Nice score Mark.
That 35 looks in good shape.
Couple of notes:
That internal horz, can cap looks to be a added repair, remove it and replace the bad multi with a Antique Electronic copy of a Princeton 40 by 4 cap. You'll need that space for your pots.
I used the exsisting board by removed all the input circuitry, lights , jacks ect.
You'll find that drilling that old high carbon steel a chore, they don't build em like that any more.
Careful of the back panel, you need to keep the on/off jumper conected or the amp won't work.
Also if you need any help let me know.
DR.Z
Hammond AO-35 build
Moderators: pompeiisneaks, Colossal
Re: Hammond AO-35 build
Thanks Doc,
I can see why you were interested in the little Hammonds when you spotted them on the shelf at the Hammond repair guy's shop, forget his name Charlie?
I'll see if I can do this right.
I can see why you were interested in the little Hammonds when you spotted them on the shelf at the Hammond repair guy's shop, forget his name Charlie?
I'll see if I can do this right.
Re: Hammond AO-35 build
Tom that A0-29 turned into a nice looking amp and I am sure the Hammond iron is healthy from what I have heard.
I have another Hammond chassis but that chassis is 40 some inches long but the power supply is separate so It will make a good amp too.
I have another Hammond chassis but that chassis is 40 some inches long but the power supply is separate so It will make a good amp too.
Re: Hammond AO-35 build
Doc,
I wired up the board for the Ghia AO-35 does this look right?
I wired up the board for the Ghia AO-35 does this look right?
You do not have the required permissions to view the files attached to this post.
-
skyboltone
- Posts: 2287
- Joined: Wed May 10, 2006 7:02 pm
- Location: Sparks, NV, where nowhere looks like home.
Re: Hammond AO-35 build
Another one bites the dust. Gosh fellers. I've destroyed a couple myself but they are getting scarce for the Hammond guys now. Why not start from scratch so that the output tubes aren't so close to the cabinet? The one I built my son is a scorcher
I sent the transformers in to Mercury for measurements and exam. He should be able to make them. I never ordered any but just tell him my name:
Dan Hall
I sent the transformers in to Mercury for measurements and exam. He should be able to make them. I never ordered any but just tell him my name:
Dan Hall
The Last of the World's Great Human Beings
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Re: Hammond AO-35 build
Holy crap, Mark. What is that?M Fowler wrote:I wired up the board for the Ghia AO-35 does this look right?
I build and repair tube amps. http://amps.monkeymatic.com
Re: Hammond AO-35 build
[quote="M Fowler"]Doc,
I wired up the board for the Ghia AO-35 does this look right?[/quote]
Close Mark , but no cigar...
Looks like a Matchless, Ha.
Z
I wired up the board for the Ghia AO-35 does this look right?
[/quote]Close Mark , but no cigar...
Looks like a Matchless, Ha.
Z
Re: Hammond AO-35 build
Can you cut the laces out and spread the wires a bit so I can follow them Mark , I think I can fix it from here. 
"It Happens"
Forrest Gump
Forrest Gump
Re: Hammond AO-35 build
passfan,
Short answer NO
xtian,
That came out of a different Hammond organ with very large chassis and over 40 tubes. The organ was not woth repairing or I would have I love to play keyboard.
Dan,
The A0-35 was on Ebay so I didn't strip it the seller did so since the damage was done I decided to make a guitar amp out of it.
Doc,
It could be a Matchless alright.
Short answer NO
xtian,
That came out of a different Hammond organ with very large chassis and over 40 tubes. The organ was not woth repairing or I would have I love to play keyboard.
Dan,
The A0-35 was on Ebay so I didn't strip it the seller did so since the damage was done I decided to make a guitar amp out of it.
Doc,
It could be a Matchless alright.
-
skyboltone
- Posts: 2287
- Joined: Wed May 10, 2006 7:02 pm
- Location: Sparks, NV, where nowhere looks like home.
Re: Hammond AO-35 build
It really is up to the Hammond guys to outbid us I guess. The tanks that the amp was designed for are all crap by now anyway, and stage players don't use tone cabs anyway. There is one leslie with reverb speakers. I forget the number. I have the cabinet for one but I'm plugging the extra speaker holes and making it into a different animal using only the Leslie turning parts.M Fowler wrote: Dan,
The A0-35 was on Ebay so I didn't strip it the seller did so since the damage was done I decided to make a guitar amp out of it.
Doc,
It could be a Matchless alright.
So good for you anyway!
The Last of the World's Great Human Beings
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Re: Hammond AO-35 build
Mark,
My chassis was super long as well.
I cut about four inches off and folded up the end and pop riveted it back together.
I used a duck billed locking plier as a hand brake to bend the end up.
Man, that is some strong steel on those chassis! Very hard to bend tightly.
After I shortened it I wished I had made it about one inch longer.
Turned out to be very tight quarters to work in.
My chassis was super long as well.
I cut about four inches off and folded up the end and pop riveted it back together.
I used a duck billed locking plier as a hand brake to bend the end up.
Man, that is some strong steel on those chassis! Very hard to bend tightly.
After I shortened it I wished I had made it about one inch longer.
Turned out to be very tight quarters to work in.
Tom
Don't let that smoke out!
Don't let that smoke out!
Re: Hammond AO-35 build
DrZ,
So I uses a can cap 40-40-40-40? That seems way more than what I need but your the doctor. Thanks
So I uses a can cap 40-40-40-40? That seems way more than what I need but your the doctor.
ThanksYou do not have the required permissions to view the files attached to this post.
Re: Hammond AO-35 build
Sorry Mark, I ment the 20 uF X 4 , like the ones used in the Princeton's.
Yes 40 X 4 would be too much filter.
I'll have to look at an old OA-35 mod but I believe I doulbled up two 20's for 40 uF on plate , one 20 for the screen, the PI has it's own fixed DC bias and plate voltage supply, and the final 20 was for V1.
Sorry for the confusion.
Z
Yes 40 X 4 would be too much filter.
I'll have to look at an old OA-35 mod but I believe I doulbled up two 20's for 40 uF on plate , one 20 for the screen, the PI has it's own fixed DC bias and plate voltage supply, and the final 20 was for V1.
Sorry for the confusion.
Z
Re: Hammond AO-35 build
Doc the A0-35 schematic is using a 40uf/450 before a 1k resistor and 40uf/450 following. No choke.
The third cap is 30uf/350 so I was thinking that 40-40-40-20 or 40-40-30-20
The third cap is 30uf/350 so I was thinking that 40-40-40-20 or 40-40-30-20
You do not have the required permissions to view the files attached to this post.
Re: Hammond AO-35 build
Mark it's been over 15 years since I built up a AO-35, my memory is a bit fuzzy. I have an original one at home I will look at it and and share some notes. Most of the multi caps were good but some did leak and remember using the CE replacements ( or original Fender /Mallory ).
I did open up V1 and used full plate voltage not 60 V like the Hammond.
Each one was an adventure I recall, as not all were in working order when I recieved them.
Z
I did open up V1 and used full plate voltage not 60 V like the Hammond.
Each one was an adventure I recall, as not all were in working order when I recieved them.
Z