away. An excellent read for all those interested in the tube sound and how it will affect our hifi lifes musically. Also worth mentioning that I find rather useful the "Maximatcher" I got to check/match power tubes. Like the glow of tubes in the dark.... Yup, not only Matched but also Balanced there ........ In fact, I don't quite like the glow of tubes in the dark as they distract my music concentration just like watching videos with all those leds and Lcds lit up on the equipment. But I do like the high curiousity when people come to my house and seeing a tube amp. Even ladies can be attracted, TBH, especially those young ones ........ Looking as if I have a Ferrari or Lambo .......... Are we still talking of in the middle of the last century?
|
|
XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
|
Post by XTRProf on Apr 23, 2012 14:35:46 GMT
So only the KT77 is a DIRECT replacement for the EL34? The rest need rebiasing? Any others? May try a EL34 amp, if cheap enough, since it can also do KT77. KT66, 77, 88, 90 and 120 all the same sounding for the same circuit topology, right? Is the EL 34 technically less high FR extended than the KT or American 6550 series?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 23, 2012 15:18:56 GMT
The FR of all tube designs is mostly determined by the output trafo, followed by topology (feedback amount and the way the powertubes are driven) not so much by the output tube themselves. EL34 = 6CA7 = KT77
|
|
XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
|
Post by XTRProf on Apr 24, 2012 0:16:10 GMT
The FR of all tube designs is mostly determined by the output trafo, followed by topology (feedback amount and the way the powertubes are driven) not so much by the output tube themselves. EL34 = 6CA7 = KT77 Thanks! I will try to look out for one EL34 tube amp with a traffo that can extend it to about 75 to 100khz. Not now, just doing the home work. Currently too poor to be looking here too!
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 24, 2012 6:31:52 GMT
20kHz -0.1 dB is enough This usually means 70-100kHz -3dB but with trafo's this could mean 40kHz could be enough depending on it's restrictions. Bandwidth can vary more with trafo's as well on different output levels.
So quoting bandwidths is only relevant when you include the -x dB points. Headphone manufacturers (and speaker manufacturers) handily make use of this.
So whenever you see someone quoting a frequency range and NOT stating at how many dB, it is a meaningless number. 20Hz to 20kHz may well be at -10dB or even -20dB. Sony and Grado are prime examples that gladly use this 'omission' to their advantage.
|
|
XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
|
Post by XTRProf on Apr 24, 2012 6:54:13 GMT
So Frans, what say you for this just for teble? AUDIO SPACE AS 9 MKIII MONO BLOCKProduct Description Mono Power Amplifier Model No. : AS-9 MkIII (290 x 425 x 195) mm Weight: N.W. 18.5kg/ch G.W. 20kg/ch Input Impedance: 100Kohm Output Impedance: 4, 8 ohm Output Power: 75W x 2 (Ultralinear), 38W x 2 (Triode) Power Consumption: Damping Factor: > 5 Frequency Response: 20Hz-40KHz / -0.5dB T.H.D.: < 0.8% 20Hz-20KHz (Ref. Output) Total Gain: 26dB Input Sensitivity: S/N Ratio: Channel Balance: Channel Separation: Tubes/Ch.: EL-34(6CA7) x 4 per channel, 6DJ8(ECC-88, 6922) x 2 per channel, 6CG7(6N6) x 1 per channel
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 24, 2012 7:04:47 GMT
20Hz to 40kHz -0.5dB should be just enough to be 'audible transparent' (NwAvGuy uses this expression a lot) The 0.8% distortion is audible but if it is the 'nice' kind (and it will be) you won't notice it as 'distortion' as the added harmonics are mostly masked by the instruments own harmonics or only add 'warmth'. The 'distortion' will be considerable lower at normal listening levels though (around 1W) and could easily be below 0.1% (so > 60 dB below the original signal) The damping factor of 5 is typical of trafo amps (actually even high) and may account for some of the perceived niceness as well in the bass area in some cases. Damping factors make nice numbers one can boast with but values >10 are pretty meaningless with real world speakers. In case you have speakers with 90dB efficiency and are listening at 3m distance in stereo you can reach about 106dB SPL. Headphones can go louder and reach above 120dB but won't appear to be as loud because of you not 'feeling' with your body nor hearing things rattle in the room. So at max power levels your dynamic range would be 106dB (assuming linearity) and any added extra's below 0.0005% would be inaudible. 0.8% (-41 dB) for the first harmonic is quite audible though but that's it's charme. Listening to classical music lowers the average listening level to around 86dB (just below 1W) but can have peaks that do not even appear to be loud of 106dB. This is why it pays to have 'power' at hand when listening to classic music on 'normal efficiency' speakers at realistic levels..
|
|
XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
|
Post by XTRProf on Apr 24, 2012 7:42:40 GMT
Oh, just for high only. It seems from your touch and go comments, it will be about ok to venture for one when $$ is around again. Damping factor don't need even apply as not for bass. Hmm, a damped tweeter? Also, additional reserve power for tweeter? Mid and bass, yeah, for classical. My mid is already at min 350W rms/channel at 6ohms and the subs are already at 600W rms/channel. With a high of about 75W rms/channel, that will be at least about 2.1KW rms power total for classical in a home environment. I think my present speaker drivers or my ears will have given up long before even the amps max rms are even excercised.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 24, 2012 8:49:42 GMT
I went a similar route but of course all SS. 200W sub (active compensated 2x40cm closed) 16-60Hz (-1dB) 2*160W mid-lows (dynamic closed 4* dynaudio 17W75) 60hz - 200Hz 2*200W electrostats (200Hz to 18kHz) So 920 W in total so it appears... It is an error however to claim '920W' though as the max SPL (distortion border) is determined by the largest signal reaching clipping level first. So in essence max power level would be equivalent to 2*150W or so in my case as the electrostats weren't high efficiency and the woofer was actively compensated. Also electrostats make distortion audible even if slight where dynamic speakers tend to be more forgiving at clipping levels. Effectively my 900W was 'only' twice as loud as if a single stereo 10W amp were used with normal effieciency speakers. loud enough for me and the neighbours ... Wouldn't use tubes for tweeters myself, personal choice as tube amps don't do HF well (as well as they don't do lows very well). because tweeters can only handle a few watt some people think you don't need a high power amp for tweeters in active systems and 5W should be enough. This is not the case as very short peaks can be quite high in power level but do not have time to heat the voice coil so peak handling can be much higher. The amp must be able to deliver the peak otherwise clipping occurs in the tweeter section (quite audible) before the rest of the system is clipping effectively lowering the max SPL. 75W is enough though compared to 350W for the mids.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 24, 2012 9:05:06 GMT
Sounds like you are trying to talk Chong out of a valve amp ! ;D
|
|