tone cab I have an ao-33 tone cabinet and I've been messing with it for quite a while. I finally parted it out. Just be aware that the two smaller output trannies have NO low end at all - this multiple amp unit is essentially a sort of tri-amped setup. I built a stereo tube amp using them and went through Hell tryng to debug it before swapping out an OT and realizing the problem was inherent in the OT. The bass OT is huge but the dry and reverb OTs are the size of something from a Princeton. The PT, on the other hand, is the size of Texas.
My conclusion on this thing is that the best way to use it is to find somebody with a broken one (an organ player, obviously) and sell him the parts. The amp design is not great for guitar with all the feedback and the really weird cathode bias grounding THROUGH the OT extra windings.
Platefire
Guest comedian
Posts: 620
(2/26/04 9:36 am)
Re: tone cab HaY TYRANNOCASTER
Thanks for your input!! I was wanting to hear from somebody
who tried this before. I was wondering about those tiny OT!!!
Well this will give me a pre-view of what to expect. I'm
making this connection box not only to see how guitar
sounds through it but also to power up the amp and test
operation. I may do like you did and part it out or even sell
it to Ken!! Har!! It's a lot easier to sell it somebody when
you can say "Working Amp" and I'm still curious on how it
will sound with guitar, my Yamaha Keyboard and to hear that reverb. Thanks, Plate
Edited by: Platefire at: 2/26/04 9:39 am
Tyrannocaster
Junior tube assistant
Posts: 47
(2/27/04 8:13 am)
ao-33 I wouldn't expect too much from the reverb; it's kind of Silvertone sounding, if you know what I mean.
Since my experience with the two small OT's was so unpleasant I've never tried anything with the bass OT, but it might be usable although it might not have much high end. The power supply (separate chassis no less) on these things is something to behold, though. It must weigh at least twenty pounds! I guess powering all nine tubes and the two recto tubes requires even more juice than I would have guessed; you can't say it's under-built, that's for sure. And the PS choke is bigger than the two (non-bass) OT's...
But be sure and post how it sounds. I'm curious.
Platefire
Guest comedian
Posts: 621
(3/1/04 12:02 am)
Re: ao-33 Hello Tyrannocaster
Well my little hookup box I made with a 3 amp fuse, pilot light,
two 1/4" pre-amp input jacks, and an on/off switch to hook to the 6 pin connector plug on the PA-40 worked like
a champ!!! The amp powered up just fine. I tested it with
my Art ECC preamp-processor but out of the three amps
I could only get sound out of the direct treble amp with 1-12"
speaker. I also discovered that the reverb driver tranformer
was not original and had a replacement shoed in that the mounting holes didn't even match the original screws holes. So it only had one screw holding it in place and was loose. Apparently the replacement never worked or has died because
the reverb wouldn't work. Also according to my schematic when you switch off the reverb to the treble and bass reverb amps the preamped signal #G1 and G2 is suppose to bypass the reverb all together and feed the signal direct into the phase inverters of those two amps, But they weren't working!! I will just have to pull that chassis when I have time and see what the deal is???? I checked all the tubes on my tube tester, they checked out OK and are burning naturally with no un-natural plate glows. The reverb selector switches may need some contact cleaner.
The direct treble amp that did work was really bassey!! I had
to adjust the EQ on my preamp to cut lows and boost treble
to get a good guitar sound. Also the gain was low. I had to boost the gain on the Art ECC to get a nice sustain/break up/volume. What I heard was nothing to get excited about!
Har! I will go back in and try to get the other amps all working
at the same time because I'm wanting to hear a lot more
volume than what I heard. I will try to test that replacement
reverb transformer to see if it working? I would like to get
it up to normal operation anyway. Plate
BTW----I have found an old console organ that is not a Hammond but a Leslie??? I thought Leslie only made organ
amp/speakers??? Is an old tube Leslie organ worth anything???
Edited by: Platefire at: 3/1/04 12:22 am
Ritchie200
Senior tube assistant
Posts: 169
(3/1/04 2:04 pm)
Re: ao-33 Plate,
You just kill me! Let me temper that with, you are also my hero! I remember the weeks and months you spent on your Bogen project. If I remember your posts, there were times when you were pulling your hair out! Now it sounds like you have picked a real can of worms to work on! I wish I had the time to pull stuff apart like that to figure out what is going on and why. You have to love what you are doing to torture yourself this way! Yooou da man!:hail Good luck! Har!
Jim
Platefire
Guest comedian
Posts: 622
(3/1/04 2:49 pm)
Muskey Dusty Old Tube Amp Man Something about those old long abandoned forgotten tube
amps lurking in the shadows all those years that makes me
want to bring them back to life again. Then I end up making
Frank-n-st-amp of it. Yes that Bogen was a real killer!!!
At least I'm not buying them off e-bay anymore, it's just
when I encounter one at a flea market or a pawn shop face to face real cheap, it's hard to resist. My mind set is generally now to leave them alone because it only amounts to more toil and labor messing with it and believe me I've got plenty of other things I need to be doing. Just ask my wife! Har!
I've past a many of old boat anchors by the past year but
just got weak this one time. Is there any tube amp counselors I can talk to here. Please forgive me!!!Plate
Platefire
Guest comedian
Posts: 626
(3/5/04 10:35 am)
Hammond PR-40 status report Happy Friday Ya'll from Central Louisiana!!! Boy!! I'm ready for
a few days of sunshine!!! Kind of sleepy too. I started working
on the Hammond Tone cab about 10:00 Pm last night and finished about 3:00 AM. I pulled the amps chassis to try
to determine why all three amps were not working. First thing I noticed was a burnt 130 ohm 3 watt resistor that is tied to
the power tube(El84)cathode on the bass amp. It was shorted out or open. All I could find was 250 ohm 5 watt so
I shoed that in there. Also found a loose wire from the reverb driver transformer to one of the plates of the 12BH7 reverb driver tube. I corrected that and fired it up and all three amps are working now. It don't get that loud but it's basically three
push-pull EL-84 amps working in conjunction with each other
driving different speakers. The speakers are working and sounding fine. I wish I knew who made them?? It has a very full sound with 2-15" on the bass amp and 1-12" on each of the treble amps. With my ART pre-amp/ processor set on a little delay, Reverb and stereo chorus it really sounds kinda awesome in stereo. I even moved it in the living room and put some lemon pledge on the cab. I had to assure my wife this was just a temporary arrangement for testing/jamming purposes. She did say the cab looked kind of cool with the glossy dark cherry finish. The reverb is still not working but I
don't think I will put any more time into it. I'll Jam on it a while
and decide what I will do with it. Thinking of selling the amp and using the speakers to build some guitar cabs with. That
was fun!! Now for some sleep. Plate
Edited by: Platefire at: 3/9/04 9:28 am
Platefire
Guest comedian
Posts: 636
(4/17/04 8:23 pm)
Re: Hammond PR-40 status report For those of you that hoped this post would die!!! I ressurected it from the dead, BOO!!!!!:cussing
Just Kidding:o)) Anyway I traced the numbers on the two-15"
and two-12" speakers in this cab and they are 285's Rolas.
This is why I have a hard time passing flea markets by. Plate
Edited by: Platefire at: 4/17/04 8:32 pm
6G6
Junior tube assistant
Posts: 159
(4/18/04 8:28 am)
Re: Hammond PR-40 status report Hey Plate,
If you've got it working and it looks good, you could try to get that reverb working and put it on Ebay.
It might bring in some income to feed your addiction.
Or maybe Ken would want it???
:lol
Platefire
Guest comedian
Posts: 637
(4/18/04 4:09 pm)
Re: Hammond PR-40 status report Yes I kinda wanted to hear that reverb just to see what it
sounded like. Never seen reverb springs hanging out in mid
air like that before. Got any recomendations how to trouble shoot that reverb to find where the problem is??? If I rember
correctly you could hear the reverb when you shook the springs through the speaker but no reverb when you operated
the amp, so the problem must be in the input??? The reverb
driver tube checked OK. Plate
pabloxyz
Hey get your own solder
Posts: 203
(4/21/04 6:08 pm)
re: Hammond tone cab There's a spring locking device you engage when you're moving the cabinet, to keep the springs from flopping around. Be sure that's disengaged when you're ready to play the thing. Hammond also made a fluid type reverb in which the energy from the spring was dampened in an oil bath. In a pinch you could substitute transmission oil for the Hammond stuff.
Which sounds weird (or genius depending on your point of view) until you consider how the old tone wheel organs make their sound. A motor, through a series of gears, drives sixty something notched discs, or cams. A magnetic rod surrounded by a coil comes up to the notched edge of each spinning cam, which produces a small voltage in the coil. The speed of the cam and number of notches determines the frequency of each tone. Every gear and motor has its own bearing which is oiled by a tiny cotton thread. The whole thing seems unlikely but they were built like a you know what and with a little oil every now and then will run until the 2nd coming.
pab
Topic: Help Ken!! I picked up a Hammond PR-40 This Weeken (Read 39299 times)