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Messages - phatt

#2026
Just adding this mud map showing how the 3 units are linked.
True Bypass on everything really helps when using different Amps/gear as you often need to find out the response of what you plug into.
Makes for a more versitile setup.

The other though here is that all 3 could be housed in a floor unit if you so wished but you will need a stomp GEQ for that.
I've housed it in a small rack and I tend to leave it set to one sound as it's so dynamic I don't need to keep changing it.

I use a small fet signal booster stomp pedal if I need a little more drive.
Just giving some ideas for you all to kick around.
Phil.
#2027
Quote from: rodriki1 on May 15, 2010, 09:52:13 PM
Hi Phill,

Thanks for a refresh on your ideas here phill.

I am interested in asking you if you know a cheap circuit
for me to try in a way that i could "feel" the so called
tube compression...
sometimes i think i have some sort of problems with my ears!!!
after i did the presence control that is a cheaper version of
a cab sim... i think that 80% of the sound of the tube amp
is caused by filtering effect of output more the kind of wood
box (usually huge and expensive)...
the best stompboxes outthere uses cabsim...
WHAT I MEAN IS:
THE TUBES ARE NOT RESPONSIBLE FOR EVERYTHING IN THE SOUND OF TUBE AMPS.
Why people still keep believing that tube is so important???
besides it is not that cheap to make a real good vintage tube amp.
thanks

Heck I don't think that you can get it much cheaper than what I've given here.  ;D

How on earth do I explain it?
Tubes/bananas/transistors/fets, all of em distort.
The sound that you *Likely* refer to is power tube compression Which comes mainly
from power stage quirks of some famous valve amps. (*bry melvin* has covered some
already)
The only difference between Valves and SS is the simple fact the valves tend to
compress rather than just distort/clip.
The output of a SS power Amp will not do the soft compress trick so you have no
choise but to make it happen in the preamp stages by using some circuit tricks.
I choose to do it the tried and tested way,, only twist is I impliment the tone
circuit and add a cheap GEQ.
(I'll never win awards for it but it gets some great sounds)


Worth a mention;
(This is why a Tube screamer will sound quite stunning through an old valve amp from
yesteryear but plugged into a all SS Amp it may well sound harsh/fizzy,,very different to say the least. Some Classic tube circuits rip off a lot of high freq hash in the output stages whereas SS amps do the exact oppisite,,so you tend to get all the high freq crap which destroys any smoothness)

Once you can grasp that tube amps work very differnt from SS you will see how darn
important the tone shape is.
Tone is everything if you are trying to extract specific sounds of certain genes of
music.

Forget Wood, Valves and PU's and all the hype, Understand this simple observation.

Tone is just the shape of the frequencies amplified,,, more importantly the ones
that *Are Not Amplified* deliver better results.

*****It's about what you don't hear that makes for fantastic guitar tone*****

Some classic tube amps did this tone shaping by design so when designing SS gear you
have to be very aware of this point.

(my favorite setting with above circuit is a big deep notch CUT @ 300/400hZ *Before distortion* and then cut again *after dist* at 800/1000hZ)
In other words you achive vastly better results by cutting certain frequencies then boost the gain.
Then you get far less circuit noise which means you have heaps more head room before
the dreaded noise/hiss of stupid hi gain stuff.

And that is how you get great distortion sound even with simple cheap SS gear.
If you have access to a *parametric EQ* then use that in front of a dirt box/TS99999,(Pick a model) Then use a graphic after it.

Again The trick with paraEQ is to *CUT,,,NOT boost*.
The Graphic; try a flat setting and just full cut at 1khZ.
Even without the Cabsim this alone will make a big difference.

Worth a mention is Speakers.
I'll tell you a little story;
My friend of many years came to me with his Teck21 Trademark60.
He simply asked if there was any way to make it sound like my gear.
I won't bore you with details but he was stunned at the result.

I simply replaced the speaker with a far *LESS Efficent* speaker.
***Remember***
Modern Amp makers use very high SPL drivers simply because the louder it sounds in
the shop the better chance of a sale.
(apparently young minds only respond to loud sounds)

High SPL drivers are ALWAYS Highest output in the 3khZ freq range and this makes the

amp sound a heck of a lot louder but you pay for it in tone,,,Harsh as all hell.
If you are chasing the sweeter tones of older amps then use of freaky slick named drivers is likely to seriously impair your progress.
The older less efficient drivers generally deliver a sweeter sound,,Hint.
Have fun,
Phil
#2028
Hello Teemu,
                  Have a look at the dreadful *cutoff at V3* on the TW circuit.
Experts seem convinced that saturation is much smoother than cutoff,, yet as you note it maybe of little concern.

In My (limited) Experience, TW and really old Marshalls also,, The OT's have a very low primary winding and this (I believe though I can't mathamatically explain it)
Makes one hell of a difference to the end result.
I don't know the TW OT primary winding but I do know that some early Marshalls had very low primary.  ie; 1700 Ohms pp.
This I think you will find forces limiting of bandwidth (under load) and definitly accentuates the *Second harmonic*.
BTW, Obsolete Electronics had a whole blab about this but the site is now ,,,well Obsolete :o

I have built a 6V6 Amp with a 6k6 pp OT and it was very harsh.
short story;
Went down to 2k6 pp and the difference was staggering.
Absolutely the sweetest sound.

Taught me a lot and opened my eyes as to what can be done.
As you may be able to tell I've learnt to train my ears a lot and I pay a lot of attention to the tone shaping,, SS or Valves.
Phil.
#2029
Quote from: J M Fahey on May 12, 2010, 12:28:37 PM
In a nutshell, the problem is this:
modern SS amps are practically perfect voltage sources, with "almost" zero internal impedance.
They achieve that by having massive internal gain and equally massive feedback, which for DC is almost always 100%.
That's why the output DC voltage , which could easily slam against a power rail, gets reduced to less than 50 milliVolts.
They do that by supplying to the load as much current as needed (tens of amperes if necessary) to bring output voltage to where the input differential amp says it should.
Now imagine two amplifiers with joined outputs: you have two "brains", absolutely ignorant of each other, driving the "muscle" (output transistors) to get a certain output voltage, on which they do not agree. I do not care about the load, they will try to force the other equally powerful opponent's output to submit to their will, killing each other in the process. Or at least oscillating madly, overheating, the works.
Neanderthal solution nº 1): put a 4 ohm 50W resistor in series with each output, the node feeds the speaker. It works, sort of, although you gain no power and waste a lot.
A somewhat-less-Neanderthal solution nº2) : you match all resistors to 1% or better, match chips from a large batch or at least use those from the same box, same manufacturing code, draw a special board where all traces have the same resistance and inductance, mount them to the same large, thick heatsink to minimize thermal differences, lower the 4 ohm resistors to 0.1 ohm, relax and think "what a great Engineer I am " . Well, not bad for a Neolithic village Engineer in around 4.500 B.C.
Yes, it may work, but, why worry?
Increasing chip count carries the complexity up where it pays to use a boosted-chip or even discrete design, where you can design for as much current as you want because, remember, parallelling chips you only get more current capability, nothing else.
As an example, in the 70's I sold a lot of 400W RMS into 1 ohm bass amplifiers, using 8 x selected RCA or Motorola 2N3055H as output devices. They drove 8x12" LEEA speakers (the local ALTEC licensed factory), consider I used the equivalent of 8 Altec 12" woofers in big boxes,  they *easily* beat Ampeg SVT's in Stadiums.
3) The real beauty of using 2 chips lies in using them bridged, because they supply *a lot* of power into a single 8 ohm speaker.
4) Of course, Teemu's and Armstrom's idea of using them "in stereo", each one driving its own speaker, is excellent. Even if you are not interested in stereo per se, you can send the signal from a single preamp to both of them.

Thankyou JMF, You have explained that very well. :tu:
The bridged output seems to be quite attractive,,, 4 times the power I think.
Hum,, I do have some old stereo STK modules under the bench somewhere.
Oh so many thoughts but never enough time. :'(
Phil.
#2030
Quote from: Zappacat on May 13, 2010, 12:26:29 PM
Quote from: phatt on May 12, 2010, 09:21:54 AM
Sorry Zappacat,, yep Jayfett got it.

Jayfett, if you wish I can post all the circuits I use?
My setup does at least deliver the *touch response* that blues type chaps yearn for. 8|
Phil.

I'd sure like to look at those circuits.  Please post them.
Hi Zappacat, done :)  Check under Schematics and Layouts. :tu:
#2031
The Schematics Stuff I've posted has gone missing but not to worry I'll repost a few here :tu:

The DDC (Dynamic Distortion Control) by itself won't blow your mind but by implimentation of the *PhAbbTone* circuit *in front* of this will reap some classic guitar tones from a bygone era.
(All these clipping circuits distort,,,, but this is very touch responsive.)

The addition of a simple cheap Graphic Equalizer *After* the DDC will deliver more tonal options than most music shops have Amps.
Yes I use these circuits in my setup and I play live gigs (although not to much these days) ;D

So I can vouch for their ability to deliver. :tu:
Phil.
#2032
Sorry Zappacat,, yep Jayfett got it.

Jayfett, if you wish I can post all the circuits I use?
My setup does at least deliver the *touch response* that blues type chaps yearn for. 8|
Phil.
#2033
You know,,,
with respect,,, a one wheel car might have a better chance :-*

JM Fahey and Teemu are 2 Seriously talented chaps with years of experience under the hood. So I think if it was a great idea they would have already persued your concept.
I do understand that when you start out playin with stuff you get all sorts of crazy ideas that at the time look like they may just work,,, hum if I do this,,, and IF I can find some rare .1% poofoo valves.
Then you end up filling your shed with square wheels.
If it makes you feel better,,, I've got a whole shed of (good idea at the time) projects that never worked.
In close on 30Years of messing around with 100's of circuits I've only designed/built a couple of circuits that I'm seriously proud of.

If you can't let it go then may the force be with you 8|
Phil.
#2034
Quote from: JayFett on May 10, 2010, 02:21:22 PM
Wow, that Wampler Pinnacle II demo does sound real Eddie Van Halen-ish.

I guess I am looking for a preamp that is NOT primarily a huge distortion sound, but rather a warm, thicker, smooth non-sterile clean, to slight tube overdrive sound. I can sort of get it with my Boss Blues Driver pedal, but it still has a raspy transistor cut-off artifact to it.

Can anybody recommend something like that?
Hard to nail down everyones particular tonal needs ,, but from what you say you need the old fashioned rattle with a bit of drive,,, Think early stones songs.

Save yourself some pain,,, go grab a S/hand Graphic EQ> (yes the RCA plugs are a pain but easy fixable)        ***No don't use the Boss GEQ it's a nightmare***.
Now insert the Graphic *After* your Blues driver.

Next build the *Marshall Cab sim circuit*,,, (Google *Ed Rembold Marshall Cab sim*)
it's dead simple to build and unlike some vastly more complex circuits it works.

Insert CabSim *between BDrive and GEQ* before poweramp/guitaramp.

Now if you wish to pull off more cheap tone tricks just build an old fashioned tone stack circuit and insert that *Before* the blues driver.

This tone stack *infront not after* distortion will open your eyes to just how much tone shaping effects the distortion character.
As you may know pedals usually end up in front of tone controls,,,, and it's not enough.

You will then have more tone options than most gear sold today.

Understand what kills modern gear (for the tones I think you maybe wanting)
Is way to much high frequency response.
So watch out when choosing speakers as some are loud as hell but will make your guitar sound harsh. (Metal n Thrash no matter so much they want and need more top and bottom cause they have nothing else,,, no mid.)
also SMPSU's are not really that great you would be better served going with the tried and tested Transformer for PSU.

You can't get much amplifier with 15VDC anyway.
Car Amps might read 100watts but often in  the *Real world* they are not as powerfull as they claim to be.
At least look at some of the chip amps for power amplification section they can run from lowish 20VDC all they way up to 70VDC ct or (35-0-35VDC)

Re the wampler clip;
                           the unit maybe good but hard to tell with so much drowned in massive effects,,, so it's really hard to say?
Heck the above cheap setup I mention here would sound just as massive If I hook up all the effects racks :)
I did have some sound samples of my setup on here but they've gone now :(
Phil.
#2035
Hi zappa,
             It's a bubby amp,,, a Tr about the same size will work fine.
30VA rating up to anything you can grab with a 35 V ct output will be fine.
Just make sure the Rectified DC does not exceed the rating of the Electrolitics.
Have fun, Phil.
#2036
Don't hold me to it but with most of these devices the cover either slides off or pops off.
It does require a fair bit of pressure to get them off.
I very much doubt they come apart from underside,, but they all make things just a little bit different.
So work slowly and carefully,,, and walk away if it all makes you mad as that's when most folks stuff up and later regret.
BTW,
       Do you have another handle to replace with?
They do not normally sell the strap alone,,, you have to buy a whole new handle.
Just a thought.
Phil.
#2037
pin 1,5, 3 look funny so I wait for a better schem.

Meantime,,,Is this what you are trying to build?
http://www.shine7.com/audio/pa100.htm
Phil.
#2038
Hello edwardefx,
Sounds like the thermal OLoad is working.
If you can verify it is that? Then Consider adding a much larger heat sink.

I once fixed a Fender BXR Bassamp that had melted the back panel plastic.
The poor chap even had a big fan on it.

I cut some 4mm thick alloy panels for the whole back panel and it never came back. Same amp was seen 5 years later still working with no issues.

Fender make some good gear but some are Just plain SAD design.
Phil.
#2039
Hi ,
Just google *Ed Rembold Marshall Sim* as simple as it gets and it works.
I've made several of these and sold everyone. 8)

Or just find a schem of any JTM 30 or 60 Marshall Amp
The circuit is simple to see,, just delete the balanced out part.
Phil.
#2040
I maybe missing something here but at a glance,,, this is the worst possible way to blow up 2 amps. :o
I think you need to do some research.
You can *Bridge* two outputs and send out of phase to the inputs but then the speaker terminals float from ground.

Sorry to tired to think now.
Phil.