Hi all,
Here's my latest venture which at first was looking like a fail but after last weeks gig I'm very happy with the result. <3)
This is my New front end floor control board,,, A bit bigger than I wanted but it makes life easier to tweak. I've learned not to squeeze things into tiny boxes especially as I'm the fool that has to fix it *IF* it stops making music. 8|
This took forever to prototype but hey It finally worked the way I wanted.
A hybrid with 1 AX7 and a tricked up distortion with 2 EQ stages as well as a switchable notch filter.
Also a parallel loop for the LessLee and other tricks I've built.
Due to the 2 years this took to perfect The front panel and internal pictures are from the first build but should give a clue as to the layout and basic setup.
The switching is all straight forward simple analog switching. No relays to ef up, :trouble just plain old switches which unlike tecky circuits usually give a hint they are about to fail.
Powered via a plug pak from a dead printer delivering 18VDC which powers all the chips.
The high voltage is derived from the nixie psu using a 555 and inductor.
HT is around 260 VDC while the extra lm317 is set at 12VDC for filaments and also drives the nixie supply.
As to Why all this complexity? :-X :duh
Well I've discovered that distortion is actually not that hard to get,, what is insanely hard to nail is all those in between sounds. as a lot of that magic may have more to do with the quirks of triodes.
See member KMG's Work on Fets,, really helped me grasp the finer details of how they work
(or don't work might be a better term)
I would have gone with some of his ideas but I had already got halfway through this build and I knew Real triodes where a sure bet.
The rattle of those old famous Amps has been the hard part for me to reproduce and that is the sound I wanted more than just the distortion.
I know some will want sound clips but you will just have to wait. 8|
Meantime here are some pictures and some of the schematics.
there are 8 boards in the final build so you will have to join up the schematics.
Anyway have fun with it may give ideas as to what can be achieved.
Phil.
Just some more schematics.
OD circuit.
Notch circuit.
Master & Tone circuit.
As for the High voltage supply Just google nixie supply as that is all I used.
Phil.
Good one Phil. :dbtu:
Just a couple of thoughts arising; relays with gold flashed contacts seem to be more available than gold flashed switches. Got a repair on the bench where a mains rated switch has been used in the signal path for standby, and sure enough it's making intermittent contact at signal voltages.
Do you need R103? Or is there a missing blocking cap at R102?
What's R6 for, offset bias on the output of U2a?
Can't see the op-amp type.
I think the larger case is a good idea; feets is big and stage space isn't at that short. Can see this staying where it's put too.
Phil, congratulations, IMPRESSIVE job !!! :dbtu: :dbtu: :dbtu: :dbtu:
Now we *deserve* some tasty Aussie flavoured Music samples.
R103 is there simply because the first part of that circuit is mounted on a separate little pcb and just makes life easier while tweaking stuff.
I figure it's unwise to leave the grid with no DC reference.
Yes I do understand that R6 is not needed as it's DC coupled to previous stage but if removed the noise from the tone becomes a real issue and renders the buffer useless.
This was the BIG issue While building the original PhAbbTone circuit, noise is the enemy with hi Z circuits.
I'm not sure about the fine print when it comes to these tecky details but from my testing this produced the lowest noise.
It took me some years to grasp but I now fully realize just why there is a buffer in front of circuits such as the TS9.
A lot of over-hyped boatweak pedals actually remove the buffer and wack a massive amount of gain on the very first opamp.
The result is lots of gain but sadly 3 times the noise. yucko puckas.
My rule of thumb is thus; High Z input and high Gain then expect noise issues on a grand scale.
Buffer converts it too a much lower Z and THEN you up the gain.
But hey I'm all ears to learn if there are better ways to divide the square root by 13. winky.
Relays,, what!! oh god more circuitry,,, I'll be dead and gone before I ever get a handle on all that clever stuff you chaps build. lol
I guess it's a 2 edge sword as you are quite right a lot of those stomp switches are very cheap quality now and few hold much more than a few years.
Maybe one day I'll get brave but bad memories of my first fender Amp failing because of dodgy relay setup haunt me.
I've still got a Carling switch here some where that came out of a junked Wah from the 60's and it still going strong in a pedal So it shows that they did once make decent switches.
Thanks for the input, Phil.
Mr Fahey will just have to ,,,, wait for sound clips :P
:( :'( :'( :'(
OK Mr Fahey has waited long enough,, 8|
I got some time to whip out a few takes of my pedal, Yes I even miked it up to grab the true sonic effect as best as possible. :P
The midi track is credit to a little demo from Cakewalk 7 files called *Boston Rain*
The guitar is the same old Casino $150 elcheapo Strat copy.
Not being the expert on the old midee stuff I think I've recorded the midi click by mistake but who cares,, it does not impair the sonic result.
I scratched my head trying to get my head around all the different sounds I can produce from this little box but that would take forever so a simple little riff of the sound I use the most.
As mentioned,, distortion is easy but the in-between stuff has always been a struggle to capture,, this box of tricks has gone a long way to cover that missing mojo.
Best way to explain that is to say; clean distortion that has a liquid feel when playing.
Only effect on guitar track is the Spring Reverb in the Laney (Now modded with the Tverb trick.)
I played this back through 3 different speaker systems trying to get an idea of the balance of tone but this should be big and fat with just a nice presence to the top end.
Dumbing it down via mp3 makes it even harder to define exact sound balance. I think it lost a little top end but to late to argue with inventors of mp3s xP
cheers all hope you like, Phil.
Quote from: phattThe guitar is the same old Casino $150 elcheapo Strat copy.
...
Dumbing it down via mp3 makes it even harder to define exact sound balance. I think it lost a little top end but to late to argue with inventors of mp3s xP
Ay, I've got one of those as my workshop guitar; only paid $100 for mine 'tho (friends with the guy in the 2nd hand shop ;) ). Not great maybe, but quite satisfactory on stage too. If you haven't tried it into 5 megs input impedance you should, really brings it up tonally. :tu:
Had to do some MP3's for a web site and even diddling with
Lame parameters the dynamics of some tracks were so badly compressed we dropped them from the sampler.
Even on crap 'puter speakers, then cans, that's a very nice demo Phil. +1 :dbtu: I'll try running it out to the big system in the morning (heh heh).
Incredibly good sound :dbtu: :dbtu: :dbtu:, *very* tasty playing :dbtu: :dbtu: :dbtu: , congratulations <3)
Thanks heaps guys, I really do appreciate the vote of confidence. :)
Well after all the years of blowing up stuff maybe I've finally been able to make something
folks would enjoy playing. :cheesy:
What I like about this is that it's all mostly coming from the pedal So if the Laney goes
futt on me I still have 2 other Amplifiers that can be rigged up to power speakers and deliver much the same result.
Of course if the pedal dies then I'm up the creek but oh well you can't cover everything. ::)
@ Roly, yep Cheap strats and they work. :tu:
Only issue I had was the windings are prone to howl/squeal. :grr
Wax potting made a big diff but do be very careful with the heat and time dunked in wax as the
plastic bobbins are very cheap and not thermally stable,, as I found out :o
Only other mod was the addition of one small switch which joins Bridge + Midddle pu in series (effectively creating a humbucker).
Come to think of it I don't believe I've seen this trick done in this manner,, I'll post
the idea if there is interest.
Besides not having to purchase a new scratch plate and on older strats a rerouting of pu
pocket.
The advantage of this over a real HB is that it guarantees a balance when using HB sound as
I've always found it incredibly hard to find a level balance when using HB's with SC in the same axe.
I've actually done this series mod for several of the local chaps with rave reviews.
In my other guitar I do have Real ~60's era Fender PU's and they have a little more bottom
end response. Other than that there is not much difference between the 2.
Neither of my Strat guitars have big out put and if you do have those you might want to adjust the inputs to suit.
I did have a PRS here some time back and the PU output was so insane hot that I certainly would have no use for that crazy output.
My thinking is if you need that much output from a pu,,, you need a better amp. :duh
Re the big input Z;
Yep thanks for the tip, but I'll have to pass as I've had very little success with big Z inputs,, way to sensitive and just asking for trouble with hi gain circuits.
I've spent most of my time trying to get rid of excess bandwidth as it just destroys the sound,, especially at gig levels.
tho, it might work in a studio situation.
Just my observations.
Cheers,, Phil.
http://www.till.com/articles/PreampCable/ (http://www.till.com/articles/PreampCable/)
'tho I'd be more inclined towards a Source follower, but the thing is, presented with a very high Z the natural pickup resonance isn't damped and this makes it sound richer, this...
(http://www.ozvalveamps.org/pickups/strat02c1000.gif)
vs. this...
(http://www.ozvalveamps.org/pickups/strat03r47k.gif)
Now that is a nice sounding box of tricks you have made. :tu: :tu: :tu:
I am tempted to scrap my ideas and just build a PhAbbZone pedal.....
something to aim for...
Kevin
Sounds great Phil, good job!
**edit**
Maybe I missed it, but what opamp did you use for that?
Quote from: Roly on April 16, 2013, 09:17:43 AM
http://www.till.com/articles/PreampCable/ (http://www.till.com/articles/PreampCable/)
'tho I'd be more inclined towards a Source follower, but the thing is, presented with a very high Z the natural pickup resonance isn't damped and this makes it sound richer, this...
That's what a good buffer is made for: present a very Z to the pickup while feeding the following circuitry with a more manageable low impedence signal.
Edit: Actually typed too fast, as in "before reading your (very informative) link". Anyway, I do think a good buffer at the input of the phabb zone will do exactly that, provided the first guitar cord and contacts are of very good quality.
Nice sound clip by the way.
Thanks QReuCk and Roly,,
I guess my reply would be, ok try it suck it and see? :-X
Yes you can up the Z if you want but you will likely run into trouble trying to balance the clean sound which will then have the hump as well as a lot more treble ,,which is EXACTLY what you Don't Want for this type of sound.
This mismatch is what sends the novice round the twist (did for me :'() because quite obviously a lot of modern amps have way more bandwidth than is needed for rock guitar tone and finding the balance between the clean sounds and OD sounds is hard to balance even for professionals.
In My Demo the first quarter is done with only the preamp THEN I stomp on the DDC circuit which just adds more crunch but most ears would not notice the slight loss of top end.
NOW if I open up the input Z that balance will be lost and you will be forever fighting between a overly bright clean sound and a Distortion that is Too dark.
THAT issue is the main reason It took me so damn long to perfect it.
Both sounds worked but the darn thing was not balanced. :grr
If I had a dollar for every multi channeled wizz bang dog box Amp that has that EXACT problem I'd be stinking rich. :lmao:
High Z on old Amps with one channel and minimum Valve count YES you need to get as much energy to enter the circuit and I'd agree You have no choice but to use high input Z.
Bear in mind the High Z input on old Valve Amps has not changed in 40 plus years but pu's and pedals have changed all that to the point where even a budget pu may have more wire than the Dingo fence in Australia. lol
In modern hi-gain multi channel Amps this High Z input is no longer needed ,,,IMHO only of course
The other side of this debate is that yes I have no doubt if you have the talent you could use very high Z inputs and still achieve same/similar outcome.
For me, the budget restricted amateur with limited knowledge,, well this way makes life so much easier. Add,, why make life hard if there is no need 8|
A real example of what bone this dog is chewing on about;
I'm sure Roly has heard of Phil Emmanuel,
When I came to live in Nambour I had the pleasure of hearing Phil Emmanuel gigging at the local RSL hall as Phil E lives just out of town.
(for the benefit of others, Phil E is one of our top Aussie guitar players, the brother of Tommy Emmanuel).
I noticed Phil E used a *Carvin Legacy Amp 212 combo rig* so I did some research and found the schematic.
V1 Grid resistor is 220k,, even more interesting is PI input has 100k across the grid. HUM?
One could easy assume that 220k input would severely hamper the higher freq.
Having spoken with 3 players who have gigged with Him it seems to be common knowledge that Phil E likes to dial up the top end. So having now heard Him live as well as recordings I'd say Anyone who says that Phil Emanuel's sound lacks treble needs to get a hearing checkup. :o
I'd also hazza guess and suggest that the reso hump which is accentuated with higher Z inputs may actually add even more complexity to the above problem.
Maybe someone with better ability can shed a better light on this subject as I don't fully understand it all,, but at least my real world experiments have shown me there maybe a lot more goin on inside the world of guitar sound and just hanging a 1 Meg resistor off everything may not equate to the desired sonic mojo.
Phil.
Quote from: joecool85 on April 17, 2013, 11:06:35 AM
Sounds great Phil, good job!
**edit**
Maybe I missed it, but what opamp did you use for that?
Hi Joe and thanks for the vote.
Arrh good point?? opps :-[
yeah some TL074, simply because they take up less space.
Some LM883 and a mix of a few spare parts bin stuff 5448.
The first opamp is a single NE5534.
I built it mostly in stages,, so while the Valve preamp was mounted a lot of the rest was still on the breadboard.
Hence a lot of buffer stages may well be not needed but having been caught out with big losses by not having them I left it all as it was tested,, cause It worked,, so don't keep messing just throw all the boards into the box and hope like hell I've not missed something.
I did fluff up one board,, etched it wrong way round but who is going to know? :-X
Phil.
Quote from: kevin b on April 16, 2013, 03:22:26 PM
Now that is a nice sounding box of tricks you have made. :tu: :tu: :tu:
I am tempted to scrap my ideas and just build a PhAbbZone pedal.....
something to aim for...
Kevin
It's a lot of work :duh but at least you have heard it and have some idea of the outcome. :tu:
Phil.
Quote from: phatt on April 19, 2013, 09:08:22 AM
Thanks QReuCk and Roly,,
I guess my reply would be, ok try it suck it and see? :-X
Yes you can up the Z if you want but you will likely run into trouble trying to balance the clean sound which will then have the hump as well as a lot more treble ,,which is EXACTLY what you Don't Want for this type of sound.
This mismatch is what sends the novice round the twist (did for me :'() because quite obviously a lot of modern amps have way more bandwidth than is needed for rock guitar tone and finding the balance between the clean sounds and OD sounds is hard to balance even for professionals.
Disclaimer: I do play with multi chanel amps that have
separated EQ for each chanel...
And as far as bandwidth is concerned I do think you can have a big part of the benefits of presenting a high input Z to your PU's without suffering all the troubles: I don't know exactly what physical phenomenon it is linked to, but if you allow your PU's to resonate and filter out the excessive high end, you will still have the rich sound of the attack (heard cause these harmonics are on a very different octave than the root so they don't need to be at the same amplitude) rapidely decreasing into a more filtered sound (high order harmonics
from the instrument do fade pretty quick). I won't say it sounds amazing with very high gain, but for clean or for moderate crunch I think it sounds pretty cool, especially if you attack quite heavily with the right hand (oh and don't set the pick ups too close to the strings, nor the strings too close to the frets, these things need some air to vibrate).
Well that's what I came up with after a few tests with commercially available boxes, but it might not fit perfectly another player. Trouble is: you have to think your tone from one end to the other. One of these ends being the player himself, it's not easy to come up with a do-it-all solution.
Hi QReuCk,
Well sounds like you are like myself,, still learning,, lol.
But we are all on a learning curve and We share our findings. Good stuff :tu:
FWIW,, here is some of what i have learned;
Ok take that screen shot of Hi Z/Low Z input comparison that Roly has so kindly shown to us.
Now if you have a Parametric EQ available to You then try this test out on your ears to try and capture the concept of how reso boosting will impair the ability to reproduce a good sound/tone result.
OK,, Select Mid bands, Narrow Q and Boost the hell out of it and maybe sweep the freq knob (if available).
If you find anything useful then fine I accept that as we all have different ideas on tone. (munsons curve stuff)
Now try the INVERSE of the above.
Cut the Boost/Gain knob to full Cut. (delivering the inverse of what you previously heard, a Deep notch CUT)
My bet is that most folks will find the second tone shaping effect (Deep narrow cut) much more rewarding while trying to extract a decent sound from most audio equipment. (Especially Guitar gear)
A boosted Para Eq with narrow Q will deliver a tone shape not unlike what Roly's Screen shots show.
In My Experience this is a Nightmare to work with and you will have a hell of a time trying to find a good result.
I doubt even the novice will take long to grasp that narrow Q tone BOOSTING is problematic by design and will frustrate them at least until they have emptied their bank accounts on fancy pants addon pedals or other gimmicks that get sold like french fries at Macca'z.
In this Mad world where everything that says/implies MORE of anything is better than less has a long way to go before they understand the intricate details of sound.
It may well prove that what is NOT heard is what makes great sound.
Well that is my take on it all BUT I reserve the right to be Wrong and if shown how so I will bow
gracefully. 8|
With some of those old Valve Amps from a long ago era I can give you more USEABLE
Treble for Guitar from the *LOW* input (68k/68k voltage divider) than any other High Z input ever devised. It will cost you about 20 cents for the trick,, lol :-X
Phil.
Thanks for the answer.
Rest assured I do think I have more to learn from you than you from me. ;)
Interesting point you have... and presented like this I fully agree with it: I do think as a general rule high Q band cutting is often better than high Q boosting.
But:
My preamps setting are often around the onset of clipping and as a consequence I try to maintain the other rule of thumb in my thinkings: Every filtering before the preamp (or first clipping stage) serves only the purpose of shaping the response of the clipping. Predicting how this will affect the clipping is very difficult as highs ride on lows (the assumption that pretend we can treat each frequency separatedly when thinking about it is an over simplification that might not work very good). Currently, even if this oversimplification works a bit to grasp the concept, it doesn't replace to me fiddling with any possibility before the clipping stage and hearing what happens. And my hears tell me both my guitars sound better (especially for clean to moderately overdriven tones) when buffered at a 3Mohm input than straight into the amp (which are more like 1Mohm if I remember correctly).
Well, as you say, I still got a lot to learn, and I really appreciate your views on this. Confronting different views does help learning things.
Oh and back on topic, you published a schematic of something that according to the sound sampled you put does work great. So even if I am always tempted to digress and ask for details that are not always relevant to the point (best way I found to learn things), you must be doing something right even if I don't fully understand how you do it.
And by the way I did some more testings and found out that exacerbating this resonant peak doesn't sound very pleasing when dealing with a higher gain setting that what I'm used to (I can live with that though as I very rarely use this kind of tone).
You might find it interesting if you care to go back in time when guitar amplifiers were rather sad affairs with terrible distortion figures and poor bandwidth, driving crap speakers.
Yet a vast majority of younger folks ask how to attain those old sounds. 8)
They will struggle with modern equipment because the New world of hiteck digital everything claims to give you more than you will ever need. :duh
I've found that word MORE to be most of the problem. wink.
you actually need less and in my humble experience works so much better and gives far better note definition.
Remember the fundamental freq of 90% of every note /chord you can play on guitar is hardly ever going above 1khZ.
With modern higain monster pu's and one Amp may contain more Amplification than a 60's rock concert,, well it's all just getting in the way.
Why just last Sunday I heard 2 guitar players. One chap playing one of those fancy Line 6 combos with more patches than a hells angels convention. A Great player with a lot of technical style but his tone just disappeared into one big pile of crap noise.
Frankly it sounded like a cheap bit of gear and I would never wish to own such gear.
The other player also very good,, but I heard every note he played and enjoyed it even with a couple of mistakes.
I can only assume the line 6 has all that digi efex stuff built in and has high spl drivers which I know can get nasty at hi levels. so it's harsh and the excess bandwidth can easy destroy higain sound.
The other guy had far less bandwidth,, I should know,, I built it for him. 8|
sorry if I'm blowing my own trumpet but it's a great buzz for a little backyard tinkerer to hear his own ideas up against some of the big brands like that. <3)
Tone focus is what gets the job done and that is very hard to get your head around and likely harder to impart in writing. :(
You need to hear these differences in real time, A/B testing.
Phil.
I agree that tone focus is key for the following reason:
- high order harmonics do sound bad, and some of them are even not hamonically correct (especially those from 7x fundamental frequency and higher). Filtering them out both before and after clipping is a good idea, especially after heavy clipping (square wave signals contain a lot of them). Before clipping they usually are a lot less prominent due to the natural behaviour of a guitar.
- when playing several notes (chords, double stops, etc), you will generate some intermodulation distortion, which is not bad in powerchords (the only case where the intermodulation actually adds harmonically related frequencies), but will be dissonant for most other intervals. The more clipping, the more intermodulation. You can filter some of it with low end filtering after clipping but the best way to limit that is to reduce the bandwidth before clipping, especially lowest end, cause you want to avoid clipped-generated harmonics of the lowest notes of your chord with the same amplitude as the fondamental of higher notes of your chord (especially considering a major third will be generated as the 5th harmonic... not that good in a minor chord...).
- highs ride on lows. Clipping apply to the overall signal. So your highs will be asymetrically clipped (here comes the south after even harmonics) with a modulation of this clipping. To me it sounds quite good, but applies only when a) your clipping device sees some harmonics that are there already b) you do not squash them by changing the whole thing into a square wave anyway (ie clipping the lows so hard you don't even let any room to still have the original highs in the signal). So this applies more in the region between clean with a bit of warmth and slight crunch.
It seems your device uses just these concepts, and it sounds good, so you must be doing something right. What I'm more interested in these days is the last of the conceptual aspects I detailed above. Accoustically, an electric guitar will have a lot of harmonics, but with a lot less amplitude than the fondamental and first octave. Put some low input impedance stompboxes and a long guitar cable with capacitance problems after a passive pickup and you have very few harmonics to enhance your "warmer clean" tone.
You are a better man than myself if you can grasp all that. xP
so good on you :tu:
I just stick to simple stuff to explain it.
The best explanation of distortion I read,, (so long back can't remember who/where but likely one of the guitar focused sites)
Went simply thus;
*Half wave distortion followed by Square wave dist.*
If you simulate some of those old famous Valve rigs that is indeed what happens. 8|
the triodes produce the rattle and the power stage squares it off at higher power.
The rest is tone shaping.
The trick is getting the signal swings to line up at each stage if you want the dynamics to happen.
Of course if all you want is fuzz with no dynamics then throw away that idea and turn everything up as far as you can and start playing around with tone shaping.
Phil.
I'm not a better man than any one here, i'm just someone who happens to have been teached some engineering and math stuff a long time ago and have a tendency to overthink sometimes :lmao: :duh
Regarding your approximate concept of tube tone, we do agree:
Tone shaping (guitar pickup, guitar tone and volume circuit, even picking technique, guitar cable, components that might be added/set before the first buffer; then if you put it in pre-clipping EQ/tone tweaking stage) - half wave clipping - tone shaping circuit - half wave clipping - tone shaping circuit - (repete those two for the number of triod stages you have) - tone stack - symetrical clipping (push pull stage) - tone shaping device (guitar speaker).
In my opinion, chosing between high input impedance or not is a choice (I do not pretend one is "better" than the other) impacting the first tone shaping stage of your rig even if it's not the one you would think you act on if you are working on *an amp* or *a stompbox*. Good on you if with your choice you make a good sounding overall rig, which is the case here. And I've heard a lot of people make good use of very low input impedence devices (old school fuzz boxes for instance), I just can't get my head around it as it implies some dynamically changing tone shaping. That doesn't mean it's not right to do so.
And according to Hartley Peavey, the output transformer of tube amps could very well perform also some dynamically changing tone shaping, which is hard to perfectly emulate, but also very hard to understand in for me.