D-inspired amps

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

Moderators: pompeiisneaks, Structo, mhuss, HeeBGB

10thTx
Posts: 1453
Joined: Sat Dec 30, 2006 1:13 am

Re: D-inspired amps

Post by 10thTx » Wed Jul 09, 2014 1:43 am

Someone was asking about a quad 6AQ5 power amp on another forum, so I drew this up.

Idea would be to use a VVR to lower the plate voltages on the 6AQ5 to around 305v (similar to Gibson Scout GA-17RVT).

But keep the voltages up higher on the preamp.

Layout should work with schematic, but IF there is a difference, go with the schematic.

B+ rail and VVR is on page 3 of the schematic.

With respect, 10thtx

I am also adding a Tweed Overdrive Special (TOS) with 6BM8 power tubes using the triodes of the 6BM8's for the LTPI. I figured to post it here along with the 6AQ5 TBM for anyone looking for a low to moderate wattage/volume overdriven amp.
You do not have the required permissions to view the files attached to this post.
Last edited by 10thTx on Sat Aug 12, 2017 12:33 pm, edited 1 time in total.

10thTx
Posts: 1453
Joined: Sat Dec 30, 2006 1:13 am

Re: D-inspired amps

Post by 10thTx » 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
You do not have the required permissions to view the files attached to this post.
Last edited by 10thTx on Sun Dec 21, 2014 6:28 pm, edited 5 times in total.

10thTx
Posts: 1453
Joined: Sat Dec 30, 2006 1:13 am

Re: D-inspired amps

Post by 10thTx » Fri Aug 29, 2014 10:43 am

Here is a couple more takes on the "DeClean". This allows some boosts and/or an FX.

With respect, 10thtx

CHECK for errors. Compare schematic with layout. IF there is a discrepancy, go with the schematic.

EDIT: 11/29/2015

I am adding a Deluxe Reverb idea with Dumblized tone stack. There are some values in the original DR that I changed to make it more D-style friendly.
You do not have the required permissions to view the files attached to this post.
Last edited by 10thTx on Sun Nov 29, 2015 8:04 pm, edited 1 time in total.

10thTx
Posts: 1453
Joined: Sat Dec 30, 2006 1:13 am

Re: D-inspired amps

Post by 10thTx » Mon Sep 22, 2014 6:03 pm

This idea is a take off of the Tweed Overdrive Special but a smaller version of it in a small 12" lunchbox type chassis that Hoffman sells.

CHECK for errors! Compare schematic with layout and if there is a difference, go with the schematic.

With respect,

10thtx
You do not have the required permissions to view the files attached to this post.

10thTx
Posts: 1453
Joined: Sat Dec 30, 2006 1:13 am

Re: D-inspired amps

Post by 10thTx » Fri Feb 27, 2015 2:03 am

My favorite amp of all I have built. Both 5879 OD & active FX loop. I'm using an Emminence Delta Pro-12 with it.

With respect, 10thtx

EDIT:

I wanted the OD channel to have the same bass oomph as the clean channel but when I increased cap sizes beyond the 3rd gain stage, things got muddy.

So I came up with this idea where the tone stack is engaged on clean and bypassed on OD. This has worked out remarkably well and the bass response on the OD now is quite tight and not muddy at all, IMO.

with respect, 10thtx
You do not have the required permissions to view the files attached to this post.
Last edited by 10thTx on Sat Oct 24, 2015 2:18 am, edited 2 times in total.

10thTx
Posts: 1453
Joined: Sat Dec 30, 2006 1:13 am

Re: D-inspired amps

Post by 10thTx » Sat Oct 24, 2015 2:14 am

Haven't built this one yet, but hope to someday. This is sort of a hybrid
between the HoSo56 that DaGeezer came up with and a Tweed OD-Lite that I did build that just uses a single 5879 in the OD section.

with respect, 10thtx

I am adding some tone stack bypass options also to this design.
You do not have the required permissions to view the files attached to this post.

10thTx
Posts: 1453
Joined: Sat Dec 30, 2006 1:13 am

Re: D-inspired amps

Post by 10thTx » Wed Dec 02, 2015 6:02 pm

Another variation of greatly altered Fenderish/Dumblish blending but with a 5879 OD section. Never built this. DRAFT idea

Look for errors! Any discrepancy between layout and schematic, go with the schematic.

With respect, 10thtx
You do not have the required permissions to view the files attached to this post.

10thTx
Posts: 1453
Joined: Sat Dec 30, 2006 1:13 am

Re: D-inspired amps

Post by 10thTx » Fri Feb 10, 2017 1:57 am

Carolina BluezMeister AB763 schem and layout

Another idea I've had and would like to build at some point, but have not built.

With respect, 10thtx
You do not have the required permissions to view the files attached to this post.

10thTx
Posts: 1453
Joined: Sat Dec 30, 2006 1:13 am

Re: D-inspired amps

Post by 10thTx » Sun Apr 09, 2017 9:15 pm

OK, I did build this one & I like it alot!

I am continuing to experiment with different Dumblish inspired designs where you have a clean and an overdrive channel. The PT on this one is 300-0-300 150ma. A tweed bassman OT would work well with it, I think.

My goal on this one was to use 3 gain stages in the clean channel to try and keep the tone reasonably clean up to 12 noon on the volume dial. I feel like I succeeded reasonably well with this. It has nice full tone to it, IMO and has some musical sweetness in the tone. It is reasonably Fenderish but slightly less mid-scooped.

One of the things that really surprised me was how quite the thing is at idle. Even at volumes beyond what I will normally play at, the idle noise is very very quiet. The original Princeton Reveb I owned once was more noisy at idle then this is. I think it could be easy to walk out of the room and forget to turn the amp off? However, when you hit a chord, it is surprisingly loud.

The overdrive is also to my liking and is very touch responsive with the 5879 tube. I may try tweaking this some more, but if it never got any smoother, I'd still be very happy with it. The 5879 tube does have a little chime inherent in it's tone.

This has more contrast between the clean truly being clean and the overdrive being more noticeably overdrive compared to the clean tone.

CHECK for ERRORS! Compare schematic with layout. IF there is a discrepency, go with the schematic.

With respect, 10thtx
You do not have the required permissions to view the files attached to this post.
Last edited by 10thTx on Tue Aug 22, 2017 12:52 pm, edited 1 time in total.

User avatar
JazzGuitarGimp
Posts: 2205
Joined: Mon Jul 23, 2012 4:54 pm
Location: Northern CA

Re: D-inspired amps

Post by JazzGuitarGimp » Mon Apr 10, 2017 3:00 am

Ehm.... Sorry, for some reason, I thought I was talking to Martin Manning - my apologies, with the warning: "don't get old, it ain't good" :-)

10thTx, do you know if there is an iPad app that will open these .sch files for viewing?

Thanks,
Lou
Lou Rossi Designs
Printed Circuit Design & Layout,
and Schematic Capture

User avatar
martin manning
Posts: 8088
Joined: Sun Jul 06, 2008 12:43 am
Location: 39.1N, 84.5W

Re: D-inspired amps

Post by martin manning » Tue Apr 11, 2017 2:45 pm

There used to be a version of Jschem for OSX, but no more; don't know if there ever was one for iOS.

User avatar
pompeiisneaks
Site Admin
Posts: 862
Joined: Sat Jan 14, 2017 4:36 pm
Location: Washington State, USA
Contact:

Re: D-inspired amps

Post by pompeiisneaks » Tue Apr 11, 2017 4:22 pm

There still is a version of jschem for os x. It's just weird that it want's the old java 6 stuff, but you can still run it just fine.

First you'll need to install the latest java to get the above to work, download that here: http://www.oracle.com/technetwork/java/ ... 33155.html

Specifically the link named Mac OS X jre-{version}-macosx-x64.dmg (replace {version} with the latest version out now. That changes over time. As of right now its 8u121 so that would be jre-8u121-macosx-x64.dmg on the page above.

When the download completes, double click the dmg file and it will install the latest java (8 in the case above)

Then you need to get the latest jschem from here:

http://dhost.info/jschem/

After downloading and installing, I find it works best if I do the following.

Open finder, go to wherever you put the app (/Applications usually)

Right click on the app and click on "Show Package Contents"

Then double click the following folders: Contents->Resources->Java

Then double click Jschem.jar and it will run just fine.

If you double click the app icon at the first there, it wants you to install legacy java which I highly recommend you do not do.
tUber Nerd!

User avatar
JazzGuitarGimp
Posts: 2205
Joined: Mon Jul 23, 2012 4:54 pm
Location: Northern CA

Re: D-inspired amps

Post by JazzGuitarGimp » Tue Apr 11, 2017 5:39 pm

Thanks, Phil. That at least got me up and running on OS X, and is much appreciated.
Lou Rossi Designs
Printed Circuit Design & Layout,
and Schematic Capture

User avatar
martin manning
Posts: 8088
Joined: Sun Jul 06, 2008 12:43 am
Location: 39.1N, 84.5W

Re: D-inspired amps

Post by martin manning » Tue Apr 11, 2017 8:43 pm

I got as far as the request to install legacy java and bailed. No néed for Jschem other than viewing these files.

User avatar
pompeiisneaks
Site Admin
Posts: 862
Joined: Sat Jan 14, 2017 4:36 pm
Location: Washington State, USA
Contact:

Re: D-inspired amps

Post by pompeiisneaks » Wed Apr 12, 2017 12:01 am

If you follow my steps above you don't need to install legacy java :)

~Phil
tUber Nerd!

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest