Salem?

[JohnnyB]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...item=7338651082

[Rockola]

Looks sweet. I'll bet it has a deep, Rich sound with a RioGrande BBQ.

S.

[salem]

I love, love, love, tweed amps. They are instruments to write on. They have a vibe all their own: down and out, in a hotel room, addicted to heroin, writing a country blues love song. Keith Richards, Neil Young, Eric Clapton, Pete Townshend, are just some of the rock stars who use tweed.

You can tell I love tweed.

[MCChris]

You can tell I love tweed.

And heroin.

[Moose]

You can tell I love tweed.

And heroin.

There's a difference?

I'm afraid many modern guitarists don't realize what's special about tweed circuits. People seem to think that volume and tone just isn't enough, but the tweed Deluxe is a remakably versatile circuit. Sort of an amplifier version of the Korina Junior -- there are a hell of a lot more sounds in there than you'd think, and all of them are good.

Those who always seem to ask "Does it have more gain than boogie? How 'bout more than a 5150?" won't apprecialte the charm. That's understandable, but there's a lot to be said for 15 watts, early breakup, great touch sensetivity, and a tone that just makes you grin while you play it. Records like a dream, too.

The Deluxe is one of the truly great tones of the rock and roll era.

[salem]

You can tell I love tweed.

And heroin.

There's a difference?

I'm afraid many modern guitarists don't realize what's special about tweed circuits. People seem to think that volume and tone just isn't enough, but the tweed Deluxe is a remakably versatile circuit. Sort of an amplifier version of the Korina Junior -- there are a hell of a lot more sounds in there than you'd think, and all of them are good.

Those who always seem to ask "Does it have more gain than boogie? How 'bout more than a 5150?" won't apprecialte the charm. That's understandable, but there's a lot to be said for 15 watts, early breakup, great touch sensetivity, and a tone that just makes you grin while you play it. Records like a dream, too.

The Deluxe is one of the truly great tones of the rock and roll era.

Moose, I'm not sure if you'll come back to this thread, but are you able to talk a little about how the interactive volume controls work? I haven't had a chance to play a deluxe yet.

I understand that the volume control on the channel you are not using affects the tone. What happens if the other volume control is all the way down? All the way up?

Also, What exactly is "sag?" I understand the 5Y3 rectifier offers "sag."

[bobbymack]

You can tell I love tweed.

And heroin.

Hashoil too.

[Guest teefus2]

that's joe's, isn't it? the same guy selling the virt, dbl neck and the cali, i think.

[Moose]

Moose, I'm not sure if you'll come back to this thread, but are you able to talk a little about how the interactive volume controls work?  I haven't had a chance to play a deluxe yet.

I understand that the volume control on the channel you are not using affects the tone.  What happens if the other volume control is all the way down?  All the way up?

Also, What exactly is "sag?"  I understand the 5Y3 rectifier offers "sag."

Deluxe is a strange animal. I'm going to make some oversimplified statements here to try and explain this.

The first two channels are tied together at the cathodes of their first tube AND at the tone control. Also, both channels hook up to the output of the tone control, but only one has a tap at the other side of that control.

A tone control, like a volume control, works by dumping excess signal to ground. The difference is, the tone control only dumps high frequencies, the volume dumps it all.

On the deluxe, if you trace one signal path you have:

input -> tube -> tone control -> volume control -> tone control variable part -> poweramp

the other goes:

input -> tube -> volume -> tonecontrol variable part

So, you see, that volume control on the first channel has to be on zero to let the tone control work normally for the second channel.

Here's the trick, though. If the volume knob of the first channel isn't on zero, the second channel can run around to the ground side, bypassing some of the tone control. And the amount of that bypassing varies with the setting of that other volume control.

So, when you plug in to one channel and then start twiddling the knob for the other channel, you're both losing some of the signal to ground AND you're running some of the signal into the tone control from the other direction. This changes the timbre of the amp entirely, not just as a tone change, because there's the resistance from that other volume control in the mix, as well as the fact that you're affecting the cathode of both tubes.

The net result is, if you plug into the bright channel and start dialing up the dark channel as well, you get a darker sound that's different than if you just rolled back the tone. Also, if you point the channel you're in to about 9:00 and the other channel to 3:00 or higher, you can find some really strange harmonics that are exceedingly pleasant, but unlike most other amps you've ever heard. I actually like to rig a rhythm tone by running the dark channel at full blast, the bright channel at about 3:00, and then dialing back the dark channel until I find the tone I'm looking for.

Really, all you have to do is start twiddling and you'll figure it out pretty easily, though there are a zillion things you can try. You can also bridge the channels like on a plexi, and one of my customers actually runs a backpack on his with a rack that includes a single rack unit with chorus and reverb -- he goes into the bright channel 1, goes out of brght1 into the rack and back into dark channel 1. Then he uses the knobs to mix wet and dry signals.

As for sag, from your standpoint it translates as touch sensetivity. Basically, a tube recto has a certain amount of resistance and when you strike a big, loud chord you're drawing more current. When you draw more current across resistance, the voltage drops. So, if you're turned up and hit gentle notes, you're running at higher voltage than if you strum a big ass chord, where the voltage sags. Higher voltage makes cleaner sound, lower voltage makes tubes break up earlier and differently.

The neat thing about sag is that it allows you to play clean when picking gently or rolled back and strumming chords, but when you crank it over it adds some compression and distortion to the sound. It doesn't get a lot louder after a point, but it gets more compressed and harmonic, which makes your guitar volume control super useful and your right hand actually causes a response that is much like an acoustic instrument.

All this is a LOT easier to understand when you have the amp in hand. You twiddle the knobs, plug in something with a humbucker, then start pickin and grinning.

[ET_KenW]

that's joe's, isn't it? the same guy selling the virt, dbl neck and the cali, i think.

Yes it is Joe. Might be interesting to look at what else he is selling. I think the Celestial Chap is cool, but my lack of talent cannot condone buying it. I'll stick with my bottomfeeder guitars.

[salem]

So Moose, would it be correct to say:

If you are plugged into channel 1 and turn up the volume on channel 2, you will increase the effect of the tone control and remove some of the midrange.

If you are plugged into channel 2 and turn up the volume on channel 1, you will gradually remove the effect of the tone circuit and add midrange to the tone of channel 2.

I thought this quote from Dan Torres on the subject was interesting too:

"When you are turning the unused volume control you are “fine tuning” the grid load resistor to the next stage of the amp. An optimum (best sounding) value is not all the way up, but somewhere near the middle – the lesson? Tubes are NOT linear or mathematical devices – they do not respond to exact mathematical figures and have “hills and valleys” in their response – maximum performance can not be calculated directly – you have to hear it and you have to be aware that the “truth” may not be at some exact calculated place, but at some far more imprecise figure."

[Moose]

So Moose, would it be correct to say:

If you are plugged into channel 1 and turn up the volume on channel 2, you will increase the effect of the tone control and remove some of the midrange.

Pretty much, yes.

If you are plugged into channel 2 and turn up the volume on channel 1, you will gradually remove the effect of the tone circuit and add midrange to the tone of channel 2.

Sort of. The tone circuit will still work, but you'll remove the effect of half of the tone circuit.

If you want to think if it in terms of bright and normal (the channel lables originally used) the bright channel has an extra capacitor on it that the normal channel does not. This cap effectively bypasses the run from the volume to the tone control, leaving a little high end through and making it brighter.

Well, if you're in the normal channel, and the bright channel is on zero, there's a buttload of resistance between you and that brightening cap, and the brightening cap is effectively grounded so signal never passes through it. But, as you dial up that unused volume control, you get LESS resistance between you and that cap, and MORE resistance between that cap and ground -- making more of the high end bleed back into the signal.

Again, it makes a lot more sense to just start twisting the knobs and listening, because there are MANY other variables here, including the fact that the cathodes of both the bright and normal channel are tied together, so the frequency response is even controlled to a minor extent on the OTHER side of the tubes.

Another thing to point out is that, when you turn the unused channel all the way up, you'll actually lose significant amounts of gain. Back it off just a little bit and you get the gain back. Think about it -- it's on full volume, so all its resistance is on the ground side. The full effect of the used channel gets to pump back into the plate of the unused channel, and it does some crazy things with the other channel. They sort of work against each other. Just a little resistance in line there mitigates the effect, so going from full volume back to 9:00 on the unused channel can be the difference between a funky strange sound and a rip roaring fire breather.

I think you'll find it great fun to experiment with all this.

I thought this quote from Dan Torres on the subject was interesting too:

"When you are turning the unused volume control you are “fine tuning” the grid load resistor to the next stage of the amp. An optimum (best sounding) value is not all the way up, but somewhere near the middle – the lesson? Tubes are NOT linear or mathematical devices – they do not respond to exact mathematical figures and have “hills and valleys” in their response – maximum performance can not be calculated directly – you have to hear it and you have to be aware that the “truth” may not be at some exact calculated place, but at some far more imprecise figure."

Kind of sounds mumbledygooky to me, but his point is clear. Twiddle the knobs and listen. Your ears are the best determining factor.

As for fine tuning the load on the next stage, that is also true. Most tube stages are loaded with a resistor from the grid to ground. Some are loaded with a volume control (a variable resistor) but the effect is the same. If you're moving the volume knob of both channels, you're changing that effective loading.

In the deluxe, you have two volumes in parallel, PLUS the tone control. The tone control really doesn't change much because adding more on one side takes away from the other, but the volumes DO change things, even if they aren't being used actively.

Honestly, I don't think Leo designed any of this for the sake of making a signature tone. I think he was a tightwad and it was the easiest way to consistently make a 2 channel amp that people could afford. It wasn't until a few years later that guitarists started turning their amps up too loud so they could hear the harmonics!

[Guest Mike Lee]

Les copied a lot of his amp schematics right out of the Westinghouse book of sample tube applications. Some of them, especially the "two-channel amplifier with 3 band EQ and presence control" (Bassman), work very well for guitar by complete accident.