Joule Electra preamps and amps. What is your impression?

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.

inna, I've owned a JE LA-150 with the phono stage for several years.  Most of that time it drove Parasound JC-1 monoblocs.  I never had issues with noise, even with low output cartridges.  I heard several JE amps over the years and always enjoyed their rich, musical presentation with the right speakers.  Most OTLs don't match well with low impendance models.  My speakers dropped to around 3 ohms at two different frequencies so the JE amps didn't work for me.  Also I live in SoCal without AC so heat was a concern.

I would also agree that Jud's retirement should not be an issue.  Rich at Signature Sounds is friends with Jud and has been a dealer for many years.  He continues to service and sell Joule Electra (used) products so prospective buyers and owners can have confidence.

My older Sound Labs are very difficult to drive, but newer ones are easier, so I am not best to opine on that.

Just a FWIW, sbank, there are some simple mods to the Sound Labs that make them a lot easier to drive and also better sounding regardless of the amplifier. Or you can just get the new backpanels for them.