Danelectro Mystery Amp?

[plexi50]

This one is a mystery to me. I can not find a schematic or any other Danaelectro amp using a (7) tube compliment as this one is.
It is using:

(2) 6SJ7 Preamp

(3) 35Z5GT half wave rectifiers

(2) 50L6 Power tubes

Interesting/    Gut pic's in next post.

[John]

I know you already know this, but with those tubes I don't think there's an isolation transformer, which means the chassis might be hot if you plug it in. And of course, I don't see a tranny on the top side anyway.

[plexi50]

Yes i am being careful with this one. Enough voltage going through that field coil to get my attention. Here are some inside chassis pic's/

The volume is low at full CCW volume position. All tubes test in the very good range.

[PRR]

> Enough voltage going through that field coil to get my attention

Nevermind the field coil. The CHASSIS is more-or-less directly connected to one of the wall-plug prongs.

Get an isolation transformer.

[PRR]

Schematic is probably similar to the Envoy:
http://bmamps.com/Schematics/Danelectro/danelectro_envoy.pdf

Yes, that PDF is hardly readable.

And note that the chassis (and your cord thus YOU), are *never* at safe potential. Unlike most such junk, this has a voltage doubler supply. You are holding -110V DC through 75K and ? cap. If true, that's a heck of a sting but maybe not lethal. However that cap WILL short with age.

This plan shows two rectifiers (25Z6?) and two 25L6 power bottles. How sure are you that the right tubes are in it??

Are the rectifiers glowing happy, or dull?

In any case, I do NOT think you should plug this in until you install an isolation transformer. This is even more stupidly dangerous than the the usual $9.95 hot-chassis amplifiers. 75VA is needed.

[DummyLoad]

try this one... seems close & a bit more legible.


--pete

[plexi50]

Schematic is probably similar to the Envoy:
http://bmamps.com/Schematics/Danelectro/danelectro_envoy.pdf

Yes, that PDF is hardly readable.

And note that the chassis (and your cord thus YOU), are *never* at safe potential. Unlike most such junk, this has a voltage doubler supply. You are holding -110V DC through 75K and ? cap. If true, that's a heck of a sting but maybe not lethal. However that cap WILL short with age.

This plan shows two rectifiers (25Z6?) and two 25L6 power bottles. How sure are you that the right tubes are in it??

Are the rectifiers glowing happy, or dull?

In any case, I do NOT think you should plug this in until you install an isolation transformer. This is even more stupidly dangerous than the the usual $9.95 hot-chassis amplifiers. 75VA is needed.

I am not 100% sure these are the correct tubes.
The schematic would confirm. The 6SJ7 preamp i believe is correct.
The power tubes are correct from the tube data cross reference sheet 50L6GT = 25L6GT = 12L6GT.
The rectifiers i have no clue other than they are half wave rectifiers. No sub reference for the 35Z5 shown.
The rectifiers are glowing bright and happy.

The Danelectro Envoy is the only schematic showing to be very similar. Thanks Pete!

 

[PRR]

> 50L6GT = 25L6GT = 12L6GT

No! They function the same *except* they take different heater voltages.

Like putting 12V headlights in a 6V 1941 Plymouth: too dim. Or the 6V lamps from the old Plymouth in a 12V car: way bright and instant burn-out.

But investigation probably leads to internal power-on voltage probing. Which is dangerous. Get an isolation transformer.

[PRR]

Alternatively: make wall-art out of the chassis and speaker, tuck a 4 Watt chip and speaker inside that fine fine cabinet.

[plexi50]

Understood. That reminds me of the time back in 1971 that the 6 volt battery in my 1949 Chrysler spilt windsheild coupe died at night.
Put a 12 volt battery in it and could see the Stop sign light up at 30th ave 8 blocks away. Amazing. Didn't blow the voltage regulator either/

I like the blue tick hound decal on the cabinet. At first thought it might give me a clue as to it's model. That's crazy how they used 115+ A/C as the power supply. Guess a PT was to expensive for them. Nice cabinet though.

[kagliostro]

A bit more readable (may be ....)



Franco

[DummyLoad]

A bit

Franco

franco,
see reply no. 5. ;-)
--pete

[PRR]

See reply #4.

These are all the same image.

For me, the PDF comes up quite small. I blow it up to 200%-250% and it fills the window. I think Franco also bumped the grey to black. Still impossible to be sure of some details.

The 2-rect vs 3-rect is about your field coil. Alnico was very expensive, but at some point it became cheaper than the FC plus the FC power supply. Yours is the older type.

I don't *think* it can be as sensitive as classic Fender. 6SJ7 with huge resistors is gain like 140. **L6 needs like 7V peak drive. This gives input sensitivity of like 35mV, so you have to strum twice as hard as a SilverFace.

[kagliostro]

I think Franco also bumped the grey to black.

Yes, something like that

Franco