User Feedback for Sophia
Electric 300B & 205D Mesh Plate Tubes
Just wanted to give you my impressions of your great Mesh tubes (205D and 300B 2.5V). As a dealer of fine vintage tubes for over 10 years, Lazy Lightning NOS Tubes, I have always had a fondness for mesh-plate tubes such as:
Telefunken RS237 (Typ I from 1937) and REN904
Marathon 245 and 250
Cardon 585 (mesh 50)
and the new-production AVVT 2A3 Nickel version.
I have also used these fine solid plate output tubes (All Globes)
Telefunken RV218 RV258 RV239 RS241 RE604 RE134 RE304
Osram PX4 and PX25
Mazda PP3/250 PP5/400
Electro-Mecano S-6 (ST)
WE300A and 300B 275A (Globe) , 205E (tennis ball)
RCA Single Plate 2A3 71A 12A 31 and many others...
Yesterday I used your 205D and 300B mesh and found them to have the delicacy and detail of my favorites while retaining the sweetness that I enjoy. Of all of these tubes above, yours are among the very best! I was astonished that Sophia has achieved the sound quality only achieved before with some of these 70 year old designs.
My favorite brand of tubes is Telefunken and only my mesh-RS237 sounded better overall than the 2 Sophia models. These tubes are worth well over $1,000 pair, so they should sound good. However, the WE205E are very valuable as well and here I preferred the Sophia Electric version (no doubt the mesh-plate contributed here to improved delicacy and detail).
Speakers are Edgarhorns with horn-sub (35Hz sub, 100Hz mid-bass with TAD 12", 300Hz round tractrix mid with TAD 4001, and Fane supertweeter).
Amp - I built an amp that allows me to use any DHT output tube (all of the ones above) , and any of 4 OPTs (3k Tamura F-5002 amorphous, 5k F-7003 Permalloy, Tribute 10k amorphous, and a custom pair of handmade German 3.2k Permalloy. Input tube is currently Valvo Red Series E80CC driving output tube through Tribute 10k:2k5 Inter-stage transformer.
Grant Gassman, Lazy Lightning NOS Tubes