On Sat, Jan 17, 2015 at 7:12 PM, Ralf Mardorf <ralf.mardorf(a)alice-dsl.net> wrote: "They"? Who is "they"? Some of us use real amps, with tubes in them, even :-) -- Brett W. McCoy -- http://www.brettwmccoy.com ------------------------------------------------------------------------ "In the rhythm of music a secret is hidden; If I were to divulge it, it would overturn the world." -- Jelaleddin Rumi

On Saturday 17 January 2015 19:36:09 Ralf Mardorf did opine And Gene did reply: Yup, I grew up with tubes, some of which in the later years were quite novel. And not all of them work by modulating the current through the tube. In the high power world of UHF broadcast, the final stage was, back in the 70's, a klystron. And high power is not an exaggeration since it takes at least 130KWH to run just one of them. Not many left today as newer, more efficient technology is in use. At the peak of their use in the mid-70's, I was probably one of perhaps 30 men in the country who could uncrate one of them after Varian had collected their $130K and shiped, remove it and hang it up by a chain hoist, fit all the resonant cavities to it along with its cooling water (70 GPM) set it in the dolly, center it in the magnets or center the magnet wobble plates on it, bring it up at very low power & tune and adjust the magnets, raising the power, step and repeat until it was at full power. Mind you this was a device that a wrong magnet setting would cause it to self destruct in 10 milliseconds. If that happens, then you pick up the phone and call the governor & tell him to get a quorum together so they can authorize another $130K expenditure. I never had to make that phone call. There are some choices today, that are at times even better because the pickup coils are velocity sensitive, which isn't entirely suitable for a bass axe. I have in recent years seen several different kinds of microphones used as git fiddle and axe pickups, including one guy who adapted a PZM (electret condenser at its heart) to his acoustic axe and it sounded pretty darned good. When he gave the big string a pull, that whole barn made into a theater breathed well enough you could feel the breeze in an open window. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS

On Sat, Jan 17, 2015 at 6:39 PM, Ralf Mardorf &lt;ralf.mardorf(a)alice-dsl.net&gt; wrote: Can I mention the piezo pickups I installed in my accordion. Gawd they sounded awful :) (Accordion wasn't bad back then when I actually knew how to play one). -- **** Listen to my FREE CD at http://www.mellowood.ca/music/cedars **** Bob van der Poel ** Wynndel, British Columbia, CANADA ** EMAIL: bob(a)mellowood.ca WWW: http://www.mellowood.ca

On Sun, 18 Jan 2015 03:44:14 +0100, Ralf Mardorf wrote: JFTR, IOW a piezo pickup is the better choice compared to a coil. Using the correct directionality by a capacitor mic, even for live usage might be the much better choice for recording an accordion ;).

On Sat, 17 Jan 2015 19:10:18 -0800 (PST), Len Ovens wrote: Parents should use isolating transformer/galvanic isolation in every room ;). When I was a child drawers and pillboxes were not childproof, nobody I know ever was hurt by a drawer or pill, but we all were electroshocked when we were young.

On Sat, 17 Jan 2015 20:42:32 -0700, Bob van der Poel wrote: and still ok for this purpose, but we were talking about guitars and coils and not about piezos for other instruments. At what position should be a piezo be useful, when using it for a _solid body_ guitar?

On Saturday 17 January 2015 21:28:42 Bob van der Poel did opine And Gene did reply: You can Bob, but nomex underwear might be a good idea. :) The only piezo pickups I ever encountered were rigged so as to be so highly driven that overloading of the preamps was at about 30 db down from normal picking. Most pickers would plug them into their sears guitar amp, and of course the preamp flattopped long before it even got to anything that looks like a gain control. On an accordion I could see 30v p-p out of one, which of course also led to short life as the rochelle salt crystal wasn't designed to be driven that hard. You got the result, sad to say. Well designed electret condensers could survive that nicely. Biggest problem with the electret was the 2nd harmonic distortion when driven to higher levels. Even the legendary Altec M-21 suffered when it was driven to more than 50 volts p-p. It could do 150 p-p! The distortion comes from the square law of condenser element spacings, but it was still good enough to handle the cannons when hung 6" below the muzzle when Mercury recorded the 1812 Overture back in the later '50's. That mic, FWIW, I have had the pleasure of working with. You, unless you are an idiot, cannot do a bad recording with it. But in the late 1950's, you needed a loan shark handy to buy one, the basic unit, 20 feet of cord and its power supply were just north of $600. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS

On Saturday 17 January 2015 22:12:20 Ralf Mardorf did opine And Gene did reply: Any of them unless they are built with matching but reversed biased from side to side stationary plates. The capacitance between 2 objects has a square-law relationship when the distance is varied. Since its a difficult problem trying to drive the central plate, the diaphragm, the movable by air pressure plate when its in close proximity to a stationary plate on both sides, they are are built only with a stationary back plate. As long as the spacing variation is a small fraction of the overall spacing, its not too bad, and has even been compensated for by using a FET preamp with the correct bias etc to introduce a compensating 2nd harmonic of the opposite polarity. The electret condenser type has a huge advantage in this case because they contain their own permanent charge, and its a quite high voltage, so the spacing can get sloppily large (= cheap to make) and still have adequate output to drive the FET buffer in it at quite low distortion. Radio Shack used to sell, for a tenner, a pencil mike that ran the FET on a pair of AAA cells, and it was pretty darned good for a 10 dollar mic. Way the heck and gone better than the $60 Shure clones they had at the same time. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS

On Sun, Jan 18, 2015 at 11:48:00AM +0100, Ralf Mardorf wrote: So what do you recommend to obtain to electronic components in small quantities in Germany ? Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow)

On Sun, 18 Jan 2015 12:37:49 +0100, Ralf Mardorf wrote: PS: If you can't get some very special components from Reichelt, than you've got bad luck. If needed, in the past we ordered from Merkelbach, but it doesn't exist anymore, so you need to bite the bullet and order from RS. However, most of what we need for audio circuits can be ordered from Reichelt for less money.

On Sun, 18 Jan 2015 14:26:39 +0000, Fons Adriaensen wrote: You are welcome! I can't recommend their no-name connectors. Likely Reichelt still sells "Sortimente", such as electrolytic capacitors from 0,47 to 1000 uF providing averaged voltage needed for audio circuits (the provided voltages are unusable to build or repair switching power supplies), IMO it's worth to buy such "Sortimente" instead of ordering selected components again and again. 2 Cents, Ralf

On Mon, 19 Jan 2015 09:55:26 +0700 Kazakore &lt;dj_kaza(a)hotmail.com&gt; wrote: In the UK I find that Farnell is often cheaper than RS. Also their website shows their stock level of each item. RS will let you check if there is enough stock for what you want, but if you order 1 of something and they only have that 1, it could easily be committed before you complete your order, and the item will automatically be put on back order without it being made obvious to you :( -- Will J Godfrey http://www.musically.me.uk Say you have a poem and I have a tune. Exchange them and we can both have a poem, a tune, and a song.

On Sat, 17 Jan 2015 20:21:17 -0500, Gene Heskett wrote: I don't remember the type designation of those tubes, but Dirk Brauner owned many of very small tubes, aged, but still very good around one or two decades ago, when we were friends. I guess most people think that tubes are as big as a bulb, actually some tubes are not much larger than a few transistors.