D-inspired amps

Dumble schematics, designs, pictures. Only members may post files here.

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martin manning
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Re: D-inspired amps

Post by martin manning »

pompeiisneaks wrote: Wed Apr 12, 2017 12:01 am If you follow my steps above you don't need to install legacy java :)
Yes it does work, but it doesn't "just work" like .pdf or .jpg or .png which open for viewing with one click. Also, downloading these files I get something named file.php which I have to then rename with .sch extension. This has occurred with some other file types too. What's going on there?
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pompeiisneaks
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Re: RE: Re: D-inspired amps

Post by pompeiisneaks »

martin manning wrote:
pompeiisneaks wrote: Wed Apr 12, 2017 12:01 am If you follow my steps above you don't need to install legacy java :)
Yes it does work, but it doesn't "just work" like .pdf or .jpg or .png which open for viewing with one click. Also, downloading these files I get something named file.php which I have to then rename with .sch extension. This has occurred with some other file types too. What's going on there?
that seems to be some bug with the browser. Chrome and Firefox both do it, but at random. I've read up on it and it happens in any php application, not just phpbb. Annoying as hell. Yes I get that it requires work to get it to open, but it's better that no sch viewer, or issuing java 6

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GuitarBloke
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Re: D-inspired amps

Post by GuitarBloke »

10thTx wrote: Tue Jul 15, 2014 10:32 am I changed the D'Mars ODS to have two cathode followers.

The board shown is the original Hoffman style layout board sold by Doug Hoffman (EL34 World).

This is my best sounding amp build to date. VERY VERY sweet musically!

Nice smooth sustain and great clear clean tones, IMO. Best I can describe this is sort of a 60% Dumblish tone and 40% Marshall type tone.

I am using a Classitone OT 4-18000.

I am including a paralleled layout style if one prefers that.

CHECK for ERRORS! Compare layout with schematic. If there is a discrepancy, go with schematic.

With respect, 10thtx
Sorry 10thTx, I'm doing a bit of thread Archaelogy here and I just dug this up, and I also just realized who you are from another forum that I used to go to for information with mostly Fender type builds. Anyway as you might expect from this sleepy corner of Europe, I am clearly a few years behind the curve. For a next build I was wondering what a Tweed Bassman with overdrive might look like and I ended up with a half Triode spare so I wondered how that would work as a cathode follower at the end of the D style overdrive circuit. And by cutting and pasting stuff and info from Weber, Tube Wizard, Rob Robinette and TAG I generated the attached. I haven't checked values etc but it's my starting point. Of course I'm hoping your schematics will help me figure out the details. Here is my initial sketch. Its only my starting point so lots of work still to do, but rather than just being a concept I am glad to see you have proved the principle already, so thanks for posting these very interesting schematics.

Regards,
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John
10thTx
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Re: D-inspired amps

Post by 10thTx »

Editing the D'Mars schematic and layout is relatively easy using ExpressSCH. Please let us know what you eventually come up with. I wasn't sure what you are considering with the reverb drawn in your "cut and paste" schematic?

With respect, 10thtx
'
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GuitarBloke
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Re: D-inspired amps

Post by GuitarBloke »

10thTx,
I should probably start a new thread for this since it looks like I'm not supposed to discuss builds in this reference part of the forum, and I don't want to distract from your thread, so I probably will in time. I found your schematics after I finished the first draft of my cut and paste sketch and I have downloaded the ExpressSCH app now so yes I will probably use your schematic as a starting point. I haven't looked at it in great detail, but if it is what I think it is, i.e. Fender 5f6a circuit with Dumble style overdrive into a cathode follower that's my starting point. I'm not going to start this build until after the summer holiday season, so probably in Q3 to start. The reverb will be a digital reverb module on a DPDT toggle switch or relay which will sit between the master wiper and the PI input. Not exactly what might be expected but it may save me a whole lot of space, cost, noise and time spent troubleshooting noise, at least that's my experience.
Anyway thanks for sharing your schematics and for your interest.

Sincerely,
John
samrock55
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Re: D-inspired amps

Post by samrock55 »

This. sch file cant seem to be opened?? Obsolete app?? 🤔
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pompeiisneaks
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Re: D-inspired amps

Post by pompeiisneaks »

You need an app that can open .sch files

Something like ExpressSch or JSchem both are free. ExpressSch only works on windows I think, but JSchem works on windows/linux/mac

~Phil
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