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 2019, 02:47

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 524 posts ]  Go to page Previous  1 ... 48, 49, 50, 51, 52, 53  Next
Author Message
PostPosted: 24 Jul 2019, 04:43 
Offline

Joined: 13 Jan 2018, 21:33
Posts: 231
Location: australia
not sure if the issue is temperature related? In the heater circuit after the bridge rectifier, i would have expected more than 6.1v rectified ac ie 6v * root 2 less voltage drop but that’s all I could muster. Hammond did suggest going to a 7v or even 8v transformer, but the 6.3v @2.5 amp has worked out ok i think and that is what the thermal design (heatsinks) is based on. I think I will go for that unless there are any reservations I should consider.

_________________
John


Top
 Profile  
 
PostPosted: 24 Jul 2019, 21:35 
Offline

Joined: 23 Feb 2017, 02:02
Posts: 559
7-8v Is deffintaley what you want, you need extra voltage head room so it can regulate properly
But of course comes at the expensive of increaced heat in the regulator


Top
 Profile  
 
PostPosted: 24 Jul 2019, 22:27 
Offline

Joined: 23 Feb 2017, 02:02
Posts: 559
Temeprature only reduces the output voltage at regulator input.
As long as you have enough voltage then is not a concern


Top
 Profile  
 
PostPosted: 31 Jul 2019, 20:22 
Offline

Joined: 13 Jan 2018, 21:33
Posts: 231
Location: australia
Thought I would post the circuit as currently stands for my build of this great sounding amp and prepare to move on to next project albeit slowly which I hope will be simpler and cheaper on vacuum tubes at least. Some differences to the circuit on page 33 are noted in the schematic. Have to order a new filament transformer that will reach 5v quietly. May try going back to the capacitors in the original circuit after the transformer arrives and put into the box . Thanks for all the input everyone. :up: If mistakes are spotted, happy to receive input.


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


_________________
John


Top
 Profile  
 
PostPosted: 31 Jul 2019, 22:16 
Offline

Joined: 23 Feb 2017, 02:02
Posts: 559
For the powersuplly, add a 0.1uF in parallel with the caps in all the filtered rails.
This will provide a low impedance path for HF and improve the sound quality
large caps have high inductance, dosen't work at HF


Top
 Profile  
 
PostPosted: 01 Aug 2019, 04:02 
Offline

Joined: 13 Jan 2018, 21:33
Posts: 231
Location: australia
Thanks mate. Will go to see my friendly Jaycar shop again. The staff will probably suggest I make a list, the number of times I have been in there lately.

_________________
John


Top
 Profile  
 
PostPosted: 02 Aug 2019, 04:56 
Offline

Joined: 23 Feb 2017, 02:02
Posts: 559
If you look at rs components you can get metalised polypropene hv caps for cheap.
Its unlikley jcar will have the voltage ratings your currently at I think

RS components does free shipping even if your buying $1 of components.


Top
 Profile  
 
PostPosted: 08 Aug 2019, 01:49 
Offline

Joined: 13 Jan 2018, 21:33
Posts: 231
Location: australia
Would there be any issues using the following filament transformer to supply the 5v regs?
https://au.rs-online.com/mobile/p/toroi ... s/6718937/
The price is good compared to the hammond 266L12 at about $55aud. No deliver charge either for the Rs components. Comments welcome. Thanks.

_________________
John


Top
 Profile  
 
PostPosted: 11 Aug 2019, 19:31 
Offline

Joined: 20 Feb 2014, 10:35
Posts: 59
Location: NZ
I've used Triad Magnetics transformers in similar applications, much cheaper than the equivalent Hammonds.
Mouser has F-344X 12.6V@2A A$22 and F-326X 12.6V@2.5A A$28.


Top
 Profile  
 
PostPosted: 12 Aug 2019, 01:36 
Offline

Joined: 13 Jan 2018, 21:33
Posts: 231
Location: australia
Chris65 wrote:
I've used Triad Magnetics transformers in similar applications, much cheaper than the equivalent Hammonds.
Mouser has F-344X 12.6V@2A A$22 and F-326X 12.6V@2.5A A$28.


Thanks for info Chris. Will check it out.

_________________
John


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 524 posts ]  Go to page Previous  1 ... 48, 49, 50, 51, 52, 53  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 13 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