mike stehr

I had a pair of tapped autoformers for volume control use, and the brand are rather well known. It was a kit more or less, except one had to provide an enclosure/case, and connectors. I took my sweet time and made sure things were properly wired. In use, I liked the midband to top audio band of the autoformer's "sound". But the bass wasn't there, no matter how I stacked the laminations, which was an option. And there was this sort of subtle saturation sound when in use. And I checked over the connections several times, even asking questions on the site's forum. In the end, the "sound" of the tapped autoformers just wasn't for me. It's a excellent product however, and I really like the guy, and maybe I did something incorrect. But with regard to just using a passive type volume control, a simple resistive potentiometer or a stepped attenuator is the choice for me. Out of boredom one day I took each autoformer and connected a signal generator to the input, and a scope lead to each tap, (unloaded) and ran square waves from 50Hz to 30kHz, monitoring the scope for ringing of the autoformer's on each tap. Each autoformer had a bit of a ringing overshoot on the front left edge through the whole audio band. (all taps) 30kHz was a mess, but the harmonics of higher frequency square waves will round out the "square" of the wave at the source, not necessarily the device under test. You can do the same thing with a simple resistive potentiometer, (carbon trace, whatever) and the pot will pass fine square waves with of course no ringing. I brought this up to local retired audio engineer...his comment was something to this regard: "It is to my knowledge that a transformer/autoformer should never be used as a resistive divider."

Trust me, back then I had WAY too much fun, and had gotten into WAY too much trouble back in Couer d'Alene!

Good lord, it seems whatever one will do will result in criminal charges. May as well follow the drone to the operator, break his hands, and take the lumps for assault charges.

Years and years ago some friends and I went to the (Iron Horse?) where they had a house drink called a Derailer. It came in a big bucket. We convinced the folks that we wanted a double Derailer. The drink was strong enough to start melting the plastic bucket...you could taste it in the drink! One between three of us, and we were trashed.

The cheapest seem only good for 260 feet. But you figure for 30 bucks, a guy and his buddies could buy several and play Midway with the offending drone. https://www.walmart.com/ip/Ematic-Nano-Quadcopter-Drone-with-2.4GHz-Control-and-6-Axis-Gyroscope/50973014?sourceid=csesh01321cd3b5438a4ff5a86c36a2c3a913d3&wmlspartner=shoppingcom&affcmpid=1476790452&tmode=0000&bcfg=a8991f6015cdc05603b3b9780ad9dbae&veh=cse#about-item

The VPI integrated amplifier's appearance gives the impression of a modern day Altec 345A.

Does it get loud?

Power Output: 2 x 38W / EL-34 (8Ω, Ultra linear). ( KT-88 /40-Watts) 2 x 20W / EL-34 (8Ω, Triode). ( KT-88 /20-Watts) Tube Complement: 4 x EL-34, (or KT-88), 4 x 12AU7, & 1 x 5AR4 Frequency Response: 9 Hz ~ 52 Hz (-3 dB) THD: 1% (1kHz) S/N Ratio: 89 dB Input Sensitivity: 400 mV, 600 mV (Pre-in) Input Impedance: 100-kΩ Output Impedance: 4Ω, 8Ω Classic Design Special-1: Headphone Output Classic Design Special-2: Tone & Treble Control MM Phono Total Gain: ~ 45 dB ( Upgrade ) Input impedance: 47.0-K Ohm Power Consumption: AC-120 Volts @ 280 Watts Weight: 68 lbs. Dimensions (WDH): 16" x 15" x 7" Love the typo of 9-52 hertz.

Monoprice mentions on their site; "Life is too short for audio products that don't sound great!" Too short for cheap Chinese pre-amp tubes feeding power slop amps

Like Joe Roberts says; "It's hard to build a bad 2A3 amplifier."

At least it isn't some 150 dollar Chinese abortion...

That's why kinda crossed my mind. The cap sees raw rectified DC pulses being the first cap right after the rectifier tube...I dunno... Is that still with the damaged Solen capacitor?

Maybe the guy figured he needed a lot of headroom. I rather doubt the LaScalas were damaged, unless you noticed a lack of top-end or midrange from blown drivers or lack of bass from a dead woofer. My guess is just weird synergy from large monoblock amplifiers, which LaScalas wouldn't really benefit in sound quality. I had some LaScalas I had for a time...my opinion is they shine with tube amps...single-ended class A stuff...

Wouldn't a AC voltmeter work for this sort of thing?

That's a lot of current for 93 decibels.