johnsonwu
Responses from johnsonwu
| Technics vs. Focal Just got my pair of SB-C700s this Monday.Decided to buy them because I was wowed every time I go to the Technics showroom in Osaka to listen to the SBR1s. Figure if the affordable sibling can give me a glimpse of the very neutral and detailed soun... | |
| Over and Under Biasing as means for tone control That’s only a for power tube biasing. Also won’t work for the likes of 6C33B. | |
| Over and Under Biasing as means for tone control Harmonics control may I say?if you are talking about power tubes I highly discourage overbiasing to warm upthe sound. It just gives you supernova and runaway tubes easily. Gain and driver tubes are a different story. You can get pretty good retu... | |
| Bypass capacitor position? small difference in the 2 amps.... the Frankenstein uses a "Hail Mary" type of biasing on the 300B as far as I can tell. The sound is very dependent on the plate voltage of the 6EM7. Good luck getting the 2 to sound the same. | |
| Fairy Tales by Radka Toneff Track 2 is the most challenging. Highlight how well B+ regulation is done in each amplifying component. Much better test record than the likes of Teresa Teng. | |
| Review: Audio Research Corporation HD 220 Amplifier Cant help myself but to revive this thread after all these years.Those who are reading this must either have a broken SD135/HD220, or got a bit annoyed with the progression from a positive "dimensionality instead of paper cut outs and fixed images... | |
| Review: JM Labs Diva Utopia Be Speaker 75 is plenty for a ported medium sized speaker like the Diva.The 2 inductors connecting the bottom woofers suck out power so you'd be wasting money on monster amps that don't sound as good as the CJ11. | |
| recommendation for speaker wire to soften the highs if possible @nasaman I can start a dissertation on how to use LTSpice to run simulation on how an LC filter strapped in parallel to an LCR load (speaker) will work to roll off high frequencies at which point by how much of a slope, or I can just suggest with... | |
| recommendation for speaker wire to soften the highs if possible Strap a 4 ohm resistor and a 0.33uf cap wired in series across the speaker terminal/binding posts. That creates a very crude low pass that rolls off highs. Let your ears be the judge. Cost you $2 or so. Better than buying $500 snake oil. | |
| My Amp is Broken - Not Sure What to Do - Any Recommendations? 3 matched devices per phase per channel on the SD135.Usually you can get a matched triplet every 10 devices AT LEAST.Now if the SD135 had say 10 devices per phase per channel that’s a completely different story.Getting 3 devices to match is much m... | |
| My Amp is Broken - Not Sure What to Do - Any Recommendations? Not hard for a guru like you Ralph! But I have had the pleasure of dealing with botched jobs of those $25/h audio repair experts who couldnt figure the difference between emitter and collector that I think dealing with a 5 pin output device would... | |
| My Amp is Broken - Not Sure What to Do - Any Recommendations? Even the manual found online says the original devices are 3281D and 1302DReplace the defective channel's output devices with MATCHEDDG versions and you are good to go. | |
| My Amp is Broken - Not Sure What to Do - Any Recommendations? OP lucky you the schematic is HERE:https://elektrotanya.com/PREVIEWS/63463243/23432455/audio-research/audio-research_sd135_amplifier_sc...I bet not everything is toast likely 1 phase of 1 channel.Get a tech WHO KNOWS HOW TO MATCH OUTPUT DEVICES.Bu... | |
| My Amp is Broken - Not Sure What to Do - Any Recommendations? https://www.mouser.com/ProductDetail/ON-Semiconductor/NJL3281DG?qs=sGAEpiMZZMvFp%252byPHbnZYyVkaBWrH...3281D was INDEED obsolete.Original collateral dated June 2006http://www.onsemi.com/pub/Collateral/NJL3281D-D.PDFreplaced by 3281DG Same applica... | |
| My Amp is Broken - Not Sure What to Do - Any Recommendations? The parts did not go obsolete. Check OnSemi, aka ON Semiconductor who manufactures the parts. Audio Research EOLed the SD135 and HD220. |