mike stehr

We used to drink Carling Black Label

One may get 10,000 hours out of a actual Mullard El84 if you run it real light. Those sort of hours apply more to preamplifier tubes.

I once found a 71A laying next to a trash can at a vintage garage sale once...tested strong, like it was new. Years ago, I bought a NOS GE 2A3 H plate from a friend for 50 bucks. I finally found a mate at a garage sale for two bucks four years ago. It tested just as strong as the NOS tube. 71A should still be found for reasonable prices as NOS. Or get an adapter socket like A1UC mentions and use 46. 46 can sound just as good as a 45 and can be had for a cheaper price. (never have heard 46 however)

Mine is a kit as well. The price for a 5AR4/GZ34 rectifier in 1961-62 was 4.50 to 5.00 bucks. At least the tubes came with the kit... I have my Eico ST70 currently on the bench, and will follow the Tronola mods.

I doubt the suspect amplifier issue is from clipping....as both should start clipping at the same point/time. You swapped the amplifiers and the problem went away, after ruling out everything else with regard to speakers, power tubes, driver tubes. Considering you recently purchased the amplifiers new, I would get ahold of Mike Sanders. He may help with you with troubleshooting/diagnostics, and give him an idea what's wrong with the suspect amplifier.

DG is Dave Gillespie. Dave is no slouch when it comes to tube audio. He seen/read all the hype on AK about these little Magnavox 8600 series console amplifiers. Curious, he picked up one to see what the big deal was about. He wasn't too impressed with a bone stock Magnavox circuit, so he built his own...DG-SE1. My friend up north picked the EFB (enhanced fixed bias) circuit for a Dynaco ST-35 amplifier project. He really likes how the EFB works with the amplifier, and very very happy with the sound. Daves Store: Dynaco SCA-35 ST-35 EFB Upgrades and Restoration (tronola.com)

Hybrid implies either solid state devices, (transistors) used for output, and vacuum tubes for preamplifier stages. Or the output stage uses vacuum tubes, with solid devices for the front-end (preamplifier) stages.

Yugo wiring harness...

meh

Fabricating cabinets would be the cheapest part of the whole project

That's a screaming deal. GLWS.

Mark Deneen

The "original" caps that came with the guy's Cornwalls are the motor run oil capacitors that were used at the time. From what I can gather from him explaining that the "original" caps are physically leaking. The "Correct" cap for replacement which has been authorized by Klipsch is the TI brand polyester capacitors sold by JEM. IMO...

Arthur Brown - Fire 🔥 (1968) - YouTube

Check this one out. Some serious glass blowing work in this vid... Philips Factory Thirties - YouTube

They both appear to be radios.

Microsoft Word - CX12A90.DOC (amkspeaker.com)

Don't see any practicality having a 12" coaxial for the bottom driver...maybe a 12" woofer on the bottom and a 12" coaxial on top. Keep in mind this was suggested design/build plans in 1952 for the line of Jensen drivers at the time, from the G-610 triaxial on down. I don't think Jensen ever commercially produced this suggested BLH design. They did with the Imperial...but I'm not sure about this corner version. The BL250 tri-plex (and variants?) were commercially produced, and also had design/plans in the 1956 catalog under Ultraflex. I have a pair of the CT100 Concertos made from plans, which is just the plain stripped down version of the BL250. These were the days of mono, with the cabinet in a corner of a big open house, playing big band music...boom was king.

RIP Bob....Cornscala lives!

But I'll need $400 for Bondo...

Offer to haul them off for free

I would stick with the plans for 12" drivers at 27" height...unless you want to eventually build another motorboard for 15" drivers. My cabinets are more in line for 12" drivers at 30" tall. The full height for 15" drivers is 36.5"...a bit more area than 30". I have no idea how a 12" driver would work in a Jensen BLH cabinet for 15" drivers...but I do know my cabinets are too small for 15" drivers. There was bad peaking issues around 300Hz with a 15" driver. https://www.diyaudio.com/forums/multi-way/169755-cabinet.html

ZZ (GZLOZONE) EAR834 clone awaiting PS transformer.