Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: fiftynine on January 06, 2011, 11:00:05 am

Title: Integrating the 1-Tube Reverb into the DR lite
Post by: fiftynine on January 06, 2011, 11:00:05 am

I've got the 270k top left simulating the removed second channel (signal path is just the blue line currently) and the gain level is perfect. I'm planning the 1-tube reverb but do I need to run the 100k resistor in parallel with the blue wire or send the whole signal through the 100k?

(http://i285.photobucket.com/albums/ll70/20sksebay/reverbsmall.jpg)

Thanks

Title: Re: Integrating the 1-Tube Reverb into the DR lite
Post by: sluckey on January 06, 2011, 11:26:04 am

If you put a 100K in parallel with the blue line, the resistance will still be the blue line. IOW, the 100K will be shorted out. So, you need to run the whole signal thru the 100k. Cut the blue line.

Actually, adding the reverb circuit is going to change the signal level (gain). I would totally remove the 270K and 220K, put the reverb circuit in place, and see how it sounds. At this point, you're no longer trying to keep the circuit true to the orig. DR normal channel.

Title: Re: Integrating the 1-Tube Reverb into the DR lite
Post by: tubenit on January 06, 2011, 11:30:38 am

FYI, for yourself or others reading this thread ...... there is an ARCHIVED thread on this topic here:

http://www.el34world.com/Forum/index.php?topic=7957.0

With respect, Tubenit

Title: Re: Integrating the 1-Tube Reverb into the DR lite
Post by: fiftynine on January 07, 2011, 08:41:08 am

I read through that thread but it still wasn't completely clear. I think I proved why with my previous post (blush).

I'm trying to devise a switching scheme to bring the reverb in and out with one switch. When it's up, the circuit is exactly how it is now. I hear from Dr Z Maz 18 Non-Reverb users that the Maz 18 Reverb looses a little something with the reverb circuit added. I'd like to be able to switch the reverb in and out completely and see for myself.

Thanks for the gain tip off. The red resistor value is to match the reverb mode gain but I still have a problem if the 270k bleeds too much to ground. That might need a switch aswell.

(http://i285.photobucket.com/albums/ll70/20sksebay/reverbsmallboth.jpg)