Orange OR80 Style Build

Tube or solid-state, this section goes to eleven!
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Dr Tony Balls
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Post by Dr Tony Balls »

diegoribba wrote:Hi Dr Tony Balls
i have a question for you: is it possible to use another output transformer? i really like the Classictone ones (http://shop.amppartsdirect.com/Transformers_c2.htm) and i would really appreciate if you could help mi out finding a replacement (this is not because i'm lazy, its just because i really don't know the value of the output resistance in ohms) of the Heyboer HY OT45.
i thought that this one (http://www.classictone.net/40-18039.pdf) would do it, but i'm not shure.
i'd really appreciate it!
thanks!
Diego

Hey Diego,

The OT you picked would work, but the primary impedance is listed at 8K (probably its intended to be used with KT66s). 2 EL34s like in this schematic should produce an output impedance of around 3.4K (roughly half of 8K). So if you used that transformer you'd have to half all of the secondary impedances also. Instead of 4/8/16ohm taps, they would be 2/4/8ohm. Its probably more convenient and less confusing to go with the following transformer which is made for the correct primary impedance, and will provide you the 4/8/16ohm outputs you probably want: http://www.classictone.net/40-18025.pdf

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diegoribba
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Post by diegoribba »

Thanks! you are the man!

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GJonesy
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Post by GJonesy »

Hi Dr Tony Balls
Many thanks for checking it out
I'll build an OR120 version with the 1.5k then
G

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qatte
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Post by qatte »

Wooh, this build looks nice.
Anyway, I'm just a beginner with building amps but I've been looking for some vintage Orange style build for a long time. Thought of doing a Deluxe Reverb kit first as an introduction while learning some of the theoretical parts from Kevin O'Connors books. But what do you think, would a OR 80 build too challenging as a second project?

Bests
A

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diegoribba
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Post by diegoribba »

Hi Dr Tony!
im sorry to disturb you once again, but i'm wondering which is the right replacement for the PT. you said that the weber w022798 should be the correct, but i really like the classictone ones, so i'm looking there for the right one. i surfed their web and i came out with this one, a fender type that haves all the secondaries as the weber, but it haves just 2 primaries: 110 and 240. i'm from Chile, south america, and we have a 220v. network, so i'm wondering if that fender type would be the best replacement.
here's the PT that i'm talking about: http://shop.amppartsdirect.com/Vintage- ... -18029.htm

i've read on this web http://users.telenet.be/orangefg/orange_diy.htm that the specs for the or80 are quite different:
"6.3V heater rating: 2xECC83 + 2xEL34 = 2x0.3A + 2x1.5A = 3.6A (at least)
180-0-180 winding: 2x0.006A + 2x0.100A = 0.212A (max ratings used)
Bias winding, mostly 100V"
if that would be the case, this 100w jcm800 PT replacement should do the work. http://shop.amppartsdirect.com/Marshall ... -18024.htm

as i said, i'm sorry to be bugging you, but it's the only way since i dont have acces to weber trannies, cause thei'r not sending them to my country.

thanks again! you are the man!

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Dr Tony Balls
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Post by Dr Tony Balls »

qatte wrote:Wooh, this build looks nice.
But what do you think, would a OR 80 build too challenging as a second project?

Not bad a second project if it was a full kit, but having your second project be a scratch build or a highly modified kit could be challenging. Just make sure you have all your ducks in a row when you get started.

diegoribba wrote:Hi Dr Tony!
im sorry to disturb you once again, but i'm wondering which is the right replacement for the PT. you said that the weber w022798 should be the correct, but i really like the classictone ones, so i'm looking there for the right one. i surfed their web and i came out with this one, a fender type that haves all the secondaries as the weber, but it haves just 2 primaries: 110 and 240. i'm from Chile, south america, and we have a 220v. network, so i'm wondering if that fender type would be the best replacement.
here's the PT that i'm talking about: http://shop.amppartsdirect.com/Vintage- ... -18029.htm

i've read on this web http://users.telenet.be/orangefg/orange_diy.htm that the specs for the or80 are quite different:
"6.3V heater rating: 2xECC83 + 2xEL34 = 2x0.3A + 2x1.5A = 3.6A (at least)
180-0-180 winding: 2x0.006A + 2x0.100A = 0.212A (max ratings used)
Bias winding, mostly 100V"
if that would be the case, this 100w jcm800 PT replacement should do the work. http://shop.amppartsdirect.com/Marshall ... -18024.htm

as i said, i'm sorry to be bugging you, but it's the only way since i dont have acces to weber trannies, cause thei'r not sending them to my country.

thanks again! you are the man!

No worries. The original OR80 PT would be very differently spec'd. For one, they just used the same PT that would be in the OR120, i presume just to keep things simple. But by no means do you need to use a 100W transformer for this. And the second note is that the original OR80 and OR120 circuits use a transformer with a lower secondary voltage and use a voltage doubler in the power supply section to get up the right voltage. I could have done that with this, but the idea was to use as much of an existing kit as possible, just because its easier and less costly than farming everything out. Plus its an affordable way to get a nicely made cabinet. So I designed it around using the Weber PT which they use for their 50W heads (marshall, hiwatt, etc) with a full wave rectifier. You could use the fender type one that you first posted without issue.

Also, are you sure Weber wont ship to Chile? You might email them and ask, if you want to use them. They might do it anyway.

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Post by diegoribba »

thanks Tony! really !
i think i'll email weber again.... i did it but i got no answer.
thanks man!

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Post by Harold »

Dr Tony Balls wrote:
Aharon wrote:Hi Dr Tony Balls,beautiful amp!! :applause:
I have a question,what amps is that 2mH inductor ?
I'd like to make this amp but with 6V6s.
Thanks for posting this.
Aharon
That's a .8A inductor, but it doesnt need to be near that high.
How much current will flow through that inductor? Less than 200mA? -> https://www.ebay.com/itm/311003346206


I'm thinking about building an OD80 from my Marshall 1987x so I'm looking at what components to buy for the transformation ...
DIY-Layout.com: Online stripboard layouts

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