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Author Topic: PhAbb SS AmpDemo  (Read 16262 times)

phatt

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PhAbb SS AmpDemo
« on: January 06, 2010, 12:40:25 AM »
Hi everyone,
                 Could not decide where to put this but as there is no actual *PowerAmp* being used to generate the audio then this seems the most logical place.
Well I figured enough talk why not a little demo of my PhAbb SSAmp Setup.

As just about any bit of gear these days (including mine) can produce copious amounts of distortion then why not demo those in between dynamics that are probably harder to reproduce with all SS equipment.

Tube Amps have an area which is on the edge of distortion and this was my aim, to nail/capture that in between *Rattle* that a lot of those famous tube amps where able to do so easily.
The Knophler sound is often a tricky one so I tried it out, see what you think.

First track is done with a bog stock Chinese Strat copy, I like it for this stuff because the Pup's are low winding only 4k DCR.
The second bit is Recorded with my other guitar (real 60's era Strat pup's)

(Maxiverb is a stand alone Spring Rev unit I desiged and built about 10 years ago,, and still going strong.)

Signal path;
Maxiverb > My PhAbbTone box > DDC (My Dynamic Distortion Control)
> A Realistic HiFi GraphicEQ > signal into Line mixer> Into Audigy SCard.
Adding no post efx of any kind.

There is very little difference between the line rec out sound and a real 100Watt power amp driving a guitar speakerbox (To my ears at least) but your speakers will colour the sound to some degree no doubt.

If any interest I will post more short demos and all the setup schematics, might give you some ideas to work on.
Sorry the file is short but only 500kb allowed.

Hope you enjoy, Phil.
Edit 2011
> Reloaded the files and Dloaded back to myself and it seems to be working OK now.<
« Last Edit: January 22, 2011, 12:14:28 AM by phatt »

phatt

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Re: PhAbb SS AmpDemo
« Reply #1 on: January 06, 2010, 01:49:07 AM »
Just another short clip 4u all,
This is all done with ROC Strat copy, Same recording setup just cranked a bit.

Meantime a question if I may?, regarding uplaods,
Posting page states this;
"Maximum attachment size allowed: 512 KB, per post: 6"

Does that mean 6 attachments of 512KB Each,  or 512KB Total?
Thanks, Phil.
« Last Edit: January 22, 2011, 12:11:17 AM by phatt »

Zappacat

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Re: PhAbb SS AmpDemo
« Reply #2 on: January 06, 2010, 04:02:45 AM »
Sounds fantastic.
I put my pants on just like the rest of you - one leg at a time. Except, once my pants are on, I make gold records.

J M Fahey

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Re: PhAbb SS AmpDemo
« Reply #3 on: January 06, 2010, 11:58:13 AM »
Sounds fantastic [2]
I think it's 500K per individual attachment, not total.
Anyway "the proof of the pudding lies in the eating", just *try* to send 3 or 4 500 k attachments in the same message, they will either be accepted or not. 8|

phatt

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Re: PhAbb SS AmpDemo
« Reply #4 on: January 09, 2010, 09:21:10 AM »
Hi Zappacat and JM Fahey, Thanks for the  :tu: vote

Will have a go at posting multiple files soon,, meantime there is always other things to do in life. :(
Phil.

phatt

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Re: PhAbb SS AmpDemo
« Reply #5 on: January 13, 2010, 10:01:44 PM »
Hi all,
Just a picture from the shed, My SS Rig.

Signal passes through,
Reverb> Tone box + DDC> Graphic> onto 120Watt SS PowerAmp.

Everything has *true bypass* switching.

The *White unit* is the *PhAbbtone and DDC* all in one box.
As I've mentioned the DDC circuit is a modified Nobels SST,
So these are plonked on top to give you some idea of what is inside the White unit.

(Also shown to give some idea of how the signal path could be setup with other equipment.)

This graphic utilises *both L&R channels* via an In/Out/In switch (Red switch top right) so you can insantly switch between two preset secondary tone shapes.

Oh the Maxiverb has no speakers, it was one of my many failed attempts at making a small amp but now just houses the Spring Reverb, hey why build another box.

Under that is the no name 12 inch driver which is a shame as it's one of the better Q'ed sounds I've heard from cheap speakers, Very close to a real Celestion.

The ugly brown bit down the very bottom is a *Rotery Speaker* disected from an old B5bR Yamaha organ. It only delivers a subtile sonic spin but I miss it when it's not there.
 
I also have a 15 inch Dia-achi 150Watt driver which I also like a lot, it's a toss up which one sounds better but the 15 has just a touch more treble suprisingly.

The 120Watt poweramp (black just under the white unit, partially hidden) is an old *Inkel* factory PA. I only use the poweramp part as it has a *link-in* on the back panel.

Just thought it might give people ideas to work with.
Cheers Phil.

Brymus

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Re: PhAbb SS AmpDemo
« Reply #6 on: January 14, 2010, 02:06:30 PM »
Hey Phatt
VERY IMPRESSIVE INDEED
That sounded like a high end guitar rig for sure.
I am just curious why the reverb is first in the signal chain?
At any rate it definatly works good that way.
What is your noise floor like ?
And what part of the chain contributes the most noise ?
The single coils or one of the other pieces of equipment ?
Thanks for sharing I definetly enjoyed seeing/hearing your set up!!!!

phatt

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Re: PhAbb SS AmpDemo
« Reply #7 on: January 15, 2010, 07:56:46 AM »
Hey Phatt
VERY IMPRESSIVE INDEED
That sounded like a high end guitar rig for sure.
I am just curious why the reverb is first in the signal chain?
At any rate it definatly works good that way.
What is your noise floor like ?
And what part of the chain contributes the most noise ?
The single coils or one of the other pieces of equipment ?
Thanks for sharing I definetly enjoyed seeing/hearing your set up!!!!

Hello Brymus thankyou for leaving a comment.

Reverb unit in front is old school thinking and as hundreds of famous guiter tracks
where recorded in this manner ,,,Why change it?

Took me many years but it finally went clunk one day when I saw a photo of SRV with a *Standalone REV unit* sitting on top of his famous Dumble head.
Ding! the penny dropped, he was not using the internal REV circuits on fenders.
They where never designed to be driven into very hard clip.
When you drive them really hard the frist triode stage clips and multiplied again
via the Rev Driver circuit. By then the whole rev sound just claps out and distorts badly.

Outboard rev units don't normally suffer this fate which delivers the signal into
the Amp clean leaving your triodes (if using valves) to do one job well, not a compromise of two jobs.  
This is tricky to explain but simply put if the REVERB is Created CLEAN then you
can Drive the signal into Heavy distortion *After* Reverb creation and it sounds
fine.
Hope that makes sense.

I've spent years working it out and I've found that most *Onboard* reverb circuits are deadpan when compared to mine (or most other well designed OutBoard rev units)
There is a newfound interest in the older valve rev units but way out of my price
range so I wanted to perfect a SS unit that would come close to being as good as the the old valve unit's.

Noise floor;
            Very low when comparing to shop sold gear I'm very happy with mine.
Hum is close to negligable, Hiss goes up when using the *DDC* but the gain and
drive knobs hardly ever need to be past half on, 12 O'clock.
(in those Heavy samples the the drive knob was on 10 O'clock (4)
and the Gain knob at 9 O'clock (3) level out 12 O'clock (5)

I think most go wrong by assuming you MUST HAVE MORE GAIN no matter what and deal with the hiss and hum via some other means.

When really there should be much more focus on the *tone shaping* of distortion.
**If you amplify the right frequencies you don't need all the gain.**
Casscading Fets or triodes is a no brainer simply because neither can actually
produce square wave well and until that happens it won't ever sound as convincing as a simple well EQ'd diode clipper,, which actually CAN produce a close approxamation of the signal passing through a Valve power stage.
(power tube compression is considered by some the holy grail of tone)

Just EQ either side of the old TS9 circuit and it might suprise you. :o

A good example of the POWER of tone shaping can be shown thus;

Take ANY of those old VALVE Amps, fenders or marshalls from a bygone era and plug in a fender strat, now crank all the tone knobs well past halfway and then crank the volume past 7.  Play HARD and LOUD.
Now assuming the amp is unmodified and stock then I doubt whether you will like
what you hear as the MASSIVE bass will most likely turn it all to MUD.

So how come SRV was able to get such incredable tone out of amps like these.
Answer is simple,, *tone shaping*.

Via a simple little tone shaping trick any *STOCK* Super reverb or Vibroverb or
Marshall can produce that same sweet almost clean compression,
That distinctive Bell like tonal signiture.

This trick is totally external so any stock amp from that era will reproduce similar results. Sadly 9 out 10 Valve amps today don't have the part needed to make that trick possible as they deleted it. :'(

EDIT, point being send the *Right Frequency Response* to the output valves and Amazing things will happen.
BTW this simple trick can't be done with ANY SS Amps,, sorry:(

Back to the subject of my gear;
Most of my stuff is all old school but just well EQ'd.
If Fet's are to be used then use them as MU boosters into a well setup clipper
setup and that maybe more user friendly and a lot less NOISE.

When I started out I wanted what most want,, that being an ALL in one neat little box amplifier, most call it the combo amp.

But having spent neary 30 years frigging around with all sorts of ideas I've come
to the conclusion that *ComboAmps* are a mugs game as there's always a compromise involved.

So obviously I have a totally modular setup now.
If the Amp goes down I can take my Maxiverb and PhAbbtone to any other Amp and get close to the same tonal signiture. ;)
For me the all in one box concept is just to limiting now.
Cheers Phil.
« Last Edit: January 16, 2010, 07:42:32 AM by phatt »

Mangas

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Re: PhAbb SS AmpDemo
« Reply #8 on: January 22, 2010, 06:27:52 PM »
Nicely done!  :tu:

phatt

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Re: PhAbb SS AmpDemo
« Reply #9 on: January 29, 2010, 05:15:36 AM »
Thanks Magnus,, I've got the sound.
Now I just need to make my circuits look as professional as your's  ;D

Just adding the schematic for the DDC as the PhAbbtone circuit is already on this site. The DDC is the only thing not posted, the rest is gear purchased s/hand.

Please note I own the original Nobels SST1 and it's now beyond fixing,
I've just taken the bit that works well and refined it.

I think it's important that I state it's not entirely my design, So I can't claim any originality here. I've just tweaked it and made it a lot more dynamic and returned the bass response for use with a real speaker.
Being a headphone unit they most likely wiped a lot of bass.

Although this will be old school teck to those in the know it is certainly capable (with the aid of a simple tone stack *Before* and Graphic *After*)
To capture many different tonal signatures that a lot of guitarists are chasing.  

The interesting thing is the rather low R2 68k, most circuits would use a much higher value here. in real world testing hanging 1Meg resistors on the front end may well do little.
Sure you get more bandwidth but then it gets killed off via the cabsim.

Thing is you just amplifiy more hiss and hum and get closer to oscilation,,
so it's a dog chase tail.
Have fun, Phil.
« Last Edit: January 29, 2010, 05:48:48 AM by phatt »

rodriki1

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Re: PhAbb SS AmpDemo
« Reply #10 on: February 08, 2010, 06:39:58 PM »
First i wanna thank you for your capacity to share that kind of knowledge.
I MUST SAY that is incredibly rare and precious...

i have been reading and researching those kind of stuff for years (i mean
- ideas about tube amps made with SS)...
but it´s very sad that we cannot find very much ideas to apply..
when the thing is good it is always protected..

I personally agree that tone shaping (equalization) can make the sound you want..
but sounds to me that a good circuit for tone shapping
in general gets very expensive...
in many ways it is very hard to me to get the sound of tubes in my country.
the problem is entirely mine, but i like the distortion produced
by tube amps...

below is one idea for tone of 4x12 box that i found the other day...



It gets one peak arounf 4Khz... very good for ac/dc....
baxandal controls are used after this thing...
your distortion circuit sounds very good (the most natural distortion-
better than DS1 aproach and many others)...
I hate ts9 aproach for distortion..
If we look at Stephan moeller work (not very easy to find today- he
simulated vox ac-30 from op amps and diodes) he advices us to use
op amp at inverter configuration...

i am trying to get AC/DC perfect emulation (sorry if some hate this word)
from op amps (and whatever is possible - since it is SS)...

thanks again hope you be happy with your research.

phatt

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Re: PhAbb SS AmpDemo
« Reply #11 on: February 09, 2010, 08:59:31 AM »
First i wanna thank you for your capacity to share that kind of knowledge.
I MUST SAY that is incredibly rare and precious...

i have been reading and researching those kind of stuff for years (i mean
- ideas about tube amps made with SS)...
but it´s very sad that we cannot find very much ideas to apply..
when the thing is good it is always protected..

I personally agree that tone shaping (equalization) can make the sound you want..
but sounds to me that a good circuit for tone shapping
in general gets very expensive...
in many ways it is very hard to me to get the sound of tubes in my country.
the problem is entirely mine, but i like the distortion produced
by tube amps...

thanks again hope you be happy with your research.

Hi Rodriki,
Very kind words so I thank you and I'm glad that you find my observations useful.

Re cost of good tone;
try this, http://www.ssguitar.com/index.php?topic=1136.0
That is the circuit I designed and built and is the tone control used in these clips. 8|

The tonal possibilities here are very broard and I can't imagine you could not get something close to ACDC sound.
Not counting the Reverb unit all the preamp gear here is cheap enough to build.
The *PhAbbtone* parts cost me about $30 Aus.
*DDC* is similar cost but more complex,, all doable for anyone with resonable pedal building experience. So in a box complete I can't see it costing over $150.

Oh and the *Graphic EQ* cost me $8 at S/hand shop. ;D
----------
Re thoughts on tone:
A big *arh huh! Now I get it moment* for me was once I discovered that tone response is much like a garden hose laying on the ground,, where when you lift one point (the Q point) off the ground you also lift a fair part of the rest of the hose. Passive tone shaping does the same thing. (so tone is all just a big rubbery thing)

A bigger moment was understanding that tone is constantly altering as it passes through each passive and sometimes active components,, Not just the tone stack.

For want of a better explaination;
Tone is just one tone shape (response curve) imposed onto (or into) another element with a different shape.
What I think makes it difficult to grasp is that we all tend to go hunting for that *One magic circuit* that delivers the major component of a specific tone.
Truth is it's a culmination of many circuit topographries and tricks all working together that makes the final result.

Adding to that already complex situation  :loco is the simple truth that there may be many ways that effect the same end result.

For a novice, this is much like walking through a 3D mine field with so many twists and turns that getting it right first go is impossible. :duh

The magic of the classic Marshall amps that are now famous actually have a unique Flaw.
""It is in fact the design Flaw that makes it so great.""

if you ever find yourself with a *Genuine* older model all valve Marshall,, try this out.

At low *level volume* turn the tone controls up and down and note how they affect the freq response.

Now crank the volume way past halfway and play a few rifts/power chords,,, while you are doing that start playing with the tone controls again ?
You will now realise they don't work very well and depending what guitar and how far you crank some tone controls may no longer seem to function AT ALL  :o

The compressing output stage renders the tone stack almost non existant?? Hum??
Early Marshalls tend to develop a huge wall of midrangey honk that suits the rock compressed sound. below 100hZ just falls like a brick and the combination of dramatically altering impeadences and output transformer limitations of high freq kill off above 4khZ. choise of speakers helps too.
It more complex than that but I won't get into pointless detail.

Now take a Peavy Bandit, All SS (only cause I've been fiddling with these recently)
Try cranking up the drive and notice how the tone controls still work as effectivly as they did with no gain/distortion.
technically it could be argued that the Peavy tone works better than an old Marshall?,,
No argument from me,,, but which Amp would you rather use? :-*

You see the Peavy uses *Active* Tone shaping,, not passive.

It also suffers from WAY to much bandwidth,, way to much low freq content below 100hZ and the treble is extreme even by comparison to some other SS Amps.

Yet some players love those Bandit Amps? and that's kool,,Everyone want's something different but if you wish for a Bandit to sound like my clips you will be tweaking it for a very long time. :'(

What I've found is that passive *Before* the distorting device and Active *After* seems to work very well together. There are probably other ways but I do actually play guitar and I've only got one life.
What is most interesting is that my setup seems to have the very same tone control flaw as the Marshall. :tu:
----

Try googling *Ed Rembold Marshall cab sim* or grab a schematic of
a Marshall JTM 30 or 60 Valve Amp where you will find the *Built in Cab sim* which is an add on SS circuit which does a respectable job of the sound required.  (No distortion though just tone shaping).
The marshall cab sim is a little less complex than my DDC but delivers similar results. I've built 5 of them so I know they work.
----

You mentioned Vox, I'll assume here you are reffering to Brian May Sound?

Consider this,, Brian May used the *** Normal** Channel,,not the *Bright* channel  (as most assume) to get his particular sound.
So simulating the tone stack seems rather pointless because the normal channel on a Vox AC 30 *Has No Tone stack*. The signal passes through a 500k volume pot and the only other tone altering device is a *Top cut pot* mounted across the PI section.
Simply by implimentaion of a rather basic treble boosting transistor circuit in front of the Normal input will deliver that particular tone.
---
Re the circuit you give seems to do nothing in my simulation but I may have missed something?

Have fun with it all, Cheers, Phil.

rodriki1

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Re: PhAbb SS AmpDemo
« Reply #12 on: February 09, 2010, 06:57:04 PM »
Thanks Phil...

as soon as possible i will try the phabbtone and DDC.

the circuit i posted was an idea close to some circuit i found
on the web that gives the curve of a treble booster.

http://www.elecfree.com/circuit/tone-control/treble-booster-by-741/
(but i used it accidentally after the distortion and sounded good)

i found it very useful together with a traditional baxandall to get
marshall 4x12 when using HEADPHONES...
as you mentioned it has a fall after 4Khz... and the curve grows evenly till
it gets the peak on 4khz.

I mixed ac/dc music on headphone to ensure that my ears could not lie to me....

Considering the huge amount of diferent conditions that my humble room/laboratory
is from ANGUS stage, i found it very useful....

The hard stuff is to get the sound when the volume is not
very much high (i don´t know how to say).
the kind of compression that makes tube amps very famous..
When touch hard the string and the notes sounds like screaming...
very famous at blues genre... sounds very natural...
maybe because of compression caused by interraction between
phase splitter and output tubes...

I was not aware of the fact that you said about cranking marshalls and tone controls...

I am actually finding digital software with graphic equalizer very useful to help to understand what we need... One good example is Cool Edit (just to mention one)...

thanks again. hope some body enjoy your ideas too...










phatt

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Re: PhAbb SS AmpDemo
« Reply #13 on: February 10, 2010, 06:52:13 AM »
Hi rodriki1,
              Just one point,, if you build *Both* in the same box, notice the schematics for tone box is single supply whereas the DDC is split supply.

If you wish to build them both the easiest way round it is to convert the tone box circuit to a split supply.

My advice is *True bypass everything* that way you can instantly recall/compare differences.

Just thought I sould mention it.
Phil.

phatt

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Re: PhAbb SS AmpDemo
« Reply #14 on: February 12, 2010, 04:03:58 AM »
Hey rodriki1,
                 I've spent the whole afternoon messing with your *Treble booster*
Very good work on your part 0:)

I was concerned that it could make the sound resonantly harsh,,, but with some tweaking it certainly can be made to work. 8)

Gee wizz ,,, I may even incorperate it into my next Tone box build. :tu:

Here is what I've done to the basic concept.
Insert a 10k liner pot in place of the 2 x 5k6 resistors. (the center lug of 10k pot connects to the Cap)
***Bingo you now have an instant *presence* circuit***.

Used in conjuction with my circuit it certainly helps.

Suggested changes if using my setup;
1/  Insert 10k pot instead of to fixed resistors,, as this gives it the ability to cut or boost the notch,,, very nice.
2/ change 1nF to 2nF (helps to flatten the peaking effect)
3/ change 47nF to 150nF

So I've done my time finding out stuff now you can take it further,,, good luck.
Phil.