EF86 pre & parallel SE build Pics

[tubeswell]

I wanted to try Merlin's morph control as well so I was just wondering if I needed a triode as well (before or after EF86?). I think that you have answered my question with your diagram. Many thanks.

Fun isn't it? I find the extra triode makes it act like a 'normal' champ/princeton with the morph control in triode mode, and in pentode mode its a screamin' piece of rock'n'roll with 6V6s, or with the 6F6 or the 6L6 it adds more flavour to the clean tones for a bit further on the dial (but it all breaks up in the end).

Seeing as how the Weber PT I put in it has 350-0-350 and 280-0-280 taps on the HT winding, I installed an HT hi-power/lo-power switch this afternoon, and have updated the idle voltage notes with a variety of output tube and rectifier tube types (see posted pdf) altho' I am still too scared to run a 5U4G in there on the 350-0-350 tap. As it is with the 350-0-350 tap, 2 x6V6s are idling at max with just a 5Y3G.

(If you are ever in NZ, don't be shy to look me up. You can help me cart my truck load of amps to the local blues club - if its the last Thursday night on any given month, that's jam night where anything goes)

BTW what is the 'ball and socket' in the top left hand corner of the trem circuit?

It is slang for a RCA jack but I just used a phono jack in the end - I s'pose I should correct that.

[tubeswell]

Did some 'proper' soundbytes tonite, through an SM57 and my desk into garbageband on the mac.

Most of the tracks were with the morph control at 50% and the treble dimed, which gave me a tone that I quite fancied, so I might have to think about decreasing that first coupling cap or trying a different tone stack or something

(Edit - Going to 4n7 on the first coupling cap did the trick.)

[cminor9]

I saw this post when you first started a while back. Then yesterday I was sitting there thinking how much fun it would be to build some single ended high gain amp. Maybe an ef86 front end and an el34 power section. Then I re-found your thread. Looks like I have a starting point now. Thanks tubeswell! Nice looking amp, as always.

[tubeswell]

Trem sounds with the 6L6 on board on the low (280-0-280) HT tap with a 5U4G rectifier. Slight change to the trem circuit from previous - a .03uF cap where the .02 cap was initially

Updated schemo also attached

[tubeswell]

FWIW I sold this amp in April, and have just finished a Push pull version along similar EF86 preamp lines. here:

EF86 with morph control in PP gigging amp

[teleDex]

Hi, For some reason I can't get the pdf to download by clicking on the link. Can you send it to me via this forum, or if not, via email?

Thanks!

[tubeswell]

Yeah somethings happened to the attachments. I may need to update my subscription. Try this attachment

[big_teee]

Yeah somethings happened to the attachments. I may need to update my subscription. Try this attachment

I can't open the pdf file.

[tubeswell]

Well I don't know what's going on because it opens fine with adobe reader at my end; Here's a link to a .jpg of the same sort of thing

[tubeswell]

And here's a word document with the voltages noted

[big_teee]

I now see everything but the PDF.
One of the problems that we have been having, probably!

[teleDex]

Thanks!

Same problem with pdf (probably on my end), but JPEG serves the purpose. I had an old JPEG of this design but most of the text on it was illegible. My immediate purpose is to modify my Champ clone to run a 6L6 with a little more headroom, using your power supply and output stage as my starting point.

Any comments are welcome.

[tubeswell]

Remember that 6L6s draw 900mA of heater current, and you want to allow about 100mA peak DC current draw on the PT HT winding (and any HT choke) and OT primary. If you use a slightly bigger SE OT than a standard champ OT, that will sound better. Also I prefer 6L6s in SE when they are running quite low plate voltages (but high current), and with a 10" speaker. YMMV

[thehoj]

The pdf's as well as mp3's don't seem to work for me.. :/ Was kind of hoping to hear this thing.
The jpeg's work.

[tubeswell]

Stuck some mp3s up again