How does your system remove the horror from the recording? I still find it funny reading the audiophiles waxing ecstatic over Mercury or RCA recordings from the 50's and 60's carbon comps all.
Aside: can't remember who but someone commented a few years ago how carbon comp can be remarkably stable over time despite rumours to the contrary. A quick dig into my 1966 Radford STA25 shows that can be the case. So for all their horrors, drift of value over time doesn't need to be one.
Still replacing them all...
Still replacing them all...
Waxing over the Classic reissue which is jaw dropping. No carbon comps in the Grundmann remaster, but the original tapes probably so and lots of nice RCA black nickel plate tubes in the recording chain. The dynamics and detail of that reissue.
With an original RCA/Mercury unfortunately one must replicate the horror in the playback, but in making the silk purse, everything else becomes a sow's ear. The original LPs are not a reference, but they can be very special.
Made in Milwaukee, when I was 18 my mother made be go apply for a scab job during a big strike and I got called every 4 letter name and was spat on. I ended up riding the village garbage truck for the summer.
Hi John,
-Chris
I just don't see it. They got what they got and no one was any the wiser back then. IRC was a good name too, as was Ohmite and probably others. What was put into equipment back then was whatever the procurement department got them in the factories. 5% parts were tight tolerance used for test equipment. 1% parts were off the scale for price (I couldn't afford those!). 20% parts were the norm used by repair shops and 10% was used for "good stuff". If something needed to be exact, it got a trim pot.
-Chris
I've got a bag of NOS AB CC resistors (wow that was some alphabet soup!). I think they were marked 10%, but most of them are not even close to that. Some are so far off I wondered if I was mis-reading the colour codes. I assume these are not the "baked" ones, and I also assume a few decades of poor storage and hygroscopic adsorption have caused them to drift like crazy.
I managed to find a few that measured close to their marked value and used them as gate-stoppers (because somebody told me that low inductance is important in that application).
Hi nezbleu,
-Chris
Absolutely correct! You can safely use the others in tube circuits as no current normally flows in grid circuits. For gate stoppers I don't think that a 10% variance would hurt anything unless the values were marginal to begin with. As long as no current flows in the circuit, Carbon Composition resistors will be fine for noise.
Baked resistors can easily go way off value. Moisture is an equal opportunity party pooper. The ones that last are baked and sealed with a coating.
-Chris
When I was at: Ampex, instrumentation, audio, and then research (video), we used almost exclusively Allen Bradley 'baked carbon' fixed resistors. We only used 1% metal film resistors for precision attenuators. They were checked out rather thoroughly at some point and that is why we used them almost exclusively.
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It has been about 40 years since I last used an Allen Bradley resistor for anything important, but serious evaluation has been going on for more than 30 years. At first, I sourced an incredible variety of 1% or better resistors for about $0.10 each. All kinds of colors, different lead types, some gold plated, the ultimate being about .005% glass cased resistors with gold plated Kovar leads. Wow, I thought I hit the jackpot! I made a personal preamp out of a few modern circuits, with the line amps being Levinson JC-2 stock, added servos, and the volume control was a straight line Penny and Giles studio pot. It should have been wonderful, BUT IT WASN'T. It just didn't sound right. I ultimately abandoned it. Now what went wrong? The line amps were proved out with the Levinson JC-2, the phono stage was all discrete and the same quality. But it just didn't sound right. I think it was the ULTIMATE precision glass resistors that I used, it was one of the only variables that I could not be sure of. I hope to use my present test equipment to find something, if I can. Kovar leads? Maybe that was the problem. Perhaps I can find out. In any case, resistor brands and types do sound different, you just have to listen carefully.
I am sure Google can help you find a suitable RF site which will answer your question in as much detail as you wish. However, the quick answer is that directional couplers sense both voltage and current.M Gregg said:
Where did the 'grid stoppers should be low inductance' meme get started? A corollary of this is the 'best grid stoppers are CC' meme. In some cases a lossy inductor can be a better stopper than a resistor.
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