DIY Audio Projects Forum
 NEW  Bruce Heran outlines the details and construction of his simple DIY 6DJ8 (ECC88) Tube Hi-Fi Headphone Amplifier Project.

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 01 Oct 2014, 19:19

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 99 posts ]  Go to page 1, 2, 3, 4, 5 ... 10  Next
Author Message
PostPosted: 21 Apr 2011, 16:48 
Offline
User avatar

Joined: 05 Nov 2010, 21:07
Posts: 658
Location: South East US - Tennessee
Oatley Electronics has updated their K282 RIAA phono preamp kit! The new kit now has a discrete power supply in place of the original SMPS. 110/240 VAC is supplied direct to the PCB instead of a wall wart.

I am going to build this kit and give it a try on my Pioneer MOSFET amp with a BSR TT (that I'm going to have to dig out of storage. I blame C.J. for this. ;) )

Check out the NEW Oatley K301 kit!

Image
I've got stacks of vinyl I haven't heard for years simply because I didn't have phono in jacks on my Pioneer surround amp and no descent phono pre-amp to use.


::
The FireFly is still on my project board. This phono preamp is just a little side track. :smoking:

_________________
The key to a successful build is to keep the smoke IN the circuit.
-Les

Science without religion is lame, religion without science is blind. - Albert Einstien
_________________________________
LM380 Bridged Guitar Amp, Oatley K301 Phono Pre-amp, Oatley K272 Headphone Amp, Tube proto-board
Current project: 6V6 "pseudo Champ" prototype
Still to come (On hold): 6CG7/12AX7 Guitar amp (modified FireFly)


Top
 Profile  
 
PostPosted: 27 Apr 2011, 12:27 
Offline
Editor
User avatar

Joined: 28 May 2008, 21:53
Posts: 4271
Location: Winnipeg, CANADA
Thanks for the heads up on this kit.

Too bad they don't perforate the PCB so one could detach the PS section so it could be located further away from the sensitive tubes and high gain circuitry. [Update - the updated kits now come with a separated power supply. viewtopic.php?p=26632#p26632]

Mark, have you had a chance to try out this new kit?

Cheers

_________________
[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]


Top
 Profile  
 
PostPosted: 27 Apr 2011, 16:54 
Offline
User avatar

Joined: 05 Nov 2010, 21:07
Posts: 658
Location: South East US - Tennessee
Gio wrote:
Too bad they don't perforate the PCB so won could detach the PS section so it could be located further away.............

Doesn't mean I wont find a way to do it otherwise. ;) The only problem I have with the integrated PS otherwise is the use of old school "brute force" regulation. The design is not particularly immune to ripple. My plan with this is to design an LM317T based regulator with enhanced ripple rejection. I've been able to accomplish super quite power supplies using the LM78xx, but I haven't tried that with the 317 and the 78xx series does not go above 24VDC. This pre-amp uses 30VDC.

BTW: Thanks for editing in the pic!

_________________
The key to a successful build is to keep the smoke IN the circuit.
-Les

Science without religion is lame, religion without science is blind. - Albert Einstien
_________________________________
LM380 Bridged Guitar Amp, Oatley K301 Phono Pre-amp, Oatley K272 Headphone Amp, Tube proto-board
Current project: 6V6 "pseudo Champ" prototype
Still to come (On hold): 6CG7/12AX7 Guitar amp (modified FireFly)


Top
 Profile  
 
PostPosted: 28 Apr 2011, 16:43 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 3786
Location: Australia
I have built two of the original kits and found both very good. Not just my opinion but a few audio club buddies really liked the preamp to. Wheather the SMPS or my DC version both performed extremely well.

I made the comment to Oatley that some do not like SMPS and so he has made this kit. Also he has sourced some tiny power trannies. Not sure I would like 240V AC so close to the phono cct. though.

_________________
Projects: "Parley" - Tube preamp with Pass B1 buffer | "VoXConcentriC" - Beyma high efficiency 12" speakers | "Black Lace" - all Ozzie tube 6V6 Power amp - old school
Website: [ retro-thermionic ]


Top
 Profile  
 
PostPosted: 07 May 2011, 11:26 
Offline
Editor
User avatar

Joined: 28 May 2008, 21:53
Posts: 4271
Location: Winnipeg, CANADA
Hi Mark, does the on-board transformer have any mechanical noise?

_________________
[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]


Top
 Profile  
 
PostPosted: 07 May 2011, 19:48 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 3786
Location: Australia
Gio: I don't have the latest kit on hand to know. If it is the same Tranni as in the tube buffer and I'll bet $1,000,000 it is, it runs dead quiet. They are incredibly small and take 120 or 240V.

_________________
Projects: "Parley" - Tube preamp with Pass B1 buffer | "VoXConcentriC" - Beyma high efficiency 12" speakers | "Black Lace" - all Ozzie tube 6V6 Power amp - old school
Website: [ retro-thermionic ]


Top
 Profile  
 
PostPosted: 09 May 2011, 09:38 
Offline
User avatar

Joined: 05 Nov 2010, 21:07
Posts: 658
Location: South East US - Tennessee
Finally received the kit Saturday, May 7.
Attachment:
k301 kit.jpg

Will start assembly this week.

I'm going to give the designed PS a chance to prove itself. If it turns out too noisey, it goes bye-bye. The PCB traces are such that I can cut the PCB and separate the PS from the rest, but I would lose 2 mounting holes and there really isn't room enough to bore 2 new ones. We'll see how it goes.

Paul sent 5 of the JAN6418 with the kit. This combined with the 10 I already have, I should be able to get 2 well matched pair and hopefully have a well-ballanced pre-amp.


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


_________________
The key to a successful build is to keep the smoke IN the circuit.
-Les

Science without religion is lame, religion without science is blind. - Albert Einstien
_________________________________
LM380 Bridged Guitar Amp, Oatley K301 Phono Pre-amp, Oatley K272 Headphone Amp, Tube proto-board
Current project: 6V6 "pseudo Champ" prototype
Still to come (On hold): 6CG7/12AX7 Guitar amp (modified FireFly)


Top
 Profile  
 
PostPosted: 09 May 2011, 16:41 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 3786
Location: Australia
Keep us informed.

_________________
Projects: "Parley" - Tube preamp with Pass B1 buffer | "VoXConcentriC" - Beyma high efficiency 12" speakers | "Black Lace" - all Ozzie tube 6V6 Power amp - old school
Website: [ retro-thermionic ]


Top
 Profile  
 
PostPosted: 10 May 2011, 08:54 
Offline
User avatar

Joined: 05 Nov 2010, 21:07
Posts: 658
Location: South East US - Tennessee
Most of the kit build is completed. I am now in the process of "tube matching". Oatley provided a procedure for doing that and it real straight forward - you're just measuring plate current draw. Of the 5 tubes provided, only 2 had a close match (2mA diff.) @ ~75mA. The remaining 3 were; 55mA, 66mA, and 110mA. As previously stated, I have 10 more that I have procured separately (via ebay). I will be testing those tonight. I want 2 closely matched pair, I have 1 so far. I don't care how close the 2 pair are matched.

Sorry, no pictures at this time.

_________________
The key to a successful build is to keep the smoke IN the circuit.
-Les

Science without religion is lame, religion without science is blind. - Albert Einstien
_________________________________
LM380 Bridged Guitar Amp, Oatley K301 Phono Pre-amp, Oatley K272 Headphone Amp, Tube proto-board
Current project: 6V6 "pseudo Champ" prototype
Still to come (On hold): 6CG7/12AX7 Guitar amp (modified FireFly)


Top
 Profile  
 
PostPosted: 10 May 2011, 15:51 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 3786
Location: Australia
mA or uA?

_________________
Projects: "Parley" - Tube preamp with Pass B1 buffer | "VoXConcentriC" - Beyma high efficiency 12" speakers | "Black Lace" - all Ozzie tube 6V6 Power amp - old school
Website: [ retro-thermionic ]


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 99 posts ]  Go to page 1, 2, 3, 4, 5 ... 10  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: Bing [Bot], Google [Bot] and 5 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 / Opamp Projects :: DIY Phono Projects :: DIY Cable Projects :: HI-Fi Audio Schematics
© diyAudioProjects.com - Terms of Service - Privacy Policy