Toroid 2 and PX (including bass focus) panel upgrades for U1-790!

One more chapter to my (above) SL 1 & 3 experience:
Now that I have the beyond spectacular A-1 PX Bass Focus w/ T2 transformers back and functioning my plan was to sell the A-3 PX T2 system… but the A-3 system sounds so excellent I can’t bring myself to selling/losing them…and “suffering” from sellers remorse. Where can I squeeze them into operation? Anyone selling some Sallies?

• This reply was modified 2 years, 1 month ago by WillB.

Very good to hear you upgraded Sunmoon95 and could not agree with you more…The Sound Lab group/family are first rate in their speakers and their support for us users.

1. About $2300 in 2013.
2. About $7500 in 2016 for original PX.
3. Backplates were sent to Sound Lab for upgrade so they kept old parts. Kept old cores for many years but eventually tossed them.
4. Very satisfied with both purchases. Improved bass response, sensitivity and tonal neutrality

I’ve had the following experience with two pair of Sound Lab ELS/backplates:

I believe sometime around 1997 I bought a used pair of A-1s (90 degree dispersion) that were manufactured in the early-mid 1990s. The backplates had already been upgraded to Toroid 1s. No crates.

I used them with Audio Research tube amplifiers until last year when the panels developed issues. I communicated with the excellent people at Sound Labs and the decision was to upgrade the panels to PX Bass Focus (BF).

Coincidently at the same time a pair of used A-3PXs (45 degree dispersion) with Toroid 2 backplates and crates were being sold nearby so I bought them and used the A-3 crates to ship my A-1 panels (out of the frame) back to Gunnison UT.

I found the A-3PX Toroid 2 system to be excellent sounding, although lacking the extreme low bass when compared to the larger A-1s. My plan was use the Toroid 1 backplates (from the A-1s) with the A-3PX and the Toroid 2 backplates with the ‘new” A-1PX BF system.

Shortly before the A-1PX BF were to be shipped back to me I compared the two pair of backplates on the A-3PX speakers. The following statement applies only to my old (over twenty-five years) Toroid 1 backplates because other Toroid 1s might sound different than mine.

Within seconds I realized (my ears told me) I could not live with the old backplates. I tried to listen again, the next day. Same result.

I called Sound Labs and worked out getting another set of the latest backplates. Thats my quick summary of my experiences.