tweed od lite

[BrainDeadAmps]

After perusing old posts, I've found a few mentions of a Tweed Od lite amp.

I think I'm going to try my hand at building one but before I do, I wanted to ask if the most recent revision is from 2013? attached is the most recent schematic I've found.

Thanks!

[tubenit]

I found this one.  I think it was what I ultimately ended up with?   You can add the one tube reverb to it if you wanted. 

You should think of this amp as one you build then tweak to your own tastes in tone. 


IF you use a paralleled turret board or a tagboard that's paralleled, it's usually fairly easy to mod the layout.


IIRC,  I think I used Orange Drop PS series caps and Vishay-Dale RN65 resistors on just the plates?


Both the rhythm and lead were played on the Tweed OD Lite on this tune:   https://soundclick.com/r/s5p8ac 



With respect, Tubenit

[BrainDeadAmps]

Thank you tubenit for the schematic.

I’m almost done wiring the pre-amp of my New build.

I have a question.

What is reason for the 220k 100k and .01 cap immediately following the OD drive pot and into the phase inverter?

perhaps to keep dc from entering from the effects loop?


If I do not include the effects loop can I omit them?

I do not plan on including the loop, but once I complete the basic amp setup I will consider a 1 tube 12dw7 transformerless reverb.

I have seen in your tweed od reverb schematic, you insert the reverb on either side of the same 100k resistor I mentioned earlier.

I’m thinking this is to insert the reverb after the pre-amp overdrive instead of the more traditional insertion point I’ve seen around the tone stack between the first two gain stages.

Any advice is greatly appreciated,
Braindead

[tubenit]

You can elimiinate the 220k and the 100k.  I would keep the .01 into the entrance of the LTPI.


With respect, Tubenit

[BrainDeadAmps]

After lots of tweaking I've arrived at a modified t-lite with added 12dw7 transformerless reverb. The by-passable OD section makes the amp very versatile. However I'm stuck on this little issue I've encountered with the reverb circuit. When I crank the reverb and have the dwell above let's say 7/12. The amp putters out and signal is completely lost.

I have the basic t-lite circuit in there with a few modifications to accommodate my recycled chassis. substituting a 6sl7 for the PI and adjusting the values accordingly. I altered the reverb mixing circuit I see tubenit usually uses of 150k/330 with 100k/100k and replaced the fixed voltage divider in the swart circuit for 1m linear dwell pot.

With the OD bypassed the reverb only cuts out at the very end of the pots travel and when the OD is engaged the onset of the reverb cutoff is sooner.

I've linked a video below demonstrating the reverb.

Any ideas?

[SILVERGUN]

Did you eliminate the 100K resistor between the R and R2 connection?


based off of this question:

What is reason for the 220k 100k and .01 cap immediately following the OD drive pot and into the phase inverter?

EDIT:
Sorry, I see you addressed the reverb mixing resistance in your last post. You might want to update the schematic to reflect your actual changes for everyone who might be playing along. I'll have another cup of coffee.

[BrainDeadAmps]

Here is the updated schematic. I've also included the Swart schematic for reference.
The Swart reverb return is sent through a .02uf cap after the 100k mixing resistor following the Reverb Level pot. I omitted that cap.


Best,
Braindead

[Williamblake]

Well if it works it works but i think it is good practice to not have high voltage at the reverb tank so you might consider a cap between the driver tube and the tank.

[BrainDeadAmps]

Well if it works it works but i think it is good practice to not have high voltage at the reverb tank so you might consider a cap between the driver tube and the tank.

I believe I do have a capacitor in place. 0.22uf from the plate of the driver to the input of the reverb. or are you referring to something else?

[PRR]

> I believe I do have a capacitor

I believe you do too.