Stereo guitar preamp

[Toxophilite]

So I've been ogling Hoffmans stereo guitar pre.
It uses more tubes than I would imagine seems to have 4 gain stages per channel with a bassman 5F6-a-like cathode follower tone control
I was curious as to the rational as even the bassman only seems to use 3 gain stages
Can someone explain it? Is it simply a matter of more gain?

Looks neat though
I might try something simpler though as I like to have a straight in guitar pre for recording late at night(in my apartment)


I've built several of these and used to use one all the time for quiet recording:
http://www.beyondsanityproductions.com/index.php?option=com_content&view=article&id=13:akai-roberts-preamp-mods&catid=18:diy-articles&Itemid=28


Which gives you two preamp channels , with one feeding into a SE amp
It was easy for me as there was essentially a cookbook like recipe for me to follow
Has anyone built one of these? they're useful. I sold my last one
Because of the time I spent here I think I could get the 12ax7 channel on one of these a little hotter which would be cool


However I think a Hoffman like standalone stereo pre would be even more useful and fun to build
Have to find or make an appropriate chassis

I have several PTs which might be appropriate I wonder how skookum they would have to be??

 I see my unit as basically running 2 12ax7 ( 2 Ab763 preamps)
Next I'd have to build a revibe!!..it never ends!!

[EL34]

You should link to the documents on my library page so the guys know what you are referring to
here's the link to the schematic
http://el34world.com/projects/images/stereopreampschematic.gif

My tube pre amp is just the pre amp out of a Marshall type amp and it has the same tone controls


V1B and V3B are just there so you could try and get less clean sound in the pre amp if you want thatVolume pots up - Master down

Or not, Volume pots down -  Master up to get a cleaner tone

On the PT, I already stock the PT I used on that project and the Re-Vibe

It's the Mojo779 on this page

http://hoffmanamps.com/MyStore/catalog/TransformersMobile.htm

[Willabe]

Your counting cathode followers (CF) as a gain stage. They are not.

[Toxophilite]

Right, sorry about that
Thanks for answering those questions
I'm completely unfamiliar with Marshall schematics, being a newbie, though I did know they came from the same source
I quite like the whole stereo pre and revibe combination you made!
THanks again!

[EL34]

There's a bunch in the schematic library
http://el34world.com/charts/Schematics/files/marshall/Marshall_50w_2204s.pdf

[Toxophilite]

Cool, and thanks
I'll check those out, i was looking at the 18 watt at one point but for my first few builds I've been pretty Fender-centric .