For starters you don't have Bob Crump, or Bear's directional silver wire. Read the thread. it's clear the BT is not a "schematic".
Snarky comments aside...
If you try to copy the Blowtorch, you'll run into a couple of problems from a purely practical point of view:
Firstly, it uses components that are no longer in production and are extremely difficult (if not impossible) to get hold of today.
Secondly, the schematic you copy will only show you component values and part numbers. It won't tell you e.g. how to measure, match and select individual components.
So even if you find the "right" parts and build a clone that looks identical to the original in every detail down to component values, PCB layout and materials, it still won't work properly or perform the same as the original.
(I'd prefer to stay out of the arguments about whether different types of resistor, capacitor and wire sound different etc, so just pointing out a couple of practical non-contentious issues)
Can we have a PCB layout to admire, then, John Gerbers will do (in fact prefferable)
To quote one colourful character from the Russian satirical literature of the 1920s:
"Perhaps you'd also like the key to the apartment where the money is stashed?"
:-D
Yes please.
Please note these Gerbers would not be used in any way to reverse engineer a product, I would not read them into CAM350, select and create components, extract nets then export a CADIF or similar format that I could use to check a schematic against
Actually this would be a purely academic exercise for my own enjoyment, i like to study PCB layouts...(very sad person).
Please note these Gerbers would not be used in any way to reverse engineer a product, I would not read them into CAM350, select and create components, extract nets then export a CADIF or similar format that I could use to check a schematic against
Actually this would be a purely academic exercise for my own enjoyment, i like to study PCB layouts...(very sad person).
When it comes to building the exact CTC Blowtorch, that is almost impossible, but perhaps many of you can do better. PMA certainly thinks so. It is just like making a 'successful' automobile model, maybe subjectively better than many of its 'successors'. It is not the Gerber files or blueprints that are going to make a difference, but the 'ideas' and 'concepts' put into the 'successful model' to be hopefully passed on to the next generation of auto builders. Many of the 'ideals' that we put into the Blowtorch are snarked at by Scott, SY and others, but to me they are the ESSENCE of what makes the design successful, NOT JUST THE SCHEMATIC. And the simplified schematic has been put forth here, by others, with my encouragement, years ago, and even simulated by PMA, who did an excellent job, by the way.
Once again, much of the success with by BEST designs is in the 'physics' rather than the engineering, or just the schematic. What makes me controversial here is that I try to 'give away' the 'secret' of my success, and typical engineers don't believe me. So be it.
Once again, much of the success with by BEST designs is in the 'physics' rather than the engineering, or just the schematic. What makes me controversial here is that I try to 'give away' the 'secret' of my success, and typical engineers don't believe me. So be it.
Now, in order to complete my original 'promise' to tell everyone the 'secret' to my success as a phonostage designer:
I have found that to reduce the annoyance of ticks on a record, that a gain stage that is very fast, very linear and with very high dynamic headroom, is necessary, in order to minimize the duration of the 'ticks' and mistracking artifacts (that often happen with many recordings and MC cartridges). This necessitates a two gain block phono stage, rather than a single one, like the original Levinson JC-2. I did not invent this approach, it was first done by HK in germanium, and later by Electrocompaniet, following the HK approach. I have just taken it a bit further, with some success, I might add.
I have found that to reduce the annoyance of ticks on a record, that a gain stage that is very fast, very linear and with very high dynamic headroom, is necessary, in order to minimize the duration of the 'ticks' and mistracking artifacts (that often happen with many recordings and MC cartridges). This necessitates a two gain block phono stage, rather than a single one, like the original Levinson JC-2. I did not invent this approach, it was first done by HK in germanium, and later by Electrocompaniet, following the HK approach. I have just taken it a bit further, with some success, I might add.
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Siemens Styroflex too, when was the last time you saw leads that thick on a polystyrene cap?
Of course! They're some of the best sounding metal film resistors ever made. Have you tried the Philips MRS25 resistors?
Now that Roederstein is gone and the Vishay MBB0207 are questionable replacements... What sort of metal film resistors do your prefer? Vishay still makes the MRS25 resistors.
Then one gets into audiophile products like PRP, Takman Rex, TKD, etc.
Just curious to see if you found a current production metal film resistor which sounds as good as the Resistas?
And before someone mentions the various Caddocks, Nude Vishays, etc. They certainly don't sound like Resistas. Measure better sure, but definitely don't sound as sweet as the Resistas.
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slightly off topic but apropos of parts
This just showed up on "Planet Analog": Planet Analog - Tim McCune - AEA's Ribbon Microphones & Linear Systems' JFETs
Note that no mention is made that Dooley's ribbons are, afaik, still using transformers ahead of whatever preamp is used.
Also, although Fred Forssell is mentioned as a designer, I believe Duke Aguiar did a preamp for AEA as well.
This just showed up on "Planet Analog": Planet Analog - Tim McCune - AEA's Ribbon Microphones & Linear Systems' JFETs
Note that no mention is made that Dooley's ribbons are, afaik, still using transformers ahead of whatever preamp is used.
Also, although Fred Forssell is mentioned as a designer, I believe Duke Aguiar did a preamp for AEA as well.
Which then has to be extended throughout the entire system, from one end to the other ... that's the "secret" of good sound ...
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