pilot light bulb for 2nd generation

[Runaway J]

Hi,
talked with the owner of an 2nd generation ODSR today.
He is playin' that amp since the early 80s without ever
changing a single part or having the amp repaired.
The only thing broken is the bulb of the pilot ligth (since 2005 or so).
Can anyone point me to a correct replacement ?
Thanks!
Juergen

[jelle]

Do you have close up shots? I might have it. Jelle

[Max]

Can anyone point me to a correct replacement

Hi Juergen,

maybe - at least if this is an "export ODRS 50W":

AFAIR the kind of pilot light of a "2nd generation style" (sliding switches) ODRS 50W (AFAIR in the #002X range), that Alexander Dumble exported to Europe and that has been sold by Applied Accoustics (fitted into a lumber core plywood combo cabinet with wicker grill - of course of larger width), it was the same kind of pilot light as in the exported 2nd generation ODS amps.

So if the ODRS you are talking about should perhaps be this 2nd generation style "export ODRS 50W" combo, this kind of bulb may perhaps fit (see attached picture):
http://1derfullife.selfip.com/product/1 ... -Bulb.html
http://www.bulbamerica.com/ge-381-1w-6- ... -bulb.html

AFAIR I've an (old-fashioned analogue) picture somewhere of this "export ODRS" in a wicker combo cabinet and in the #002X series number range, but buried somewhere and not at hand right now. But if you should be interested to know, if we're talking about the same ODRS, I could look for the picture as soon as I find the time.

But I've attached a picture from Rob Livesey's site http://www.roblivesey.com/dumble/ (Dumble #unknown 10) of another ODRS with a wicker head cab and a wicker 2 x 12 speaker cab with offset speakers (I don't know, if these cabs have been built by Applied Acoustics or by some other cabinetmaker by order of the owner). Anyway: This one has the same kind of pilot light as the wicker ODRS combo I know of. So if the pilot light of the ODRS you're talking about looks similar, this bulb (see the links above and the picture below) will perhaps fit.

But Jelle is of course right: Posting a picture here would of course obviate the need to speculate about which ODRS and pilot light you're talking about.

Cheers,

Max

[Runaway J]

Hi Jelle and Max,
'Dumble #unknown 10' IS the amp I'm talking about and it is #030.
As I mentioned in an earlier thread my brother was the first owner of that amp. The picture is of poor quality 'caus it's a scan I've made from an old photo I got from my brother.
After his band split up he had the chassis built in a flight-case-style combo with one of the Altecs 417 to make it more usable for practicing at home. Then he decided to sell it to finance a Larrivee acoustic guitar.
Yesterday my long search was successful and I managed to get in contact with the guy who bought that amp from him. He's a really friendly fellow and we talked for about 30 min.
He said he really loves that amp and he uses it frequently on stage. It never failed or had to be repaired in all those years. The only thing that's broken is the pilot light bulb,
which he can't find a replacement for.
I'd be proud if I could help him out, at least with some information or a link.
The pilot light is indeed the typical 2nd generation type (like #033, #040, ..., see pic). Received a new picture of the amp today and will post after I got the OK from him.
The amp is in remarkable good condition, looks like brandnew.
My brother bought the amp here in germany from applied acoustics I think around '79. I still have the left over solid mahogany enclosures they made standing here.
What's interisting is that the amp already has a 'mid'-switch instead of 'accent' but still has the old 'guitar/mic' switch.
I'd love to get some gut pics but I don't think he would be willing to make some.

Thanks for your help.
Juergen

[Runaway J]

... forgot to mention: according to the dumblebook applied acoustics only imported 1 ODSR to germany. So this is it.

[jelle]

I have seen at least 4 types of pilot lights on these 70's amps, I cannot verify if they were built originally with all 4 types so without a high res pic it is hard to say. I habve also seen pics of ODRS sn 30 in a black flightcase with a Altec speaker. 50W. But these pics do not have sufficient resolution to show me what I need. For this reason I have pulled examples of the types I have in stock and made a pic. Maybe the picture you have is of a better quality allowing you to make out if it is indeed the second one from the left or not.

Jelle

[Max]

... applied acoustics only imported 1 ODSR to germany. ...

Hi Juergen,

AFAIK this info isn't correct: I definitely know of one more ODRS 50W in the #002X series range that Alexander exported to Germany. This one has been sold by Applied Acoustics in a combo cabinet of the same style as their first version combo cabinet for the exported ODS 50W amps (lumber core plywood sides, top and bottom, wicker grill, oval hole).

AFAIK the "Mid" switch of ODRS amps - or "Mid Accent" switch as it's sometimes labeled - that is placed where you'll usually find the "accent" switch - is something different than the mid switch that replaced the deep switch with the introduction of the skyline tone stack. AFAIK it works more or less just like the usual accent switch. - AFAIK in some amps even the cap value is exactly the same.

As your brother's ODRS is the one I posted a picture of, AFAIK the bulb you're looking for is the 6.3V 1W type with flange I posted a picture of, too.

As you seem to know "A Dumble Book" and are located in Germany: AFAIK in one of the interviews in this book you'll find the name of a Dumble tech in Germany. Perhaps he knows where to buy such a bulb in Germany.

BTW: In my personal opinion these "export Dumble amps" are an important part of the "Dumble history" (AFAIK around half of all the 2nd and 3rd generation ODS amps have been exported to Europe!) - just like Park amps are an important part of the "Marshall history" e.g. So you and the current owner of this ODRS could perhaps think about a reunion of the original export cabinets with the original export chassis? Just an idea.

@ jelle:

Jelle, AFAIR all the 2nd and 3rd generation ODS amps I know have this same (mechanical) style of pilot light. Only the coloured lamps that you see on the outside of the chassis, and that you all can screw out from the front to change the bulb, have different styles and colours. So AFAIK this kind of bulb with the flange will fit into all of them. AFAIR changing the bulb of these pilot lights needs half a minute.

Cheers and all the best,

Max

[ER]

Had my eye on it for a long time but just yesterday tested the voltage on the lamp on my QRK turntable; 120v. Going to pull it and use it on my current build parallel with the PT primary from the on switch. Had a regular 6.3v lamp to use, but I think I want to keep all the heater amperage just on tubes.

Glows a nice mellow orange. Should look nice in the dovetail walnut cabinet with wheat or spider cane grill.

[img:425:350]http://www.261.gr/history2/QRK-12.jpg[/img]

-ER

[jelle]

Max, Thanks for the info. I never studied the pilot lights too closely, nor did I try to replace one on a older dumble.

Jelle

[Max]

Can anyone point me to a correct replacement?

Hi Juergen,

here's a data sheet of such a 6.3V T1 3/4 midget flange base bulb (scroll down): http://www.onlinecomponents.com/viewer.aspx?p=10219296

And here's a supplier offering a version of his website in German language. So he will be used to export his products to Germany or he might even know where to buy it in Germany: http://www.onlinecomponents.com/te-conn ... p=10219296

Cheers,

Max

[Runaway J]

Hi Max,

Thanks for the information.
I think the pilot light could be Arcoelectric LH A62/63 or LH M62/63.
http://www.arcolectric.com/pdfs/USA_cat ... 5_2006.pdf
So both flange base and screw base for the bulb could be possible.
But I guess you're rigth. More likely flange base.
I asked the owner for a high resolution picture.
Let's wait and see.

The export amps are really something special imo, not because of technical things, but of the history and the time it all happened.
Anyway- they are fascinating me more than later ODS generation.

A reunion of amp and cabinets would be an interesting idea, but unfortunately the cabinets are in bad shape.
The wicker cane was damaged and replaced with a pretty ugly brownish fabric long ago, the first thing I threw away.
The speaker cab had a closed back and was damped with wool insides. Can't believe that this was Alexanders design.
The baffle seems to be made of scrap wood. I'd rather recommend the owner to buy a nice combo cab from tube-town or so.

Thanks all for the input.

Cheers
Juergen

[BobW]

That particular bulb, also called a peanut bulb is used in a lot of older US MIL equipment. A surplus website may carry them.

[Runaway J]

Hi,
so this is the amp and its pilot light.
Flanged base, so far is clear. Think I'll find it now.
Thanks everyone.
Juergen

[Runaway J]

... btw - the tubes.
The Amp is completely original and has never been opened.
Told the owner that the death cap should be removed.
Cheers,
Juergen

[Max]

The Amp is completely original...

Juergen, first of all thanks a lot for posting these very interesting pictures.

Two questions concerning these pictures:

Why do you think, that the OT, that you see IMO on the right side of the choke on the picture "DSC02930.JPG", is original?

Why do you think, that the Bassman OT, that you would expect to see in an ODS 50W from the same period, is missing?

I ask, because AFAIR the ODRS 50W in the #002X series number range I know of, that has been sold by Applied Acoustics in an wicker combo cabinet, did have a Bassman OT (022871).

Cheers,

Max