Lockdown Valve Amp

A place for DIY project discussions.
User avatar
SteveTheShadow
Posts: 1646
Joined: Thu Sep 12, 2013 5:24 pm
Has thanked: 272 times
Been thanked: 339 times
Great Britain

Re: Lockdown Valve Amp

Unread post by SteveTheShadow »

NOS Tung Sol, 6SL7 input valves in black glass:
2EB75117-74C6-45E2-8DB5-1D92578CB0C6.jpeg
2EB75117-74C6-45E2-8DB5-1D92578CB0C6.jpeg (104.06 KiB) Viewed 3373 times
Old short bottle Hitachis were on the way out, so needed replacing.
Somebody’s telling me the latest scandals.
Somebody’s stepping on my plastic sandals. Joe Jackson (1979)

User avatar
zebbo
Posts: 1738
Joined: Thu Jul 12, 2012 8:22 am
Location: As close to France as you can get.
Has thanked: 7 times
Been thanked: 28 times
Great Britain

Re: Lockdown Valve Amp

Unread post by zebbo »

I'll hijack this thread for a second, hope you don't mind. Just need to pick your collective brains. I want to replace the phono sockets on my Phono 3 as they are getting pretty loose. Although I don't have to touch any of the internal wiring apart from the actual sockets, I'm wary of touching anything that might be carrying some hefty voltage. The, BBPS's are still connected but switched off. Will everything discharge on it's own or can I do something to discharge everything? Cheers.

Image
These users thanked the author zebbo for the post:
Alfi (Sun Apr 12, 2020 9:09 pm)
Audio Grail "Sable" Garrard 401 with Cumbrian Green Slate plinth / Audiomods 6 / Benz Micro Gullwing SLR, Phono 2, NVA INT400sa. (Oh and a Copland CDA823 CD Player, for when I fancy a bit of the devil's spawn!) :lol:

User avatar
savvypaul
Posts: 8635
Joined: Tue Oct 11, 2016 7:14 pm
Location: Durham
Has thanked: 1657 times
Been thanked: 2978 times
Contact:
Great Britain

Re: Lockdown Valve Amp

Unread post by savvypaul »

zebbo wrote: Fri Apr 10, 2020 3:19 pm I'll hijack this thread for a second, hope you don't mind. Just need to pick your collective brains. I want to replace the phono sockets on my Phono 3 as they are getting pretty loose. Although I don't have to touch any of the internal wiring apart from the actual sockets, I'm wary of touching anything that might be carrying some hefty voltage. The, BBPS's are still connected but switched off. Will everything discharge on it's own or can I do something to discharge everything? Cheers.

Image
Send a PM to ithilstone (Tomasz)
I am in the hi-fi trade
Status: Manufacturer
Company Name: NVA Hi-Fi
https://nvahifi.co.uk/

Daniel Quinn
Posts: 8586
Joined: Thu Jul 12, 2012 7:16 am
Has thanked: 24 times
Been thanked: 399 times

Re: Lockdown Valve Amp

Unread post by Daniel Quinn »

Unplug it. Dont work on anything if its live.

Wait a day -overkill- for the caps to discharge.

Ps. Thanks for posting, very interesting.

valvesRus
Posts: 562
Joined: Sat Feb 24, 2018 2:34 pm
Has thanked: 25 times
Been thanked: 63 times
Great Britain

Re: Lockdown Valve Amp

Unread post by valvesRus »

Daniel Quinn wrote: Fri Apr 10, 2020 6:52 pm
Wait a day -overkill- for the caps to discharge.

Are you absolutely sure ?

Daniel Quinn
Posts: 8586
Joined: Thu Jul 12, 2012 7:16 am
Has thanked: 24 times
Been thanked: 399 times

Re: Lockdown Valve Amp

Unread post by Daniel Quinn »

There only 3400

valvesRus
Posts: 562
Joined: Sat Feb 24, 2018 2:34 pm
Has thanked: 25 times
Been thanked: 63 times
Great Britain

Re: Lockdown Valve Amp

Unread post by valvesRus »

Daniel Quinn wrote: Fri Apr 10, 2020 8:04 pm There only 3400
So you're not sure then. :)

Either test across them with a meter, or have a shorting lead with a resistor to bleed them down.

Daniel Quinn
Posts: 8586
Joined: Thu Jul 12, 2012 7:16 am
Has thanked: 24 times
Been thanked: 399 times

Re: Lockdown Valve Amp

Unread post by Daniel Quinn »

24 hrs is adequate.

Also if your going to introduce techniques, you need to explain them.

Lurcher300b
Posts: 933
Joined: Tue Jun 14, 2016 1:58 pm
Has thanked: 0
Been thanked: 16 times

Re: Lockdown Valve Amp

Unread post by Lurcher300b »

Should be safe 5 minutes after being disconnected. The caps are supplying op amps, so at most +- 20v. The op amps will keep pulling power when it disconnected until its discharged. There are no transformer in that box so no mains voltages to worry about.

valvesRus
Posts: 562
Joined: Sat Feb 24, 2018 2:34 pm
Has thanked: 25 times
Been thanked: 63 times
Great Britain

Re: Lockdown Valve Amp

Unread post by valvesRus »

Daniel Quinn wrote: Fri Apr 10, 2020 8:09 pm 24 hrs is adequate.

You are right Dennis.

But, better be safe than sorry.

Post Reply