What are these amp's??? For HI FI ???

[hilldweller]

Hello everyone,
I found three of these in the trash yesterday. Does anyone know what these are? Would this be a good project for hi fi applications? It uses several 6V6 And 6SN7 Tubes.

http://hilldwellerstl.myphotoalbum.com/ ... me=album05

[TomMcNally]

I wonder if H O Co is Hammond Organ Company ?
I'd google around and see if you can find anything.

[jeffdavison]

BEWARE OF WEBSITE>>>>>


tried to install malware on my computer when checking pis out!

[sorenj07]

to the first poster: yes, i think you could make a pair of very credible monoblocks out of those.

to jeff: get NoScript for Firefox, and never worry about that type of stuff again.

[kheper]

It looks like a tone amp for an organ.

The smaller output transformer might for
the treble. The larger for bass.

You could make a nice biamp system
with these.

[cartoonweirdo]

Those are indeed tone cabinet power amps for a Hammond Organ tone cabinet. I pulled that exact set (and many more) out of the garbage when the organ repair shop in town decided that they paid more rent to house the old things then they were ever going to make useing them as parts.

The block you have asked about routes line level signal in on the multi pin cable (just like a leslie), and bi-amps the signal into two separate power amps.

The larger OPT was for the bass frequencies (duh) and in this case pushed them out of nine 10'' speakers wired in series/parallel at 8 ohms facing forward in an open backed enclosure.

The smaller OPT routed trebble through two 12' speakers in parallel (4 ohms) fireing straight up into a box about a foot and a half tall with speaker grill over the opening.

Needless to say it was a beast to move. Good luck with it. Any organ repairman ought to have the schematic for you as Hammond was good about providing shematics of even the very old items to it's servicemen.

[hilldweller]

Those are indeed tone cabinet power amps for a Hammond Organ tone cabinet. I pulled that exact set (and many more) out of the garbage when the organ repair shop in town decided that they paid more rent to house the old things then they were ever going to make useing them as parts.

The block you have asked about routes line level signal in on the multi pin cable (just like a leslie), and bi-amps the signal into two separate power amps.

The larger OPT was for the bass frequencies (duh) and in this case pushed them out of nine 10'' speakers wired in series/parallel at 8 ohms facing forward in an open backed enclosure.

The smaller OPT routed trebble through two 12' speakers in parallel (4 ohms) fireing straight up into a box about a foot and a half tall with speaker grill over the opening.

Needless to say it was a beast to move. Good luck with it. Any organ repairman ought to have the schematic for you as Hammond was good about providing shematics of even the very old items to it's servicemen.

Thanks a lot! That was very helpful. Do you think these would be suitable for Hi-Fi applications? I mean, would it be worth the effort and expense???

[cartoonweirdo]

That depends on how much effort, how much expense, and what either one is worth to you. I tried inputing a guitar into the cabinet and liked the sound quite well. I didn't try anything else. If you have time but not money you could give it a go (didn't you get the chassis out of the trash in the first place?). If you have more money than time you should imediately bench test the output transformers as they are the real limiting factor here (caps and resistors are cheap). Perhaps someone else has a better idea a how well Hammond Organ designed their iron?

[hilldweller]

That depends on how much effort, how much expense, and what either one is worth to you. I tried inputing a guitar into the cabinet and liked the sound quite well. I didn't try anything else. If you have time but not money you could give it a go (didn't you get the chassis out of the trash in the first place?). If you have more money than time you should imediately bench test the output transformers as they are the real limiting factor here (caps and resistors are cheap). Perhaps someone else has a better idea a how well Hammond Organ designed their iron?

Yea, I know that! I guess if the tranny's and choke test out OK, I will give it a go I will need to strip it down and check all of the tranny's and choke. The chassis is in great shape. A paint job will do well. I still would like to find a schematic and specs for these before I procede. I like the fact that each one is essentualy(excuse my spelling), a bi-amp circuit. My speakers are set up for bi-amping. I will reuse the tagboards but thats about it. New tubes, tube sockets, and new resistors and caps will be required. I wonder what the heat disapation will be on these? I have heard of someone who has completely submerged A tube power amp in mineral oil for cooling. A little extreeme, No? Anyway, It should be an interesting project! Yellow_Light_Colorz_PDT_14

[cartoonweirdo]

Both amps were designed to put out 20 watts if my memory of the schematic holds. No idea whether we are talking 20 clean watts or not (it was designed for use with an organ). This seems low for four 6V6's so I imagine it is either a conservative rating or the iron is the limiting factor.

If you are going to do a complete redesign anyway why not hook the OPT's to either your speakers or dummy loads and scope them up. If you have a frequency analyzer available so much the better, but at least check the hi and low end out to see if you have a significant fall off (or more likely to see where that fall off is) this will tell you wether to make this a hi-fi project, an instrument amp project, or a trip to recycle the copper.