Question about vintage reciever

[lanceputnam]

Hello I have a question about a receiver that I rescued from my grandparents garage. It's a Grandco sp 809. I noticed that it had tubes so i thought it would be fun to hook it up to my audio technica atpl120. I cleaned it up and it plays out of the speakers that are on the receiver. I do however hear some hum in the speakers what could this be? Also I have a pair of boston acoustics a70's. Would I be able to adapt these wired speakers to rca? Also It doesn't seem to light up. Can it be as simple as just replacing the bulb? I can't post a picture of it because I have less than 5 posts. Is there a quick way around this?
Thanks!
-Lance

 

[highfigh]

Hello I have a question about a receiver that I rescued from my grandparents garage. It's a Grandco sp 809. I noticed that it had tubes so i thought it would be fun to hook it up to my audio technica atpl120. I cleaned it up and it plays out of the speakers that are on the receiver. I do however hear some hum in the speakers what could this be? Also I have a pair of boston acoustics a70's. Would I be able to adapt these wired speakers to rca? Also It doesn't seem to light up. Can it be as simple as just replacing the bulb? I can't post a picture of it because I have less than 5 posts. Is there a quick way around this?
Thanks!
-Lance

I'm not familiar with the brand but to a large extent, tube amps/receivers are tube amps/receivers. The hum is caused by leaky electrolytic capacitors and with a piece that's more than about 20-30 years old, it's best to replace those caps before turning it on again because they could cause damage to other parts.

What is the number on the tubes?

 

[lanceputnam]

RCA 50c5
RCA 12ba6
12al5
12ax7

 

[markw]

Are you sure it's not a "Granco" unit? If so, the only reference to that brand is some tube radios from the 1950's. Is that a stereo unit?

As previously stated, the hum is PROBABLY the result of bad filter capacitors which, being over 50 years old, are most likely ready to spew forth their guts from the bottom, if not simply explode.

Dependin on your experience and willingness to throw $$ into getting this up to a safe operating position, you might want to give it some serious thought.

Since I'm assuming that your TT has a magnetic cartride, I'm surprised it works well through it.

[edit] Just saw your new post. That's a mono "All American Five" AC/DC table radio with a solid-state rectifier. Don't go poking around inside with the power on unless you really, really know what you're doing. But, the capacitor replacement should be fairly easy, and a good way to get a start with this stuff.

 

[lanceputnam]

Yup you are right It's granco. I will post a few pictures once I get 5 posts. Thanks for the responses this is really interesting!

 

[lanceputnam]

Right now I have a onyko tx 8211 receiver. Would this granco sound a lot better than my onyko if I got it fixed up? And is there a way to hook my boston acoustics to it?

 

[markw]

Let's not get too carried away here.

It's fine for what it is, but it isn't any more than what it is.

What it it is an old AM table radio that puts out maybe two watts from it's one channel amp to it's internal speaker and has no provisions for any other inputs or speakers.

Would a old horse drawn buggy be better than a modern automobile?

 

[lanceputnam]

Can you direct me to any sites that would teach me about what to replace?

 

[lanceputnam]

 

[lanceputnam]

On the system it comes with two speakers that connect by rca cables. I could be wrong I don't know the name of these. I figured that there would be a way to rig up each of my wired speakers so that they can connect by rca.

 

[markw]

That LOOKS like it might be an early stereo unit but those four tubes you list don't indicate as such, nor do they indicate more than AM. Let's see a picture of the back showing any inputs.

Do a google search for "all american five radio" for more info.

In any case, it (that 50C5 audio output tube) doesn't produce enough power for your newer speakers.

 

[highfigh]

Here's the data for that tube-
http://www.nj7p.org/Tube4.php?tube=50C5

 

[lanceputnam]

 

[TLS Guy]

It is an old AM/FM stereo table radio with external speakers.

Those types of units were never high end units. Speakers for tube gear like that generally have to be 16 ohms.

In no way is this unit suitable to use in a modern Hi-Fi system.