Username:
Password:
BKP Home
Home
Help
Search
Login
Register
Bare Knuckle Pickups Forum
»
Forum Ringside
»
Tech
»
want to change amp from 6v6 to el84, having to simplify
« previous
next »
Print
Pages: [
1
]
Author
Topic: want to change amp from 6v6 to el84, having to simplify (Read 4431 times)
sgmypod
Welterweight
Posts: 3765
Truly bad since 1972
want to change amp from 6v6 to el84, having to simplify
«
on:
May 09, 2012, 11:07:45 PM »
aimed at amp blokes, would like valve, bases etc everything to do, is it possible obviously will have 6v6 or el84 in but have the two valve bases permanently connected. have provided schematic and drawing
«
Last Edit: June 03, 2012, 12:03:12 PM by sgmypod
»
Logged
Autotune My Arse
Crawler,nailbomb & Ltd Ed Emeralds, apache, now riff raff..EX- N/bomb, IT, Mquee
jpfamps
Lightweight
Posts: 767
Re: want to change amp from 6v6 to el84(leaving orig valve base in so can swap back)
«
Reply #1 on:
May 09, 2012, 11:20:02 PM »
We built a single ended amp with switchable EL84/ 6V6.
I think we used a DPDT switch to simultaneously lift the cathode on the unused valve and switch the filament supply off. This was with both valves connected to the OT.
By doing this we avoided having the unused valve on and wearing out, and avoided any switching of high voltages.
I could probably generate a schematic.
Logged
www.jpfamps.com
sgmypod
Welterweight
Posts: 3765
Truly bad since 1972
Re: want to change amp from 6v6 to el84(leaving orig valve base in so can swap back)
«
Reply #2 on:
May 10, 2012, 07:37:26 PM »
cool how much schematic and parts
Logged
Autotune My Arse
Crawler,nailbomb & Ltd Ed Emeralds, apache, now riff raff..EX- N/bomb, IT, Mquee
jpfamps
Lightweight
Posts: 767
Re: want to change amp from 6v6 to el84(leaving orig valve base in so can swap back)
«
Reply #3 on:
May 11, 2012, 05:19:25 PM »
I've composed a schematic and will try to remember to bring it into the workshop where I have internet access.
Logged
www.jpfamps.com
HTH AMPS
Middleweight
Posts: 5649
Re: want to change amp from 6v6 to el84(leaving orig valve base in so can swap back)
«
Reply #4 on:
May 11, 2012, 06:43:50 PM »
It'd be cheaper to buy an Epi Valve Junior, strip out the guts and wire it PTP.
The Harley Benton ones are the same, but slightly cheaper.
Logged
www.youtube.com/TeleCustom72
www.soundclick.com/bands/default.cfm?bandID=876738
www.facebook.com/pages/HTH-Amplification/263958270289235?sk=wall
sgmypod
Welterweight
Posts: 3765
Truly bad since 1972
Re: want to change amp from 6v6 to el84(leaving orig valve base in so can swap back)
«
Reply #5 on:
May 11, 2012, 07:57:43 PM »
Would have thought that would be more, would'nt I need to buy new trannies for them
Logged
Autotune My Arse
Crawler,nailbomb & Ltd Ed Emeralds, apache, now riff raff..EX- N/bomb, IT, Mquee
jpfamps
Lightweight
Posts: 767
Re: want to change amp from 6v6 to el84(leaving orig valve base in so can swap back)
«
Reply #6 on:
May 12, 2012, 11:49:12 AM »
Here's the schematic.
The resistors marked in blue probably aren't needed, and I wouldn't include them.
I've not included the screen grid circuit and guestimated the cathode resistor values etc.
Logged
www.jpfamps.com
sgmypod
Welterweight
Posts: 3765
Truly bad since 1972
Re: want to change amp from 6v6 to el84(leaving orig valve base in so can swap back)
«
Reply #7 on:
May 13, 2012, 12:12:48 AM »
Thanks frank, could you supply bits
Logged
Autotune My Arse
Crawler,nailbomb & Ltd Ed Emeralds, apache, now riff raff..EX- N/bomb, IT, Mquee
sgmypod
Welterweight
Posts: 3765
Truly bad since 1972
Re: want to change amp from 6v6 to el84(leaving orig valve base in so can swap back)
«
Reply #8 on:
June 03, 2012, 11:53:40 AM »
frank i have run out of, space and skill. so am going to just swap out 6v6 for the el84 (obviously swapping pins)
so with bits you sent need swapping on the original schematic
6v6 C9 22uf 25v (el84 100uf)
6v6 R9 470R 2w (el84 150ohm)
6v6 R8 10k (el84 1k)
6v6 R10 470r (el84 10k)
am i correct or miles out (as say will connect pins correctly on top of this)
Logged
Autotune My Arse
Crawler,nailbomb & Ltd Ed Emeralds, apache, now riff raff..EX- N/bomb, IT, Mquee
sgmypod
Welterweight
Posts: 3765
Truly bad since 1972
Re: want to change amp from 6v6 to el84, having to simplify
«
Reply #9 on:
June 06, 2012, 12:14:04 PM »
Was slightly out, thanks frank
Logged
Autotune My Arse
Crawler,nailbomb & Ltd Ed Emeralds, apache, now riff raff..EX- N/bomb, IT, Mquee
Print
Pages: [
1
]
« previous
next »
Bare Knuckle Pickups Forum
»
Forum Ringside
»
Tech
»
want to change amp from 6v6 to el84, having to simplify