L-100's in great shape, I'd say around $500 tops.
As to the upgrades to the 220's... I used Mundorf silver oil paralleled with Jupiter HT cross bread, so to speak, to the tweeters. 1uf each, adding up to 2uf for the tweeter circuit.
I used Jupiter Vintage Flat caps to the mids. 3 total. Parallel 8uf's for the 16.5uf, and another 8uf single at the end of the mid circuit. These are in the signal path directly.
I left all the other shunt caps alone, except for the electrolytic caps in the woofer circuit. I put a Sonicap Gen 1 here... Adding all these caps made things much more clear and coherent.
For the big 2.5mH choke to the woofer, I used a 12ga. Alpha Core copper foil inductor. This made a huge improvement. Took the nasal sound out of the speaker, and improved the bass response in all ways. This one is a must!!
All the resistors in the mid and tweeter circuits were replaced with Mills MRA-12's. Yes, I replaced them all with the 12W Mills, even the big 25 waters. No need for more than that, especially with the Mills resistors.
I believe this all costs around $900, and I got everything from Sonicraft. You may look into replacing the binding posts on the speakers as well. The JBL Twist Lock connectors suck.
The speakers that dethroned them are the Joseph Audio Perspective's. They are absolutely transparent and perfectly coherent. By design and costs they should be, but the JBL L220's are very damn good for the money and I do play them from time to time. They responded tremendously to the upgrades. Much more than I thought they would. The Joseph's are not as sensitive as the JBL's and I do miss that using the tube amps..
My amps are NOS Valves VRD Mono's, and the front end is all Bel Canto. The DAC3.5Vb MKII, Reflink USB/SPDIF Converter, fed from a 2009 Mac Mini with SSD and 8G Ram. The supply for the Mini is a Paul Hynes SR5-18.5. It sounds killer for sure.
