MATON V606 PROFESSIONAL

[TIMBO]

Hi guys, This is another of our local builders and the MATON name is up there for quality builds.
From what I can see there is not a lot wrong with this one, the owner said that it stopped working after they moved house.

There is an air vent at the bottom of the cab and the metal grill had come loose and something had broken a screen resistor off the socket tag.

The only other sign was some heating around the reverb tube socket and the plate resistor on the circuit board.

The Ecaps aren't showing signs of age and I think at this stage i'll leave them as is, although I feel that the caps on the SCREEN supply seem a little low in value compared to other builders circuit, usually 50uf either side of the dropping resistor.

SS tremolo, interesting.

[DummyLoad]

nice. you come across the weirdest stuff tim. that's stated in a good way.

looks like a fun restoration. up the wattage value of that power resistor and get up higher off the board. it has a nice layout. i'd replace the electrolytic caps: regardless of visual condition.

--pete

[TIMBO]

Hey pete, I've got to say that the local builders may have been pinching some ideas when it comes to the circuits, but they were really thinking out side the box when it came to the design.

[TIMBO]

I was hoping that I didn't have to replace the ecaps,as they have bolted the circuit board down onto an insulating board under the circuit board, may be hard to remove/replace the caps.

[kagliostro]

may be hard to remove/replace the caps

Naah, not for you 

Ciao

Franco

p.s.: You really find a lot of old nice stuff 

[DummyLoad]

Hey pete, I've got to say that the local builders may have been pinching some ideas when it comes to the circuits, but they were really thinking out side the box when it came to the design.

that does seem to be the case.

do you have a schematic for this one?

--pete

[TIMBO]

Top post

[DummyLoad]

Top post

aha! i.c. it now... :-) 


--pete

[Willabe]

Tone stack tail R you have 68K, should be 6K8(6.8K)?

[eleventeen]

Do we have a 12 A_7 (assume phase splitter/inverter) placed between two octal output power tubes here? Kind of interesting.

[trobbins]

Hi Tim, would you be able to post a pdf of the schem? Ta.

[kagliostro]

I've just saved the schematic as pdf

K

[TIMBO]

Hey guys, Going to move this one along, so I'll fix a few things before I do.
The two 5w power resistors have blacken the board, but are not showing signs of distress and measure close to spec.
Both are mounted hard to the board, but have not actually damaged the board.
I have raised both off the board and have replaced the 4.7k with a 14w equivalent and it still gets very hot.


The standby switch is connected to the 6DQ6's cathode, I'm not sure if this is the best way to mute an amp, thinking of muting the junction of the 220k mix resistors.