New Posts New Posts RSS Feed - "Green" Reflex Tweak
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Welcome to the Graham Slee Audio Products Owners Club

 

Open to all owners plus those contemplating the purchase of a Graham Slee audio product wishing to use our loaner program: join here
Subscribe to our newsletter here (Rules on posting can be found here)


"Green" Reflex Tweak

 Post Reply Post Reply Page  123>
Author
Graham Slee View Drop Down
Admin Group
Admin Group
Avatar
Telling it as it is

Joined: 11 Jan 2008
Location: South Yorkshire
Status: Offline
Points: 13439
Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Topic: "Green" Reflex Tweak
    Posted: 15 Jan 2008 at 4:23pm
This is a tweak for the few owners of the pre-release "green" Reflex who bought via the Rockgrotto offer, and applies to those phono preamps shipped before today's date (15th Jan 2008).

It requires a simple value change to a resistor in the discrete voltage regulator section. There is a bank of 5 resistors and a diode above one of the op-amps. The resistor furthest away next to the diode is currently 470R. It should be changed to 1k. It's a good idea to use a Welwyn TI MFR4 type which is the type used throughout the design. After modifying the board it is wise to check the voltage across the series zeners (located in the centre of the pcb) which should be 18.2V plus or minus 5%.

I'd detected a very slight "sizzle" on some vocals and instruments like saxophone and decided it must be an artefact of the switched-mode power supply. The tweak reduces the zener current sufficiently to curtail this subtle distortion.

If owners can't detect anything like I've described, not to worry, the unit will carry on working without this mod.
Not simple enough for Google-Bot to understand...
Back to Top
Sol View Drop Down
New Member
New Member


Joined: 14 Jan 2008
Status: Offline
Points: 28
Post Options Post Options   Thanks (0) Thanks(0)   Quote Sol Quote  Post ReplyReply Direct Link To This Post Posted: 15 Jan 2008 at 8:33pm
Blimey .. give me a chance Graham - I haven't even plugged the thing in - it having just arrived today Wink
Semper in excretum, nil profundum variat.
Non illigitimum carburundum!
Cuius testiculos habes, habeas cardia et cerebellum
Back to Top
John C View Drop Down
Admin Group
Admin Group

gspaudio moderator

Joined: 13 Jan 2008
Location: Sheffield
Status: Offline
Points: 170
Post Options Post Options   Thanks (0) Thanks(0)   Quote John C Quote  Post ReplyReply Direct Link To This Post Posted: 16 Jan 2008 at 12:02am
Don't worry Sol, he does it to me all the time....
 
Oh!! hello Graham, didn,t see you there....Embarrassed LOL LOL
Back to Top
hooograa View Drop Down
New Member
New Member


Joined: 19 Jan 2008
Location: Australia
Status: Offline
Points: 3
Post Options Post Options   Thanks (0) Thanks(0)   Quote hooograa Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jan 2008 at 12:31pm
Being the holistic person you are Graham what kind of solder do you use? I've got some plain lead and some silver/lead types. As I can vaguely remember electrical differences and interference being a bugbear that you had to fight in development. Thanks David
Back to Top
Graham Slee View Drop Down
Admin Group
Admin Group
Avatar
Telling it as it is

Joined: 11 Jan 2008
Location: South Yorkshire
Status: Offline
Points: 13439
Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jan 2008 at 2:50pm
Hi David,
 
We use Multicore 99C which is mainly Tin with a trace of Copper. Lead is a banned substance in European Community and Californian consumer electronics manufacture. 99C was the best of the Lead-free solders I could find - the rest gave "dry-looking" joints. Even after using Lead-free since 2004, I miss the Lead based solders for their ability to flow out properly and desolder when required with great ease. Visit most European assemblers or repair shops and you should hear numerous exclamations of "solder you bas****!" from extremely frustrated staff...
Not simple enough for Google-Bot to understand...
Back to Top
John C View Drop Down
Admin Group
Admin Group

gspaudio moderator

Joined: 13 Jan 2008
Location: Sheffield
Status: Offline
Points: 170
Post Options Post Options   Thanks (0) Thanks(0)   Quote John C Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jan 2008 at 2:59pm
Originally posted by Graham Slee Graham Slee wrote:

Visit most European assemblers or repair shops and you should hear numerous exclamations of "solder you bas****!" from extremely frustrated staff...
 
I'll second that one. I know Leo will agree too LOLLOL
Back to Top
ServerBaboon View Drop Down
Senior Member
Senior Member
Avatar

Joined: 16 Jan 2008
Location: NW England
Status: Offline
Points: 945
Post Options Post Options   Thanks (0) Thanks(0)   Quote ServerBaboon Quote  Post ReplyReply Direct Link To This Post Posted: 28 Jan 2008 at 11:21pm

Have noticed what seems to be a bit of distortion on a couple of old 60s tracks (repressing/reissues not originals) especially with some Saxaphone which I took to be a bit of overload in the studio does it manifest in loud parts or climaxes or is noticable in quieter passages?

To be honest I am sorting out getting a new cartridge as mine is quite old and so I have also wondered if its this. I will compare with my Gram amp 2SE.



Edited by ServerBaboon - 28 Jan 2008 at 11:23pm
Back to Top
 Post Reply Post Reply Page  123>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.01
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.078 seconds.