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In the Forum: Audio News
In the Thread: Lamm Industries: a special interview with a special company
Post Subject: DHTs and A2 operationPosted by Paul S on: 9/5/2008
Nice, primer, Romy. Thanks.
I had a pair of Wright WPA3.5s until last year. They are a very simple DHT (2A3) SET and that easily slips into A2. Although they use some sort of cathode follower-type loop of the 6SN7 driver's "pairs" to pump up the volume, they do not to my knowledge use any other form of feedback. IMO, these amps sounded by far their best in A1, but they could operate right up to the limit of A1 without problems, so there was a tremendous feeling of power and "ease" compared to other 2A3s. Once they went into A2, however, the distortion shot way up.
I am guessing that Lamm has arranged some sort of feedback to track and/or compensate for added distortion in A2 operation. He obviously has no special aversion to feedback, nor should he, IMO, based on prior results. After all, this amp is aimed at a certain target, and my guess is that this thing would provide a "solution" to the one-amp-per-channel connundrum faced by most checkbook audiophiles, given still-reasonably-efficient speakers (say, 95 dB).
It does seem, though, that people keep forgetting that one must at least double the amp's power to get each 3 dB of headroom, and that the conversion ratio is much worse at LF. Naturally they will be used on the big Wilsons, etc; but I would not recommend it (unless bi-amped!).
Best regards,
Paul SRerurn to Romy the Cat's Site