@ OP: if you want to play guitar powered only by solar power, use an acoustic guitar and become a vegan.
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Quote[...] The unit runs 2x LM3886 in parallel driving a 4 Ohm woofer and a single LM3886 for tweeter.You already know the answer then.
[...] but that chip was too hot to touch and measured rail voltage on the output which obviously burnt out the tweeter.
[...]No real heat sink except for a 6mm flange which is also bolted to outer alloy case.
QuoteParalleling *voltage* sources is a disaster waiting to happen.Well... maybe. Pretty much no really high power amplifiers in existence get by without emitter resistors. The emitter resistors are there to wash out the microscopic differences in Vbe. Engineering has pretty well accepted that sometimes you can't get big enough power devices and you're going to have to parallel them sometimes.
The additional condition that now gain must track each other within 1% or less, any volume, any frequency, plus NEEDING cheesy series resistors to somehow help speaks volumes about what a poor Engineering choice it is.
QuoteNot sure I follow you: you use 4 x 3886 in parallel to drive a 2 ohm cabinet through a single cable pair or a special connector with 4 individual speaker cables? Not problem in a combo, not so sure in a head+cabinet situation.Yeah, that's how it looks at first blush. Combo, no problem. Head and cab, you get into funny speaker cables or replacing speaker cables to run many outputs.
Quote from: LJN on March 17, 2016, 02:55:41 AMOrgan makers used 1/2W carbon comps because they were the *cheapest* resistors back when the organs were made. The organs had signal levels of several to many volts so the internal uglinesses of the carbon comp resistors were not very noticeable.
[...]1/2 watt carbon composition types
QuoteI'm planning on using them in my more important fuzz pedal builds.?? More important fuzz pedal builds??
QuoteThey seem to work really good in my Tone Bender MkI clone.How exactly are you measuring "good"?
QuoteIn fact, it sounded better to me after changing over to these old resistors, which have drifted with age.In formal psychological research, designing experiments to find out what people really like or not requires that the experiment hide what is being tested because people simply cannot be objective about outcomes on tests they make themselves. They will like **whatever** they do, thinking it makes a positive change.
QuoteAnyway, I'm wondering what you guy's opinions are on the subjectFirst, some facts, rather than opinions.
QuoteNo. A few hundred ohms is not enough to significantly affect the outcome.
and if a few hundred ohms difference is really enough to significantly affect the outcome.
Quote from: engelheimer on December 18, 2015, 08:41:32 PMThat's a pretty ominous start.
I posted this on the Marshall Forum last week and they gave me the boot,
QuoteThat doesn't make any technical sense. The difference between ±15 and ±18V doesn't make that much difference to the signal an opamp can put out. Even if it were clipping at 15V and not at 18, the difference in signal level is only about 1.6db.
Swap the 7815/7915 TO220's with 7818/7918 TO220's, with the +3 and -3v supply boost you get headroom and crunch out the wazoo.
QuoteSo maybe you're being absolutely straight with us - you're here to cause havoc. Most forums do not take kindly to that. There's quite enough of that with everyone trying to play nice.
My objective here is to entertain, annoy, confuse and send others off on tangents.
Quote from: plugger on October 19, 2015, 11:00:51 AMIt probably isn't. At least it isn't until you look more closely at the word "gain".
Can someone explain why substituting one op amp for another in a preamp stage [...] would result in more gain through the preamp stage? I can't really square this with my understanding of how op amps work. [...]
Why would this be?