New Posts New Posts RSS Feed - Valve questions from a total numpty
  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)


Valve questions from a total numpty

 Post Reply Post Reply Page  <1234 6>
Author
morris_minor View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 27 Mar 2012
Location: Surrey
Status: Offline
Points: 4531
Post Options Post Options   Thanks (0) Thanks(0)   Quote morris_minor Quote  Post ReplyReply Direct Link To This Post Posted: 03 Jan 2016 at 12:44pm
Thanks Graham.

BTW the tubes are Chinese 6n1 . . .

I think any explanation of biasing will go right over my head . . .Ermm
Bob

Majestic DAC/pre-amp
Accession MC/Enigma, Accession MM, Reflex M, Elevator EXP, Era Gold V
Solo ULDE, Novo, Lautus USB and digital, Libran balanced, CuSat50
2 x Proprius + Spatia/Spatia Links
Back to Top
Chris Firth View Drop Down
Moderator Group
Moderator Group


Joined: 16 May 2013
Location: Rossendale, UK
Status: Offline
Points: 755
Post Options Post Options   Thanks (0) Thanks(0)   Quote Chris Firth Quote  Post ReplyReply Direct Link To This Post Posted: 03 Jan 2016 at 1:15pm
The comment about capacitor discharge brings back memories of taking a guitar amplifier head in for repair.
The repair tech carefully removed the chassis from its cabinet and placed it upside down on the bench.
He then picked up a very large and well insulated screwdriver, and contacted it on the legs of the large reservoir caps, which emitted a very loud crack on each cap.

How loud was it?
I nearly soiled my undergarments.

The guy did explain to me that he had once started to work on an amplifier and he hadn't checked that the caps were discharged, and he got a belt off one of them that threw him against a stud wall.


Back to Top
morris_minor View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 27 Mar 2012
Location: Surrey
Status: Offline
Points: 4531
Post Options Post Options   Thanks (0) Thanks(0)   Quote morris_minor Quote  Post ReplyReply Direct Link To This Post Posted: 03 Jan 2016 at 1:37pm
This 1998 article from the IEEE is interesting . . .

Bob

Majestic DAC/pre-amp
Accession MC/Enigma, Accession MM, Reflex M, Elevator EXP, Era Gold V
Solo ULDE, Novo, Lautus USB and digital, Libran balanced, CuSat50
2 x Proprius + Spatia/Spatia Links
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: 8652
Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 03 Jan 2016 at 6:03pm
Originally posted by morris_minor morris_minor wrote:

This 1998 article from the IEEE is interesting . . .



Oh dear, another one taken away by the tube monster Sleepy

(only kidding... I hope Wink)

The IEEE claims to be the World's Largest Professional Association For The Advancement Of Technology.

I don't really claim anything but what I do is to try and find, tie down and overcome all the little things nobody else seems to want to talk about because it's not sexy. For example: parasitics which modulate the music signal and to be honest that's basically all I do. Pretty boring stuff to talk about and far from glamorous I know, and completely dead boring compared to glowing tubes. No way I could ever compete.

Did I tell you about the little parasitic oscillations on the output of a linear voltage regulator and how different implementations can make a night and day difference to your music? Of course I didn't, because it's so utterly boring. Nuff said.


Edited by Graham Slee - 03 Jan 2016 at 6:21pm
Not simple enough for Google-Bot to understand...
Back to Top
Fatmangolf View Drop Down
Admin Group
Admin Group
Avatar

Joined: 23 Dec 2009
Location: Middlesbrough
Status: Offline
Points: 5169
Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 03 Jan 2016 at 6:25pm
I have several guitar amps with valves in them and they sound great when used as expected. thermionic valves/vacuum tubes don't last forever and yes they should be powered down when not in use, the warmed up through standby before use.

My knowledge of valves is from repairing and modifying guitar amps. The supply voltages are pretty high so dangerous and I use discharge resistors not screwdrivers to make the chassis safe to work on!

Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
Back to Top
morris_minor View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 27 Mar 2012
Location: Surrey
Status: Offline
Points: 4531
Post Options Post Options   Thanks (0) Thanks(0)   Quote morris_minor Quote  Post ReplyReply Direct Link To This Post Posted: 03 Jan 2016 at 6:48pm
Originally posted by Graham Slee Graham Slee wrote:


Oh dear, another one taken away by the tube monster Sleepy

(only kidding... I hope Wink)
You can breathe easy, Graham - I'd no more have a valve amp for quality listening than chose Bose speakers . . Shocked

In my little bedroom system the amp comes downstream from a Novo, fed directly from a Raspberry Pi "squeezebox". The amp's only driving an old pair of Sony music system speakers anyway; it just makes a "pleasant noise" . . .Wink
Bob

Majestic DAC/pre-amp
Accession MC/Enigma, Accession MM, Reflex M, Elevator EXP, Era Gold V
Solo ULDE, Novo, Lautus USB and digital, Libran balanced, CuSat50
2 x Proprius + Spatia/Spatia Links
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: 8652
Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 03 Jan 2016 at 7:06pm
Originally posted by morris_minor morris_minor wrote:

it just makes a "pleasant noise" . . .Wink


Of course it does Bob, just like "Cathode Ray" (RIP) explained it would in a very old issue of Wireless World.

(https://en.wikipedia.org/wiki/M._G._Scroggie)
Not simple enough for Google-Bot to understand...
Back to Top
 Post Reply Post Reply Page  <1234 6>
  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 0.094 seconds.