Rev F Dual Rec presence / NFB

[fusedbrain]

Can anyone who has actually played a Rev F dual rec , tell me if the Orange Presence control does anything when Orange is cloned to modern.
Also, what's the consensus best way to run these?
Orange Modern
Red Modern
How do you guys set these up?
Thanks!

 

[peterc52]

Orange modern and boosted too

 

[cardinal]

It's been a while, but short answer is yes: the orange presence worked in either vintage or modern. But in modern mode, it doesn't do very much.

The orange presence is a traditional presence control, but in modern mode there's no negative feedback, so there's not much for that presence control to work with.

Red channel gets around that by having a different "presence" control: it's a high cut like a Vox AC30. (And in Red Vintage, both channels' presence controls now impact the tone).

The three channels get around this by having the type of presence control switch when you switch modes, but that also means you lose this ability to get different sounds.

 

[BesaMoogie]

The orange to modern can be dark. I remember turning the presence and treble up on this one.
Generally, keep the gain low for a tighter bass or boost it.
The orange to modern sounds more organic compared to the red channel

 

[Racerxrated]

The orange to modern can be dark. I remember turning the presence and treble up on this one.
Generally, keep the gain low for a tighter bass or boost it.
The orange to modern sounds more organic compared to the red channel

This.
Always dimed the P in the F, or C I had. In Orange/Modern.....which, imo is the only channel to use. Unless you gig and need 2 channels. Red is always way more sterile/clinical sounding to me.
I did C mod the last F Triple I had....that mod improved the red ch a bunch to me. You also increase the pot values for Orange P, Mids and gain. If I remember correctly.

 

[Beyond Black]

Dime the presence and treble to taste. This is the way.

 

[Bxlxaxkxe]

Somewhat related but not really. I’ve never seen anyone comment on this but I have found on 2 channel rectos that regardless of what channel/mode you are on, every single control affects the sound. For example, playing on channel two and change the mode for channel 1 on the back from clean to vintage gain…changes the tone on channel 2. All the tone controls of one channel slightly affect the sound on the other as well. Maybe I’m crazy but I messed with this a bunch and it’ll drive you nuts. Even happens on the Multiwatt, particularly with the modes for the channels you’re not playing.

 

[RedPlated]

When you’re on red, orange presence significantly affects the red channel. I usually run orange presence higher, at least 3 o clock.

If you look at a schematic you’ll see how everything works. It’s not really a true 3 channel amp. It’s basically one circuit path where components are added or lifted, and gain stages bypassed, to reduce or increase the gain and create different “channels.”

There are individual tone stacks and gains/ masters for red and orange, of course. But otherwise it’s pretty much the same circuit. All those problematic LDR’s are switching things in and out all over the place when changing modes.

The schematic actually has a description of what each LDR does in each mode

 

[Exo-metal]

When you’re on red, orange presence significantly affects the red channel. I usually run orange presence higher, at least 3 o clock.

If you look at a schematic you’ll see how everything works. It’s not really a true 3 channel amp. It’s basically one circuit path where components are added or lifted, and gain stages bypassed, to reduce or increase the gain and create different “channels.”

There are individual tone stacks and gains/ masters for red and orange, of course. But otherwise it’s pretty much the same circuit. All those problematic LDR’s are switching things in and out all over the place when changing modes.

The schematic actually has a description of what each LDR does in each mode

View attachment 431830

The reissue did away with LDR's, correct?

 

[mnemonic]

The reissue did away with LDR's, correct?

No LDR’s, all relays.

Insides pictures here

Thread 'Mesa 90s Rectifier RI - Pics & Info'

Jan 21, 2025

Been getting a lot of texts and messages asking about the Recto RI, so instead of answering them all one-off, thought this may be easier. Here’s a synopsis of what I’ve been telling folks, along with some pics.

Disclaimer: I bought the amp to try and to document. I wasn’t keeping it regardless of whether I liked it (though I do), and told everyone it was getting sold before it even arrived.

First impression plugging in was…it sounds like a “new” 2 channel Recto. I know that sounds obvious, but it’s sort of hard to explain. A little more urgent, a little cleaner and clearer in the gain...

• NewWorldMan
• Replies: 6
• Forum: Rig-Talk

• 
• 

 

[fusedbrain]

When you’re on red, orange presence significantly affects the red channel. I usually run orange presence higher, at least 3 o clock.

If you look at a schematic you’ll see how everything works. It’s not really a true 3 channel amp. It’s basically one circuit path where components are added or lifted, and gain stages bypassed, to reduce or increase the gain and create different “channels.”

There are individual tone stacks and gains/ masters for red and orange, of course. But otherwise it’s pretty much the same circuit. All those problematic LDR’s are switching things in and out all over the place when changing modes.

The schematic actually has a description of what each LDR does in each mode

View attachment 431830

Thanks for all the reply's guys!
I actually have this schematic.
In both Orange modern and Red modern, LDR 19 is off, which disconnects the NFB from the presence control and the PI tail. ( not withstanding the LDR's open resistance.) So it looks like there is no NFB in the 2 most used modes.
Adjusting the Orange presence control in modern mode appears to only affect the PI tail, and that would explain why the effect is described as subtle.

I probably should have posted this in the tech section, and I should probably explain what I'm up to:
I haven't had a Recto in the house since I sold my G triple about 5 years ago, and I miss the tone.
I'm not interested in spending the $5k Canadian for a re-issue, and seeing as I live in the middle of nowhere in Northern Ontario, finding a decent used anything locally is not going to happen.
So, I started thinking ....... I have the schematic above, and seeing how most of us only use one sound, I could figure out the circuit path for the money channel and build a one channel Rev F clone pretty easily.
I asked the question about the presence control doing anything because I seem to remember my Rev G Orange presence functioning normally in modern mode, but on this Rev F scheme I didn't see how that was possible. Maybe my memory of the G triple is off, IDK.

Also, when you look at that schematic, the number of LDR's and relays in the switching matrix is crazy! It's kind of funny to me that there are all those options and switches etc., and we all just set it to one sound and go.

Thanks again to everyone for all the input

 

[RedPlated]

LDRs are not truly on or off like a relay. It is a resistor after all.

You'll usually see 80 to around 250 ohms resistance through the LDR's when they're "open", depending on which one in the circuit you're measuring. The cathode bypasses, for example are usually around 105 ohm or so. So yes, the components are never truly seeing ground.

I believe in the newer rectos with actual relays they add 100 ohm resistors, or something close to that, between ground to emulate having an LDR there.

 

[tvegas99]

great replies and a fascinating thread, so much knowledge!!

 

[Exo-metal]

Just wait till there's mods for the new amp.