It is currently Mon Mar 16, 2020 2:21 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 6 posts ] 
Author Message
Post subject: 5E3 Build Question
Posted: Fri Aug 08, 2014 4:07 pm
Offline
Aspiring Musician
Aspiring Musician

Joined: Sun Oct 27, 2013 7:11 am
Posts: 318
I'm just finishing up a 5E3 build and have a PT question. I'm using a Hammond 290AX and it's a direct replacement for an original as far as the wiring is concerned. I decided rather than grounding each individual socket to the chassis, (pins 9, 1 & 2) I would just use twisted wire and run them back to the lamp along with the heater. My question is, would this create a grounding issue by not connecting one of the green from the PT connected directly with the red/yellow to ground, being that it's grounded by way of the lamp anyway? Should I run a wire from the ground star to the lamp? Artificial center tap maybe, two 100 ohm to ground?

Thanks for any advice.

Image


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: 5E3 Build Question
Posted: Fri Aug 08, 2014 10:10 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Run the twisted green wires to the power lamp, first. Run a 100-ohm resistor from each leg to the chassis --- as long as the heater line does not have its center tap grounded.

Hook the heater wires to each green line. Be sure that the wires that go to the same heater pins on each 6V6GT. That is, pins 2 = one green line. Pins 7 = the other green line.

And the same wire goes to pins 4 & 5. The other to pins 9, of the 12AX7 and 12AY7. Wiring this way, will insure twisting the heater lines will cancel out hum most effectively.


Top
Profile
Post subject: Re: 5E3 Build Question
Posted: Fri Aug 08, 2014 10:38 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
BMW2002Ti wrote:
Run the twisted green wires to the power lamp, first. Run a 100-ohm resistor from each leg to the chassis --- as long as the heater line does not have its center tap grounded.

Hook the heater wires to each green line. Be sure that the wires that go to the same heater pins on each 6V6GT. That is, pins 2 = one green line. Pins 7 = the other green line.

And the same wire goes to pins 4 & 5. The other to pins 9, of the 12AX7 and 12AY7. Wiring this way, will insure twisting the heater lines will cancel out hum most effectively.


+1

Though it's AC, the heater legs are "phased" to a degree. Uniformity within the entire heater ensemble is vital for optimum noise-free operation.

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: 5E3 Build Question
Posted: Thu Aug 21, 2014 5:45 pm
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Thu Feb 19, 2009 8:33 pm
Posts: 457
Location: Bushnell, FL
I bet you paid a pretty penny for that MM and it only specs 2A on the heater and rectifier heater lines. Kind of cutting it close with not much room for substitutions. Glad I didn't use one. 1.8 A for the power tubes and .3A for the preamps = 2.1A used.

_________________
Charlie P 5E3 Build 6-14
2x12 cab Build 16, 5e3 Built 3-4-16
6G3 Head Build 3,3,18
Fend HSS Am DLX Strat 08
Fend MIM Telebot Dlx 11 Tronical Tuner
Fend SupSonic 60 2010
Gibson Robot 08, Gib. Faded Ch LP 07
Gret. G5420 16, Peavey VK112 08,


Top
Profile
Post subject: Re: 5E3 Build Question
Posted: Fri Aug 22, 2014 7:14 am
Offline
Aspiring Musician
Aspiring Musician

Joined: Sun Oct 27, 2013 7:11 am
Posts: 318
Actually it's a Hammond ($60), not a Merc Mag.


Top
Profile
Post subject: Re: 5E3 Build Question
Posted: Fri Aug 22, 2014 7:35 am
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Thu Feb 19, 2009 8:33 pm
Posts: 457
Location: Bushnell, FL
upnorth wrote:
Actually it's a Hammond ($60), not a Merc Mag.
My eyes are failing me.

_________________
Charlie P 5E3 Build 6-14
2x12 cab Build 16, 5e3 Built 3-4-16
6G3 Head Build 3,3,18
Fend HSS Am DLX Strat 08
Fend MIM Telebot Dlx 11 Tronical Tuner
Fend SupSonic 60 2010
Gibson Robot 08, Gib. Faded Ch LP 07
Gret. G5420 16, Peavey VK112 08,


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 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

Search for:
Jump to: