Stereo power amp in A0-43 chassis or A0-29

[Toxophilite]

Hello
i've taken a bit of a hiatus from amp building to obsessed by guitar modding , work, recording and playing the odd show


I've always wanted a stereo amp
i made a stereo pair of deluxes and they're cool


But my original idea was to build one amp with all the chassis in it and then have a satellite speaker
The idea is to have a compact gig-able setup that isn't crazy heavy
Largely for clean playing


I was thinking building a stereo power amp maybe 2 pairs of 6BQ5/EL84s in an AO-43 chassis
Have it sit in the bottom of the cab and then have the preamp at the top of the cab with power and signals running from one to the other using electrical conduit ala those fender pawn shop amps. in an overall arrangement somewhat Standel-esque


This might not be enough clean headroom on the main amp so I was also considering building the power amp with 2 6L6Gc and 2 EL84. THis then might require a more skookum PT (I have one from a baldwin amp that ran 4 EL84 and one from an AO-29 also a HUGE one from a 100 watt Randall bass power amp amp but it might be a little much.


I would probably want reverb and trem if possible on the main channel. probably put the trem circuit in with the power amp, not sure about the reverb


probably looking at 4 power tubes 2 PI and 5 preamp tubes alotogether. A fair amount of power requirement.
too crazy?
Any insights?

[sluckey]

The AO-43 is not a good donor candidate. Look instead at an AO-63 or AO-69. It already has exactly what you're looking for. It has a 6GW8 (easily convert to EL84) power amp and a larger 7591 power amp, two separate power supplies fed from a single huge PT. There are some on eBay right now. Here's an AO-63 with all tubes for $125. Good deal...

http://www.ebay.com/itm/Hammond-H-AO-63-Organ-TUBE-Amplifier-all-tubes-are-included-/131853517812?hash=item1eb31503f4:g:CgoAAOSwM4xXZx7N

And here's one I converted last December...

     http://sluckeyamps.com/hammond_2/hammond2.htm

[Toxophilite]

Thanks
As usual, you have the good ideas!
My friend has an A0-63(with no tubes) like yours that he got to build a bass amp out of but he hasn't got very far on it in the past year or so
Unfortunately for the power amps he has removed EVERYTHING as he was intending to just use the iron and start anew.
He gave me the smaller OT and I still have it. Maybe I can get him to part with it?
I guess realistically I won't be building anything like this under 50 lbs if it's a combo with the speaker(s) for one amp and an attached 2 channel preamp.
That amp on ebay is on my side of the 49th parallel! Though still across a largish body of water.
oh And really nice job on the Gem-vibe!

[sluckey]

The small OT from the AO-63 should be the same as on your AO-43s.

[Toxophilite]

They certainly are identical. I have a few of those.
Now if I could just get our dollars at parity...$125 US is about $160 Can right now. Great if I'm selling in US funds but bad if I'm buying in it!
Though I know 7591s sound good. my inclination might be redesign it for 6L6s and El84s  and go with a solid state recitifier
I know they have new production 7591s but I don't know about the other combo preamp/power tube guys.
Generally I'm not keen on using really expensive or rare tubes
Annoyingly a year or so back I had about 8 NIB and still wrapped in plastic Telefunken of those very tubes!

[Paul1453]

The 7591s OT should work fine with 6L6s.

What did you do with the new Telefunkens?

Those would probably sell for an outrageous price on Ebay now. 

[Toxophilite]

They weren't Telefunken 7591 they were 6GW8s if I remember correctly and I sold them on ebay for the average going rate as determined by completed listings.
I have to admit I don't have many tube brand loyalties having had so many pass through my hands in the past 10 years or so
I'm kind of sonically picky and I found that unless they were defective in some way they all worked well and sounded good. I think the magic is in the player but gear is fun regardless! So I sell the stuff that fetches high prices.
and I agree I think that Ot should be fine with 6L6s

[Toxophilite]

So I managed to get that AO-69 with tubes S.Luckey nicely showed me on ebay for $100 Can (that's about $5 US )delivered to Vancouver.(It was on Vancouver Island). Nice tubes and the pricier Mullard ones will help pay for the unit while I ponder how I will use the chassis


I guess my difficulty is that I don't normally use amps in a head form or with tubes upright as it tends to make the amps a fair bit larger (or taller).
My goal is to achieve a gig-able stereo setup with the minimum of components. 
This unit certainly has the necessary transformers (that PT is huge! and the main power amp OT looks something for a 50 watt amp!)
Just trying to imagine how I would configure the whole deal
Wondring whether I should make or find a new chassis and redo the layout


On your Gemvibe it looks like you used the power amp intact and enjoyed the result??

[sluckey]

Yes, I didn't change anything about the power amp. It has a clean sound with strong, tight bass and clear highs. It's perfect for that old Ampeg sound.

[Toxophilite]

Cool Sounds perfect for a lot of things!