New homebrew using Marstran OPT

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New homebrew using Marstran OPT

Postby clanger » Sat Jan 15, 2011 10:59 am

Just finishing up the design and build of a new homebrew amp.

The tube complement is ECC83, EF86, ECC83 PI and either 6L6,KT66 OR EL34 OP via cathode bias. SS rectification.
Ironwise the OPT is the Marstran radiospares clone although the PT came from elsewhere.

Sounds really good and does a great marshall crunch but with half the volume, which is what I was trying to acheive.

Pics and video to follow fairly soon.

Cheers Clanger.
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Re: New homebrew using MArstran OPT

Postby Brian Wallace » Sat Jan 15, 2011 11:52 am

Sounds awesome Clanger, can't wait to see and hear it.
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Re: New homebrew using Marstran OPT

Postby clanger » Sat Jan 15, 2011 9:31 pm

Well, here's pics at least. Bear in mind that this is a prototype/test mule so there's some gnarly bits where things have changed/are changing. But as of today I'm just a couple of tweaks from finished. Will try and get some video clips done in next little while.
Image
ImageImage
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Re: New homebrew using Marstran OPT

Postby clanger » Mon Jan 17, 2011 2:17 pm

With a bit of luck, some video here, disappointingly the cheap crappy mic on the camcorder does no favours to the sound. I shall have to make some sound only recordings, cos it sounds great in the room!. I guess it gives an indication of the sound.

http://www.youtube.com/watch?v=zcHPsYIH2aQ
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Re: New homebrew using Marstran OPT

Postby David B » Sun Jan 23, 2011 5:59 pm

Ah nice point to point construction 8) . Definitely crunchy with a considerable amount of gain. How loud is it and what circuit?
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Re: New homebrew using Marstran OPT

Postby clanger » Mon Jan 24, 2011 3:18 pm

David B wrote:Ah nice point to point construction 8) . Definitely crunchy with a considerable amount of gain. How loud is it and what circuit?


Hi David,

Glad you like it :lol: I haven't done a proper measurement vis a vis THD, but it's in the 20W clean range, probably 25 flat out.

One aim was to get some good crunchiness that could be handled by a 1X12 Celestion, which I've just about acheived, but I think it would blow a G12M fairly quickly is cranked continually. Should be right for a G12H though. Another aim was to get an amp that felt good to the fingers to play, but of course I can't video that!!

The circuit is my own design so I'm keeping fairly schtumm about that for now! except to say;

The tube complement is ECC83, EF86, ECC83 PI and either 6L6,KT66 OR EL34 OP via cathode bias. SS rectification.
Ironwise the OPT is the Marstran radiospares clone although the PT came from elsewhere. Tag board helped me as the design changed a bit here and there. Oh the other thing to say is that one aspect of the front end is that it has two discrete channels a la Marshall but jumpered internally, and tone controls only on the 'Normal' channel.

Cheers Clanger
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Re: New homebrew using Marstran OPT

Postby David B » Sat Jan 29, 2011 12:45 pm

Interesting configuration & still loud enough to move some air but not remove flesh from the bone :twisted: Looking forward to seeing it complete in the cab...
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Re: New homebrew using Marstran OPT

Postby clanger » Thu Aug 11, 2011 7:53 pm

Now in its case and with front panel finalised;

Image
Will try and get some decent soundclips soon.
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Re: New homebrew using Marstran OPT

Postby Brian Wallace » Thu Aug 11, 2011 10:42 pm

Sweet. :)
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Re: New homebrew using Marstran OPT

Postby clanger » Wed Nov 02, 2011 5:59 pm

Got some Sound City PA cabs up on evilbay at the moment.

Used the Ruskin amp to do a quick demo, which in turn is a nice demo of the amp;

http://www.youtube.com/watch?v=5-IB1nLfM-c

The amp now has a PPIMV on it, was running on about half way on that , with the channel volumes slowly heading towards dimed on thru the course of the clip,

Regards, Clanger
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Re: New homebrew using Marstran OPT

Postby clanger » Wed Jun 20, 2012 9:27 am

Hi gang,

Another clip of the amp, this time hooked up to an old Marsall 4x12 w/Powercell speakers.

http://www.youtube.com/watch?v=ml7mw8Ex ... e=youtu.be
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Re: New homebrew using Marstran OPT

Postby Brian Wallace » Wed Jun 20, 2012 2:37 pm

Clanger,

Both clips sound great. :)

Brian
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Re: New homebrew using Marstran OPT

Postby clanger » Wed Sep 21, 2016 5:43 am

Time flies...

Chassis number 2 at work.

https://www.youtube.com/watch?v=-7UdCMYB4Yc
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Re: New homebrew using Marstran OPT

Postby Brian Wallace » Sat Sep 24, 2016 11:10 am

Nice job. :)
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Re: New homebrew using Marstran OPT

Postby David B » Sun Sep 25, 2016 10:20 pm

Chassis number 2 , same amp? Great fat bluesy tone.

sounds like a nice rowdy audience :twisted:
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