Very nice! A couple of questions: what is the sensitivity of your speakers and why the PP Lamms instead of the SET ML2.2?
Hi,
They are 95DB but are a 4 ohm load. The JBL M2 compression driver gives 22K - 800hz sound, but it is not as efficient as most compression drivers. I'd love to try the ML2 but I'm worried that they won't be able to control the 15" drivers.
Well, the compression driver is probably being padded down to match the woofers, which I guess are wired in parallel to get the sensitivity up to 95db. Its not really the power that determines whether or not an amp can control the woofers, nor the size of the woofers, which all things being equal, are more sensitive than smaller drivers. What it does have a lot to do with is the box loading and what the overall Q of the bass system is. If it is a relatively high Q, meaning somewhat underdamped, then an amplifier with a highish damping factor might be needed not to have too big a hump in the bass. If it is critically damped or overdamped then an amplifier with a low damping factor (like most SETs) will work very well.
My Odeon horns are a good example of a speaker that actually makes better bass with a low damping factor amplifier. A typical SS amp damping factor makes the speaker sound bass shy and even thin through the midbass because now you are putting a lot of electrical (over)damping on a speaker that is already well damped from the bass horn. As your speakers are bass reflex it means that the devil is in the details how that design was executed and whether or not they put a bit of "juice" in the bass with a highish Q or not. I know old Wilson X1s sounded awesome with a good SET because they were 95db sensitive and had a well damped bass tuning on the big 15 inch woofer in a big vented box. Apparently, the XLFs also sound great with SET (I haven't heard them this way though).
We also drive our Dynamikks! Monitor 12.18 mkII with either 25 watt or 60 watt SET from Aries Cerat. This speaker also has a large woofer (18 inches) in a vented box that has variable damping. We have set for a somewhat underdamped response and then with a SET we get phenomenal bass that is tight, punchy and deep.
The Lamm ML2 has no issues delivering power into 4 ohms...maybe to 2 ohms an below it could be a problem but not at 4 ohms. That said, I am sure the ML1.1 is a great sounding amp with those speakers and will have more headroom but damping on the speaker is probably similar with both amps (most PP tube amps don't have significantly lower output impedance than SETs).
Very nice Jeff !
Nice Jeff, and looks lovely. How does the Edgar horn system sound compared to yours? Are these Edgar and tannoy autograph guys in your area?
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