orange or120 preamp

[Br4d13y]

does anyonone know how much is the D+ voltage in this schematic?

http://users.telenet.be/orangefg/OFG_SCHEM/OR120_72preamp.jpg

i want to make a standalone preamp, or rackmount maybe, of this

also, does anyone know of a single el34 power amp


thanks

[drewl]

As with most tube amps it's usually around 200volts or so.
Check out the AX84 site for alot of great single ended amp ideas/schems/builds etc.

[Ardric]

According to the 1974 version the D+ node is at 330 volts DC.  http://users.telenet.be/orangefg/OFG_SCHEM/OR120schem_74.gif

Re a single EL34 output tube, AX84 has many popular single-ended (SE) designs to build.  http://www.ax84.com/corepoweramps.html

[km-r]

i know this guy bradley! haha some orange amp fan...

just curious... is this a one-tube preamp? i thought you were looking for a dark sounding distortion similar to sleep and the like...

[Br4d13y]

i know this guy bradley! haha some orange amp fan...

just curious... is this a one-tube preamp? i thought you were looking for a dark sounding distortion similar to sleep and the like...

ha ha THANKS     nah, i was just looking for a preamp that sounds kinda different, but i want a low power el34 amp, just mulling around ideas, and how i could achieve them

[km-r]

yeah you were that matamp green guy!

i built a preamp section replica of an orange overdrive amp once, good sound but not a lot of distortion...
its what you can expect from a brit amp.

a SE EL34 amp runs like what, 25watts? my thats a huge output transformer...

good luck to you, im working hard to fund my 18watt now...

[ItZaLLgOOd]

I built a P1-Exteme from AX84 which is a SE EL34 which is only rated at 9 watts IIRC.

[Branimir]

The Orange preamp has at least two different tonestacks, the early 70s has a darker voiced tonestack and later models have a "brighter" tonestack, it's the same type Baxandall of course... The tonestack is after the first or after the second gain stage, there is an Matamp schem floating around (search the forums) and I think it has the tonestack after the first gain stage.

The Sleep tone hehe... The phase inverter of the Orange amps (concertina/cathodyne call it as you wish) has a bit less swing to the output tubes unlike LTP (marshall type PI) but it does actually act as a gain stage and it distorts much, unlike LTP which has more headroom (if I'm not mistaken). Anyways Sleep - it's the amp all the way, the preamp distorts, phase inverter and of course output tubes as well...

If I'm not mistaken about the history of mr. Pike's Matamp's... They were quite unreliable, they broke down often and eventually the transformers were changed... The whole Matamp Green hype that's sourrounding the Dopesmoker album is nothing but a amp pushed all the way and eventually suffering from design flaws, due to extreme usage... Not to mention blocking distortion, am I the only one hearing it all the time on the record, the amp is choking, trying to push the notes through the speaker but eventually it's way to bass heavy and sound farty.... That's why we love it...

Although Orange amps have a really nice clean and overdriven tone when used "normally" hehe...

Why the hell am I writing this, no one asked me... heh

[foxfire]

nah, i dig it...

[geertjacobs]

The phase inverter of the Orange amps (concertina/cathodyne call it as you wish) has a bit less swing to the output tubes unlike LTP (marshall type PI) but it does actually act as a gain stage and it distorts much, unlike LTP which has more headroom (if I'm not mistaken)

The cathodyne PI has a gain of about 1, I thought.
http://www.bonavolta.ch/hobby/en/audio/split.htm#Cathodyne

I'm playing an Orange clone and I've been reading about Oranges for years and I still find them strange amps.

[Hawkwind]

I have also thought about this. Is it possible to build this in an pedal-box and use some sort of transformer or something to get this preamp in a pedal-box.

I have built some pedals and know how to solder but maybe I'm biting off more than I can chew?

Best regards Kristoffer

[Derringer]

yeah you were that matamp green guy!

i built a preamp section replica of an orange overdrive amp once, good sound but not a lot of distortion...
its what you can expect from a brit amp.

a SE EL34 amp runs like what, 25watts? my thats a huge output transformer...

good luck to you, im working hard to fund my 18watt now...

single EL4 in class A you're looking at about half or max dissipation .. so at max about 12 watts

[Johan]

the EL34 wasnt designed for class-A operation. it works, but expect to replace the tube more often than you expected too..
J