favorite old gear to buy for parts

[eleventeen]

Free Lowrey organ. There are about 10 12AX7A across the the top, all seemed to be RCA so far. The two broad rows of tubes are types I have never even heard of, 6KM8, 6FH8. Four plate tetrodes. Sure. And 6X8's, I've heard of those. The power amp is 2-3x 12AX7 and four Syl 7591s. Not a bad tube haul.


Sometimes I go hot and cold on junk. lately, hot.

[PRR]

A "Vovcall" apparently sold in Japan:
http://fat-guitar-stock.jimdo.com/amplifier/vovcall-50-s-microphone-amp/

Robot translation:
It is the 1950s of the microphone amplifier.
In the United States, by modifying the 1950s of the microphone amplifier has it is done well to use as for the guitar.
It is a microphone amplifier, but also the performer of many blues harp thing also moderate drive can be obtained with good uses a microphone amplifier of this age.
Jack input and output for use as for guitar are exchanging.
6v6 × 3
12AU7 × 1
6AU6 × 1
12AX7 × 1
Drive sound like tweed period can be obtained and will raise the volume.
The output contributes to a about 10 ~ 15w.
Because it is originally microphone amplifier high-pass is mild sound, please use the guitar of a single coil.
Impedance 8 Ohm
Left of the knob volume
The right of the knob is treble
Second from the right is based
It does not use the second and third from the left.
117V specifications
Amplifier body is slightly microphonic but, especially problem is I think that there is no need to the volume to the full 10.


"3 X 6V6" must be wrong.

I can believe early 1950s by a small builder using-up 1940s escutcheons.

There may be date-codes on the can-caps.

[eleventeen]

I really looked for date codes, one pot was all I could see without loosening them, was 1156. That seems about right. Seems just a skosk late for those escutcheon plates...but these things moved rather slowly back then.

[Paul1453]

When you're hot, you are HOT!   

You absolutely cannot beat free stuff.   

And that Lowery is a Beast of an amp.   
Big time score there.

Talk about heavy metal, the big iron on that thing has to weigh a ton.
No really, it looks like that thing weighs 40+ lbs.
I'm guessing it puts out around 50 Watts each on 2 channels?   

[eleventeen]

Well, I got the Voycall gradually fired up to full (345 B+) blast. It's certainly able to swing a big signal at highish volume, but's getting a massive bass feedback oscillation if the gain is turned too far up. As an amplifier, it largely works, certainly doesn't smoke.


The organ has 4 7591 Westinghouse, the coveted ones. Plus 20 or so RCA 12AX7A *and* a 12AZ7 for a new toob to play with.

[eleventeen]

it sure doesn't right now, LOL. Note that the smaller transformer is a honkin filament tranny, to run all the oscillator tubes. The lower amp is pretty much a stereo amp all set to go with 12AX7 driving 7591 & dual OTs about the size of a 5E3 Deluxe. I've done lots worse.


I am almost thinking to sell the tubes (they go for 70+ a pair) and downconvert the amp to 6V6's which would luxuriate in those OTs. Make a nice creamy little home stereo. Or leave the fil tranny and use 12V6 which can be bought cheaply.


Here is a gut shot, by the way, not of mine, but a super clean identical. See how the tranny on the lower left only has black & green wires and feeds (only) the big interchassis plug? Filament tranny for the upper deck. Not unuseful. Not part of the amp.

[Paul1453]

And those 2 PP OTs on top look rather substantial.

If you can sell off some parts to fund the creation of 2 complete amps,
that would be the direction I would be heading in.

Otherwise, just converting what is there would lead to an awfully heavy head I fear.
Maybe if you built it into a big cab with coasters on it, that might be OK.   

[Paul1453]

It appears your Voycall amp was a good deal.   

I would have said that even without this confirmation.   

http://www.ebay.com/itm/Vintage-Voycall-Sargent-Rayment-Mono-6L6-Tube-Amp-Amplifier-Rack-Mount-Guitar/151986175646

[Paul1453]

My Quad 6V6GT amp was delivered today.   

Unpacking it and a quick inspection using my Army inspired sniff test,
has me noting that all to familiar smell of burnt component.

I didn't see any obviously charred items, but will need to thoroughly inspect it tonight after work.
At least it didn't smell like burnt transformer, which I'm also getting to know all too well.   

It has 2 5Y3 tube rectifiers, the PT, and it appears to have two vastly different OTs.
A thorough cleaning and inspection should reveal more about what I bought.   

[Paul1453]

After a thorough cleaning and DeoxIt application, I tested the 6 tubes.
All the GE 1956 Black plate 6V6GT tubes test strong, as well as the 2 5Y3 rectifiers.

No schematic requires much wire tracing.
So after figuring out that one pin on a jack on one side of the amp,
needs to connect through a power switch to Pin 6 on a cable exiting the other side of the amp.
I put the good tubes back in and power her up, because I didn't find any burnt components and can't isolate that burnt smell.

I get her to power up and light the tubes.
I start checking voltages, and since the amp is upside down now I notice some of the DeoxIt residue bubbling in the bottom of a cap can.
Uh Oh, flip the switch, unplug the cord, and carefully touch that metal cap can.
Sure enough, she's hot as a pistol.  I think I found my burnt smelling component.   
So I yank her out, and try the only other 30-10uf 475V cap can I have in my junk pile.
The replacement looks rough and very questionable too, but I don't have any other 475V E-caps, so I give it a try.
Same deal now, tubes light, I got +500V out of my rectifiers, this cap doesn't bubble (no DeoxIt residue) but it also gets very hot in short order.

Question on E-caps now.
Can I run say a couple of 20 and a 10 uF 350V E-caps in series to get a 30uF 700V E-cap equivalent? 

[Paul1453]

So the reverb amp came in today.   

Mailman comes late, so not much time before work.
Open her up and do the quick inspection.
No burnt component smell in this one.
Wipe off the tubes, 1 Bugleboy EZ81 rectifier and Bugleboy 6BM8, look good.   
No name USA made 12AX7 looks good, and 1 6BM8 non-Bugleboy is white on inside top and obviously bad.
Luckily I found 1 Philips Miniwatt 6BM8 in my tube collection, yeah 2 premium 6BM8s hopefully.
Will test all tubes prior to start-up.

A quick inspection of the reverb tank notes a wire on the input plug connection broken off.
Complete cleaning and inspection to occur after work.

[eleventeen]

"Can I run say a couple of 20 and a 10 uF 350V E-caps in series to get a 30uF 700V E-cap equivalent?"


Yes, that's how it's done, though your calc is incorrect. It is important and necessary to place an "equalizing" resistor across both caps, one across each of them, just like on a Twin Reverb or Super Reverb. 220K seems to be the generally accepted value, and they act to produce a roughly equal split of total B+ volts across each cap, while acting as slowish bleeder resistors. Figure a Twin makes 450 volts DC. You run in effect, 440K to ground in the form of the two 220K resistors. So 1 mil flows through the stacked resistors. Don't go higher value resistor. I just put together an amp using stacked caps and the junk R's I had were 470K. Everything worked fine but for grins, I measured volts across each of the stacked caps. I was surprised to find (on a 400 volt right-out-of-the-rectifier supply that 375 volts appeared across 1 of the caps and a mere 25 or so volts appeared across the other. Rather surprising.


Guess what happened next? The cap with 375 volts across it blew. Fortunately, not violently, just oozing and sputtering black goo coming out of it. All components were salvaged, but I DO reform used e-caps with a doohickey I built that lets me put 75, then 150, then 225, then 330, then 425 volts across a "cap under test". It's just a power supply with a stack of gas regulator tubes on the output and some bleeder resistors and some current limiting resistors. It has a meter so I can read current into the cap. That ramps big on turn on but (should) go to near zero after several seconds.


As to your math, series caps do not add ufds. They act just as do parallel resistors. a 30 uf in series with another 30 would result in a net capacitance of 15 ufd. In  a Twin Reverb power supply, you will see 2 qty 70 ufds stacked up in series. Those result in 35 ufd net. With (as per your example) a 30 uf in series with a 10 uf, the math is product/sum = net ufds. So: 30 * 10 / 40 = 300/40 or 7.5 ufd. You kind of do not want to use 10 ufds for this, since the net ufds will ALWAYS be less than the lower value cap.

[Paul1453]

I really cleaned up the reverb amp pretty well.

Fixed the reverb, added 3 prong cord, and filled her up with premium Bugleboys/MiniWatts tubes.

Put an 8 ohm speaker on and gave her an input from my other amp.  She is working!

It's not much of a guitar amp the way it is, sooo.

I decided to try to flip her quick on Ebay.  Getting good pics, and working on the write up.

I'm going to try an Auction starting at $150 & shipping.  Hell the Bugleboys it has are worth nearly that at tube fetish retail prices.   

[Paul1453]

Wurlitzer and Belvedere schematics?

Anyone know where I can purchase them?
I contacted a guy on Ebay that has tons of schematics scanned to DVD for sale.
I am hoping he will have what I need and respond soon.

The Wurlitzer has it's full circuit on it's chassis, except maybe vibrato and swell?
The controls are off chassis and need to be identified and installed.

The Belvedere is another enigma without a schematic.
It clearly does not have everything on it's chassis.
But that may be a good thing.   
It has a rather large input transformer feeding the quad 6V6's.
It has a wiring harness and a couple of ports to deal with.
It looks like the wiring harness supplies voltage to the separate pre-amp.
This might be OK to mount controls and pre-amp tubes up at the top of a housing,
and then have the main amp mounted on the bottom of the housing.
I'd just need to develop a guitar friendly pre-amp that interfaces properly with the input transformer.

Without schematics though, I'm at a roadblock on both of these.   

[eleventeen]

If you are now going to destroy fine musical instruments, you owe it to yourself to visit http://www.organforum.com/forums/


Excellent resource for finding out FOR SURE if an organ is tube or silicon. usually you can tell from the non-garish flipper switches, but not always. On that forum, one typically finds "Hey I was given this Baldwin ____; does it have any value and/or is it worth fixing?"


Then someone chimes in with "I had one of those, it sounded like early transistor  xxxxxxx and I gave it away" or, "those have a ton of tubes in them...."


I am taking apart this old Lowrey. It has about a zillion neon lamps and lots of seemingly useful parts. It's a ton of work to take apart, though.


I really don't want to take apart tonewheel Hammonds, just don't want to.

[Paul1453]

I already registered on that organ site.
Unfortunately, it doesn't seem to have the info I'm looking for.

No plans to destroy any fine musical instruments, here. 

On the contrary, the plan is to use as much of these fine musical instruments, as designed, as possible.
That is why I am seeking to purchase schematics for them.
The goal is more to give them a contemporary make-over.
Utilizing the fine design/layout and adding the necessary components to give them new life.

The Wurlitzer appears to just need it's controls reattached.
The Belvedere was the entertainment console of it's day, not an organ.

The only organ I gutted was the Hammond H-100 with 3 amp circuits on it's chassis.
There didn't seem to be any point in trying to make that one, as it was designed, into a guitar amp.
The 3 OT's it had will be made into 3 complete separate amps.  Seems the best option, to me.

My other boat anchor test gear purchases were always planned to be gutted for parts.

If I can develop a good guitar pre-amp for the Belvedere, there are a couple more of them on Ebay now.
I will try to reuse the plan to resurrect as many of them as people will buy.   

[Paul1453]

I scrounged up some info on the Quad 6V6 Belvedere.

The main amp part I have appears to also be known as a Magnavox 101A amp.

This helps some, but I was hoping to find out what kind of pre-amp is feeding this input transformer.   

[Paul1453]

My reverb amp didn't sell.  Oh well.

I've also learned a thing or two about selling items on Ebay with their return policies.
It's all good, until you run across an unscrupulous buyer.   
Then you are pretty much at their mercy.
And you will likely lose money and get a ding on your Seller rating.

So I don't think I will attempt to sell this amp on Ebay again.
I didn't have a schematic for it, but it was fully functional.
The issue is the 6BM8 output tubes it uses.  A triode and Pentode in one bottle.
So to modify this amp to say EL84s, it no longer would have what it needs to drive the reverb tank.
It has the tube rectifier, a 12AX7, and the two 9 pin output tube sockets.

Any ideas for a PP EL84 circuit with reverb that I could convert this amp to?
I know I would likely need to add at least one maybe two sockets to drive the reverb tank and complete a preamp circuit.
I will also probably need to change the OT, but I've got one of those for the EL84s.
Maybe it's easier to just convert this to a PP EL84 amp without reverb? 

I could use info on how I could possibly use this reverb tank with my 6L6 components.
How do I test the tank to verify it will work in a different circuit design?   

[jbefumo]

Old electronic instruments, especially signal generators.  The cases/chassis make great 'lunchbox' amps, they can be found cheap, and as a bonus, one almost always finds other useful stuff inside.

What are your favorite old pieces of gear to buy for parts cheap?

I have gotten some from old movie projectors, record players, stereos, and radios.  I'm looking to get some more power transformers, output transformers, pots, vintage tubes etc. from old gear for cheap.  What do you guys like salvaging parts from?  I haven't tried any old real to real recorders yet.  Like I said if I can get gear that has a usable power and output transformer in them for cheap any tubes etc are just a bonus.  What do you guys look for?

[eleventeen]

Sometimes. The chassis and box are often the most usable items. I'm not saying it's impossible, but you're not gonna make much of an audio amp from a transformer rated to deliver 250 volts B+ @ 45 ma because it was spec'ed to run a 4-tube generator with a 1-volt output swing. I've taken apart my share of test gear and there are always exceptions. If you get it cheap enough, fine.


That said, many people look for old gear to salvage on the basis of parts inside. Don't overlook the box. It can be more useful than the parts inside.

[Paul1453]

I agree that the housing is another valuable part to be considered.

I have a number of very nice rack mounting cases, that I would consider being free.
I mean the other parts I harvested from these buys have more than covered my costs.

Some of the boat anchor housings are difficult or impossible to use.
But even then the brackets and heavy duty metal could be cut and bent to meet a specific application.

Housings are a huge consideration for people like me without woodworking tools,
and considerable experience in making quality wood products.
I have a number of functional amps with no house to live in.   

I'm considering converting the reverb amp that didn't sell, into a Hoffman Stout.
I already have a component board made that worked on my breadboard.
I just need to verify the PT will supply the voltages needed, I've got an OT.
It would still need an additional 9 pin socket added.
But this chassis doesn't appear to be large enough to add another reverb driver tube and transformer.

I also was recommended to have reverb on any PP 6L6 amp I am considering building.
How can I determine if the reverb tank from this will work with a 6L6 design?
Will input/output resistance measurements get me the info I need?
Or are there other factors like impedance that are more important?
How do you find the impedance of an unknown value reverb tank?
I have learned how to figure the impedance of an unknown OT,
Thanks to the help I've received here.   

[Paul1453]

OK, with some searching of this forum, which I should have done in the 1st place, 
I found Tubenit's thread on 1 tube reverb, which contained an excellent .pdf from Sluckey explaining reverb tanks in detail.   

http://el34world.com/Forum/index.php?topic=7957.50

Once I can wrap my brain around this information, I should be well on my way to utilizing this tank. 

It appears that the little amp I have uses the transformerless 6BM8 circuit to operate this tank.
I think I will need to attempt to draw out the full circuitry of this amp this weekend.
I think I can manage that as there really aren't that many components.

If this indeed uses a transformerless 6BM8 circuit for the reverb,
would it be reasonable to conclude I could just add that circuit portion in front of the last gain stage of any amp?
There is a simple Champ circuit with the verb circuit on the grid of V1b.
If I wanted to try to add reverb to a PP 6L6 circuit,
would it work well on the grid of the last 12AX7 before the PI?   

[Paul1453]

Thanks to DummyLoad I have something to try to edit. 
I am trying to document the 6BM8 amp starting from his K10.sch
I've only got the PS and output section documented so far.
Does that part look alright?

I've managed to input some new component values and voltage readings.
I wasn't able to change the pin #s on my edited 6BM8p symbol.
Is there a tube component library I can import somewhere?
Any other tips for using this software more effectively?

It's a work in progress.
Hopefully, I will be able to figure out how to use this well enough to completely document this amp. 

No reverb transformer, but it doesn't appear to be 6BM8 driven.   

[jbefumo]

Yup, mainly grab them for the box and the chassis, but find lots of other cool stuff == those ceramic screw-in turrets are really handy. Some 12AT7s.  Mostly obsolete tubes, but found one 6BM8 that I discovered was available again (still?), and that's become a focus of interest. 

Sometimes. The chassis and box are often the most usable items. I'm not saying it's impossible, but you're not gonna make much of an audio amp from a transformer rated to deliver 250 volts B+ @ 45 ma because it was spec'ed to run a 4-tube generator with a 1-volt output swing. I've taken apart my share of test gear and there are always exceptions. If you get it cheap enough, fine.


That said, many people look for old gear to salvage on the basis of parts inside. Don't overlook the box. It can be more useful than the parts inside.

[eleventeen]

Well I came upon the mother of all tube junkpiles. Probably 35-40 Fisher, Pilot, Bogen, and Radio Craftsmen tuners and amplifiers for $125. And about 2 dozen Nixie tubes (in their sockets!!!!) which fetch ebay money. People make clocks out of them. I have to say, the project value is kind of appealing but when you can buy a used LED alarm clock for $1 at a thrift store, I can't justify the effort.


I figure I will throw out 90% of it, but parts, parts, parts, and there are a ton of transformers. Not many tubes, most gone. Oh yeah, and a perfectly functional DVM (noname but appears to work fine) and lots of screwdrivers and allen wrenches and little tools.

[Paul1453]

Very nice score!   

[eleventeen]

Certainly a pile for the ages. I carefully waited until a rare CA day when it was pouring down rain to grab it, LOL.


One thing about this pile, there are pieces here that are worth zero and I mean zero. And those items, you find your ruthless mojo. Though again, lots of times the chassis is the most useful part. There are also fair numbers of tuners (no power amp) and those might appear to have a juicy power transformer but in general they do not go high like we want for a power amp. Sometimes < 300 VDC, maybe a SS rectifier will help. So they are impressive looking trannies that do little good. I *did* get some NOS 6.3 filament transformers, always useful, and some of a particular type of tranny I have been looking for, which are 125 volts + 6.3 say 2 amps, for small projects.


I was a bit disappointed in the seeming lack of output trannies. I would have loved to get 3-4 pairs of 7591/7868 Fisher output trannies. I would have been ecstatic had I gotten something like that. They *could* be in there among the boxes of pulled-out trannies but I will have to look closer.


I am going to try to whittle this pile down and sell some Fisher glass and nameplates and misc on ebay. There are 4 Fisher 800's in this pile, but no way am I going to try to rehab them, they are really gone.

[eleventeen]

Prolly got well over a dozen of these switches. Tell me $18 for a switch isn't stupid?

[Paul1453]

Morelock's Organ responded to my inquiry to purchase the Wurlitzer 7011 schematic.

They sent me these scans and didn't even ask for any money.
I offered to send them a couple bucks through Paypal.

These seem to give me almost everything I need to convert this to a guitar amp.
The only part that seems to be missing is the connections to the 6 pin control jack.
Vibrato, Swell, and Speaker Jacks are documented.
Control jack seems to be a power and ground distribution port.
There are only 6 pins and pins 1&3 are tied to Ground.
Can any of you suggest ideas about how this last jack needs to be configured?
I appreciate any and all ideas, even if they are wrong.
They might help me figure it out.

It is interesting to have an amp with Vibrato and Swell circuits.
Just jumpering speaker jack pin 2 to 5 proved the amp is functional as it is. 
I'll be very happy to get this thing converted into a Rockin guitar amp.

[jbefumo]

Here's a little 2XEL84 I built in an old signal generator cab -- also used the power transformer and other assorted parts...

[Paul1453]

I like it jbefumo!

If you get a good price on a dead signal generator an amp like this can easily be made for under $100.

That doesn't count anything for labor, but it's hard to beat that price on an amp like this.

[jbefumo]

Thanks, and yeah, it worked out well -- PT didn't quite have the current to drive the EL84s to full power, but still pretty loud.  If I'd known about 6BM8s then I might have used a pair. (Come to think of it, I think I found my first example in there, but didn't identify it until later.)   

I like it jbefumo!

If you get a good price on a dead signal generator an amp like this can easily be made for under $100.

That doesn't count anything for labor, but it's hard to beat that price on an amp like this.

[Paul1453]

I've really slowed down on my junk tube gear purchases lately.

For two major reasons:

1.  I am getting the assistance I need here,
to convert my pile of junk parts into rocking guitar amps that actually look like a guitar amp now.
This is a slow time consuming process, but I'm enjoying every minute of it.

2.  The Ebay market has gone into the unreasonable price region again.
Items in not working/unknown condition with no returns accepted are being bid to prices
that could only be justified if the identifiable components were known to be good.
And then the prices don't meet my 2X value as compared to new prices criteria.

There was a time, not too long ago, I had a Watch list full of items that met my buying criteria,
but I didn't have the funds to take all the shots.

Now I seem to search long hours in vain for items worth buying.
Maybe this is the time I should be a seller instead. 

I am having to revert to searching the fringe markets for anything potentially worthwhile.

I hope you are all still doing well with your junk tube gear purchases! 

Best regards,
Paul

[Paul1453]

So I start complaining about not being able to find the deals   

And then it's like Manna falling from Heaven.   

I had to grab all three of these items.
I even paid the BIN price on the HP and Cordova amp.   
And now that I've already broken my budget,
the deals are popping up again.   

[Paul1453]

Some might wonder about the Recordio R-R.   

It came in today, and I went right to tearing it apart.   

It has a PT, SE OT, 6AQ5, black plate RCA 12AX7, Sylvania 5879, and a 6X4 rectifier.

The case is in good condition, with 2 small speakers that are probably not great for a guitar amp but we'll see.

So just these parts for < $28 delivered seems to meet my 2x new parts value buying criteria.   

I definitely did not buy it to have a tape recorder.

The case seems large enough to put a bigger speaker and maybe a 18W Stout inside.   

The Cordova amp is listed as out for delivery now.

I hope I did as well on that one too.   

As for the HP 214A's, I can't resist all the quality parts in these for < $70 delivered.   

[eleventeen]

You could corner the market on those HP 214s. Seriously, those are pretty interesting pieces of gear. Useful? Well....imagine one day you are retired, have a bunch of horses or cows on your farm, they are enclosed by an electric fence, and you wish to deliver a precision pulse to their hind quarters to prevent them from ramming the fence. Not too harsh, not too gentle. You're in business!

[Paul1453]

I am the buyer of HP 214A's for sellers who just want to move their item. 
I tore the 3 I had down to just parts last weekend.  I'm getting pretty good at that.
They take up less space like that, and the parts are ready to reuse now.

29 tubes in there, usually Amperex made in Gt Brittan/Holland vintage.

3 12AX7s and 9 6DJ8s ensure a good value at my price.   

The PT has proven to be useable (maybe not ideal) for a number of amps.
It has way more capacity than necessary and runs extremely cool.
Top quality pots/knobs/wire/caps round out the valuable parts.
2 more PQ Premium Quality E130Ls bring my stock of those to 8.   

[Paul1453]

The Cordova amp arrived.

I bought this mainly for the 2 12" Jensen speakers and the cabinet.
Hoping I can mount one of my amps in this cab.
Speakers look good so far, the cab appears to have water damage on the bottom.
I'll have to see what some Gorilla glue and clamps can do for that.

The amp that was on the bottom is still a mystery to me.
It appeared to have 4 octal sockets.
Two are octal, but one is 9 pin and the other 7 pin in the normal octal socket base.
The 7 pin has the AC in going directly to one of its pins?
Then it appears to use a SS rectifier and a fixed bias circuit. 
Time for some internet research.
It is going to need to be torn apart anyway.
You know how the wires get that white mold type coating on them?
That needs to be torn apart to be properly cleaned at least. 

[Paul1453]

OK, it's a Cordovox accordion tube amp.

The other two sockets are for plugs to it's tone generator.

Otherwise it uses 2 7591s and a 12AX7.

Stripped down it seems the PT/OT/chassis may be usable. 
The 7591 data sheet shows fixed bias values from 350-450VDC.
I saw at least 1 450V cap can.  A 400V B+ is a usable voltage.
The PT might have a monster 6.3VAC winding.
The tone generator had like 60 tubes in it.
Not sure if it had it's own heater supply or not.

Time will tell.  Seems the Jensen speakers were well regarded. 

[Paul1453]

The Jensen speakers sound good so far.   

I've got them connected to my Airline tube amp that I use on my computer now.

They do sound quite a bit different than the Peavey Mace speakers I have been using as my test speakers.
They seem to have less bass response, is what I have noticed so far.

It's too late for me to crank up the guitar amps with these new speakers tonight.
I expect they will sound really good when I hook them up to the Plexi tomorrow.   

[Ed_Chambley]

Actually it is easy to convert.  Just cut out the tone generator.  There are 2 raised preamp tubes which are used a Microphone inputs.  Convert this to guitar inputs and cut away everything south of this.


The amp was made to have 6 chord tubes for Accordion and to work the tone wheel.  You can forget finding a schematic.  If you insert a signal you can pull tubes and only keep the ones providing the signal and the power section of course.  Then you can simply remove all the other things.  The tone wheel and driver tubes are not good for anything.


The Jensens are C12r.  The amp was introduced at a time when companies were making instruments for Rock and Roll and the amp was cumbersome for a accordion player.  Needless to say, not many were sold.


I did a low power tweed twin circuit in one that was given to me.  I have since sold the amp to a guy who plays a lot of stones music and it really sounds good.

[Paul1453]

I didn't get the tone generator, only the main speakers/amp cabinet.

The amp is in pretty rough shape right now, with the white mold and rusting on the transformers.

I'm thinking about mounting a HoSo56 (my next build hopefully) on top of this cab.

The moldy/rusty amp can wait until I'm ready to deal with it. 

[Paul1453]

The Plexi seems quite a bit louder with these Jensen speakers.   

They sound really good with it.   

[Paul1453]

These little items are purchased for vintage parts, not repair/conversion.

So this one had 3 Webcor Made in Gt Brittan (can you say Mullard?) tubes.

1 12AX7, 1 7025, 1 12AU7. 

All with the Mullard/Amperex X marks the spot tops from their manufacturing process.

Just one of these tubes could cost you what I paid for this item.   

There are 2 other USA made 12AT7s, and then the rest of the parts are just gravy.

This is where I get the majority of my tubes from,
and my stock consists of mainly these type of premium vintage tubes.   

[eleventeen]

Latest score, not the worst ever for $125. Decent tube haul if they are OK.   





>>2<< qty Knight KM15 mono amps with cages *almost* in this good shape. 4x Mullard 12AX7 3x Mullard 6BQ5, RCA 6BQ5  Having two identical mono amps is worth more than 2x a single amp.


1 qty Bogen CHB 50, Mullard & RCA 12AX7, GE & Sylvania 6L6. Slightly futzed with but all there. 


Goofy "don't plug this in" Admiral amp from console, EXCellent chassis metal to adapt for 5E3, P-P 50L6. Value = 0. 

[Paul1453]

I really like the sound of the Mullard 12AX7s!   

I just scavenged a few more of them myself.

Took a very long Sunday drive to Akron OH today.

Picked up another Cordovox just for the Jensen speakers.

This had the tone cab, but no main amp in the speaker cab.

Tone cab yielded 1 Mullard 12AX7, 4 USA 7025s, and 3 12AU7s.

And a ton of 6X8s, and 6FH8s, doubt I'll use these.

All for $40 and a 750 mile drive.   

Listening to the speakers now.  They sound very good.   

[eleventeen]

With the Bogen, looks like the goofy (but nice) guy I bought it from just blindly put a 12AX7 in the socket that wants a 6EU7 and thought it didn't work. Well, with that tube in that socket, it sure won't. I don't have any 6EU7s so for now it goes on the PILE.

[Paul1453]

6EU7s are hard to come by in junk gear.

I know I have 1 or maybe 2 in my stock now.

They are also rather pricey on Ebay.   

[uki]

Hey guys I got a nice deal on OLX site like Ebay down here, this weird amp for 80 bucks(about 20 US dollars), check it out!
Came with 4 tubes, 3 nice transformers all in good shape. Missing power tubes and rectifier.
Tubes are:
1 Telefunken ecc83 made in germany
1 unknown tube to me but it is a 9 pin tube with the looks of a 12a_7 type, it does have a fence like around the plates.
1 Sylvania 6SL7 made in USA
1 RCA that looks to be also a 6SL7 made in USA, inside looks exactly the same as the other one.
Lots of nice resistors, pots, switches, caps, capcans, etc.

I got the feeling that is going to be hard to find the schematic.

http://sp.olx.com.br/sao-paulo-e-regiao/arte-e-decoracao/amplificador-fidelius-179315524?xtmc=amplificador&xtnp=10&xtcr=7 pics no longer available at the link.

[Paul1453]

Valvo EF86 I'd say.

You did very well on this, Score!