Joule Electra preamps and amps. What is your impression?
It seems Joule Electra is not in business anymore: http://www.joule-electra.com/ If someone is interested on OTL preamps or AMPs, perhaps it is wise to choose a company which offers reliable customer service like Atma-Sphere. enjoy the music... |
Sbank, yes I saw it too. Atma-Sphere are expensive. Did I hear right that OTL amps require a very careful match with speakers ? In what sense? I read that some use them with big Sound Labs, Classic Audio's modern vintage speakers are apparently excellent match too. But that's big unusual speakers. How about common dynamic speakers ? |
OTL amps tend to have a high output impedance. That means that, if they are matched with low impedance speakers, particularly ones with an impedance curve with wide swings up and down, the frequency response of the speaker could vary quite a bit. The ideal speaker for all tube amps, particularly OTLs and SETs (which also tend to have highish output impedance), would be one with a high nominal impedance and a curve that is relatively flat. Theory aside, all speakers require careful matching of amps. I haven't noticed, in the setups I've heard using OTLs, any particular sensitivity of the OTL type; they tend to sound very good with a wide variety of speakers. |
Well said @larryi !!! Perhaps @atmasphere would care to share a list of some of the other brands that are popular with his speakers. IMHE, they include: Coincident Silverline Merlin Fried Harbeth Most speakers rated at 8ohms nominal have a good chance at working well. For those that want to use 4ohm speakers etc., Speltz Zeroformers are a popular solution, but not my personal cup of tea. My older Sound Labs are very difficult to drive, but newer ones are easier, so I am not best to opine on that. Cheers, Spencer |
Did I hear right that OTL amps require a very careful match with speakers ? In what sense? I read that some use them with big Sound Labs, Classic Audio's modern vintage speakers are apparently excellent match too. But that's big unusual speakers. How about common dynamic speakers ?Imagine a powerful SET and you have the idea of what an OTL needs in a loudspeaker (impedance of 8 ohms or more, particularly in the bass, no crazy phase angles). One of the most popular dynamic speakers with the Joule Electra and our amplifiers was the Merlin VSM. Audiokinesis is another, Coincident, Audio Note, Utopia, Spendors, etc. |
