Help identifying tube complement: fleawatt console pull

[Ballylongford]

Looking for some help identifying what tubes should be in this amp.

Anybody?

 

[buglegirl]

Hiya,

If I had to guess

50DC4 (Rectifier)

12AX7 (Pre/Driver)

50C5 (Output)

EDIT: If its stereo ... two 50C5's then and no tube rectifier

Frannie

 

[mibag6]

How about a pair of 50C5s and a 12AX7?

 

[Ballylongford]

Is there a big difference between the 50C5 & 50C5s tubes?

 

[buglegirl]

Hiya,

He was pluralizing 50C5

Could also be 50B5's which are pretty much the same tube.

Frannie

 

[knockbill]

+1... Yep, its stereo, there are two OPTs,,, you can check which output tube by comparing the pinouts in the RCA tube manual, or a spec sheet online... I'd Google "50C5 tube data", and compare the amp output tube wiring to that...

 

[mhardy6647]

How about a pair of 50C5s and a 12AX7?

Dollars to doughnuts, that's what it is.

 

[s-petersen]

Hot chassis, Be careful! Looks like dc is fed into the amp,I can't see a rectifier

 

[dcgillespie]

Nope, it's got a very early silicon rectifier down in the bottom right hand corner -- a tan piece that looks like 1/2 of an M&M (sliced through the center of it).

Dave

 

[zandru]

Nope, it's got a very early silicon rectifier
down in the bottom right hand corner -- a tan piece that looks like 1/2
of an M&M (sliced through the center of it). Dave

A Close-Up View of The Silicon Rectifier......See attached photos.............

(could be a2E4 400v 2A Diode from international Rectifier ?)

 

[s-petersen]

Cool,I've never seen one of those!

 

[analog addict]

Cool,I've never seen one of those!

I've got at least one sitting on the shelf. However, I've never been tempted to mess with it. Maybe Bally will restore his and report back....:scratch2:

 

[Ballylongford]

+1... Yep, its stereo, there are two OPTs,,, you can check which output tube by comparing the pinouts in the RCA tube manual, or a spec sheet online... I'd Google "50C5 tube data", and compare the amp output tube wiring to that...

Yes. That was the key. Buglegirl was right on the money, as always with her tube suggestions.

I've got at least one sitting on the shelf. However, I've never been tempted to mess with it. Maybe Bally will restore his and report back....:scratch2:

I am actually negotiating w/ an AK member who is looking for a project amp to work on. I acquired this one a long time ago with an eye to a starter restoration and I have not done so; time to share the wealth.

Thanks to everyone who posted

 

[buglegirl]

Hiya,

There is gold or the very least silver in these little guys.

Frannie

 

[Pio1980]

I'm also with 50C5x2 and 12AX7.

Sent from my SM-N900V using Tapatalk

 

[Olorin67]

Its a hot chassis, so for safety it will need to be mounted in an insulating enclosure, and any component or input source you attach to it could be hot as well...

 

[mhardy6647]

Actually the better solution is to add an isolation transformer between the AC mains (wall outlet) and the amplifier -- these are readily available and not too expensive (e.g., Jameco had 'em at several different power ratings last time I looked), or one may cobble one up using two low voltage (e.g., 12 V secondary) power transformers wired secondary to secondary. Just be sure to pick a pair that have adequate power rating (which for something like this little amp probably is less than 100 watts). Even Radio Shack used to sell such transformers -- and they still might.

EDIT: Oh, and it is probably worth mentioning that, in the absence of an added isolation transformer, there's a 50-50 chance that the amplifier's chassis and any associated metal parts will be hot (connected to the AC mains) depending on the 'sense' of the AC power cord's plug when inserted in the AC outlet. Better odds than traditional Russian Roulette, but still worthy of consideration in the absence of some remediation ;-)

 

[Ballylongford]

Got the tubes on order: stand by for an update once they arrive.

Thanks to one and all

 

[Pio1980]

Cool,I've never seen one of those!

It's the sort of amps used with crystal/ceramic carted changers in the foldup 3 piece portable stereo phonos popular in the 1950s/ 1960s. Don't expect much out of it in loudness or great SQ.

Sent from my SM-N900V using Tapatalk

 

[Ballylongford]

Picked up a 12AT7 & a pair of 50c5 tubes.

Unit is working like a champ.

Thanks to all who responded.