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 20 Jul 2018, 02:07

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 31 posts ]  Go to page Previous  1, 2, 3, 4  Next
Author Message
PostPosted: 24 Jun 2018, 06:57 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4894
Location: Australia
Pete D wrote:
Hi Woodo, yes this is a problem - getting a pleasing layout whilst satisfying the electronics!

Firstly I wanted my build to be symetrical for aesthetic reasons, secondly it had perform well as well as possible with short lead lengths etc etc. Very simplistic I know, but that led me to only one possible layout.

So my mains tx and choke were central, the choke being 20mm or so from the glass of the rectifier. The output transfomers were centrally right behind the 300B's (note the mains tx is rotated 90 deg). The resultant amp has no discernable noise/hum etc.

When I did my trial layouts I found that no commercially available chassis would quite give me the layout I wanted, so had to bite the bullet and make my own.

Pete

I remove the stickers from the Hammond trannies and stick them on the base plate. That way I know what trannies have been used where. The stickers are ugly.

_________________
Projects: "Lagoon" - tube preamp with cathode follower | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


Top
 Profile  
 
PostPosted: 26 Jun 2018, 04:03 
Offline

Joined: 13 Jan 2018, 21:33
Posts: 33
Location: australia
Thanks Mark. Luckily the Edcor stickers are provided separately. I hope to find a place to stick them that I don't need to use. The box I got is a touch small.

_________________
John


Top
 Profile  
 
PostPosted: 26 Jun 2018, 17:22 
Offline

Joined: 13 Jan 2018, 21:33
Posts: 33
Location: australia
I was a bit depressed to hear a fellow building what looks like the same pcb kit found the completed amp had insufficient volume. A few solutions were advised with the chosen one substituting the 6sn7s for different valves with more gain. If of interest see http://www.diyaudio.com/forums/tubes-va ... oject.html
Hopefully it's ok to mention another forum. My apologies if not.

_________________
John


Top
 Profile  
 
PostPosted: 26 Jun 2018, 18:14 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4894
Location: Australia
Woodo wrote:
I was a bit depressed to hear a fellow building what looks like the same pcb kit found the completed amp had insufficient volume. A few solutions were advised with the chosen one substituting the 6sn7s for different valves with more gain. If of interest see http://www.diyaudio.com/forums/tubes-va ... oject.html
Hopefully it's ok to mention another forum. My apologies if not.


Generally you can substitute a 6SN7 for 6SL7 which has greater gain.

_________________
Projects: "Lagoon" - tube preamp with cathode follower | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


Top
 Profile  
 
PostPosted: 30 Jun 2018, 19:53 
Offline

Joined: 13 Jan 2018, 21:33
Posts: 33
Location: australia
Some of those small resistors are close together on the pcb! Doesn’t help i’m all thumbs when it comes to soldering. The 750 ohm resistors on the 6SN7s don’t fit in the holes so i’ll need to source some others, they seem to be substantial resistors. photo to come

_________________
John


Top
 Profile  
 
PostPosted: 08 Jul 2018, 04:29 
Offline

Joined: 13 Jan 2018, 21:33
Posts: 33
Location: australia
Visit to Jaycar found the missing 750R for the cathode resistor for the 6sn7 (is that the right way to describe this resistor). I've noticed that a number of other circuits for the 6sn7/300b use a 470R at that spot and I wondered what effect that would have on the performance of the amp. A good grasp of ohm's law and load lines would be handy. Some pics works in progress. Neatness needs improvement and can't seem to get all the sockets in the perfect alignment but I'll keep forging on.


This post has a file attachment. Please login or register to access it. Only Registered Members may view attached files.


_________________
John


Top
 Profile  
 
PostPosted: 08 Jul 2018, 05:02 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4894
Location: Australia
Woodo where in Oz are you from? I'm Southern Vic.

_________________
Projects: "Lagoon" - tube preamp with cathode follower | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


Top
 Profile  
 
PostPosted: 08 Jul 2018, 21:51 
Offline

Joined: 13 Jan 2018, 21:33
Posts: 33
Location: australia
I'm in Brisbane Matt which today is a bit chilly considering the warm winter we had been having. I realise we don't know what cold is up here.

_________________
John


Top
 Profile  
 
PostPosted: 08 Jul 2018, 21:58 
Offline

Joined: 13 Jan 2018, 21:33
Posts: 33
Location: australia
Sorry, Mark I meant. I've been reading too many projects by you and Matt and got confused.

_________________
John


Top
 Profile  
 
PostPosted: 09 Jul 2018, 04:12 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4894
Location: Australia
I'm on the Sunshine Coast, Moffat beach at the mo.

_________________
Projects: "Lagoon" - tube preamp with cathode follower | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 31 posts ]  Go to page Previous  1, 2, 3, 4  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 10 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