Topic: DIY tube preamps?

[drewloo]

Has anyone tried any of the DIY tube preamp kits?

I'm looking at this one:

Bottlehead Foreplay III
http://www.bottlehead.com/et/adobespc/foreplay3/foreplay3.htm (the top of the page might be NSFW for some people)

This looks like it should be within a  abilities & looks like a fun way to learn more about audio electronics beyond basic cable construction.  Also, there seems to be a lot of support in forums & individual enthusiest sites.

Another kit that caught my eye was this one: Welborne Labs ULTRAPATH bp http://www.welbornelabs.com/ultra.htm

It's all DC-powered & can be ordered as a 'nude' kit without the chassis (make your own) for less $.  The fact that it's all DC of course made me think of how it could be used in the field for recording, especially if one built a chassis made for protection/portability, but I imagine taking tubes in the field wouldn't be a really bright idea.  Looks like it might be a little bit more involved than the Bottlehead, too. 

I also considered a YS-Audio pre but the idea of making it myself is really apprealing.  Anyone tried something like this yet?  thanks

[BobW]

The Foreplay is simple and likes to be tweaked alot.   

I use an original Foreplay (Model I with filament snubber, cascode bias current tweak and stepper) to warm-up the output of my CD player.
There is a difference with tubes.

There are great forums for Wellborne and Bottleheads linked off their websites.

There is an interesting off-beat Pre to consider as well, not a kit:
N0rh ACA 2b

Hard to find a review, harder to find one to hear.
You can always ask at the user's group

[drewloo]

The Foreplay is simple and likes to be tweaked alot.   

I use an original Foreplay (Model I with filament snubber, cascode bias current tweak and stepper) to warm-up the output of my CD player.
There is a difference with tubes.

There are great forums for Wellborne and Bottleheads linked off their websites.

There is an interesting off-beat Pre to consider as well, not a kit:
N0rh ACA 2b

Hard to find a review, harder to find one to hear.
You can always ask at the user's group

Cool, thanks.  Interesting line of products they have.  Those norh speakers sure are a trip.  I'd be scared sh!tless that I'd drop a marble one.

[BobW]

Cool, thanks.  Interesting line of products they have.  Those norh speakers sure are a trip.  I'd be scared sh!tless that I'd drop a marble one.

And they ship out of Thailand !  Long haul for heavy and delicate stuff.

[Frank M]

Another kit that caught my eye was this one: Welborne Labs ULTRAPATH bp http://www.welbornelabs.com/ultra.htm

It's all DC-powered & can be ordered as a 'nude' kit without the chassis (make your own) for less $.  The fact that it's all DC of course made me think of how it could be used in the field for recording, especially if one built a chassis made for protection/portability... 

Keep in mind that like all preamps that are designed to drive an amplifier, it won't have nearly as much gain as a microphone preamp.  At best you could use it as a buffer between a mic pre and A/D converter.

The Foreplay is probably simpler to build, and as you've noticed, there's a LOT of user support out there.

[drewloo]

Keep in mind that like all preamps that are designed to drive an amplifier, it won't have nearly as much gain as a microphone preamp.  At best you could use it as a buffer between a mic pre and A/D converter.

Yeah, the only way so far that I could think of to run the Welborne w/ mics is:  mics>ps2>transformer>Welborne>adc

Not really sure how it would sound but I'd still like to try it someday. 

And they ship out of Thailand ! Long haul for heavy and delicate stuff.

Did you see on their webiste they say they lose 30% of the marble drums in the manufacturing process & that each drum starts out as an 800lb. block?  Ouch.