Rocker 32 tube layout chart needed

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steveo68
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Rocker 32 tube layout chart needed

Post by steveo68 » Sat Nov 11, 2017 2:18 am

i need to change the tubes in mine and i can't find a tube layout chart for this amp. i went through the same thing with my RV Mk II a few years ago. i can't understand why this isn't readily available information on their site. it would be nice to know which socket holds the phase inverter.

does anyone have this info, or a link to it?

thanks to anyone who can help.

Rlw59
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Re: Rocker 32 tube layout chart needed

Post by Rlw59 » Sun Nov 12, 2017 5:54 pm

Yeah, I don't understand why tube layout charts are secret.

Two independent power amps, so there should be two PI's. Most likely the two closest to the power tubes.

This thread might help: viewtopic.php?f=3&t=55438

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Re: Rocker 32 tube layout chart needed

Post by bclaire » Sun Nov 12, 2017 10:41 pm

steveo68 wrote:
Sat Nov 11, 2017 2:18 am
i need to change the tubes in mine and i can't find a tube layout chart for this amp. i went through the same thing with my RV Mk II a few years ago. i can't understand why this isn't readily available information on their site. it would be nice to know which socket holds the phase inverter.

does anyone have this info, or a link to it?

thanks to anyone who can help.
Have you looked at the label on the back of the chassis by any chance?

Rlw59
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Re: Rocker 32 tube layout chart needed

Post by Rlw59 » Mon Nov 13, 2017 12:40 am

The label tells you what type of tube goes in each position, but it doesn't tell you the function of each position. (The function of the power tubes is obvious of course.)

Some people believe PI tubes should be matched triodes, and many vendors promote that idea and sell matched triodes specifically for PI use (at a higher cost than unmatched dual triode tubes).

Whether PI's really need to be matched triodes is debatable/controversial.

Rlw59
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Re: Rocker 32 tube layout chart needed

Post by Rlw59 » Mon Nov 13, 2017 12:52 am

Also, since it has a tube-buffered effects loop, it could be helpful to know if the loop uses one tube or two, and which one(s) are dedicated to the loop.

Orange's mono loops usually use a 12AT7 as send and return. So the Rocker 32's 12AT7 is most likely part of the loop, but is it the mono send or the stereo return? Is one of the 12AX7's the mono send with both triodes in parallel? Or... there are a couple other possible loop/gain stage permutations.

I can understand Orange's reticence about releasing schematics. But tube layout/function charts don't need to be secret, and they'd be very helpful for tube-rollers.

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Re: Rocker 32 tube layout chart needed

Post by Jondog » Mon Nov 13, 2017 1:56 pm

It'll have two tubes for the stereo effects loop I would assume. Ususally the tube closest to the input is the first stage. If you can put a gut shot up I/we might be able figure out the rest from component layout. Likely the tube beside the first tube (closest to the input) is the 2nd and 3rd gain stage. First tube being the natural channel and 1st stage of the dirty channel. This is how it is on the Rocker 30. I wouldn't expect different.
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Rlw59
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Re: Rocker 32 tube layout chart needed

Post by Rlw59 » Mon Nov 13, 2017 2:59 pm

In the link I provided, there's a pic of the PCB. But it's mounted in the chassis so you can only see one side, and wires obscure some things.

The loop is mono send/stereo return. It would be nice to know if the 12AX7 has its triodes paralled for the send, or if there's an unused triode, or if one of the tubes is splitting duties using one triode for the loop and the other as a gain stage. In some/most Orange loops the 12AT7 is used as both send and return, it would be helpful to know how the 12AT7 and 12AX7 are used in the loop.

Edited to correct a speculation: enlarged the PCB pic and saw the black thingy is a relay for the channel switching circuit.

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Re: Rocker 32 tube layout chart needed

Post by Jondog » Mon Nov 13, 2017 4:24 pm

Heres my findings
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Rlw59
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Re: Rocker 32 tube layout chart needed

Post by Rlw59 » Mon Nov 13, 2017 5:10 pm

You da man!

I wonder if tube vendors will push the idea that not only should you buy matched triodes for PI's, but for stereo you need a matched pair of 12AX7's so all 4 triodes are matched...

(My opinion is probably worth less than 2 cents, but I don't believe in the matched triode PI hype.)

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Re: Rocker 32 tube layout chart needed

Post by Jondog » Tue Nov 14, 2017 2:25 pm

Really wouldn’t cause issue for each side to be mis-matched unless you were be extremely picky about the sound. Big Mis-matches might even create nice textures. You could run a completely different brand of EL84s on one side of the amp. A cool mod would be 6V6 on one side, EL84 on the other. I run 6V6 in my Rocker 30 right now and love it, it’s essentially a Rocker 15 now. I had an Egnater Rebel 30 which lets you mix 6V6 and EL84 together and that was my favourite sound on the amp.
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Speegman
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Re: Rocker 32 tube layout chart needed

Post by Speegman » Mon Dec 04, 2017 8:27 pm

Do these tubes need to be biased?

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Re: Rocker 32 tube layout chart needed

Post by Speegman » Mon Dec 04, 2017 8:53 pm

Another question - I believe that only the tube for the clean channel needs changing. Can I just change this one tube or do I need to change the 2nd dirty channel tube as well?
Thanks for any help!

Rlw59
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Re: Rocker 32 tube layout chart needed

Post by Rlw59 » Mon Dec 04, 2017 9:33 pm

The R32's power amps are cathode-biased so you don't need to bias the EL84's.

Preamp tubes never need to be biased.

If just the first 12AX7 is bad, that's the only one you need to change.

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Re: Rocker 32 tube layout chart needed

Post by Rlw59 » Mon Dec 04, 2017 9:53 pm

Jondog, last night I was reading the Orange website page on the R32, and Ade says that he added a tube cathode follower to one of the power amps. To give the amp a more "spacious" mono sound, and to widen the stereo field when using stereo effects.

I kinda sorta have a basic understanding of how amps work, but when I hear "cathode follower" I think "it does something or other in the tone stack".

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Re: Rocker 32 tube layout chart needed

Post by Jondog » Mon Dec 04, 2017 9:59 pm

Rlw59 wrote:
Mon Dec 04, 2017 9:53 pm
Jondog, last night I was reading the Orange website page on the R32, and Ade says that he added a tube cathode follower to one of the power amps. To give the amp a more "spacious" mono sound, and to widen the stereo field when using stereo effects.

I kinda sorta have a basic understanding of how amps work, but when I hear "cathode follower" I think "it does something or other in the tone stack".
I'll have to look that up because that would change the tube layout. I just realized it only has one effects SEND and two returns, so in that case one half of one of the tubes for the effects loops could be used as a cathode follower. Cathode follower tube stage can help drive a tone stack to prevent signal loss.
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