DIY Audio Projects Forum
 NEW  Matt presents bias and operation data for the 6V6 tube in SE operation - 6V6 Single-Ended (SE) Ultra Linear (UL) Bias Optimization.

DIY Audio Projects Forum

Welcome to the DIY Audio Projects Message Forum. Use these forums to discuss Hi-Fi audio and to share your DIY Audio Projects. Registration is free and required to post messages and view the file attachments. Registration will only take a minute and registered users do not see any advertisements. After you have completed the online registration process, check your email (including spam/junk folder) for the verification email to activate your account. New members are under moderation - so your posts will not be visible until approved by a moderator. See the Read Me 1st, Forum RULES and Forum FAQ to get started on the forum.

It is currently 13 Dec 2018, 18:57

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 3 posts ] 
Author Message
PostPosted: 30 Jul 2013, 22:23 
Offline
Project Author
User avatar

Joined: 04 Jun 2008, 20:59
Posts: 3854
Location: Arizona, USA
Hi Everyone, Recent questions about the K-12 amps made me decide to see what I could do with some similar tubes. The production Alpha kit amp uses Russian 6F5P tubes which are like 6GV8 / ECL85. Having a shop full of parts to play with it seemed a good idea. (it actually was see later in the post) Anyhow when the amp was nearing completion I needed to drill a hole near one of the output transformers (a GXPP10 without bells). The drill press could not get to the spot so out comes the cordless drill. A heavy duty DeWalt that has a huge amount of torque (I have snapped the heads off several 1/4 inch bolts with it) The drill bits are quite aggressive and have a tendency to "pull" into what ever is being drilled. So fire up the drill and zing right into the windings of the transformer. &^%$%#@ No hope for the trannie a gouge about 1/2 inch deep and 1/4 inch in diameter. Trashed. At least I had another one. BTW the amp works quite well. It will become a project when I get to writing it up. Class A U/L PP much like a Poddwatt, but lower power. Much cheaper to build as well.

Good listening and happy drilling..... :censored:
Bruce

_________________
Some of my DIY Tube Amplifier Projects:


Top
 Profile  
 
PostPosted: 31 Jul 2013, 03:40 
Offline
User avatar

Joined: 08 Aug 2009, 03:11
Posts: 2229
Location: Chilliwack, BC
OUCH! Been there :bawling:

Shoot Brian an email.... he might send you a wound bobbin for your core :idea:

The bit you seek is a split-tipped drill bit. Mostly special order nowadays, but if you have a hardware store that's been standing for 40+ years, they might still have them on the shelf. These do not wander about at all :up:

Cheers!

_________________
-= Gregg =-
* Ratings are for transistors - tubes have guidelines*
Home: GeeK ZonE
Work: Classic Valve Design


Top
 Profile  
 
PostPosted: 31 Jul 2013, 08:09 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4988
Location: Australia
Bruce: that's God just grounding. You've been served.

I also have aggressive drill bits. The split bit idea could be a life (and tranni) saver. I have date with the drill press for most of tomorrow. Bruce, stay away!!

_________________
Projects: "Grace" - Psvane 6SN7-SE Globe preamp | | "VoXUno" - Single driver MarkAudio 12P speaker | | "Lagoon Take 2" - Single stage tube preamp | Website: retro-thermionic


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
DIY Tube Projects :: DIY Tube Amp Kits :: DIY Speaker Projects :: DIY Solid State Projects :: DIY IC / Op-amp Projects :: DIY Phono Projects :: DIY Cable Projects :: Hi-Fi Audio Schematics
© diyAudioProjects.com - Terms of Service - Privacy Policy