John Curl's Blowtorch preamplifier part II

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We understand the principle. We can't support the amount of reciprocity required to substantiate the claim.

I will just continue to be guided by the results, everything else is academic.

I don't see my role as explaining the universe, only to explain how I see it and what it brings to the table.

Not claiming anything, just sharing.

Cheers, Joe

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So if I am using the balanced input on my miniDSP I'll need about 34dB of gain for an MM and 10dB more for an MC if we reckon a 4bits for overload margin. What's the view on a cheap and easy way to get playing with this? The twisted pair Retro boards have a certain simple charm if you remove a gain stage as $26 for a pair of PCBs seems a no brainer in time saved provided the gain can easily be dropped down, but sure there are others for the case where you want to know it will just work to try things out?
 
...A 100uV out at reference level MC with 6 Ohms coil resistance gives 16.7uA current (shorted) so by these arguments 16.7uA into the cartridge should defect the stylus as much as the reference level groove. Damping requires force, right?

Guess I'm on Joe's ignore list just as well.

What list? Didn't even know that I had a list? :scratch:

Maybe indeed 16.7uA is audible. Something sure is. I am as open minded as anybody here, but when we vary the load on a cartridge, it is very audible indeed. And it is easy to blind test (although there has to be a level adjustment as you typically loose a few dB). So if anybody has a better explanation, I am all ears.

Force? I am not so sure that the damping has to do with trackability, but rather that of the coil and motor as a generator.

I note thermodynamics gets played very often here. Not sure if this entirely applies here, but then an argument could be made that it always does with anything that happens in the universe. Just not sure if it unlocks anything here though.

Was it Tim de P. who many years ago calculated the smallest details in a microgrove and its physical dimensions into the wavelength of light... it was a long time ago, sigh.

So, I have put a few things on the table, we have an observation made by many, we have a way of applying it in a beneficial way - by all means get some academic answers (and I would like that), but isn't that really more of an afterthought?

Meanwhile, let us not be put off by applying what we can all observe (sorry if this comes across as a bit preachy, not intended).

I love Roman history, they were engineers rather than scientists. They got things done.

Cheers, Joe

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So if I am using the balanced input on my miniDSP I'll need about 34dB of gain for an MM and 10dB more for an MC if we reckon a 4bits for overload margin. What's the view on a cheap and easy way to get playing with this? The twisted pair Retro boards have a certain simple charm if you remove a gain stage as $26 for a pair of PCBs seems a no brainer in time saved provided the gain can easily be dropped down, but sure there are others for the case where you want to know it will just work to try things out?

I'm spending the next couple of weeks exploring all the angles of this.
 
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mixed up example there. The justification for the A380 was economic. As there was a business case for a frickin enormous plane the engineers were set to work.

Ref Porsche (and by extension CFA power amps) the justification is that people will pay good money for that pointless stuff. And if you start amptastic corp and market the slewmagic 400 then bump into DS and say you are doing it cos there are mugs out there who lap up the voodoo he would he dismiss you? Dunno.

But is there any evidence that the CFA designs are superior in anything other than bench drag racing who can wipe out more of the RF band with their HiFi? I've not seen any. Big difference between wanting to build something for the challenge and claiming its better. If we stick to doing things cos they are fun and there is nothing on TV we would kill most of the arguments?

A 747 does the job just fine, as does a 777. Economic justification? A380's are not selling too well I hear. Re the Porche or any other super car: there's a speed limit in most civilized countries. And finally, CFA is not about anything else than being a viable alternative to amplifying a signal.
 
If you can think of any other experiment(s) to try to falsify 'hypothesis' - then let me know.

Yes. Measure the difference in damping with an impulse or square wave. If it just changes amplitude but there's no relative reduction in overshoot or ringing, your hypothesis is falsified.

Scott has explained why the motor analogy is not appropriate here.
 
Funny that, the binding posts are what first inspired my comment. Believe it or not Tuft's EE Dept back around 1990 threw all their old instruments into a dumpster. We filled our station wagon with as many as we could, maybe 100 or so. We sold duplicates but I still have a few, especially beautiful are the 1940's era power meters and electrostatic voltmeters. The jeweled movements and mechanical technology are amazing.

Yeah they are! And I still prefer a mechanical meter for some things. At least you can get an idea something's not right right away instead of waiting for a digital display to figure itself out.

se
 
Funny that, the binding posts are what first inspired my comment. Believe it or not Tuft's EE Dept back around 1990 threw all their old instruments into a dumpster. We filled our station wagon with as many as we could, maybe 100 or so. We sold duplicates but I still have a few, especially beautiful are the 1940's era power meters and electrostatic voltmeters. The jeweled movements and mechanical technology are amazing.

If you, um, ever need help, um, putting some of those amazing chassis to good use, do let me know. ;)
 
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A 747 does the job just fine, as does a 777. Economic justification? A380's are not selling too well I hear. Re the Porche or any other super car: there's a speed limit in most civilized countries. And finally, CFA is not about anything else than being a viable alternative to amplifying a signal.

So Germany is not a civilised country as it still has some (dwindling) unrestricted autobahn?

A380 deliveries 165 with the same again in orders. For a $375m aircraft those numbers don't sound bad and considerably more than the 747-8. What are you hearing? I don't see your argument here.

But I do agree with your last statement. It's an alternative. But it seems to have a cult around it which claims some magical superiority (or character). I'm all for giving the DIY'er options and alternatives so they can pick to suit their beliefs biases and masochisms, but I can't buy that it's inherently audibly better.
 
A typical oversimplification, a brutal one at that. I will self censor any further comments, listening to some Andean folk music. Tim de P. is a scary person.

Am I on your list?

Romans brutal? You bet. They went a long way to invent (perfect?) state terrorism. Don't have to be a Muslim you know. ;)

Yeah, Tim is one of the hardest people to start a conversation with, don't start with audio, start with vintage cars (motors especially) and flying... then gradually get him talking about audio. (Thanks to Max T for the tip).

But he uses a lot of "rules of thumb" such as, in output transformers use this ratio of steel and copper. It's interesting stuff. I have a video of him at ETF'06 speaking for an hour and a bit. Lot of it down to earth. Practical "rules" are very practical - he said it saved him a lot of time. It wasn't necessary to agree with him all the time, but at least some of the time.

I think Tim might have made a good Roman. :D

Cheers, Joe
 
billshurv,
I don't think that Ostripper is claiming that the CFA is superior to the VFA, only that they are somewhat different in presentation. He prefers the VFA for bass on his subs but thinks subjectively the CFA is a little better at 20Khz. That is about the only differences noticed at this point with all the different input sections that go with the output section. He has just optimized both types using the same op section. There are no magic claims as far as I know.
 
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Oh BTW Joe I did this 25yr. ago...
 

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