Phosephene Marshall Four Hole Style Head

Make it loud here.
User avatar
HNB
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 13513
Joined: Tue May 10, 2011 7:55 am
Location: Puyallup, Washington
Contact:

Phosephene Marshall Four Hole Style Head

Post by HNB » Wed Oct 21, 2020 11:41 am

I got this cool 50 watt head in trade from fever606 :)
fever606 wrote:
Tue Aug 25, 2020 5:36 pm
"like a Marshall 1959/1987 4 hole circuit, but with only one input jack, feeding both the bright and normal channels, in parallel". Partridge transformers from a Sound City head.”
It is really cool. I got to get a look at its guts when trying to figure out why the master volume pot wasn't doing anything. Turns out it is a push pull so if it isn't pulled out, it doesn't do anything. :) I think it needs new power tubes. When I cranked both channels with master volume low I was getting good distortion and then I noticed popping noises and the tubes were flickering with the popping sounds. The bright channel is cool, but much noiser than the other channel. I like being able to blend the two channels or have one up or the other. :) Here are some pictures for the people more techy than me.

ImageIMG_20201016_160534 by Christopher Louck, on Flickr

ImageIMG_20201016_153451 by Christopher Louck, on Flickr

Image2020-10-21_12-40-01 by Christopher Louck, on Flickr

ImageIMG_20201016_152940 by Christopher Louck, on Flickr

ImageIMG_20201016_152951 by Christopher Louck, on Flickr

ImageIMG_20201016_152958 by Christopher Louck, on Flickr
Last edited by HNB on Thu Oct 29, 2020 5:27 pm, edited 1 time in total.
Christopher
Lilith Guitars

User avatar
fever606
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 1146
Joined: Sun Oct 17, 2010 3:03 pm
Location: district of columbia

Re: Phosephene Marshall Style Head

Post by fever606 » Fri Oct 23, 2020 11:36 am

It’s a cool one for sure, glad it found a good home! Like most 4-input amps, blending the channels is where the magic really happens... this just saves you a cable! :D

User avatar
marqueemoon
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 7343
Joined: Mon Jun 20, 2016 9:37 pm
Location: Seattle

Re: Phosephene Marshall Style Head

Post by marqueemoon » Fri Oct 23, 2020 12:05 pm

Those caps are not messing around.

User avatar
HNB
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 13513
Joined: Tue May 10, 2011 7:55 am
Location: Puyallup, Washington
Contact:

Re: Phosephene Marshall Style Head

Post by HNB » Fri Oct 23, 2020 1:10 pm

They are like D batteries. LOL
Christopher
Lilith Guitars

User avatar
HNB
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 13513
Joined: Tue May 10, 2011 7:55 am
Location: Puyallup, Washington
Contact:

Re: Phosephene Marshall Style Head

Post by HNB » Thu Oct 29, 2020 5:27 pm

I am going to replace the tubes when they come in. I got two matched Mullard EL34's to replace the JJ 6CA7 power tubes. I also ordered a set of three Mesa Boogie 12ax7's for the preamp. Hopefully they work. :) I am hoping it was just those JJ's time to go and not something wrong I did. (Cranking channel one and two together and using the master volume to have it living room volume.)
Christopher
Lilith Guitars

User avatar
fever606
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 1146
Joined: Sun Oct 17, 2010 3:03 pm
Location: district of columbia

Re: Phosephene Marshall Four Hole Style Head

Post by fever606 » Fri Oct 30, 2020 4:17 am

I’ll say those JJs had some life on them - not a particularly hard life as it was used almost exclusively for recording but they’ve put in time.

Which is another way of saying turning both channel volumes up and taming with the MV is precisely how this amp was meant to be run. The fact that I never bothered with the MV (how did I not know it was a push/pull? :fp: ) is no shade against the amp...

User avatar
HNB
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 13513
Joined: Tue May 10, 2011 7:55 am
Location: Puyallup, Washington
Contact:

Re: Phosephene Marshall Four Hole Style Head

Post by HNB » Fri Oct 30, 2020 8:24 am

When I cranked both channels the tubes popped and flashed so I figured it was time for some new power tubes. :D
Christopher
Lilith Guitars

User avatar
HNB
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 13513
Joined: Tue May 10, 2011 7:55 am
Location: Puyallup, Washington
Contact:

Re: Phosephene Marshall Four Hole Style Head

Post by HNB » Mon Nov 02, 2020 3:27 pm

Got the Mullard power tubes today. I did my first ever bias. According to the internets, EL34's should bias around 37. When I powered it up, my multimeter showed it to be about 39. I turned the bias pot until it hit 36.9/37. Seems to be all good now. I turned the volume up on both channels and no popping or crackle. :) The preamp tubes should arrive tomorrow I think. Then I can seal it back up. :)
Christopher
Lilith Guitars

User avatar
HNB
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 13513
Joined: Tue May 10, 2011 7:55 am
Location: Puyallup, Washington
Contact:

Re: Phosephene Marshall Four Hole Style Head

Post by HNB » Tue Nov 03, 2020 3:00 pm

The Mesa preamp tubes came in. :) Sounds good to me! I wonder why the bright channel is so noisey.

https://youtu.be/1vHPIsC8zPM
Christopher
Lilith Guitars

User avatar
HNB
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 13513
Joined: Tue May 10, 2011 7:55 am
Location: Puyallup, Washington
Contact:

Re: Phosephene Marshall Four Hole Style Head

Post by HNB » Tue Jan 12, 2021 7:51 pm

For people who have asked in my build threads, this is the amp I have been using on my guitar demos. I have it plugged in to my Orange 4x12 with vintage 30's. :)
Christopher
Lilith Guitars

User avatar
Shadoweclipse13
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 12435
Joined: Fri Feb 07, 2014 9:22 pm
Location: Stuck in the dimension of imagination

Re: Phosephene Marshall Four Hole Style Head

Post by Shadoweclipse13 » Tue Jan 12, 2021 11:12 pm

HNB wrote:
Wed Oct 21, 2020 11:41 am
I got to get a look at its guts when trying to figure out why the master volume pot wasn't doing anything. Turns out it is a push pull so if it isn't pulled out, it doesn't do anything. :)
I wonder what the point of that is. Does it do something else when the push-pull is pushed in?
Pickup Switching Mad Scientist
http://www.offsetguitars.com/forums/viewtopic.php?f=8&t=104282&p=1438384#p1438384

User avatar
fever606
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 1146
Joined: Sun Oct 17, 2010 3:03 pm
Location: district of columbia

Re: Phosephene Marshall Four Hole Style Head

Post by fever606 » Wed Jan 13, 2021 5:15 am

Bypasses the MV...

User avatar
HNB
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 13513
Joined: Tue May 10, 2011 7:55 am
Location: Puyallup, Washington
Contact:

Re: Phosephene Marshall Four Hole Style Head

Post by HNB » Wed Jan 13, 2021 8:16 am

I normally use it with master volume bypassed. It is cool though if you want to crank it at a lower volume. You just pop out the push pull and you can crank one or the other or both channels. :)
Christopher
Lilith Guitars

User avatar
s_mcsleazy
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 18423
Joined: Thu Jul 28, 2011 7:30 am
Location: glasgow

Re: Phosephene Marshall Four Hole Style Head

Post by s_mcsleazy » Wed Jan 13, 2021 8:56 am

cool amp. the big issue is i really can't see the word phosphene without thinking of the imperial china album from 2010.
https://www.youtube.com/watch?v=VpVscXQeSCA

but i'm a big fan of those big ol marshall amps for clean tones.
offset guitars resident bass player.
'Are you trying to seduce me Mrs Robinson? Or do you just want me to solder a couple of resistors into your Muff?'

User avatar
Dr Tony Balls
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 476
Joined: Thu Mar 12, 2015 10:05 am
Location: Brooklyn, NY
Contact:

Re: Phosephene Marshall Four Hole Style Head

Post by Dr Tony Balls » Wed Jan 13, 2021 9:00 am

HNB wrote:
Tue Nov 03, 2020 3:00 pm
I wonder why the bright channel is so noisey.
Could be any number of reasons. Bad solder joint, routing, failed parts or parts of an incorrect value....lot of possibilities.
Instagram: thetonyballs

Post Reply