John Curl's Blowtorch preamplifier part II

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Well, we are at stage 2: 'It exists, but it is not important.' '-)

It better not be or you, Nelson, and Chales Hansen are in trouble! ;).

Please read the results, even the lowly AD712 does't register. AD797 UNDEGENERATED bi-polar, no reading, no PIM, no TIM, results even from your side. Don't get me wrong a 50 cent op-amp might be 5 orders of magnitudes DIFFERENT than a ZEN amp, I think the door is open now to find one of those euphonic colorations that causes preference. We might want add lots of PIM for the right sound after all most mechanical forms of recording are packed with it..
 
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It better not be or you, Nelson, and Chales Hansen are in trouble! ;).

Please read the results, even the lowly AD712 does't register. AD797 UNDEGENERATED bi-polar, no reading, no PIM, no TIM, results even from your side. Don't get me wrong a 50 cent op-amp might be 5 orders of magnitudes DIFFERENT than a ZEN amp, I think the door is open now to find one of those euphonic colorations that causes preference. We might want add lots of PIM for the right sound after all most mechanical forms of recording are packed with it..

Good insight. I brought this observation up to Jan at AES. All we need is a flutter generator with the right modulation spectrum to get class A sound. People seem to prefer an LP cut from a digital master to the original digital master that is not available. All you get is a collection of distortions plus noise in the lp but people love it. I have also heard that running a track through a tape recorder (in and out) to add some tape "sweetening" like flutter and noise with some saturation distortion "enhances" the sound.

We have been pursuing the wrong goal all along.
 
Scott; working on a "grand piano" effect for bass guitar I discovered that PIM is useless, it causes NASTY sound. Let's forget about "euphonic" epithets for this phenomena.

If people still prefer "you, Nelson, and Chales Hansen" let's search for the answer in the different dimensions.

I said it last week, I don't think this will lead to many answers just having some fun. Trick or Treat!

:Pumpkin::Pumpkin::RIP::Pumpkin::Pumpkin::witch:
 
We have been pursuing the wrong goal all along.

Congratulations Demian!

Now you have a chance to start perusing an another goal. You heard already an example how Nelson speaking about added on purpose distortions even turning away from microphones sounded like Nelson speaking in the big room away from microphones, but louder. And no more distortions were needed so hear that it was Nelson Pass speaking turning away from microphones.

Let's speak of systems that work humbly, as if they don't exist at all?
 
Out of all that, the only thing I came away with was greater respect for the Constant Charge Electrostatic speaker .. for bass .. unfortunately its mid & treble hasn't the potential to topple Rice & Kellog's invention.
Well, you threw a bomb here. This is contrary to all I have heard and read. Can you put some more words on this?
Electrostatics and Isodynamics need a supporting structure. On the ESL, this can be made part of the acoustic system. More difficult for Isodynamics. The rare-earth magnets allowed this to be smaller so made them viable though it is still a problem. I'll discuss the ESL-63 as IMHO, it is the best Electrostatic.

I bought one of the first ESL-63s and discussed it at length with Peter Walker. It has probably the best Delayed Resonance Curve of any speaker I've seen ... up to about 1kHz.

AES E-Library Analogue Loudspeaker Measurement with -3-D- Display We called these PAFplots after Peter Fryer as opposed to the CDS KEFplots which are now a 'feature' of all fancy acoustic measurement packages. KEFplots have no resolution below about 1kHz

It's performance above that isn't bad but the contrast with lower frequencies is so marked that it sticks out in a Blind Listening Test.

It's caused by the dust covers without which the speaker lasts about 3 mths. The wonderful looking curves for the ESL-63 in their AES paper were done without dust covers. :eek:
 
You can put dust absorbers next to the speakers, like Chizhevsky lamps that will attract all garbage particles and emit good for health ions. :D

PS: my line arrays in walls, looking like picture frames, deserve high WAF number, and work almost 3 years without any maintenance. An array of light cones each driven by small powerful motor, almost like isodynamics. You can't repair a peace of an isodynamic speaker, but you can replace one of failed drivers in an array.
 
You can put dust absorbers next to the speakers, like Chizhevsky lamps that will attract all garbage particles and emit good for health ions. :D
ESL-63 without dust covers are very efficient dust absorbers, in fact very similar to your Chizhevsky lamps.

If you don't mind sending your ESL-63 for factory re-furbishment every 3 mths, I recommend you try them w/o dustcovers. But please don't wait until they arc over before you do that or your bill will be somewhat greater. :D

If you live in the UK, your 3 mth service is probably no more expensive than NOS Mullard EL34s or Gold Lion KT88s for your amp.
 
What did I say? That FM distortion is the ONLY important distortion left? Seems to me that xover distortion is what is most audible today. Today, I am working with a design that has a 350 ohm load, and the part is rated for 600 ohms (nominally). Can't measure much, anyone think I might have a problem, subjectively? Me, being me, I am concerned. Don't worry Scott, your op amp is not under consideration, here or in the JC-3.
 
Overall, audible non-linear system distortion is still the answer. It obviously exists, otherwise every system would sound the same as the next. If you want to get fussy, throw in a decent DSP to guarantee that the linear distortion is absolutely minimal, but .... still they differ!!

The final frontier ...

Frank
 
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