I played a date a couple weeks back with a fill-in guitar player that played a Tele through a modified SE record player amp (He thought a Cailifone, internet is saying a Newcomb). It sounded great & it was amazingly loud, even in a band setting.
I gave it a quick look as we were packing up & was able to get a bad phone pic of the schematic which was pasted into chassis. The only mods he said he had made were a couple input resistors & I have not gotten a chance to follow up with him for more information after getting to check out the schematic.
Looking it over, one of the things I am not at all familiar with is the separate OT screen tap (& intentionally higher voltage than the plate).
I am assuming he modded the phono channel as he DID use the tone controls.
Any insights from those more knowledgeable?
Apologies for the photo quality or lack thereof.
EDIT: Guessing this is UL..Did not realize Ultra Linear could implemented on an an SE output. Had it firmly in mind that it was a P-P thing only.
SE OT with screen tap
Moderators: pompeiisneaks, Colossal
SE OT with screen tap
You do not have the required permissions to view the files attached to this post.
-
flemingmras
- Posts: 111
- Joined: Sat May 02, 2026 5:07 am
Re: SE OT with screen tap
That is a 40% "Ultra Linear" tap. It combines characteristics of triode and pentode operation, giving the high power output of pentode mode with the linearity of triode mode. The closer the tap is to the plate, the more "triode-like" it performs. The closer to the B+ tap, the more "pentode-like" it performs.
Never seen it done on a Class A Single Ended amplifier.
Never seen it done on a Class A Single Ended amplifier.
-
Stevem
- Posts: 5604
- Joined: Fri Jan 24, 2014 3:01 pm
- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: SE OT with screen tap
Single ended UL 75 watt 28 lb output.
The darn thing tips the scales like does many combo amps with a 10” speaker !
So one EL 84 was loud enough in a band setting with a Drumer?
How many speakers was the guy playing through?
The darn thing tips the scales like does many combo amps with a 10” speaker !
So one EL 84 was loud enough in a band setting with a Drumer?
How many speakers was the guy playing through?
You do not have the required permissions to view the files attached to this post.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: SE OT with screen tap
That is a crazy OT, I would not want to haul around an amp with that in it.
But yeah, a 4-piece with a drummer. He was using 1-12" guitar speaker, no idea what it was.
A kind of small room, but moderate volumes (old-school electric blues) & you could hear the thing pretty well.
He has an EE background/repair experience & he said it wasn't even recapped.