Marshall 18 Watt Lite

[sluckey]

Here's a simple little conversion I finished this week. It's a Hammond AO-39 conversion to 18 Watt Lite. It was fun working with point to point again. I have just under $80.00 in this amp.



http://home.comcast.net/~seluckey/amps/hammond/hammond.htm

[tubenit]

Sluckey,

That turned out VERY nice!  You did a fabulous job with the conversion. 

How do you like how it sounds?

With respect, Tubenit

[sluckey]

It's just a typical Marshall 18W sound. Gets loud very fast and needs to be cranked to get the growl. So far I've only heard it thru my Fendery speakers. Next week I'll be back at work and can hear it thru my Marshally speakers. I expect it to sound about like my other 18W, sans tremolo.

You know my ears and fingers are about dead. If not, I'd be all over the stuff you and Geezer are doing. These days I'm into this stuff mainly from the electronic side of the coin. I'm being pulled more and more back to my acoustic dark side!     

[tubenit]

my acoustic dark side! 

Tell me about it .......... I picked up a figured Koa Larrivee in Dec. 

With respect, Tubenit

[Fresh_Start]

Very cool project! 

Sorry for the shredder icon... I just couldn't resist.

Chip

[bluesbear]

It's a thing of beauty... but aren't they all?!
Dave

[jojokeo]

Nice work sluckey! I love working w/ the Hammond chassis amps. Lord knows I've got tons of them.

[LooseChange]

Nice. I like these kind of projects too.

[phsyconoodler]

The 18 watt lite circuit is the best there is with the paralleled triode.It fattens up the sound really nicely.
  Try it with 4-EL84's. 

[DummyLoad]

nice work slucky!

looks like mostly vintage tubes?....   

[jojokeo]

Question for "old chassis" builders - Sluckey, I noticed the nice new caps and you ditched the old ones. Do you ever have problems w/ leaving the old ones in? I'm always afraid to use them, and after all of my work, the last thing I want is cap issues and having to re-do stuff.

[bluesbear]

"I noticed the nice new caps and you ditched the old ones"

Never leave an old electrolytic cap in there. You're right to change them out. They're almost certain to be dried out or leaking.

Dave

[sluckey]

I never leave old electrolytics in place. However, I gotta say, the last two projects I worked on were 50 year old Hammond units. All 3 cap cans in those units worked very well. I didn't try reforming, just brought 'em up all at once. My plans were to evaluate the circuits as is before doing any mods or spending any money. I was pleasantly surprised.

I would never leave an old filter cap in place though. I don't trust them. And filter caps can take out much more expensive components if they fail shorted. Replacing e-caps is kinda like taking out an insurance policy.

[RicharD]

Modern tubes may not be as good as "vintage" tubes, but modern electrolytic caps far exceed old caps.  This coupled with knowing old cap failures can be catastrophic makes it a no brainer.  I can understand leaving them if it's a 1959 all original Fender, but if they're failing one might hide new caps inside of old cap bodies.