My Rig and how I can get a beter sound

[phatt]

Oh I'm the dumb one
A picture would help explain the above.
silly Phil.

[spud]

Phil,

Wow - thanks for the detailed descrip and pic.  I have a few questions - can you lay out the single chain for me?

Is it something like: 

Guitar ->  GEQ -> PHABTONE -> AMP

Are your effects in parallel to both the GEQ and PHABTONE or just the GEQ?

I think I might be able to find GEQ like that for cheap somewhere - online, thrift shop or even my local pawn shop.

Jim

[phatt]

Guitar > presense circuit > PhAbbTone > OD > GEQ > AMP.

(Tone and OD are on a true bypass setup).

The Amplifier has a side chain loop built-in as well as a basic spring reverb.
(the white buttons switch these in/out for each input)

I play keys as well as Axe so this amp gets a lot of use.

Now that I've refined this circuit I've opted to make it a lot more compact.
The Idea is to combine the whole thing into one big floor unit.

The new setup has a triode front end much like the clean section of a Vtwin pedal. (The Triode really jumps the SPL and well worth the extra fuss).

Then > PhAbbTone > OD > Notch filter > Presense > FX side chain > master out.

ODrive/Notch and FX will be bypass switched.

Phil.

[mexicanyella]

Cool rig! I'd like to hear it in action. Is the Laney keyboard amp a 1x15 + horn/tweeter? 1 x 12 + horn/tweeter? How many watts?

I'm experimenting with an Acoustasonic Jr. as a slave amp and considering disabling the tweeter, adding an attenuator to it or just eqing excess frequencies out of the sound between the source amp and the slave. Does the graphic do everything you need for that, running your front end through a full-range amp?

[spud]

Ok - thanks Phil.

Man, I've got some reading to do.  Been chasing down all your posts you linked to and then links inside of them.  Got it all downloaded and I'm going through it - this is so cool!   

Thanks so much,

Jim

[phatt]

Cool rig! I'd like to hear it in action. Is the Laney keyboard amp a 1x15 + horn/tweeter? 1 x 12 + horn/tweeter? How many watts?

I'm experimenting with an Acoustasonic Jr. as a slave amp and considering disabling the tweeter, adding an attenuator to it or just eqing excess frequencies out of the sound between the source amp and the slave. Does the graphic do everything you need for that, running your front end through a full-range amp?

@ *mexicanyella*,
The Amp came with a 12 inch FANE Driver (No Horn) but it had insane hi FREQ output.
It was used for a long time as a fold back (for voice) but that is no longer needed so it sat for a long time.
Rated @50Watts into a 4 Ohm load,,, which in real terms means it's more like a 35~40 Watt Amp @ 8Ohms.  So my earlier comment of 35 Watts is a conservitive estimate.

The Amp though basic and *very un guitar* did have spring reverb and 2 efx loops. Hum

So after many hours of testing I found another speaker which had a much flatter response.
Sadly it has absolutley no markings on it so it's origin is unknown but very much like the great Celestions I've heard, new and very old.

Re acutronic,  Yes definitly disable the horn for OD guitar.

IMO ( O is for *Observation*)

Most modern gear (I play in shops at least) has miles too much bandwidth for good guitar.
People just assume MORE IS BETTER and higher SPL drivers can add even more pain to your learning curve.

It took me a while to catch onto the Fane Driver problem. OK you loose a little percieved power but it makes fine tuning the audio path a lot easier.

If all you do is strum an acoustic and sing a few songs then stop reading now but once you introduce ANY Form of hard driven guitar sound then bandwidth is a BIG gotcha.

Anyone can make distortion but refining the tone is a whole other subject that gets little attention.

My PhAbbTone in front of even the most basic TS9 stomp box will open your eyes about how Tone shaping can dramatically alter a basic sound.

To the casual observer tone controls are just knobs but in reality tone shaping is a culmination of many tone alterations all the way through the signal path.

If you keep your bandwidth narrow then focus on the important frequencies it will make your learning happen a lot faster than trying to use 20/20 HiFi rated digital wizardry to improve tone.

My rig is loud and clear simply because I wiped out all the extra bands that just muddy the signal.
(I'm talking about Internal tweaks not just the ext GEQ)

If I EQ the laney to hifi specs then I only have half the volume because the poor thing will be trying to reproduce very low freq content which it's not capable of reproducing cleanly.

I also have a 100 watt Amp that turned to mud when I tried to use the Keyboard which produces a lot more very low freq content than guitar. A few cap changes and then I could use the power.

Be aware it takes a lot more wattage to produce clean low frequency content which is why a 30 Watt AC guitar Amp can be as loud as a 400 watt bass rig.

Point of interest;
One of the most famous guitar amps was also the worst designed/built.
Marshall had big money issues at one point in time and decided to use cheap inferior components and transformers.
Those plexi amps are now much prized for their unique tone and sell for insane money.

Want a good guitar Amp? then find a crappy cheap circuit that covers the basic fundermental frequencies and find cheap parts. 
I believe Leo used to source 2nd's from the factories.

Yet today nothing short of the very best is considered of worth.
And still they wonder why their sound has no soul

When will it dawn on folks that you get MORE with Less. 
Phil.

[mexicanyella]

I hear you about limiting frequencies; doing more with less, etc. I don't think I've followed that path to the extent that you describe, but I've gotten a lot of mileage in a full-band context with a little 12-watt Peavey...in the right setting. It was enough by itself for basement practices and it could cover live club gigs with one other similar sized amp (old tweed Valco 1 x 10, Crate GX15...I tried various things in that size range) to double the wattage and speaker area.

The right setting: a drummer who could play with attitude but didn't necessarily have to hit hard with giant sticks, a bass player who liked a middy sort of R & B tone from a smallish amp (sized to work with the controlled drum volume) rather than a giant megawatt thundering explosion, and an amplified acoustic guitar. Against that backdrop, a lightly distorted and sort of cutting tone could come through without having to be that loud. And by being cutting (some might say "thin," but I thought it was "good") it left room for the other instruments to do their thing without being too loud.

Once you experience a group of people who have that kind of awareness of what you're trying to do and operate with that kind of chemistry, it's addicting! It would be hard for me to go back to everyone having 100 or more watts and cranking them over monster drums. You can bring the rock at lower levels if everyone's on board with that concept.

Say, phatt, got any recorded stuff to post up in the thread I started yesterday in Player's Corner? I'd like to hear your rig in action, if you do...

[spud]

Phil,

Looks like I'm going to end up building your PhABBTone -    - read a lot of the other threads and like the sounds in the clips.  Still working on getting some that I can show you what the sounds are like now and after I get it tweaked. 

The Jet City worked well - for almost the whole practice I used it with my HO - SE all tube, about 10 watts.  The amp was barely able to keep up as the other guitar player had it volume up.  It did ok.  At the end of practice I tired the Marshall and it really does improve the sound - deeper and fuller.  Also, because the speaker is 16 ohm, it is less volume at the same settings but that's good as I'll have more lee way in adjusting it - if that makes any sense.  I did try backing off the gain and getting cleaner signal even on the OD channel and that seems to also help with the "cutting through".  I'll have to retrieve the Marshall as it's still over at the drummer's house and play with it at home where I can work on the EQ settings and trying to tweak that.  So progress is being made but there's more work to do to get it optimized and I'm sure I can get killer sounds out of it with the right EQ - I'm going to build the PhABBTone and try that out too! 

Many thanks to all for the great insights - ROK ON ! 

Jim

[phatt]

Yes there are a couple of low quality clips posted here somewhere.
But not sure which ones.
Here's one I quickly whipped up while breadboard testing the Valve boost circuit.
I had to manually stop to engage the OD which was not set correct but no matter it gives the idea.

So the signal path is ; Guit > Valve > PhAbbTone > OD (DDC) > GEQ > Amp.
Delay is on the side chain built into the Laney and of course some onboard Reverb mixed in.

This is a direct line out recording straight into Cakewalk on my laptop with nothing done except MP3 conversion.
No doubt you can't hear the speaker influence but it's close to what you get.

Obviously a lack of bass if playback thru small speakers.

Guitar is the same elcheapo Casino strat copy,, LOL you can purchase these fake Scoils for about $15 AU each.
I also own another Strat which has genuine Strat PU's and those are just a bit darker.
I did have to wax pot the fake ones to stop them squealing but for a $150 Guitar I was impressed.

Have fun,, Phil.

[erokit]

Interesting factoid. I don't remember where what equation this based on. But doubling the speaker impedance from the amp output impedance reduces the wattage by 31%. So an 8 ohm 80w amp into a 16 ohm speaker is 80 * .69 = 55.2w.

 

[mexicanyella]

Yes there are a couple of low quality clips posted here somewhere.
But not sure which ones.
Here's one I quickly whipped up while breadboard testing the Valve boost circuit.
I had to manually stop to engage the OD which was not set correct but no matter it gives the idea.

So the signal path is ; Guit > Valve > PhAbbTone > OD (DDC) > GEQ > Amp.
Delay is on the side chain built into the Laney and of course some onboard Reverb mixed in.

This is a direct line out recording straight into Cakewalk on my laptop with nothing done except MP3 conversion.
No doubt you can't hear the speaker influence but it's close to what you get.

Obviously a lack of bass if playback thru small speakers.

Guitar is the same elcheapo Casino strat copy,, LOL you can purchase these fake Scoils for about $15 AU each.
I also own another Strat which has genuine Strat PU's and those are just a bit darker.
I did have to wax pot the fake ones to stop them squealing but for a $150 Guitar I was impressed.

Have fun,, Phil.

Wow, that's nice and sparkly...very lively, and goes well with what you're doing on the instrument, which sounds like it's combining a lot of fretted notes and open ringing strings. I like the Bigsby-esque shallow trem-bar dives and quivers in there too.

I'm reminded of the Phantom, Rocker and Slick song "Men Without Shame," combined with Montrose's "Rock Candy" and various songs by Walt Mink. Cool tone.

Erokit: that's interesting about the watts/ohms relationship. Does it then follow that halving the ohm load increases the wattage by 31%, until the amp smokes?

[spud]

Well, if this example is any indication I'd say it's more -

So as Mexi pointed out, we have:
80w at 8 ohms
What is the wattage at 16 ohms given that doubling impedance will reduce the wattage at 8ohms by 31%. 

So 100% - 31% = 69% so the reduced wattage is 69% of 80w so:

.69 * 80= 55.2

But to go back:

X% of 55.2=80

And we solve for X:

(55.2 * X) / 55.2=80 / 55.2

Then simplify:

X=80 / 55.2
X=1.449275362318841

So let's just say it's 1.45  - so going the other way is 45% more (if I did that right - and that would be amazing as I'm pretty math challenged)

I think that the danger is that if you drop it further than the rated impedance, it tends to have a run-away condition when the actual impedance drops even lower.  Keep in mind that the 8 ohm impedance is "nominal" meaning it can vary - less and more depending on frequency.  So really at certain points, if it drops too far, poof, there go the output transistors:  crackle, roast, melt...

So if we go a head and do the last part:

1.45 * 80 = 116

So 116w at 4 ohms

What about 2 ohms (which it will hit at various frequencies)?

1.45 * 116 = 168

So double the wattage at 2 ohms!   It all really depends on what the transistors are rated for.  I'll have look them up. 

Jim

[Roly]

Interesting factoid. I don't remember where what equation this based on. But doubling the speaker impedance from the amp output impedance reduces the wattage by 31%. So an 8 ohm 80w amp into a 16 ohm speaker is 80 * .69 = 55.2w.

 

Nope.   

Power Law.

P = E^2 / R

E-squared remains the same because it is determined by the amplifier supply rail voltages (the output voltage does change slightly due to amp internal supply resistance with heavy loading, typically less than 0.5 ohm, but this is minimal until the amp is being seriously overloaded anyway).

Therefore P varies inversely as R.

Double R, half P; half R, double P.

Worked example, 80 W in 8 ohms

P = E^2 / R

80 = E^2 / 8

E^2 = 80 * 8 = 640

E = 640^0.5 = 25.29 volts RMS


Set R = 16 ohms

P = E^2 / R

P = 640/16 = 40 watts


Set R = 4 ohms

P = 640/4 = 160 watts, then smoke because the output current is now double what the amp is rated for.

[J M Fahey]

This Math is fine in amps with *very* good and quite over rated transformers; usually in both extremes : Lab equipment (as in the transistor or chip Manufacturer's own Labs) or hobby makers who don't mind paying extra since it's for own use anyway.
The 95% others (Commercial manufacturers) use *just* what's needed and nothing else.
Or they suicide commercially.
There's much cut throat competition out there.
So normal practice is often to use transformers so rated that the voltage rails, under max load (which is what happens when you are measuring max power) fall between 20% (*very* good) to 30%.(average).
Just yesterday we were commenting about the happy repairing of a Sunn 300 amplifier (a very high quality unit).
Rated power was:
300W/2 ohms
200W/4 ohms
120W/8 ohms.

I repeat, the Math is right, but Accountants rule the World ... or so it seems. 

[Roly]

When in doubt, throw it up against the universe and see what sticks.

Tests on some 50 watt solid-state amps in the workshop.
Percentage watts

Load	4	8	16
[td}Jade 100ke (commercial)	149%	100%	58.3%
Homebrew "Red"	164%	100%	62.9%
Homebrew "Black"	155%	100%	64.4%

Not too surprising that the overbuilt homebrew amps did somewhat better than the commercial one.

None of these amps are characterised for 4 ohm operation so the prospective 4 ohm power output was derived from measuring the output voltage at the same current point as 8 ohm clip level, and is therefore a bit dodgy and may be somewhat less.  All values corrected from real load values to exact resistances; all 1kHz sine.

The only valve/tube amp to hand "smoked" during warmup after being dragged out of long term storage, before any figures could be obtained (damn EL34's again).