Quote from: bry melvin on June 25, 2010, 12:39:15 PM

QuoteNo other passive tone circuit I know of can pull the mid notch like HiWatt.

Curious  if that included the on guitar circuit board and tbx  (Eric Clapton signature strat)

I build (or have built) all of my strat type guitars with that circuit

I've never used a HiWatt.

Yes I know that's an "active" guitar setup...just curious of the comparison if someone has tried.

I understand the confusion as it's rather hard to get your head around these tone shapes.
In short NO Clap Strat tone circuits are dead. a mere hump of about 5/6 Db from memory. (someone here a while back asked about TBX and I simulated it for them. Sorry no time to search at the mo)
If you feel those onboard tricks bring positives to your sound then by all means use them but bare in mind that it's often only that one guitar an so what you gonna do when you bust a string 2 min before you walk on stage and you are forced to use a bog standard Axe.

I always look at it from a live gig situation/ on the road so to speak.
When you are famous you can have anything you want,,, heck they will come to you then.

Meanwhile having built all the famour tone circuits (In Amps) there is Absolutly none that can do a true *Notch Mid Cut*

Side note:
Jack1962 ,, observation is (I assume) talking about the AMP As A WHOLE.
Whereas I'm refering to *Tone Stacks* as a *Seperate Entitey*
Entirely observed on there own merit.
It would be an eye opener if Jack inserted the HiWatt Tone into the Dumble,,
He would be in for a big suprise.
That said if smudgy tone is your thing then I have no arguement.

For me the *notching effect* is far less lossy that big sloping curves.

Heres how it works:
LOOK carefully at the pic,
If you make any CUT in freq broard and shallow then you also pull out a lot of energy in the signal path. (some could argue that with the power of a Dumble POWER matters little,,, yeah right and like EVERYONE OWNS an Dumble???)

Meanwhile back in the real world.
Where was I?
By implimenting a steep notch when cutting the mid you achieve better results as you suck less energy from your signal. You are wasting less energy this way.

I can't find the snap I wanted of a HiWatt / Dumble shootout so this will have to do tonight. It will give you some *Visual idea* of what is happening.
Notice the *Tonemender has a soft dished effect on the sound*.
This is the classic Fender mid scooped effect.
Now look at my Modded HiWatt tone !!!! Trust me this is stunning in front of a simple fuzz box like a TS9.
And I'm sorry to say that the Clapton or TBX tone circuits can only dream about these tone shapes.

Hope it helps,,Phil

Hello bry melvin,
                      Yep a bit of a trick one but as it's *Driven by an Opamp* it's quite likely that a lot will work.
As long the *Driving transducer* in the tank measusres somewhere between 30 to 60 Ohms (that's DC resistance not the Z) then it's going to work give or take.

Someone here may have that Amp and could give you the number on the tank?

It 's not the greatest Reverb circuit so you may wish to consider putting the money towards a Reverb pedal instead?  Just a thought. :tu:
Cheers Phil.

LOL, At my age anything after 1980 is modern  :lmao:
If you love the sound it makes then great but if the amp you speak of is the one pictured above it has not had a hard life in it's 30 Years.

Any serious on the road live gigs will soon show up all the design flaws in amps of this era.
I purchased a brand new *Montreau* model,, years back and it broke within a couple of months. IME these things are very flimsy inside.
So any serious on the road work they just stuff up.

Obviously you love the Amp and I Hope you get it sorted out so you can enjoy playing it. :tu:
Phil.

alfredomatta,
                  Yep JMF is right, no speaker out,,, then scap it till you learn more. :tu:
Phil.

Quote from: alfredomatta on June 15, 2010, 11:00:14 AM
Well possible,, IF you plug the *princeton* into the 4 x10 speakers
Phil.

would that be by plugging the yamaha to the princeton's effect loop out?? or would this have to be done by wiring them to the princeton amp?

No no no,,, Whoops sorry
I mean the *Speaker out* on Princeton Driving the 4 speakers in the Yamaha.

Connect The princeton *speaker output* to the speakers in the *Yamaha box*.
*****I'm assuming you understand that you *NEVER* join 2 Amps together at the speaker end?*****

Without the amps in front of me I don't know if it's straight foward so if you are not sure don't mess with it.
Phil.

Then you need to FIX it!!!  :trouble
The incoming Ground wire should be *Bolted* (with the proper washer and lock nut) to the Metal Chassis of the Amp.
Drill a new hole if need be but *failure to Ground the Amp* might be the last mistake you ever make 0:)

While we are on the subject;
Don't tie any in coming *Mains wiring* to low voltage or signal wires.
Keep Mains seperated from all the other stuff.
The reason should be obvious 8|
Phil.

Quote from: f_b_ilies on June 15, 2010, 09:49:16 AM

Btw, the 220/110 transformer doesn't have grounding, is that OK?

Primary ground?
             I believe that one has already been answered. 8|
CT of the *secondary* is normally used as the *Common* node.
Phil.

The solder issue is only the tip of the iceberg. :trouble

Quite frankly a lot of these amps will become land fill in a few years as the general build quality is just pathetic. (As long as they look pretty they will sell)

Fixed a Marshall JTM 60 a while back and the boards where so badly buckled from heat stress that it had also broken/snapped the plastic efx jacks on the back panel.
The ribbon connectors where breaking just by touching them (the cheapest plastic on the planet next to Valves :duh)

A redneF Performer 1000 SS rig,, again shocking layout/design, really bad heat stress on the board. Laying HOT components flat on a circuitboard might look neat and tidy but just plain stupid if you want to build reliable equipment.
I would never waste time on fender gear now, I've not yet found a new SS model I like.

As to good well built gear,,, I worked on a Teck21 Trademark 60 a while back and although I hate surface mounted double sided boards the general build quality and layout was very good.

I'm only into it for the hobby thing so I don't see that much gear but,,, I've seen enough.

Enough from me,,, end of Rant :grr
Phil

Well possible,, IF you plug the *princeton* into the 4 x10 speakers :tu:
Phil.

Hi Enzo,, love your style mate. :tu:

So a DMM and a hammer can fix almost any electrical problem. :lmao:

Seriosly though it's a good simple way to tell if you have suspect joins.
Good one.
cheers Phil.

Hi folks,
         My old Eagle eyes spotted this on a pile of junk and I could not help myself I had to see what was inside.
Lo and behold,, *An LM3886* complete with a big/reasonable PSU.

So after a few head scratching hours I disconnected all the fancy sub circuitry and I have myself a 50 Watt Powered Speaker.
Just finished adding a small input socket and preamp to the side panel,, works a treat with my other guitar preamps. <3)

I was not expecting much from the little 6 inch *Elcheapo* speaker but to my suprise it reproduces Guitar signal quite well.
Although the speaker is a little low in the SPL department it can still be loud enough to play over a Drummer.

The speaker looks funny from the front but a closer inspection of the rear shows it's just a normal cone with the concave dish added on the front.
So it's not a dedicated *long throw hifi type woofer* which of course would not work for guitar signals at all.

PSU delivers 36-0-36 VDC and drops via Resistor and zener for the 12-0-12 VDC to run the opamps ,,Oh how thoughtful they where.   Everything needed to make a simple cheap but gutsy little compact rig.
I'm stocked chaps.

I think this got dumped because the *Signal sensing circuitry* obviously was switching off but not switching back on when another signal came through.

So if you see one of these grab it,, just for the chip and complete PSU alone.
All the bits needed to make a 50 Watt Amp ,,,how kool.
Cheers Phil.

Quote from: DFH120 on August 28, 2009, 09:16:43 PM
I understand.    Ain't nothing like real thing.  In hindsight, I should've known if it was possible, 'cause someone would have done it.  Thanks!

Just had a look at the schematic and *IF* you just want the preamp parts (A and B Ch)
Then I believe it would be a doable project.

Even easier if you only want *One Ch* as a stand alone preamp.
Just delete all the relay stuff,, that will bring the part count right down for you.
Just a thought.
Phil.

Hi Rutger,
            Try this for a quick run down.
http://www.electronics-tutorials.ws/opamp/opamp_1.html

Google is the go,, Try "basic op amp tutorial" in a search,, you will get heaps of links. Some stuff is not easy to grasp at first but you are bound to find one that's well written and makes sense for the novice.

It will of course help if you have a basic grasp of electricity, magnetics and basic physics.:tu:
Phil.
Edit ; LOL Arrh Teemus' beat me to it 

Quote from: f_b_ilies on June 11, 2010, 08:06:15 AM
Thanks Phatt!

I actually said that the 36.8V is AC, that's why I was surprised. If you check the diagram, I also stated there that all voltages are in AC. It makes sense now with blue/black/blue wires, but I still don't understand the two brown wires where I get the 10.2 VAC. Is that powering another area of the boards or something? So I still don't know what to ask for if I go to a shop. A 220VAC to 36.8VAC/10.2 VAC transformer, 75W? Is that it?

HI FB,
Look I've missed a couple of things,, sorry for that.

With all due respect if people here do not even understand the function of the transformer then those people put other folks in a very awkward situation.
Safety is a real issue when playing around inside gear.

I quote you from a previous post;
"I also measured the output voltage on the transformer and was surprised to get AC instead of DC."

It's those kind of comments that tell me you don't have enough knowledge to fix this thing. :grr

JMF has given the best advice,,,if you are smart quit now and hand it to someone with the ability to trouble shoot what's wrong,,,or trash it as you've likely fried it all anyway.

No disrespect mate but I'd rather you hate me than to find out you are DEAD. 8|

If your measurements are indeed correct (unlikely but possible) then there is a very high risk of FATAL electric shock.  NO Not from just the mains ,,,BUT FROM the 2 DC rails which may have 100VDC floating between them. 36x 2= 72. 72x 1.4= 100VDC that's 50-0-50VDC Rails.
Touching both Pos and Neg rails will leave you with no time to say;
Hey man, maybe, Zit I should have, Zit taken Phil's advice, Zit.

Anything above around 70/80 Volts (DC or AC) is deadly dangerous and should be treated with the same respect as the mains. :trouble

I have an Amp here right now with 140 VDC between the Rails,,, spooky ,,
I hate working on this big stuff.

So go check those 2 Big Capacitors (next to the square black blob, the Rectifier) and *Read The Working Voltage* **(What does it read?)**
The VDC inside the Amp circuit will/should always be *Less* than what is written on those.
That will at least give you some idea of what your DMM should be reading.

*****I sense, Something is very wrong with those measurements you give******
Phil.

Quote from: J M Fahey on June 08, 2010, 11:22:36 PM
Well, Phatt himself has an *incredible* reverb driving circuit (search around in this forum) which absolutely smashes the reverb drive into submission, it sounds HUGE.
Of course, instead of the puny +/- 15V, 5mA (max) cheap op amp used nowadays by EVERYBODY,  he slams them with +/- 35V, and 1 A transistors, no wonder he has *too much* reverb.
Give it some of your time, you´ll find it very well spent.

Thanks JMF ,, you are so kind 0:)
Yes I know I've got *TO MUCH* reverb,, ,but hey I wanted to scare those *Valve Nerds* into submission  :trouble that you can get great sound from SS gear and I truely believe My * Maxiverb* is as good as a Valve driven reverb unit. :lmao: :lmao:
Phil.