Hammond AO29 to guitar amp?

[bluesman52]

I have a Hammond M3 Tube Amp

Amp/Output: 11 Watts

Tubes included:
2- 12AU7
2- 6C4
2- 6AU6
1- 12AX7
2- 6V6
1- 6BA6
1- 5U4
H AO 22111-1 power transformer
355-0-355V @ 150MA, 5V @ 3A, 6.3V @4A

I was wondering if this amp would be useable to convert to
a guitar amp, as it has no pots or input or output. Yet it has a decent transformer and compliment of tubes. I have read similar posts and you all have been very helpful. Would I be better off with an old PA or monoblock.

 

[benny]

you could definately do this.

what do you want out of the amp??? is it going to be used for clean or distorted sounds? this will effect how to aproach the final design a lot.

I recomend you keep the output stage as is, and looking at your tube list i'm guessing it's the two 6V6's in pushpull config... 11W seems pretty reasonable for this... and did it come with the output tranny? you didn't list it below... if you got this seccond hand and someones already taken it, you're gonna need a new OT.

also, do you know how old the tubes are??? if they came seccond hand with the amp, then you should find someone with a tube tester to test them for you to see what's good and what's not.

cheers

 

[fenderkid]

u can use all of it . i have done it ! i built a 5e3 out of it witch is y i call it the HE3 . any who i used 90% of it including tubes , chassis , circuit board ( with a little moding), sockets etc hole thing cost me 55$ . just keep an eye on bias b/c plate voltage is just a bit high . i ended up puting a 300 ohm cathode bias resistior in instead of a 250 ohm. i wouldnt go any higher then 300 ohm tho as it will afect the tone in a bad way . the ao29 is an allmost perfect match for a 5e3 circuit . good luck

 

[ChrisA]

I have a Hammond M3 Tube Amp

Amp/Output: 11 Watts

Tubes included:
2- 12AU7
2- 6C4
2- 6AU6
1- 12AX7
2- 6V6
1- 6BA6
1- 5U4
H AO 22111-1 power transformer
355-0-355V @ 150MA, 5V @ 3A, 6.3V @4A

I was wondering if this amp would be useable to convert to
a guitar amp, as it has no pots or input or output. Yet it has a decent transformer and compliment of tubes. I have read similar posts and you all have been very helpful. Would I be better off with an old PA or monoblock.

Yes you can do it. The conversion is of the "gut and re-build" type. Leave the power supply and tube sockets in place but remove everything else. Then look up a guitar amp schematic you like. Maybe you want a Fender "baseman" but with lower power 6v6 tube. That could work. The only tubes you'd need are the rectifier, the two 6v6. and the 12AX7 and a 12AU7.

There are no pots or jacks. Add those. Maybe you will place a 12x4 inch turret board down the center of the chassis.


I would certainly replace the power supply's electrolytic caps and all the other small parts,resistors and so on get tossed out

 

[DavesNotHere]

the 12au7's, 12ax7 6v6 sounds fenderish.what can you do also 2-6c4 used as tube distortion.

 

[ChrisA]

the 12au7's, 12ax7 6v6 sounds fenderish.what can you do also 2-6c4 used as tube distortion.

Yes. That was why I said to just use those. You could build a Fender-like amp.

The 6c4 looks like half of a 12AU7 tube. Maybe the best use of it in a guitar amp is to add and effects loop. It could be the driver for the loop.

But another reason I said to use only the 12AX7 and 12AX7 and6v6 is that these tubes are still in production. You can buy replacements that are brand new for not a lot of money. How are you going to replace a 6c4? and what can it do the 12AU7 can't

Just my opinion but I'd not going to design and build new equipment that requires out of production parts.

 

[Printer2]

The 6AU6 could be used for a second channel with a different sound than the 12AX7's. Some like the sound of pentodes distorting, more so for a bluesy type of sound, not sure if you would be interested in that.

 

[trigger96]

I see this is an old post and I guess I'm gonna bring it back to life. I just bought a complete AO 29 amp, I have never built anything like this and would like see some pics of conversions that have been done to include before and after and a look at the internals once modified and installed.

I've seen several Fender schematics that look simple enough to put together, but with such a nice selection of tubes on this amp, how many different configurations can be set up and which ones work best in this beast?