5150 JFET project?

[debutvm]

This is probably a gay topic but are there any 5150 JFET projects around? I would like to try and do one, but don't know how complex it would be..What are your guys oppionions on this? I have done 2 pedals so far, so my expierence is fairly low.

[John Lyons]

What does homosexuality have to do with a 5150 jet project??

[markm]

I think he meant it was "probably a HAPPY topic".
I mean......there are alot of posts  about problems with circuits and such here,
Perhaps this Gent feels as though we are fairly depressed here in our
little corner of the net.

[tcobretti]

In general, the ROG-style jfet pedals are more difficult to build than many fuzzes.  I would rate them as "medium" difficulty in the world of pedals.  The 5150 in particular looked fairly complex to me, which is why I was never tempted to build one.  I'm not saying you shouldn't build one; I'm just warning you that it may be your most challenging build thus far.

[debutvm]

Thanks for the input guys. Just was wondering if its too big to chew for me, and it sounds like it is. Oh well, perhaps after some more pedals I will give it a shot.

[petemoore]

  I'd get an overview of what makes the amp distort like it does, and if it's tubes that are doing it, particularly preamp tubes, building a Jfet version of it will look exactly as hard as the snippets of the schematic chosen for the transistor version, as 'simple' as replacing transistors into the tube positions and biasing and whatever else is decided on such as swapping Q's in the sockets and possibly modding it.
  Will it 'work'...yes, if all the rules are followed.
  Will it do exactly what you expect it to?..unknown
  Will it 'behave'?...maybe, being higher gain puts it at higher probability for oscillation or noise...ya never know.
  Is it a 'big' project?...fairly, working with individual stages makes getting each one working a smaller than the whole, not to say Jfets are always a breeze to get biased, but a working unit is possible.
  Checking out all the ROG texts and emu's will give you a good idea what's up with Jfet / Tube transferral schemata, and listening to the sound clips and 'eyeing the gain stages may help relating how increasing gain, or number of gain stages causes different types of distortion, voicing component placements and such.
 

[JimRayden]

Wow, just checked the amp's schematic and it looks like it would become a 8-10-stage FET circuit. Although it would be a nice project (along with the relay channel switching and all the EQ'ing), I'd recommend building a fuzz face first. Or a ROG Eighteen.

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Jimbo