anatech

I've worked on Carver equipment and Bob's earlier designs for a very, very long time. All kinds of gear for MI and consumer use. Nearly 50 years now being paid for what I do. I also have a test and measurement background and use HP / Agilent / Keysight equipment mostly. Resistive dummy loads. Yes, they are there so you can make claims that are reproducible by others with standard, industry agreed upon equipment characteristics. This is for starters. Early on, Marantz had us connecting capacitors in parallel with the load resistors. You can also use inductors and capacitor-inductor networks, but then you are not on any standard. This is useful for internal design direction so you can drive real loads well. However I draw the line at stupid loads. Unhappy amplifiers will not perform at their best, so why design a speaker that puts amplifiers in this position??? (Infinity and Ohm come to mind). Anyway, before any of you criticize testing with the standard industry resistive loads, stop and consider why this is done. Those tests are valid. Mine are those 250 watt, Dale 1% non-inductive 8 ohm things, I have three sets mounted on heat sinks. Some folks use heating elements and claim they are valid (ahh - no). You can get a base comparison and weed out the junk so you can focus on equipment that is designed well by looking at those tests. We look at spectrums these days, not a needle pointing at a number. I find Bob's designs inspired and frankly I see him as a very gifted engineer with a flair for promotion. Also, the lower the distortion, the better something does sound. I do feel the music and commonly run things at very high SPL. Bob designed some very fun products, although people who blew woofers in LaScalas driven by M 1.5 and PM 1.5 amps make me wonder (did Klipsch warranty too). I do have one burning question for Bob and others in design. Why the devil would you use a 4136 quad op amp? Not great performance and a non-standard pinout. Low current draw sure, but who cares? It forced me to use an adapter PCB (I designed decades ago, others have them now) and install better power supplies in some products. Just asking .... -Chris

Merry Christmas Everyone!!! I haven't been around much lately, but I plan to attend more regularly. Thanks for a great site and great members!