Abnormal Current in SE EL84 on first power up

[JoeTele]

New. EH EL84 and Shuguang EF86 and 5AR4. That 2k2 is from my earliest modeling, and before I understood how little it would affect the EF86 plate in the real world. I'll revert to the 3k9 for the screen. That probably has a good deal to do with why I'm running hot, no?

Joe

[rp]

Listening to her now through the bass reflex enclosure/Fostex full range 4" 93db driver I built to go with it. Outstanding. Will post a full review with pics as some people on a different thread about it earlier back were interested... The volume is perfect for my apartment.

Crap - now I really want a 3-3/Fostex 4" mini system - which I totally don't need. And I need to get back to the States where there's still some modicum of disposable income - as long as there's enough for a little tube project every couple months I'd be content.

Strange all the build problems you had. All those Mullard circuits are supposedly very sensitive to layout, this may be one build where attention layout drawing is more important than the schematic. That starved EF86 supposedly doesn't tolerate much deviation, ditto the NFB circuit. From what I gathered reading through DIYAudio posts you can deviate but you have to really know what your doing. Knowing the quality of engineers Mullard had back then I would think you can't do much better than stock unless you just want to play around out of curiosity.

Looking forward to a sonic report. Picts of you little fostex box?

[JoeTele]

For sure! I just need to get it painted and looking nice. Should happen next weekend. Most of the problems started with the desire to sub in the 5AR4 for the EZ80 and perhaps ignorance on my part in prioritizing published voltages over component values, or just geeking out too much on the PSUD software. Perhaps I should have just chosen the dropping resistors to get the first filter cap voltage correct, left the stock component values beyond that, and let the voltages fall where they may? In any case, I will lower that screen voltage. Thanks for pointing me toward that Kanspea setup! It's what ultimately led me to 4" driver and box, and I swear it sounds like the band is practicing in that little box. And while I don't claim to have an audiophile ear, I seldom need to turn up the bass past the halfway point. That single driver/port tube set up is surgically suited to my small space lifestyle.

Will have the full report when everything is buttoned up and presentable.

Joe

EDIT: P.S. Spero che la vita italiana stia bene per te!

[martin manning]

Perhaps I should have just chosen the dropping resistors to get the first filter cap voltage correct, left the stock component values beyond that, and let the voltages fall where they may?

That should be the only change necessary to accommodate the rectifier tube swap.