PDA

View Full Version : Maton Super Twin refurb



dave.king1
03-02-2020, 06:02 PM
One of my mates has just thrown some cash at one of these ancient beasts.

Apparently new valves and recap are going to be in order and almost certainly rebiasing.

I've had a bit of a search and not found a circuit diagram yet, does anyone have leads to one to save time getting it back out the door and making the sounds it should.

DrNomis_44
03-02-2020, 07:22 PM
Not sure if this is the same model of amp you have, but found this after a quick Google search:

https://ozvalveamps.org/maton.htm


Does the amp you have look like this one?:

https://foundsound.com.au/products/10743

dave.king1
04-02-2020, 04:06 AM
It's only the head but Scott said that's what he said it looks like, he gets it next weekend.

I also saw that on valve heaven, hopefully there won't be too many variations in the circuit

DrNomis_44
06-02-2020, 04:57 AM
I tried doing some google searching for schematics, but the best I could manage is what's on the Ozvalveamps website.

I'd say that it's definitely worth restoring/refurbishing the amp cause it is part of Australia's musical history, apparently those old Maton amps were really good sounding amps.

matthew
06-02-2020, 06:10 AM
Stupid question, but have you asked Maton?

dave.king1
06-02-2020, 11:29 AM
Stupid question, but have you asked Maton?

The only stupid question is the one that isn't asked and at this point in time no I haven't because the new owner hasn't picked it up and delivered it to me yet so I'm not entirely sure what to ask for.

Maton weren't much help when I wanted to restore the L202 before handing it off unfinished to the guy who has purchased this amp.

Scott thinks it may be this beast https://ozvalveamps.org/maton02.html#SRG75 SRG75

Simon Barden
06-02-2020, 04:00 PM
Well, you can obviously replace like-for like. You'll end up de-soldering and re-soldering lots of components like resistors to check if they are still in tolerance. Let's hope that the valves are common ones and easily replaceable.

dave.king1
06-02-2020, 05:28 PM
Like for like is easy if you can still read the values and are the originals, only time will tell

Simon Barden
06-02-2020, 05:38 PM
A chap here seems to have repaired one. Maybe contact him if you are struggling

https://www.guitargear.net.au/discussion/index.php?topic=35061.0

dave.king1
07-02-2020, 04:35 AM
A chap here seems to have repaired one. Maybe contact him if you are struggling

https://www.guitargear.net.au/discussion/index.php?topic=35061.0

Thanks Simon, no struggle until I open it up but I will document here as best I can once I start

I've just signed up to that forum and will almost certainly be asking questions there

dave.king1
08-02-2020, 12:20 PM
Scott has just taken delivery of the amp along with the schematics, this could possibly be a much easier project than anticipated

Having said that, over the years I have met that bastrad Murphy and every single one of his known relatives ;)

dave.king1
10-02-2020, 05:47 PM
The amp turned up tonight and let's just say it was an interesting sight.

One of the filter caps is missing, a couple of resistors show significant heat damage and there are a number of wires swinging in the breeze.

The thing that startled me most is that quite a bit of the wiring is 0.4mm solid core telephone wire, from 200pr cable for those who are familiar.

Not a big deal to fix but a major surprise, my first amp build was an AC30 clone back in 1965, I worked for the then PMG and had access to anything I wanted but did use proper hookup wire that was fit for purpose

Marcel
10-02-2020, 06:38 PM
An old saying springs to mind..... Better you than me Gunga Din....

Simon Barden
10-02-2020, 08:16 PM
An old saying springs to mind..... Better you than me Gunga Din....

"You’re a better man than I am, Gunga Din" [/pedant]

DrNomis_44
11-02-2020, 01:52 AM
The amp turned up tonight and let's just say it was an interesting sight.

One of the filter caps is missing, a couple of resistors show significant heat damage and there are a number of wires swinging in the breeze.

The thing that startled me most is that quite a bit of the wiring is 0.4mm solid core telephone wire, from 200pr cable for those who are familiar.

Not a big deal to fix but a major surprise, my first amp build was an AC30 clone back in 1965, I worked for the then PMG and had access to anything I wanted but did use proper hookup wire that was fit for purpose


Can you post some pics of the amp chassis?, you might be able to order replacements for all the filter caps, and the other caps from this website:

www.evatco.com.au



They also stock all sorts of bits and pieces related to guitar amps as well as some nice cloth covered hookup wire, typically used in valve amps.

dave.king1
11-02-2020, 04:29 AM
I've already priced up all the bits from Evacto and it shouldn't be too painful

dave.king1
11-02-2020, 05:44 AM
A couple of pics, note the yellow/green and yellow/red wires there are other colours that aren't seen in these pics

As delivered to the previous owner
33719

As delivered to Scott
33720

The circuits that came with the amp.

33721
33722

Marcel
11-02-2020, 08:14 AM
Yummm.... plenty of sweet spicy Mustard in that amp.... and far too much lethally exposed 240VAC mains.

DrNomis_44
11-02-2020, 08:25 AM
A couple of pics, note the yellow/green and yellow/red wires there are other colours that aren't seen in these pics

As delivered to the previous owner
33719

As delivered to Scott
33720

The circuits that came with the amp.

33721
33722


The fact that you've got some schematics for the amp should make repairing/restoring it a lot easier.

DrNomis_44
11-02-2020, 08:31 AM
Yummm.... plenty of sweet spicy Mustard in that amp.... and far too much lethally exposed 240VAC mains.


I've heard that hose Mustard caps are supposed to be great for tone, assuming that none have gone leaky, I'd probably try and keep them soldered on the board if at all possible, hopefully none of the resistors have drifted out of tolerance.

FrankenWashie
11-02-2020, 10:22 AM
That doesn't look like my idea of fun...

DrNomis_44
11-02-2020, 11:44 AM
To me, it looks like a relatively simple enough amp circuit to understand, a lot of it is pretty standard, the tone-stacks for the two input channels appear to use typical Fender component values, so the schematic seems to be a bit Fender-ish, with a different type of power tube used in the power amp, a pair of 6DQ6A tubes rather than 6L6 tubes, all the preamp and phase inverter tubes are 12AX7, so my guess is that Maton based the amp on one of Fenders models, so once it's back up and running again it should have a Fender-ish tone.

dave.king1
11-02-2020, 12:52 PM
my guess is that Maton based the amp on one of Fenders models, so once it's back up and running again it should have a Fender-ish tone.

From the very few reviews I've been able to find it is very clean and bloody loud.

It's called an STB 75 which I assume means Super Twin ( Chanel ) Bass 75 W, but there is a switch on the front that is labeled 50/50-100 and they talk about it being a half power switch

Simon Barden
11-02-2020, 04:22 PM
Looks like you're limited to using a 16 ohm load, so a single 4x12" cab or 1x12" cab (or 2x8 ohm speakers in series).

Of course you could change the output transformer to a multi-tap one, but that would change the character of the amp.

dave.king1
11-02-2020, 04:30 PM
Ah Simon that's pretty much the conversation I had with Scott, we both like 10s but he's thinking a single 12.

Maybe a 10 & 15 in series if there's suitable options

Simon Barden
11-02-2020, 04:37 PM
Indeed. Probably best to get the amp working first, see what it sounds like, and then start thinking about custom cab options.

Simon Barden
11-02-2020, 04:42 PM
Those 6DQ6A were mainly used as TV valves, so in plentiful supply back when the amp was made. You're reliant on finding NOS valves now, so it might well be worth getting some spares for the future whilst you can. At lest you have the option of using 6DQ6B valves as well, which widens the options slightly.

dave.king1
11-02-2020, 05:39 PM
There are other more modern valve options that don't require major mods.

Anode to socket rather than cap and obviously rebias plus a bit but not rocket surgery

Simon Barden
11-02-2020, 06:07 PM
But then it's not quite the same amp.

So it all depends on whether your mate just wants a nice working amp or an original looking and sounding Maton. I don't regret having all the changes made to my Sound City head so that it's a very different amp now to the original and sounds so much better (and quieter). Had the OP transformer not required replacing (with a Marshall one for availability reasons) then I'd probably have kept it all original.

king casey
11-02-2020, 06:37 PM
There are other more modern valve options that don't require major mods.

Anode to socket rather than cap and obviously rebias plus a bit but not rocket surgery

Brain surgery or Rocket science (pendant)

cheers, Mark.

dave.king1
12-02-2020, 03:19 AM
Rocket surgery, you obviously haven't heard Kerry O'Keefe speaking ;)

dave.king1
13-02-2020, 12:06 PM
Referencing the circuit above the unknown PT is a Ferguson PVD105, specs exist online so finding a suitable replacement isn't difficult not that one is required.

I have written to Evacto about a turret board to replace the cracked and broken circuit board and once that is sorted I'll start ordering bits.

DrNomis_44
13-02-2020, 12:19 PM
Referencing the circuit above the unknown PT is a Ferguson PVD105, specs exist online so finding a suitable replacement isn't difficult not that one is required.

I have written to Evacto about a turret board to replace the cracked and broken circuit board and once that is sorted I'll start ordering bits.


Making a custom Turret board isn't that hard to do, although you do need some simple tools for installing the Turrets, last time I visited the Evatco website they had all the materials and tools in stock needed to make Turret boards, you could use the old board (it looks like a Fender-style eyelet board) as a guide, and then draw a layout on some paper, note that I have never in my whole life made a Turret board so I'm no expert, but I wouldn't mind learning how to make them myself.

dave.king1
13-02-2020, 12:30 PM
Making a custom Turret board isn't that hard to do, although you do need some simple tools for installing the Turrets, last time I visited the Evatco website they had all the materials and tools in stock needed to make Turret boards, you could use the old board (it looks like a Fender-style eyelet board) as a guide, and then draw a layout on some paper, note that I have never in my whole life made a Turret board so I'm no expert, but I wouldn't mind learning how to make them myself.

I'm entirely with you on this, if I can design and build a car I'm sure I can copy a simple cct board that I have in front of me

It can't be that difficult, mind you I won't finish up with the rats nest that currently passes as P-P wiring

king casey
13-02-2020, 01:23 PM
if I can design and build a car I'm sure I can copy a simple cct board that I have in front of me

It can't be that difficult,

33757

cheers, Mark.

DrNomis_44
13-02-2020, 03:57 PM
I'm entirely with you on this, if I can design and build a car I'm sure I can copy a simple cct board that I have in front of me

It can't be that difficult, mind you I won't finish up with the rats nest that currently passes as P-P wiring


Typically, the Turrets are usually spaced 3/8 inch apart, that's 1cm in metric units, so if you buy yourself a few A4 sized books of 1cm square graph paper, all you then have to do is just mark the positions of the Turrets on the graph paper with a dot (pencil them in first so you can easily erase any mistakes), yeah I agree, making a Turret board looks easy enough to do, it's just a bit time-consuming, but well worth it, components are easier to de-solder in the event one needs replacing.

dave.king1
13-02-2020, 06:20 PM
33757

cheers, Mark.

Looks like something from the 24 hours of Lemons ( sort of like the Shitbox Rally but on a circuit )

Simon Barden
13-02-2020, 07:37 PM
You should know, Dave. You took the photo!

dave.king1
24-02-2020, 05:52 PM
Sent an email to Evacto with some questions a week or so ago and nothing back so they won't be getting a bulk order just the couple of bits I cant get from Jaycar

dave.king1
19-03-2020, 06:37 PM
Been at a total standstill with this since my last post, been super busy preparing the house for sale and first open is this Saturday.

Still have work to do on the house but will hopefully break free mid next week and get my life back

dave.king1
28-04-2020, 03:15 PM
Sadly I'll be handing this amp back to the owner tonight for him to take to the local amp repairer.

I've literally not had time to go near it, on Friday we sold the late MIL's house, our house and bought a new one, so 60 years worth of stuff from the MIL's place and 30 years worth from ours has to be sorted through and re-homed or dumped between now and the 5th of June.

We are also moving from Sutherland Shire down Wollongong way so the extra distance becomes an issue as well.

Andy40
28-04-2020, 03:17 PM
Wow, you got your work cut out for you DK

dave.king1
28-04-2020, 03:37 PM
Wow, you got your work cut out for you DK

Don't muck around.

BTW. I didn't mention the race car project that I inherited in December that will get underway once I get workshop space lined up

Should finish up looking something like this one that I can't keep up with in the car in my avatar

34806

dave.king1
28-04-2020, 06:41 PM
After talking to Scott the repairs will go ahead after we move so I have two projects

dave.king1
14-07-2021, 02:51 PM
Life got in the way of the restoration so I sent it back to Scott who found someone else to finish it off.

He got it back last week and is very happy with it, maybe I'll get to play through it after this lockdown stuff is done