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 21 Aug 2018, 07:06

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 177 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6, 7 ... 18  Next
Author Message
PostPosted: 01 Nov 2013, 21:33 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4918
Location: Australia
A little off topic but inline with small caps, can anyone tell ma what dielectric Ducon used in these old small value caps. Is it Polystyrene, Polypropylene, Mylar, Polyester ??? I think it may be Polystyrene. The vales are 0.0033 and smaller.

And I see mustards are getting big prices on eBay. I have a few NOS and slightly used. What was the make-up of the mustards?

_________________
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: 10 Nov 2013, 20:51 
Offline
Project Author
User avatar

Joined: 04 Jun 2008, 20:59
Posts: 3749
Location: Arizona, USA
Hi Everyone, An update....I discovered that the equalization for audio tape players is rather easy to implement with this preamp. So I have attached a modified schematic that ought to work. I plan to try it tomorrow on a old Sony recorder that has really sick amps.

Good listening
Bruce
Attachment:
LOMC IC Phono NAB Preamp November 10 2013.jpg


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


_________________
Some of my DIY Tube Amplifier Projects:


Top
 Profile  
 
PostPosted: 10 Nov 2013, 22:31 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4918
Location: Australia
Lets try that again with the images this time:

A little off topic but inline with small caps, can anyone tell me what dielectric Ducon used in these old small value caps. Is it Polystyrene, Polypropylene, Mylar, Polyester ??? I think it may be Polystyrene. The vales are 0.0033 and smaller.

And I see mustards are getting big prices on eBay. I have a few NOS and slightly used. What was the make-up of the mustards?
Attachment:
PB022525.JPG


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


_________________
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: 11 Nov 2013, 11:14 
Offline
Project Author
User avatar

Joined: 04 Jun 2008, 20:59
Posts: 3749
Location: Arizona, USA
Catsup? No clue. way back though many used paper.

Good listening
Bruce

_________________
Some of my DIY Tube Amplifier Projects:


Top
 Profile  
 
PostPosted: 13 Nov 2013, 06:58 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4918
Location: Australia
Here is my take on Bruce's phono pre. On\off switch at the front left with yellow led below and battery test point on the right. On the rear two sets of RCAs for two TT with the selector switch between the two pairs. One set of output RCAs near 50\100ohm load selector for MC carts. and bottom switch is for MM or MC selection. The enclosure is heavy die-cast Al.This build is at enclosure only stage though I have all the parts to complete the project.

I intend to run the preamp on 4 X 9V batteries which will be held internally to provide +/-18V. OK lets talk about the colour. Firstly it is not yellow but according to the spray can it is Sunburst Gold. I will accept Lambogini Yellow. Stop laughing I'm serious!!
Attachment:
AssembledI.jpg
Attachment:
AssembledII.jpg
Attachment:
AssembledIII.jpg


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


_________________
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: 13 Nov 2013, 08:29 
Offline
Project Author
User avatar

Joined: 04 Jun 2008, 20:59
Posts: 3749
Location: Arizona, USA
Mustard?
Did you not the possible mod to use it for NAB tape head play back? It works great at that.

good listening
Bruce

_________________
Some of my DIY Tube Amplifier Projects:


Top
 Profile  
 
PostPosted: 13 Nov 2013, 15:49 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4918
Location: Australia
gofar99 wrote:
Mustard?
Did you not the possible mod to use it for NAB tape head play back? It works great at that.

good listening
Bruce

Mustard? Is that as good as you can do? How about puss? No tape EQ just some flexibility with inputs and MC loading. I don't have a huge amount of room once the four 9V batteries go in.

_________________
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: 16 Nov 2013, 19:00 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4918
Location: Australia
Cct. brd. is near completion just one or two components to go to drive the "on" LED. The prototype brd is only 1.75" square. I was going to use higher quality components but that would have made brd. assembly even harder. I chose small components which would fit on the brd. for a neat build. On board is the differential power supply resistive network. This will give me +/- 18V (from 4 X 9V batteries). The PS caps are LOW ESR 220uf\25V and output caps NPs. The resistors are metal film and other caps MKT and Mylar\polyester. Not supper high grade components but these will allow me to build a neat and compact unit complete with its own PS. With real estate being tight I go 3D and place components underneath the brd. Wire links (4 of) are all solid pure silver and silver solder used.

I have included a switch to switch between 50 and 100ohms loading for the MC stage which better suits my Ortofon Rondo Blue cart. I have added split soft rubber grommets to the sticky stand-offs and bituminous heavy Al foil to the lid and bottom of the cast Al enclosure to control resonance and vibration. Hope to have it up and going in the next day or so.
Attachment:
Isolation.jpg
Attachment:
CctBrd.jpg
Attachment:
CctBrdII.jpg


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


_________________
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: 16 Nov 2013, 22:24 
Offline
Project Author
User avatar

Joined: 04 Jun 2008, 20:59
Posts: 3749
Location: Arizona, USA
Hi Mark, You have to love those mini boards. Here they are sold by Radio Shack. I use them and "surf" boards rather often. If you normally use SUTs, the combination of SUT and preamp seem to sound better to me. Without the SUT mine reminds me of the Moon LP3 I have. Clean and accurate but not as lush as I would expect.

Good listening
Bruce

_________________
Some of my DIY Tube Amplifier Projects:


Top
 Profile  
 
PostPosted: 17 Nov 2013, 03:18 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4918
Location: Australia
Dick Smith here use to sell the but they got out of components etc. I have a stack of them. What is a SUT?

_________________
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  [ 177 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6, 7 ... 18  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