John Curl's Blowtorch preamplifier part II

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The REAL problem with audio is MARKETING! They are the people who, when they get something that proves to be popular, make the BIG MONEY.
Even advanced test equipment salesmen can make BIG MONEY, if they have the right personality, and I suspect more than the actual designers of the test equipment.
 
John,
On this I can agree with you that this is not an easy business to make an honest dollar for the work involved in bringing a product to market. You only have to look at the consumer market to see what happens. Do any of us really think that the Dr. Dre headphones are worth anywhere near the price or that this company should be a dominant player in the industry? It is all celebrity driven and marketing money that has created this monster, not a quality product for the price. Selling a superior product will not guarantee success, it takes more than a great product these days to make a honest living.
 
or car fuel consumption reduction devices.

Something wrong with that also LOL

For less than $30 I reduced the fuel consumption with 35% and increased torque by the same percentage ;-)

Standard the car had full acceleration up to 140 km/h, after up to 180 km/h..

For additional $600 I got another 20% increase in torque and full acceleration up to 200 km/h..

No electronics - only pure metal parts...
 
"In yer face" has totally taken over here in the large UK cities, TV, comedy, telesales, and even here in quiet rural well mannered Scotland, although less blatent, is catching on as being the new charismatic (I don't think) approach to all personal interactions amongst the younger people. It is repulsive and needs to be stopped pretty quickly....if not, the outcome is inevitable.
 
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Fas42,
While those materials may be interesting for something like making an RF seal or something on a radome or even some simple contact circuit I would say the electrical impedance of these types of conductive adhesives would have no use in an audio circuit. These types of material can never have enough conductive material added to the adhesive and still function as an adhesive or a tape.
 
Power Frequencies Matter....

Recently I bought one of these via Ebay. lPCR500L_01.jpg
Kikusui PCR-500L AC/DC variable voltage, variable frequency power supply.
http://www.kikusui.co.jp/kiku_manuals/P/PCR_L_E7.PDF
It puts out 0-300V AC, 1Hz-999Hz, 500VA at 0.3% THD, or 0-420V DC, or AC with DC offset, or DC with AC ripple !.

An experiment I have wanted to try since forever is to run musically related power frequencies and hear what happens....now I can. :p
Preliminary findings so far, confirming suspicion is that neither 50Hz or 60Hz are actually ideal on gear with less than perfect power supply/earthing arrangements.
Switching to 55Hz causes an immediately subjective cleansing of the sound, reducing a veil of intermods and harshness.
Bass gains solidarity and 'correctness', mids lose harshness, highs gain extension.
This is on active speakers fed by directly USB soundcard (Edirol UA-25ex).

Of course this is probably not revelatory news to advocates of high quality DC regulation stages and high PSRR stages (JC and others).

Currently I am running clean sinewave output...programming via GPIB interface, this box can output clipped sinewave, sine plus noise, DSO captured waveform or just about any arbitrary waveform, including varying/stepped output voltage, varying/stepped frequency and momentary brownouts/surges.(once I get a USB-GPIB interface cable :()

All in all an interesting and very useful piece of gear for simulating/measuring power quality effects on audio gear.

Dan.
 
Hi Dan,

Nice piece of kit, good to see you are putting your money where your ears are.

Much interested in further results. I hope you will be able to objectify your findings by doing some controlled listening tests.

One question I have is about your suspicion that 55 Hz would be better than 50 or 60. What is the reasoning behind this? I can imagine that a marginally designed transformer with a core that saturates @50Hz might benefit from more cycles per second. But why would 55 be better than 60 Hz?
 
Not Interested In Any ABX Arguments For Now....

Well, that would be me, but if it's actually true, it would be revelatory news. How have you verified that this remarkable observation is correct?
I'm saying that power frequency injected hum, ripple, etc is discernible on sub-optimal gear.....it's a modulation in addition to the audio modulation = intermodulation.
Testing regime for now is sighted testing with one other person present...we both expressed the changes in the same ways.
No blind testing yet...that will follow when I get a GPIB interface.
Another observation is that US (60Hz supply) recordings sound slightly less bad with 60Hz supply than with 50Hz supply.

I find also that the converse is true...I have always found AUS/European recordings sound subtly more correct with my local 50Hz mains than do US recordings.
110Hz sounds good, 100Hz and 120Hz sounds less good also.

Just some preliminary informal findings so far, maybe a heads up for some.
Actually it confirms justification for very high performance regulator stages, power amp capacitance multiplier power supply stages and importance of correct earthing arrangements.
These factors are typically to be found wanting in 'average' audio gear.

Dan.
 
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