to phatt(user)

[paku5535]

hello

you have mentioned in one thread that you have worked with trademark 60. can u post me the power section schematic,details,psu details of trademark 60/30. this is a killer ss amp. i am not going to ask u for the preamp cause i know this is very complicated.

thanks

[phatt]

Hi paku,
           Re Pwr Amp,,Just Dload the specs for LM3886 chip. 8|

Re the rest of the amp;
Sorry to be the harbinger of bad things but the Amp has goop all over the bits you will likely wish to mod.
So tough love with Tecky 21 as very few schemos exist.

No I've never seen a schemo of that amp and nor do I need to.
I hazard a guess that most of it is derived from the Sansamp gear and like stuff they made.

You will probably find a lot of the *Character Series* pedals use very similar circuit tricks.

Go search FSB (FreeStompBoxes) as a lot of gooped chips have been successfully back engineered by the clever folk who frequently degoop such circuits.  (A whole thread on Character series)

Bear in mind the trademark 60 is a double sided PCB with very fine traces so it's not something you wish upon your worst enemy.

I very much doubt there is much to tweak inside for the novice who wishes to fiddle with a quick and dirty mod,, A fairly good chance it will turn into a nightmare.

The Amp I tweaked was insanely harsh (Far Too much hi frequency response) On top of that the bright switch was insane.

I found the Amp hard to work with as the balance between the normal and drive channels was way off.


The Owner of the amp I worked on gave me the amp and said; I don't care just make it sound like your *PhAbb System* and use the parts if useful otherwise it goes to the dump.

First thing I did was replace the speaker with a more sane lower output Etone.
(Etone are made here in Australia,, very close to old Celestions)

The Factory Speakers used in these amps are viciously bright which of course makes the Amp as loud as hell for a 50 Watt Amp but at the cost of useable tone.

Even without any other mods a different speaker makes the Amp far more controllable.
Even so the bright switch was still WAY WAY Off and out of balance with the rest of the Amp settings.

That said,,, it might be the sound you desire?  <3)

In the end the owner used my PhAbb preamp setup and we just used the Trademark 60 as a power Amp,,, bypassing ALL preamp stages.

From memory I cut the tracks and inserted a line insert which cut the preamps but made use of the internal spring reverb circuit.

When you Removed the line in plug the Amp went back to normal, That way he could at least resell it if he ever wanted to do such.

It is a shame that amp is so hard to work on as I did feel it had potential if one could only access the goop then it would be worth perusing and tweaking.

If you can find a way to back engineer it then let us know.

My bet is you will destroy the chips while trying to workout the circuit.

Phil.

[boymonkey@live.com.au]

heyy, phatt
is what you stated below what happened to the zip; has it got a phabb tone or similar circuit built into it?
i must say it has an amazing disto, pretty popular with all my mates....
its quite funny, they all laugh at the sight of it, but cry when they hear it!!!!

[phatt]

Hey Monkey boy,

Nah sorry the PhAbbTone is not inside Your Amp but it does have switches which move the tone shaping around a bit. A bit like how Dumble Amps are tricked up.

Your Guyratone Zip 555 (I think it was called) is an all fet preamp
(2SK30 I believe) but the rev section was a nightmare and it never worked well so I gave up.
I did spend a fair time working on the tone section and distortion trying to find a happy medium.
As you know it needed a new speaker as the old one was close to end of life.
I believe you have found a new speaker so lets hope it lasts.
When I got that thing it had a blown 10 inch and lucky the 12 inch driver just fits with a new baffle board.

The power stage is my own discrete setup of which I built a few. No medals there just a very simple power stage but they tend to sound better than more complex hi end stuff.
That was back in my days of trying every new trick even fiddling with current FB (see the other thred on peavey damping) but never got results.

But Fahey Amps seem to have perfected that better than myself,,shoosh don't tell Him I said that 8|

Cheers mate, Phil.