Fenderish to OD

[10thTx]

The idea is to try to approximate the Fender clean tone but add OD in the mix. Any thoughts? Think this will work? Would you change anything?

With respect, 10thtx

[guitardude57]

Feedback resistor looks kinda small......not sure what effect it will have on the OD. For clean should be ok....Fender value here.

[Bob-I]

I tried that years ago and found the OD to be quite thin compared to a Dumble. What I did to correct it was add another preamp tube that was used for the Fender type channel, then added a relay to switch between the Fender and Dumble channels along with the ODS relay. It turned out that the ODS relay was useless since I always use the Fender cleans and Dumble ODS.

[Normster]

This is eerie...I've been pondering the same idea! I'll try to study your schematic and see if it makes sense.

I just finished gutting my Blues Deluxe and putting in an AB763 circuit. I'm stunned with the clean tone of this beast. Now I want more of that in my Bluesmaster. Where I'm thinking it might be doable is by modifying the 3rd gain stage. Where the BM only uses 2 gain stages for clean, the AB763 has 3 (if you count the final mixing stage). Just need to figure out how to switch the correct values in and out.

[Bob-I]

Where the BM only uses 2 gain stages for clean, the AB763 has 3 (if you count the final mixing stage). Just need to figure out how to switch the correct values in and out.

Not exactly and not really necessary. The AB763 has so much loss in the reverb circuit with the 3.3M mixing resistor that the recovery stage is needed. Remove that 3.3M and the 3rd stage is unnecessary. In my amp I actually have too much gain on the clean channel.

[Normster]

Where the BM only uses 2 gain stages for clean, the AB763 has 3 (if you count the final mixing stage). Just need to figure out how to switch the correct values in and out.

Not exactly and not really necessary. The AB763 has so much loss in the reverb circuit with the 3.3M mixing resistor that the recovery stage is needed. Remove that 3.3M and the 3rd stage is unnecessary. In my amp I actually have too much gain on the clean channel.

I wondered about that as well, but there's no grid load so I'm not sure what actually makes it through. The AA165 only has a 220k to the third stage but uses a 470k grid load. Guess I need to visit Aiken's site for a refresher on voltage dividers. (Forgive my ignorance Bob, but I've been on amp hiatus for a couple years.)

[Bob-I]

I wondered about that as well, but there's no grid load so I'm not sure what actually makes it through.

There's a 220k grid load on the AB763's I've seen.

[Normster]

I wondered about that as well, but there's no grid load so I'm not sure what actually makes it through.

There's a 220k grid load on the AB763's I've seen.

Oops, you're right. Forgot about the 220k on the return side.

[bcook]

If you consider the recovery stage of an AB763 as OD1, you can steal OD2 from the vibrato circuit. I've done it, and it sounds quite good. I turned the intensity into the master and the speed into a variable PAB.