Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - phatt

Pages: 1 ... 132 133 [134] 135 136
The Newcomer's Forum / Re: Stereo combo amp for use with POD?
« on: May 13, 2009, 03:59:03 AM »
Hi zappacat,
Before you run off and get yourself lost in a maze of wire. Try to undersand the CONCEPT first it'll save a lot of wasted wire. If I say the Answer to great tone is EQ/Dist/EQ/Dist/EQ/Dist/EQ/Dist.

You might laugh but if you mess with guitar amplification for long enough you start to realise from the earliest of tube design to latest digital gizmo your just tweaking the tone shape. Sure in fine detail it's a lot more complex but why make it hard as all the good stuff won't happen unless you get the basics right first.

Line up a dist unit and note the sound.(or try the pod if you wish)
Next insert a Parametric EQ *IN Front* and apply a deep mid notch at around 400/500 hz. If you don't have Para EQ or you have trouble with how they work just use a graphic type but para works best at this point.
You want a deep narrow notch CUT for best results otherwise you'll pull out to much.

Stick a graphic EQ *After* the dist unit and pull down at around 1khz. I very much doubt there is much need for me to carry on as it should all become rather obvious just how many different sounds can be achieved via this simple exercise.

(I'm posting this because the site is unavailable so I can't find exact address for the whole page)

Lifted from,  []
True "secret" of amp tone - eq>dist and power attenuators
Home (amp tone and effects placement)

You can almost certainly get satisfactory sound from your existing decent tube amp,
without mods, by using, or at least experimenting with, the following  chain:
eq pedal
Comp/OD/Dist pedals
eq pedal
amp's preamp
amp's tone stack
amp's tube power amp
good power attenuator
amp's guitar speakers
The above is truly the "secret" of great amp tone.  Most postings, books,
and amp tone videos dwell on amp brands and mods and swapping tube types
and swapping speakers or pickups, but such priorities are backwards.
The real first order of business is knowing how to make the most of *any*
decent tube guitar amp.  It's a shame that most guitarists try all sorts
of things other than the secret weapon that gets straight to the point:
the eq>dist>eq pedal chain, which you can put before any guitar amp,
in conjunction with -- just as important at the other end of the chain --
some way of getting power-tube saturation independently of speaker volume,
and this amounts to the (unfortunately) "secret" of power attenuators.
End quote

My rig just takes this one step further and instead of attenuation I *reamplify* the tube power amp with another SState poweramp. Even without power tubes you can still make inroads to great tone.

This is the basic layout I use;
First a very simple DIY tone stack based on an old HiWatt circuit, SS
B> into a highly modified OD SS device
C> then a very simple tube amp which drives a resistive load
(like an attenuator cept No Speaker, you tap off a line level instead)
D> feed into an old HiFi graphic EQ
E> ultimatly driving a 120watt SS power Amp.

The tube amp is an old rewired Gramaphone from the 50's and only outputs 7watts,
no need for expensive tube gear here as you actually want a bad/cheap basic amp.
Heck it only has 1 volume and 1 tone knobs. All the rest can be done via SState.
Cheers, have fun, Phil.

Amplifier Discussion / Re: Signal Mixing
« on: May 10, 2009, 11:39:45 AM »
Just had another idea,,
                              With the onboard preamp installed just try mixing the two signals again and see if that works as there maybe enough swing from the guitar preamp.
It maybe all you need, Though turning down the guitar level pot will also turn down the line input.

The Newcomer's Forum / Re: Stereo combo amp for use with POD?
« on: May 10, 2009, 11:27:10 AM »
Ok Zappacat your obviously keen, an good on yah.

Unless I'm missing something I think you can save yourself a lot of time and money with a simple 4channel mixer that has a monitor out, They are cheap as chips these days.

Plug your pod into the first two ch's, paned L/R and send the stereo master out to your stage powerAmps, (which you wish to build).  Now just send the monitor output to FOH mix. The only drawback I can see with this is the mixer will only have a *mono* monitor out.
Anyway any soundman worth knowing will want a mono (preferably dry) signal.
You won't make many friends with serious sound guys if you want to do it your way. If you give him something he can use then he will go the extra mile to help you.
If you must have stereo, (Depending on the mixer) With a bit of thought you could use the effect send bus as well as the monitor bus to achieve another stereo signal out.
My thoughts on stereo,
Look I do understand the novelty of stereo guitar, It's fun but my advice is leave all that for the studio where it has merit. I would be more concerned about developing a good mono tone First.

Side note;
If you use the Eon 15 which I believe has a HF horn, ok might make your keys sound kool but this will just destroy guitar sound/tone. So if your using that for the guitar/pod system you gonna spend a lot of wasted time searching for the ultimate patch. I think you need to do some research on that.

I'll leave you with what I've gained over the years.
For guitar it is all about EQ. Sadly the pod type gizmos are ONLY the tip of what can be achieved.       Are they useful?
Yes absolutely but not as a stand alone One Box Answer to great tone.
You need to re EQ that as well, (This is super critical for success).
Well that's how I do it and partly that's how teck21 do it also, cept they kill it cause they missed the part where it says "Limit the Bandwidth".
My ideas are doable with the simplest of equipment, you do not need to spend a fortune to achieve great guitar tone.
Ultimate Guitar tone is a culmination of tone shapes imposed one into another.
The sentence is simple but developing a mental picture of what happens at every stage in that path takes years to sink in. (did for me, or maybe I'm just slow, wink)
It is interesting that the famous Sansamp is built into that Teck 120 you speak highly about.
The Sansamp worked because someone got the TONE shapes correct.
The darn problem with Teck21 gear (like a lot of SState gear) is they have miles to much bandwidth and they use high SPL speakers and the two together make it sound well crappy/clangorous.
Those special speakers where designed for **Tube Amps** where there is some use for extended range but this just screws up when driven by SState.
(a common SState oversight/stuffup)

Learn to nail down the tone shapes of all the famous tones and you will be well rewarded. Leaning the fundamentals of good solid rock tones are essential, only then do you add effects.
I don't want to dampen your Obvious Enthusiasm but judging from your posts there are things that you are missing you need some time to absorb and understand, hey it took me years.
It takes a lot of patience to read let alone understand.
Building pedals and basic stuff first is a good way to get your head around electronic gear.
Starting out building really complex stuff will make it ever so much harder for you.  (read as, stay away from complex mix circuits for now)
Believe me electronics is fun and addictive but my god you have to have a lot of patience,
ideally you need more patience than knowledge.
Cheers, Phil.

Amplifier Discussion / Re: Signal Mixing
« on: May 10, 2009, 11:06:13 AM »
That's kool,
then just use that very simple passive mixer that "pattonBa" suggested.
nice to chat, see ya. Phil.

Amplifier Discussion / Re: Signal Mixing
« on: May 10, 2009, 08:32:04 AM »
Phil, thank you so much!!  I'm going to give your buffer a try this weekend.  Question: Does using the pre-amp bring the piezo's signal up to "line level"?  I found a couple schematics for mixing line-level inputs - would you mind taking a look and giving me your opinion on which you think would be best?

FET Audio Mixer:

2-Input Audio Mixer:

Would either of those be a good choice?

Thanks again for your help!  I really appreciate your time.

No my circuit is down in output level but you WILL Get better sound quality over direct passive.
A 1meg Resistor for R1 in the circuit shown will give you 50meg (ish) input imp,,,plenty enough for hi Z input.

Arron cake circuit is going to work but the input imp is quite low so don't expect it to work well as magnetic guitar PU. It's just a basic line mixer.
The other one is more complex but the mic input is not really any good for guitar.

Forgive me but I'm wondering at the wisdom here?
Surely you have a small audio amp that can play music and then just play along with your ruby?
Or did everyone thow out their old ghetto blasters from the 80's :(
Heck it seems like a lot of trouble for such a small rig as the ruby is only of limited power and has a very small speaker?

Might be better to start a whole new project with two inputs.
With just a couple of opamps you could build a really versitile preamp rig which you could still plug into the ruby if you so wish but you gain the advantage of being able to plug into other powered equipment.
Just my thoughts.
Cheers Phil.

The Newcomer's Forum / Re: Stereo combo amp for use with POD?
« on: May 08, 2009, 09:01:13 AM »

Hello Zappacat,
                     Hey alot of Q's there!
I think you need to get some ideas nailed down first and kinda stick to one thing at a time,, kool?
Re the LM 4780 chip Q.
You can simply look up the specs for that and it will be obvious if it is stereo or not.
Two of those proj 101 Amps will make your ears bleed my friend and you will need at least two quad boxes to make use of all that power. Anyway the cost of the PSU at 100VAC-CTap tranny will scare you!   oh and YOU have to carry it also.
I only mentioned it because even at 40/0/40 VDC it will still have ample power.
If you want balanced outputs to send to a desk then I don't get it.
You wish to DI a 400watt Amp to a PA desk,,, like what For :duh
If you don't know *most* SState PwrAmps can handle 4 OHMS minimum load.
Less than that and you are pushing your luck. :'(
Read project 101 more slowly and absorb it,,,the Answer for that is on that page anyway.
Personally I never got the stereo trip as a good guitar sound with a little time effect and good EQ will sound far more convincing than any stereo pod.
I can do more tricks with my simple gear than most of those cab sims.
Sadly these days the player is judged more by how up-to-date his pedal board is than his ability to play good music. 
just my thoughts.

If I'm getting this right you really need two things,,,
1/ a stereo preamp (with bal outs).
2/ a Stereo poweramp.

BTW there is some bal circuit ideas on ESP site
Cheers, Phil.

Amplifier Discussion / Re: Signal Mixing
« on: May 08, 2009, 07:15:03 AM »

Hello Jack,
              Yes you will need a preamp for peizo.
Media player has line level output and you can't just join that with a PU
(of any type really).  The Ruby has a 1m5 gate R but that ain't enough for hiZ PU.
you need more like 2meg or even 10meg.   Better to make the peizo *Active*then you can plug into just about any line level which makes it versitile.

I get "Forbidden" on that link for peizo, (I have no clue with computers?) but not to worry there are quite a few and they are likely to be similar. The Fet based ones that have bootstraping will likely be the go for pz PU's as they multiply the input imp.
Anyway here is one I whipped up for a chap on the cheap.

My peizo buffer is low output but don't let that fool you as it has very high input imp and any good guitar amp will deliver the rest.
This was made to replace a painful onboard unit that suffered from way too much hi freq content which makes Acoustic guitars sound stupidly harsh and very unnatural (though some may want that)
and of course the manditory feedback issues that tend to go with acoustic Electronics.
R1 can be as low as 500k but the bootstraping of C2 will make it much larger.
Use metal film for R1 if you want to keep noise low as possible.
You need a very high imp input when using peizo's otherwise you will loose a lot of the low freq content. Again a balancing act, to much and they tend to suffer feedback.
make C1 smaller if you wish to wipe off more bass.
The optional cap across the peizo element may work on some units, depends on the peizo used.
Don't ask me to explain just try it and see what you think.
Play with C4 if you want, to cut the top higher use a smaller cap.
Try from 10nF up to 47nF and see what you prefer, If you want ALL the high freq just delete C4.
Oh yes The 9volt battery will last a long time.
A chap by the name of "Don Tillman" (I Think??) has a whole page dedicated to simple fet preamps, his ideas may give much more info.

The mixer pattonBa refers to is passive and there will be overall level loss.
If your ruby has enough grunt it may not be a problem but it will be of limited use on other equipment so may I suggest a *dual input* on the ruby Amp and be done with it.
there should be enough schematics around with 2 inputs mixed into one to give you
an idea of how to achieve that. I don't use fet circuits much but I'm sure someone here will chime in here and offer something useful in the way of mixer circuit ideas using Fets.
Have fun with it.
Cheers Phil.

Amplifier Discussion / Re: Signal Mixing
« on: May 06, 2009, 10:57:24 AM »
Hi Jack,
          A Q before I go on.
Is the peizo PU passive? (ie, no onboard preamp)
If so then even a mix buffer won't help you much.
Cheers Phil.

The Newcomer's Forum / Re: Stereo combo amp for use with POD?
« on: May 04, 2009, 08:34:37 AM »
Hi Zappacat,
         Try this one instead

Probably eaiser to build,, a Ton more grunt (depending on PSu Voltage used)

The hidden bonus for this one is it will run on just about any voltage all the way up to 70/0/70 VDC rails where it will output over 200watts into 8ohms.
I have not built one but it certainly looks like it would deliver the super clean flat response,, if that's what you want?

Also as you want stereo the price may climb quickly so have you considered some old HiFi poweramp sections they might be worth a look you may even be able to use some of the line inputs and save yourself a lot of work.
You can pick up old 70's hifi amps cheap where I live.
Cheers, Phil.

Hello everyone.  I've just finished building my second Ruby circuit (  On my first amp i used a little 8ohm 5" speaker out of an old stereo.  It works fine, but for my second project i need to balance function with  size.  I know almost nothing about speakers, so i was hoping someone here could make a recommendation.  When selecting a speaker what sort of things should I look out for? (other than a total impedance of 8ohms)  Is the size of the magnet something to look at?  Do certain speakers respond better to guitar frequencies?  What would you say the smallest diameter speaker i could use and still produce a strong sound & good tone?

Thanks for your time,

   If you are trying to get your head around speakers then I find the easiest way to explain it is thus;
There are only really two types worth understanding, those being "Low Complience" (musical instrumet/voice/guitar)
and "High Compliance", (Hifi, woofers for reproduced music).
Bass drones for cars and disco stuff.

For guitar you want LC.
What's the diff?   Easy HC wobble easy and  LC are stiff as a board.

How to tell?  HC, Woffers have a loose rolled edge (called the spider) and a rather long loose travel (easy to move with light force). These need to be in a box that is tuned to match the driver paramiters otherwise they sound crap.
This is not what you want for guitar.

LC on the other hand are very rigid with very little movement. They can be used without great need to *Comply* with box design.
In the really old days this is all that was used and I've seen early PA's with a 12" driver mounted on a 1 metre flat square board (no side or back), For voice reproduction this is all that is needed anyway.

Magnetic guitar PU's have masses of bass output and you really don't need much low freq help. Try plugin' a modern guitar and Amp through a wooffer and I doubt you will like what you hear.

The early celestion company was commissioned by the mines to make a speaker for a siren and the design called for high output at 1kHz too 3kHz.
Greenbacks as they are now called where not designed for guitar at all. :o

Just so happens, that these are the frequencies where the magnetic PU guitar needed a boost and so the rest is kinda obvious history and many folk probably don't realise that all the treble for Guitar is from 1kHz to 3KHz.
For hard driven OD rock anymore bandwidth just destroys the sound and it is no longer sweet.  (listern to Carlos Santana and I doubt there is much above 3kHZ)

These days speaker makers are going crazy making all sorts of claims about extended freq response but I have heard enough of these to say I have my doubts as to the benifits of such claims.
Unless you are wanting pristine clean then more bandwidth will just get in the way of good tone.

Good speaker effeciency (High SPL) is a bonus and worth some merit but as long as you realise the drawbacks that can come from that. I doubt that many Amp designs adjust their circuits to suit the drivers that are used.
Brand name Amps use high SPL (sound pressure level) Drivers simply because it makes there product Louder than the competion of the same wattage.
An old wise man once said to me that it would be better to design an amplifier from the speaker first and work your way back from there.    interesting thought?

I just recently pulled the very harsh Speaker from a Trademark 60 (Teck21 stuff)
and replaced it with a less efficient driver and the owner was amazed
at the difference. Yes slightly less percieved power but now a joy to play. 8|

I don't think you need a degree in sound enginering to get an idea of what works as
It really just comes down to balance,, Just think of a hifi speaker where you have bass, midrange and tweeter.
If you have one super high SPL output driver and the others only average then
it will likely sound off. It is better to have all the drivers balanced even
if they are not top of the range drivers you still get a balanced good quality tone.

You mentioned magnets.
This is another of those things that tends to just end up as a dog chase tail affiar
as the bigger the magnet the more energy required to move the darn voice coil and cone.
So pick a magnet and keep in mind that some small older types sound better than those big mag one's.
Anyway You would be better to look at the Voice coil as it's more important and
can make a big difference to the tone.

Understand that regardless of magnet size any given cone diameter can only handle about 3 octaves efficiantly and smaller VC's for same dia cone will sound more peaky at some ugly freq.
Some small speakers sound quite good if they have a decent sized VC.
(sadly a lot don't)
A larger VC for given size cone will keep the cone more stable over a broarder freq range, hence a flatter better perfomance.

Some 12 guitar speakers can sound very honky because they have a VC that is to small for the cone dia. That said some may like the peaky nature of lesser drivers found in really old Amps.  Pick a flavor?

For guitar The rule of thumb seems to be 12" cone with a 1-1/2" VC.
(Celestions had 1-7/8" VC).  So anything around that is going to be good.

Even if you only want 6 inch speaker at least now you have some idea of what to look out for :tu:
Well this turned into a marathon so I hope it helps you in your pursuit of great tone.

Tubes and Hybrids / Re: power supply for a hybrid
« on: April 24, 2009, 12:10:11 AM »
To awdman,
Your idea of Valve pre Amp SState powerAmp has been done to death
Try it the other way round and you will achieve a lot better results.
Although you get some benifits from valve preamps it's nowhere near as good as a Valve power amp stage,,,,
---------THAT is where the magic happens NOT the preamp.-------
I am speaking because I've done this stuff both ways,,,,
Just my 2 cents worth.

Amplifier Discussion / Re: kind of repairing that change the tone?
« on: April 23, 2009, 11:55:12 PM »
Short answer,, Unlikely.
The possibility exists but there are a million and one possibilities.
You'll go crazy trying to list them all :duh
If you have not used the Amp for a while then even the wheather can change they way your ears hear things.

Try setting up a 1000 Watt sound system in an empty venue test it,,,
then (without adjusting anything) come back when the venue is full and the whole thing will sound very different. :o

Amplifier Discussion / Re: Stereo 2030 amp for a jazz band
« on: April 03, 2009, 09:24:57 AM »
Well, I need an amp for my college jazz band. I always wanted a Roland JC, even before I played much jazz I thought they had the best clean tone ever. I have an idea vaguely sort of similar to the JC, two totally separate amps each running into a separate speaker, each voiced a little differently for a nice stereo effect. I came across this
and my tentative plan is to build two poweramp sections with these, using something like this
for each of the two preamps.

Thanks, this looks like a great forum!
Hi svstee,
              Unless I'm mistaken,,,
the Roland Jazz Chorus Amplifier circuit is ONLY stereo when the Chorus is engaged,,no chorus engaged = no stereo,, straight mono or but both poweramps delivering the same sound through two speakers.

The first true stereo chorus in an amp was the selling point of those amps.
A mate I knew had JC120 and it made his all white tripple humbucker LesPaul sound like a tin can.
IMHO the most overrated SState Amp of all time,,,but hey that's kool if you like em.

I know this is slightly of topic but
The HCR30 Laney mentioned here by Fahey is quite a good little Amp just needs a better tone control,, but as you are after a jazz tone then a different preamp/tone section is probably needed.
If you are even remotely thinking of tinkering with different circuits get yourself a breadboard and experiment until you find what you are after.
Otherwise you will waste a lot of time building stuff that ends up in the bottom draw as spare parts.. Just ask me I have lots of those,,,
"Seemed like a good idea at the time trashed boards"
Have fun with it,,it's very addictive.

Amplifier Discussion / Re: Mesa Boogie Dual Rectifier backup ss amp
« on: March 12, 2009, 07:44:35 AM »
Dear Phatt, that´s exactly the relatively no pain but precise way to go.
To summarize it, and compare it what´s available "out there":
the signal chain should be:
1)Active mics/active electronics in guitar/inline clean preamp
Al three amount about to the same end result: powerful, clean guitar signal; sent into:
2)Some GOOD distortion/overdrive that you like; sent into:
3)Good clean preamp, Fenderish or Marshalish or Voxish (your choice) which can be Tube (the classic solution) OR SS which sounds the same *when clean*;  driving:
4) Some *Power* tube, which can be overdriven and Transformer coupled to a real-world speaker , with all its quirks, resonance, impedance and phase shifts, nonlinearity, etc.
Here's where the real Witches Brew cooks, in that complex interaction between those three actors.
I agree with you that a PP amp is best, but even a humble Champ can prove its worth there (I´ve already tested that).
That signal should be suitably padded and re-amplified by
5) A good SS amp driving guitar speakers.
5)Your inclusion of a Graphic between 4) and 5) allows for fine tweaking of the sound, but must be used subtly and carefully to avoid destroying the sound you already have.
I agree that that´s the way to get World Class sound in a very practical way.
Please post some MP3s
J M Fahey

          Thanks for your words of encouragement, Sounds like your more into the teck side of this stuff than myself :)  I still cringe at the thought of all the maths you need to know to work it out but this is all good as the more options put forward allows people to make well informed decisions.

I look at it this way; I'm 90% there with cheap mostly secondhand or DIY equipment.
Then I look at how much $money$ I have to spend to get the last 10%  yuk
Keep in mind I do this on a strict budget so if budget is no issue then sure try all the options.

All this back EMF / RCL spk equivilants/ Damping stuff is obviously quite real. Fine, No argument from me BUT I would question how much of it you can actually hear?

If I understand you correctly I think you're coming at it from a different view, ie, your trying to capture the tone/dynamics of a said tube amp but that concept is a lot harder to impliment.
It demands the mojo tone already exists inside the tube amp whereas I'm trying to negate all of those complexities.
I'm only using the tube pwramp as a building block, a giant distorion unit if you like. ;D

I have heard enough amps in one lifetime to know that I'm still ahead of the well trodden path where everyone keeps changing Amps/Tubes/PU's/Speakers hoping for some magical mojo to materialise.
Consider EVH, in the early days he likly used resistive loads and some kind of reamping. (probably SState)
The idea may well be flawed but still good enough to make him famous.

Also Randy Bachman used a reamp setup on the famous hit song "American Woman" again technically not ideal but Wow,, what an amazing guitar track that turned out to be. (google Hertzog and Randy B)

BTW, the Guytron GT 100 "IS" based on much the same basic idea, a pair of EL84 driving a resistor then into a big power amp.
The moment I heard that Amp,, I knew it was different and I wanted that sound.

I would simply say this; OK mine is not as refined as the Guytron but in my humble experience,
Any Loss with my setup is far outweighed by the amount of Control I get in return.
Sorry but loading MP3's is out of my ability with computers, I'm still learning how to get around this web thing. OK laugh if you want but some of us older folks struggle and are still trying to catch up.
Cheers, Phil,,, Nambour Australia.

Amplifier Discussion / Re: Mesa Boogie Dual Rectifier backup ss amp
« on: March 12, 2009, 07:17:54 AM »
 Damn! Could not get both pics to load , so here is the Speaker load to Lineout drawing.

Pages: 1 ... 132 133 [134] 135 136