Bottlehead Forum

Bottlehead Kits => Mainline => Topic started by: Strikkflypilot on February 20, 2016, 09:23:51 PM

Title: Prototype Mainline on e bay
Post by: Strikkflypilot on February 20, 2016, 09:23:51 PM

Interesting offer of prototype Mainline on the bay.
No link here, not advertising, just curious about the upgrades

Edit: Appears to be gone already.

Title: Re: Prototype Mainline on e bay
Post by: JamieMcC on February 21, 2016, 08:26:50 PM

Yep I was scratching my head about those extra tubes and curious enough to save a pic for reference.

Title: Re: Prototype Mainline on e bay
Post by: Strikkflypilot on February 22, 2016, 11:27:30 AM

Thanks for the picture, Jamie!

Title: Re: Prototype Mainline on e bay
Post by: Doc B. on February 23, 2016, 12:22:59 PM

It is a 6C45 based headphone amp, but not really a Mainline. Too many differences (I would not call them improvements) to call it that.

Title: Re: Prototype Mainline on e bay
Post by: drewh1 on February 23, 2016, 03:18:40 PM

it is now up for sale on Audiogon. $1800  lot's of photos.

Title: Re: Prototype Mainline on e bay
Post by: Strikkflypilot on February 24, 2016, 08:38:48 AM

Quote from: Doc B. on February 23, 2016, 12:22:59 PM

It is a 6C45 based headphone amp, but not really a Mainline. Too many differences (I would not call them improvements) to call it that.

Thanks for the clarification, Doc.

Title: Re: Prototype Mainline on e bay
Post by: Paul Birkeland on March 10, 2016, 06:06:00 AM

I actually built this some years ago.  It roughly splits the time difference between Doc B's big headphone amp with the wood front and the current Mainline offered today. 

Title: Re: Prototype Mainline on e bay
Post by: mcandmar on March 10, 2016, 06:12:26 AM

I'm also really curious about that tube in the shield, is it a rectifier tube?

Title: Re: Prototype Mainline on e bay
Post by: Paul Birkeland on March 10, 2016, 06:22:48 AM

Yes, I was experimenting with small form factors, which necessitated the use of a power transformer with a little more voltage than I wanted.  One way to shed some of that extra voltage was with a rectifier tube.  (Hence some of Doc B's comments)  I have absolutely no recollection of why I put a tube shield around a rectifier tube, but it may have been in part to keep it in the socket while transporting the amplifier.