What to do with the "worthless channel" on Blackface amps

[markesquire]

Most BF amps have a reverb channel and a channel that never gets used. Ever.

Is it possible to modify the circuit so that you have a tweed deluxe on the first channel and a deluxe reverb on the second?

[Brett Faust]

What "worthless" channel?

[markesquire]

Am I the only person who has never used the first channel on BF amps?

It sounds almost the same but doesn't have reverb or trem. Why use it?

[DMace]

One thing to do: remove the unused 12ax7, particularly if it's a pricey NOS. I never use the non-verb channel on my DR.

[markesquire]

It would be great to have tweed on one side, blackface on the other, reverb and trem apply to both, and you could mix them in together at the same time. Probably impossible, but it would be the ultimate deluxe/deluxe reverb or bassman/super reverb

[eugenedunn]

I have seen a mod where people take the reverb out from the reverb/vibrato channel and route that into the Normal channel. Then they reverse the phase of the Normal Channel so it is the same as the Reverb Channel.......Then I think they jumper that channel into the Reverb/Vibrato channel and what that gives you is a "dwell" reverb control over the reverb section of the Reverb/Vibrato channel....

Something like that....... For those of you that have tried a 2 or 3 knob reverb circuit, it's something worth doing probably. Especially if you don't use that "Normal" channel

[JohnnyCrash]

Unfortunately, you cannot turn the Normal channel into a 5E3 tweed Deluxe.

You can:
1. Lose the tonestack and simply cascade from the input triode to the output triode (V1 is the Normal channel's dual triode tube). Losing that plate-fed tonestack will give you some gain. You could put a 500k pot between to act as a sort of Pre/MV control for the Normal channel.

2. Seperate the cathode V1's second triode shares with V2 and tweak V1's cathodes and bypass caps to be more "Marshall" (2700 resistor with a 0.68uF bypass). Cascading V1 with this type of cathode might give you a Marshall style preamp gain.

IDK, I'm sure there's other options we haven't thought of yet... cathode follower tonestacks and cascading (via losing the Normal channel entirely and using its tube to tweak the Reverb channel)...

[maestrovert]

Originally Posted by Brett Faust

What "worthless" channel?

Heya, the "Normal" channel's a lifesaver !

you can keep your spare guitar plugged into it, and if you ever break a string or have any other problem during a performance, a quick swap can save the day....
Have a guest who's gonna sit in, or do you need to quick change from the Tele to your Gretsch or Rick ? "Here ya go Bro', all plugged in an' ready to rock...."

it's also useful for teaching, as your student(s) can plug in as well.....not to mention that without the extra gain stage for the reverb circuit, it's a great sounding clean channel too...

Yep, the Normal channel's very useful....

jes' mho, ymmv

[fezz parka]

It's an easy mod to get reverb on the normal channel. That's about all I'd do to it.

[JD0x0]

mod the normal channel into a midboost channel for some more fatness a drive

[markxander]

I find overdrive sounds a little sweeter on the normal channel. Could just be my ears, but it makes a huge difference to me.

I rarely use the Reverb channel on my TRRI

[pchilson]

Depends on the guitar I'm playing but as markxander says the normal channel is better sounding with the dirt boxes usually. Some of my guitars sound better through the reverb channel with the dirt boxes though. I'm glad it has both channels.

[JohnnyCrash]

The Reverb channel by nature has more gain.

Pedals will likely feel and sound better on the Normal channel, but if you aint using it, I'm a firm believer in "waste not, want not."

[Del Pickup]

I used to plug my harmonica mic into the normal channel of my DRRI. It was always ready to go without swapping cables around.

[drewsblues]

Originally Posted by JohnnyCrash

The Reverb channel by nature has more gain.

Pedals will likely feel and sound better on the Normal channel, but if you aint using it, I'm a firm believer in "waste not, want not."

+1... I use the "Normal" channel in live situations where a lot of reverb isn't needed. To my (admittedly unrefined) ear, it sounds punchier and takes to my pedals nicely. Sounds great for blues (SFDR)...

[vjf1968]

Or you could get a Barber Launch Pad and have the use of both channels at your feet.

http://www.barberelectronics.com/LaunchPad.htm

[ojaverde]

I lifted the tone stack on the normal channel of my 64 Non Reverb Deluxe. I use an A-B pedal to switch between the channels. The normal channel now is as loud on three as the trem channel on six. It's not exactly a tweed deluxe sound but it seems to have a lot more gain and is cetainly tweedier. It works as a great boost switch.

[Ricky D.]

Somebody drops in to jam, they don't need to bring an amp.

[6x47]

Originally Posted by markesquire

Is it possible to modify the circuit so that you have a tweed deluxe on the first channel and a deluxe reverb on the second?

YES!

The conversion is shown on page 151 of The Tube Amp Book by Pittman. He spends about 2 1/4 pages on "Super Deluxe: Tweed-Style Preamp mod" starting with a Silverface Deluxe Normal Channel. No problem applying this mod to a blackface. It requires parts swapping, rewiring and adding a 8 or 10 uF electrolytic where the .1 cap goes on V1 on a ab763 circuit, but if you have the book it's easy.

[gaddis]

I happen to think the Normal channel sounds better. If I'm not using reverb I prefer to plug into the Normal channel.

[Martin R]

I do something similar, but simpler, than ojaverde, on my non-reverb Deluxe...I have an A/B switch with the Normal channel set just a touch louder and more treblier(?) than the Vibrato channel. Time for the lead, just tap the pedal...instant boost.

Martin
E. Christina Herr & Wild Frontier

[bradpdx]

The reverb is never off. That's how I roll.

[DMace]

Originally Posted by gaddis

I happen to think the Normal channel sounds better. If I'm not using reverb I prefer to plug into the Normal channel.

I think it sounds better until you get the reverb channel cranked loud enough to get past the bright cap. Then, they're the same, far as I can tell.

[JohnnyCrash]

Originally Posted by ojaverde

I lifted the tone stack on the normal channel of my 64 Non Reverb Deluxe. I use an A-B pedal to switch between the channels. The normal channel now is as loud on three as the trem channel on six. It's not exactly a tweed deluxe sound but it seems to have a lot more gain and is cetainly tweedier. It works as a great boost switch.

Lifting the tonestack leaves you with one triode cascaded into another. Very raw, gainy, and in some sense I guess "tweedy."

Originally Posted by DMace

I think it sounds better until you get the reverb channel cranked loud enough to get past the bright cap. Then, they're the same, far as I can tell.

At that point your ears are naturally compressing the sound so your brain doesn't crack :)

The bright cap is pretty much bypassed 3/4++ up the dial, but the gain on a BF reverb channel is one triode hotter, regardless. Its got more gain, tube compression, and overdrive than a Normal channel... its going through half a preamp tube more (regardless of reverb settings). Its the nature of BF circuits. Its also the magic of the Reverb channel - not the verb, but the extra tube sauce.

Originally Posted by 6x47

YES!

The conversion is shown on page 151 of The Tube Amp Book by Pittman. He spends about 2 1/4 pages on "Super Deluxe: Tweed-Style Preamp mod" starting with a Silverface Deluxe Normal Channel. No problem applying this mod to a blackface. It requires parts swapping, rewiring and adding a 8 or 10 uF electrolytic where the .1 cap goes on V1 on a ab763 circuit, but if you have the book it's easy.

Gutting the plate fed tonestack and straight up cascading it will give you a very hot preamp, but there is so much more to a tweed Deluxe than a hot front end. 5E3 tweed Deluxes have a primitive phase inverter (that acts like a preamp tube in its gain, compression, and overdrive feel - compared to long tailed pair PI's), as well as a cathode power section (with plenty of sag from an innefficient power supply), and coupling caps that make it thicker than a lard milkshake... combined with NO negative feedback, a lose power section (saggy current from the 5Y3 rectifier, small filter caps, no choke, and cathode biasing on the 6V6's).

The PI and power section of the BF or SF simply do not respond dynamically in the same way a tweed Deluxe does.

A SF or BF's Normal channel is simple - input jack feeds grid, that triode's output (the grid's coresponding plate) feeds a tonestack (plate fed tonestack, instead of a the tweed Bassman or Marshall's cathode follower tonestack), which in turn feeds straight into the PI. The Reverb channel on the other hand goes grid, to plate-fed tonestack, to reverb recovery (the reverb circuit itself splits into a paralleled 12AT7 with a "mix" pot and mixing resistor to take it to the recovery circuit), to PI - which means more tube tastiness/overdrive (an extra 12AX7 triode of gain).

You can do what you like with that Normal channel's two simple triodes, but you just can't get a real authentic tweed Deluxe sound out of it - there's much more required to get that 5E3 sound.

[strat a various]

Nothing beats the normal channel on a Twin for clear sparkly clean, especially with humbuckers. That's the channel I tend to use on BF Fenders, often into the 2nd low gain input. It's the clean Fender tone you read about.

[PeterUK]

Originally Posted by ojaverde

I lifted the tone stack on the normal channel of my 64 Non Reverb Deluxe. I use an A-B pedal to switch between the channels. The normal channel now is as loud on three as the trem channel on six. It's not exactly a tweed deluxe sound but it seems to have a lot more gain and is cetainly tweedier. It works as a great boost switch.

Originally Posted by Martin R

I do something similar, but simpler, than ojaverde, on my non-reverb Deluxe...I have an A/B switch with the Normal channel set just a touch louder and more treblier(?) than the Vibrato channel. Time for the lead, just tap the pedal...instant boost.

Martin
E. Christina Herr & Wild Frontier

I'm with these guys. I use a Radial Switchbone and "blend" the two channels, so I get

1. Normal (Channel A)
2. Vibrato (Channel B)
3. Normal and Vibrato blended (Both Channels)

The Switchbone also has a clean boost so I use this for solo work with any of the combos above.

Works for me and I love it!

Peter

[stantheman]

nothing sounds finer than putting a 2 output Boss Delay last in the chain and runnin' into BOTH sides of a Fender Amplifier. If You love the BIG Albert King,SRV,EC "studio Tone" and You need it for a Club...
Think "ForeverMan" or "Flat Tire".

[maestrovert]

Originally Posted by stantheman

nothing sounds finer than putting a 2 output Boss Delay last in the chain and runnin' into BOTH sides of a Fender Amplifier. If You love the BIG Albert King,SRV,EC "studio Tone" and You need it for a Club...
Think "ForeverMan" or "Flat Tire".

hmmm.....the normal and bright channels are out of phase with each other due to the extra gain stage Johnny Crash just explained....it wouldn't sound very good...unless you've come up with a convenient way to reverse the phase on one of the Boss Delay's outputs ?

[Tim Armstrong]

Yeah, Fender "Reverb" amps have the reverb channel out of phase with the normal channel. I've read that a simple mod to run both channels to the reverb takes care of this (and obviously gives you reverb on both channels!). But without some kind of mod, they phase cancel each other and sound like poo....

Tim

[muchxs]

I'm trying to find the "Worthless Channel" on my Princeton Reverb. There's no trace of it, even with the chassis out of the cabinet...

BF Bassman. Which channel is the worthless one?

BF Bandmaster. Same question.

It must be The Worthless Channel is on cable TV. With over 900 channels and a channel for everything else, it had to happen...

[beep.click]

Originally Posted by bradpdx

The reverb is never off. That's how I roll.

That's been my M.O., too, for 30 years now -- I just got in the habit.

After reading all the ideas in this thread though, I've got a lot of stuff to try! I immediately started thinking, "Don't I have something lying around that would invert the phase of a pedal output...?"

[bradpdx]

Originally Posted by JohnnyCrash

The bright cap is pretty much bypassed 3/4++ up the dial, but the gain on a BF reverb channel is one triode hotter, regardless. Its got more gain, tube compression, and overdrive than a Normal channel... its going through half a preamp tube more (regardless of reverb settings). Its the nature of BF circuits. Its also the magic of the Reverb channel - not the verb, but the extra tube sauce.

Yes and no. There is indeed one additional triode stage used to mix the dry and reverb sends, but the gain is reduced via a resistive network so that the Normal and Vibrato channels have approximately the same gain. I said "approximately" you will note

The mixer includes a small bit of EQ that produces a mild rise in the high end as well. Small but noticeable.

I think that one of the sonic factors is that each triode stage runs without feedback and thus generates a fair amount of "soft" non-linearity. Each additional stage adds a bit more of this funky harmonic content.

35 years of playing and I still don't have a very good use for the "Abnormal" channel. Just a Fender reverb junkie with no plans to kick the habit.

[Ben Harmless]

Originally Posted by maestrovert

hmmm.....the normal and bright channels are out of phase with each other due to the extra gain stage Johnny Crash just explained....it wouldn't sound very good...unless you've come up with a convenient way to reverse the phase on one of the Boss Delay's outputs ?

True, they are reversed polarity, but if one only outputs 100% wet to the non-reverb channel, then there shouldn't be any cancellation, because the signals being fed to the channels are quite different.

There's always a possibility that it would sound a little weird, but I would absolutely give it a try.

[gaddis]

Originally Posted by bradpdx

The reverb is never off. That's how I roll.

That's how I tend to roll too, but if I play any jazz I like it to be reverbless. If you put reverb on with jazz, it tends to sound like elevator jazz.

[varakeef]

I've sometimes used normal channel as a cranked up solo channel with a simple A/B box. Or another way around.

[Bob Arbogast]

"Worthless channel"? That's the one with the reverb, isn't it? I never have liked reverb. Fender amp reverb always seems to have a bunch of "hash" floating around murking up the sound. It's not just echoes and reflections, it's more like a dull haze. Not for me. Obviously, for many of you, your mileage does vary! Enjoy.

Bob Arbogast

[umasstele]

I always use the normal channel except when noodling around!

[rbrienzo]

I've always thought of that channel as spare parts.

[Radspin]

I can't live without reverb--I have to have it!

[tele_jas]

Originally Posted by markesquire

Most BF amps have a reverb channel and a channel that never gets used. Ever.

Is it possible to modify the circuit so that you have a tweed deluxe on the first channel and a deluxe reverb on the second?

The worthless channel?

Man, I can hear the lynch mob headed your way all the way on the other side of Joplin!!

LOL