1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
Moderator: bclaire
-
- Duke of Orange
- Posts: 9765
- Joined: Sat Jun 15, 2002 1:05 am
- Location: Amsterdam, Hollandland.nl
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
No need to remove any circuitry to run just two valves. I wouldn't bother doing anything...
Does the impedance selector (marked 'ohms') next to the speaker outputs actually have a 4 ohms setting? (Hard to tell from the pics. on the OFG or the thread I linked to early on.) If so than simply pull out the selector plug and reinsert it pointing at the desired 4 ohm setting.
If there is no 4 ohms setting you are a bit snookered for running an 8 ohms load with two valves pulled, mods or no mods. That would mean no 4 ohm ohm tap on the output transformer. You could run a 16 ohms load with the amp set to 8 ohms, but most bass cabs are 4 or 8 ohms, not 16 ohms.
BTW why are you wanting to run only two valves anyway?
Andy.
Does the impedance selector (marked 'ohms') next to the speaker outputs actually have a 4 ohms setting? (Hard to tell from the pics. on the OFG or the thread I linked to early on.) If so than simply pull out the selector plug and reinsert it pointing at the desired 4 ohm setting.
If there is no 4 ohms setting you are a bit snookered for running an 8 ohms load with two valves pulled, mods or no mods. That would mean no 4 ohm ohm tap on the output transformer. You could run a 16 ohms load with the amp set to 8 ohms, but most bass cabs are 4 or 8 ohms, not 16 ohms.
BTW why are you wanting to run only two valves anyway?
Andy.
aNDyH.
Ever tried to outstare a mirror?
In the bathtub of history the truth is harder to hold than the soap, and much more difficult to find!
Ever tried to outstare a mirror?
In the bathtub of history the truth is harder to hold than the soap, and much more difficult to find!
-
- Orange Master
- Posts: 1584
- Joined: Tue Dec 31, 2002 4:58 am
- Location: Feenix, AZ, USA
- Contact:
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
The OP doesn't have an OR145, he wants to build a clone, so omitting the parts for the extra EL-34s is totally justified. Since the amp in question doesn't exist yet, there is not presently a speaker impedance switch.
-
- Duke of Orange
- Posts: 9765
- Joined: Sat Jun 15, 2002 1:05 am
- Location: Amsterdam, Hollandland.nl
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
Thanks, makes more sense now.
Andy.
Andy.
aNDyH.
Ever tried to outstare a mirror?
In the bathtub of history the truth is harder to hold than the soap, and much more difficult to find!
Ever tried to outstare a mirror?
In the bathtub of history the truth is harder to hold than the soap, and much more difficult to find!
-
- Lord of Orange
- Posts: 10149
- Joined: Tue Sep 29, 2009 3:44 am
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
That's debatable.a.hun wrote:Thanks, makes more sense now.
Andy.
_________________
-
- Forum Moderator
- Posts: 17905
- Joined: Thu May 02, 2002 9:19 pm
- Location: Outside Boston MA, USA
- Contact:
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
Very much so...Randy Bass wrote:That's debatable.a.hun wrote:Thanks, makes more sense now.
Andy.
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
Hmm... It seems the switch only has an 8, and 16 ohm selection. Do you guys know what would happen if I were to run the circuit at 8 ohms, with 2 EL34's, and how it would be affected- leaving the supporting circuitry for the two tubes I am taking out?
Last edited by Lemos on Fri Dec 12, 2014 2:26 pm, edited 1 time in total.
-
- Duke of Orange
- Posts: 9765
- Joined: Sat Jun 15, 2002 1:05 am
- Location: Amsterdam, Hollandland.nl
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
You're right again guys...
Ho Hum... Zappp!
(Andy has left the thread!)
Andy.
Ho Hum... Zappp!
(Andy has left the thread!)
Andy.
aNDyH.
Ever tried to outstare a mirror?
In the bathtub of history the truth is harder to hold than the soap, and much more difficult to find!
Ever tried to outstare a mirror?
In the bathtub of history the truth is harder to hold than the soap, and much more difficult to find!
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
Or better yet- if I could run the circuit at 8 Ohms with the supporting circuitry for the two tubes I am taking out, in, as well as possibly adding some more circuitry to support the 8 Ohm load, and how I would go about adding some components to do so?
-
- Forum Moderator
- Posts: 17905
- Joined: Thu May 02, 2002 9:19 pm
- Location: Outside Boston MA, USA
- Contact:
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
You need to stop asking questions and just go build the thing. We've answered all of this for you already... but what you're now asking makes no sense. Go build it - then ask questions.Lemos wrote:Or better yet- if I could run the circuit at 8 Ohms with the supporting circuitry for the two tubes I am taking out, in, as well as possibly adding some more circuitry to support the 8 Ohm load, and how I would go about adding some components to do so?
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
Lemos - how about you go learn some electronics. Seriously. It will make your life a lot easier, and less dangerous.
I recommend http://www.valvewizard.co.uk/" onclick="window.open(this.href);return false; as a good place to start, the book he sells is very good too.
The same site also gives info on how to build your own ribbon microphones.
Sadly there is no info on thermal management of logs.
I recommend http://www.valvewizard.co.uk/" onclick="window.open(this.href);return false; as a good place to start, the book he sells is very good too.
The same site also gives info on how to build your own ribbon microphones.
Sadly there is no info on thermal management of logs.
-
- Orange Master
- Posts: 1584
- Joined: Tue Dec 31, 2002 4:58 am
- Location: Feenix, AZ, USA
- Contact:
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
Lemos wrote:Or better yet- if I could run the circuit at 8 Ohms with the supporting circuitry for the two tubes I am taking out, in, as well as possibly adding some more circuitry to support the 8 Ohm load, and how I would go about adding some components to do so?
It doesn't work that way. The number of tubes determines the primary-side impedance for the output transformer. That, in turn, determines what needs to appear on the secondary side of the transformer as a load for the tubes to be happy.
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
So I should not be concerned of anything blowing up with two EL34's taken out of the original circuit? I just wanted to make sure I was not running too much power to too small of a limited capacity. I will most certainly check out the website, too broke for books right now!
-
- Orange Master
- Posts: 1584
- Joined: Tue Dec 31, 2002 4:58 am
- Location: Feenix, AZ, USA
- Contact:
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
Lemos wrote:So I should not be concerned of anything blowing up with two EL34's taken out of the original circuit? I just wanted to make sure I was not running too much power to too small of a limited capacity. I will most certainly check out the website, too broke for books right now!
No. The tubes can't be subjected to more power than they need unless something is seriously wrong with the amp. If you're too broke for books, how are you going to afford the parts to make an amp ?
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
Barely enough for the amp! This should be my last question: will I need to use a certain type of wires to connect the components, as I have no printed circuit board?
Re: 1979 Orange OR145 Bass Combo Circuit Schematic/Diagram
Yes. Ones with a metal core.
Who is online
Users browsing this forum: No registered users and 225 guests