Mesa Boogie Dual Rectifier backup ss amp

[Zappacat]

I personally use a 10 Watt tube power stage in my ReAmp setup
which is loosly based on the Guytron GT100 concept.

My Signal path goes like this;
Tone box > OD circuit > 10watt PP TubeAmp > Soak/Spk-to-Line > Graphic Eq >
120Watt SState PwrAmp > 15inch speaker (sealed back)
(the first 4 are all home brew gear.)

Can you tell me what you mean by "Soak/Spk-to-Line"  Thanks!

[phatt]

I personally use a 10 Watt tube power stage in my ReAmp setup
which is loosly based on the Guytron GT100 concept.

My Signal path goes like this;
Tone box > OD circuit > 10watt PP TubeAmp > Soak/Spk-to-Line > Graphic Eq >
120Watt SState PwrAmp > 15inch speaker (sealed back)
(the first 4 are all home brew gear.)

Can you tell me what you mean by "Soak/Spk-to-Line"  Thanks!

Hey Zappacat,
                    Just a big resistor (instead of speaker) to soak up the tube power stage, then a voltage division to give you a line level output so that you can Re EQ it all and send it onto another amp of much larger power rating. Hence I call it a *ReAmp System*.

This captures the power tube compression effect which if you care to think about it for long enough is what all those fancy pedals are desperatly trying to *Emulate*.
Ouch!    Can I say that here?
The Tube Power stage is the most dynamic part of a tube amp so that's what you really need if you want great dynamic guitar sound. This enables you to pull all those tones you've never been able to get without deafening everyone.
Any OD you want at Any SPL you so wish.
Even my ten watt tube amp straight to a speaker is to Loud for practice.
This idea was obviously good enough for Eddie VH,,, so I'm happy with that.

There are many ways to do the same or similar thing but I've found this way is the cheapest to impliment and being modular you can interchange a lot of different gear,, experimenters dream for me.

Most attenuators (which is how mine basicly works) Destroy the tone if you try to drive the speaker directly from the attenuated signal and most folks (including some experts) tend to leave it alone or go the other way and turn it into an overly complex box of tricks (resorting to light bulbs amoung other things) but fail to realise you can just tap the simple resistive load ,,eq it, time based efx and many more things to it and simply reamplify it all.  Heck that's what basically happens in a Recording Studio anyway and they seem to sell a lot of records and no one even blinks.

Some tone geeks forget that most players are trying to *Emulate a Pre Recorded Sound/Tone* as that's how most of us hear things and the sound is often coloured anyway.
If you where standing in the studio when the Actual Recording was taken,
then 9 times out of ten your brain would have heard a completly different sound/tone.
Even the best of mic's add there own colour.

I'm adding my load box schematic for you,, give some ideas to work with.
The boost is just a level shift,,, a nice little add-on with no complicated relay.
Just make sure the Main load resistor is Bigger than the wattage from your tube amp.
ie, 10 watt amp use 20 to 30 watt resistor,, no need to run things to hot.

Be warned some tube amps today have utterly stupid HT voltages way beyond what is really safe so make sure you know the amp or derate it's HT via the VVR you mentioned.
My tube amp is home built useing only 240Volt HT.
I could bump it up to some stupid voltage like 360Volts but this does nothing to improve the tone/dynamics. Fact is the power tube compression works better running on lower HT anyway, so a win win.
Have fun,, Phil.

[Zappacat]

I'm planning on building an 18watt clone.  Already have the transformers and turret board.  If I built a head unit could I utilize this same type of setup?  Basically i'd be using a resistor circuit some way to bring the 18 watt heads CRANKED UP output down to line level and then sending that line level signal to a solid state amplifier?

What if I wanted to use something like a POD XT for effects?  Where should it go in the signal chain using your preferred signal path?

I really like the idea that you've presented here.  I'm on a REAL tight budget right now.  If I don't have to shell out a lot of cash for some vintage speakers on the 18 watt setup I'd like to run the output of it into something solid state as you describe.  I guess the solid state amp should be something that doesn't color the sound much.  Could I use that tone stack of yours after the attenuated line level signal of the 18 watt and send that into one of these home built chip amps based off of LM386 or something like that?  What do you suggest for solid state power amp + speakers?

Sorry about all the questions.


Thanks Phil

[phatt]

Just a small point - not only push-pull pentodes, but single ended pentodes/triodes provide the tube feel as well (all the small tube combos out there). I think an ECL86 or ECC81 power amp should be sufficient and hope to try out soon.

The Dr.Boogey pedal looks nice - I might try one later as I have a bunch of distortion pedals with quite nice sound if used with a tube amp.

Just be aware that SE output generally don't quite work as the PI section seems to be part of the sound/tone, If I remember correctly Guy Kendrik even mentions it on his site.

But yes by all means try it.

Silly me I've just realised that I missed your reply,, till now

I should (when I get time) post my whole blab with schematics under Hybrids as this is deviating from your content. Thanks, Phil.

[phatt]

I'm planning on building an 18watt clone.  Already have the transformers and turret board.  If I built a head unit could I utilize this same type of setup?  Basically i'd be using a resistor circuit some way to bring the 18 watt heads CRANKED UP output down to line level and then sending that line level signal to a solid state amplifier?

What if I wanted to use something like a POD XT for effects?  Where should it go in the signal chain using your preferred signal path?

I really like the idea that you've presented here.  I'm on a REAL tight budget right now.  If I don't have to shell out a lot of cash for some vintage speakers on the 18 watt setup I'd like to run the output of it into something solid state as you describe.  I guess the solid state amp should be something that doesn't color the sound much.  Could I use that tone stack of yours after the attenuated line level signal of the 18 watt and send that into one of these home built chip amps based off of LM386 or something like that?  What do you suggest for solid state power amp + speakers?

Sorry about all the questions.


Thanks Phil

Hello Zappacat, all is well with questions,,, taken my pills :loco
Basically try every option till you find what works with the gear you have.
Keep in mind everyone has different ideas of what constitutes great tone.

If you want to save a lot of pain drop the efx till you *Nail a good Rock tone*,,Pretty much all the other tones stem from that basic tonality.
I've simply discovered an easy and cheap way to develop most of the tones that are usually sort after without the need to buy out the fender factory.

Chip Amps ?

I just recently fixed a mates Trademark60 (Tech21) Although he was very impressed as I had swapped the overly harsh original speaker it came with for something a little more civilised giving the amp a lot more warmth.
I then made the mistake of plugging my ReAmp rig into the Return jack of his Trademark 60 Amp bypassing all the preamp stages only using his powerstage and speaker and he almost wet himself with excitment,,
The Trademark uses an LM3876 chip powerstage,,, so there you go,, Even with all the (covered in Goob) secret circuitry that lurks inside Tech 21 preamps it can't compete with the Reamp system. A fair test as the power chip and speaker where the same.
Now He wants a Reamp setup built like yesterday.

As to other power chips;
remember they are ALL DC Amps and By Design these are ALL made to have a DEAD Flat Response anyway so there is very little difference except for power I guess.
You can change the bottom end rolloff via external Cap selection but that's about it.

Getting tecky;
              The LM3876 power Transistors are all NPN and that maybe rather old hat design.
From what I've read an N and P channel device would work better. But hey it sounded ok.
All that stuff is to deep for me ,, others here will be better qualified to comment in depth.
------

Ok Re the signal path;
I've found the PhAbbTone FIRST seems to work best then > OD box > Tube amp > Soak to line > Efx here if I use them > Graphic> SState powerstage.

Cut the mid on the PhAbbTone (if your taking note,, you will know that's cutting at about 400Hz.) Then it's tilted towards the treble > tube amp > Graphic up at 100Hz, big cut at 1000Hz, then up again at 2/3kHz, past 5kHz not much happens.

This works well through my tube Amp so as you can hopefully understand with a big ultra bright tube amp it would all need a rethink.
Think long and hard about it before you build the tube amp as most HotRod tube amp info assumes it's driving a speaker directly but I found no use for *Multipule preamp triode stages*, In fact it's debateable whether triode preamp distortion sounds any different/better than SState circuits. Remember you want to hear the power tubes not preamp fizz.

If it helps,, My tube amp is only average by itself (an old slightly dark, almost muddy plain tubeamp from a bygone era) but it has the dynamic response that can't be done easily via SState. the rest is My PhAbbTone box,, Crunch box,, and Graphic after the tube amp.
If you think that you have to perfect the tube amp tone FIRST then you waste a lot of solder trying to perfect it.
BTDT,, yuk never again. All the slick tone tweaks stuff can be done outside of a simple tube amplifier.
My tube amp is really just a big oversized compressor.

BTW, go back to the second post here and read the link to Amptone page it will save me a lot of writing. Hopefully that will help shed light on what is often made to seem extremely complex. 90% of all that a guitar player needs to know about what goes on inside guitar amps is about *Tone Shaping* not Exotic Components soaked in snake oil,,,
Just put the Right EQ shapes at the right places in the signal chain and,,, presto.
------
I should mention the *Ground Lift* as anytime you join two chunks of Grounded gear together you will run into the dreaded ground loop hum issue. My guitar player brain can't cover every senerio so having the Ground Lift switch will Hopefully resolve most problems with ground loops. It's probably more pro to use an Isolation transformer but you will
need to use a good audio type and they are not cheap. I've opted for the poormans alternative which is at least SAFE.

And in case you or others get crazy ideas; Don't cut the earth plug to one Amplifier to kill the loop hum!
yes it works extremly well at killing hum,,,,And When your *DEAD* there is no hum. 0:)

I think if we continue it might be better to start a new post, as this is getting away from *pelanj* questions.
Cheers, Phil.