Help identifying amplifier! (pics)

N

Nuzzles

[H]ard|Gawd
Joined
Apr 13, 2005
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Edit: If this is in the wrong forum, sorry. ^_^ I think I got it right though. xD

This was given to me by my uncle, and it's been a good little fella. But i'm looking to upgrading the speakers, and I want to know all the details about each channel etc...

And even if I don't need to know those, I wanna know them anyway. ^_^

So without further adue...

amp3.jpg

amp5.jpg

amp1.jpg

amp2.jpg


Few of the insides for the hell of it. (yes I know a fuse is missing, discovered tonight that it blew, so I'm picking up another one tomorrow (i'm assuming it has something in relation to a 3.15A fuse??? -knows jackshit about electronics really- )
amp6.jpg

amp4.jpg
 
Oh, I'll make sure of that... I'll scrutinize it....

fuse.jpg


____

That aside, any idea about the amp. itself?
 
Well yes, I saw that, but I've already googled the number to find nothing.
 
Well, it looks like the speaker outputs can handle 8 to 16 Ohm speakers. That's all the info you'll need as far as power constraints are concerned. All the RCA jacks will be line-level (just plug your CD player into one, your tape deck into another, your tuner into another, your turntable into another, etc). As far as audiophile-type information goes...meh, don't worry about it. I can't tell you what the 'cartridge' switch does, but the "loudness" switch, when turned on, will keep the volume constant. In other words, if you're listening to a symphony, the amp will make the loud parts quieter and the quiet parts louder, so you can hear everything without being deafened by the louder parts. Incidentally, this feature is more useful in a car, but is certainly not detrimental elsewhere.

 
Thanks Mohonri.

I wasn't really sure what the loudness button did, other than make everything sound better. I'm not sure on what the cartidge button does either, though. ; /

Question: Is 8-16 Ohms capabililty 'good'?

Thanks ^_^
 
I'm not sure on what the cartridge button does either, though. ; /
Click to expand...
Haha! That amp must be really old. Before people started buying CDs and DVDs, they use vinyl records to play music. The cartridge held the needle. My dad had one.
The moving magnet (MM) phono cartridge was the easier to use.
The moving cartridges (MC) were better, but cost more.

Question: Is 8-16 Ohms capability 'good'?
Click to expand...
It’s neither good nor bad. As long as you match the impedance with the speakers you are using you will be A-ok. 8 ohms is seen more on home speakers. 16 ohms are used a lot on “monitor grade” speakers.
 
Yeah, it's really old. But you should be able to tell that from the insides of it too.

Thanks for the cartridge information. XD I've gotta pick up a record player sometime...

I've got a few more questions....not nesecarily related to the amp but meh.

Is it alright to double up on speakers? (put two speakers on the left channel on A and two on the right channel on A)

ANd, is it alright to have an 8ohm speaker on the right channel and a 16 on the left? (other configurations too, of course)
 
is it alright to double up on speakers? (put two speakers on the left channel on A and two on the right channel on A)
Click to expand...
Not a good idea. It may work, but I wouldn’t do it. If you select 8 ohms, for example, when you add two regular 8 ohm speakers to the left channel the impedance drops to 4 ohms. You could damage the amplifier!

If you must do it, wire two 8 ohm speakers in series. That will give the amp a 16 ohms load and it should be happy. Keep an extra set of fuses handy!

And, is it alright to have an 8ohm speaker on the right channel and a 16 on the left?
Click to expand...
That’s kind of goofy. I will work but I don’t know how well. It’s really best to match speakers with the proper ohms.
 
Yay for learning wiring series and parralell in science. XD

Thanks for that. ^_^

-pats his box of fuses-
 
Nuzzles said:
Is it alright to double up on speakers? (put two speakers on the left channel on A and two on the right channel on A)

ANd, is it alright to have an 8ohm speaker on the right channel and a 16 on the left? (other configurations too, of course)
Click to expand...

Don't double up speakers. The crossovers inside them are not designed to work this way and the speakers will sound like crap, especially if they are different types of speakers. Plus, putting two in series will double the resistance, which will halve the current going through them. This means you will have half the power, but twice the radiating area, resulting in no increase in volume. So for twice the cost there's no increase in volume, although the new load is more friendly to your amp.

Most modern speakers tend to "cheat" a little and go below the nominal 8 ohms rating. They do this so they can deliver more power at the same volume setting. They get away with it because most modern amps are usually good down to 4 ohms or so. Your best bet is to look for older speakers that have a higher impedance rating. Unfortunately, these tend to be hard to find due to being destroyed by aging or collectors scooping up good ones for their own older equipment.

This looks to be an '80s model in that transitional period between records and CDs. Looks like a nice torroid transformer and decent sized heatsink in there - a sign of quality. Probably about 50 watts per channel, possibly using a pair of transistors per channel. Given '80s transistor technology, the 8-16 ohm rating seems appropriate.

If you want to upgrade the speakers, your best bet might be to build your own. You can then build speakers that are more efficient and have a higher impedance than most off the shelf ones. There are several forums dedicated to this at:

http://www.pesupport.com/cgi-bin/config.pl
http://www.speakerbuilding.com/
http://www.madisound.com/discuss.html

but you may be limited by parts availability in New Zealand.
 
Thanks. I won't double up on speakers. I promise. ^_^

I was thinking about getting my current speakers repaired....They're in REALLY bad condition, The speakers themselves are literally falling apart... o_O I heard the term "refoaming" so I guess that's what I'd be doing? However, new speakers still would be nice...

The 'bigger' speakers seem fine at the moment, but the mid and tweeters are a bit fucked up. I'm guessing I could just replace them in the same cabinet?

If worse comes to worst, I could probably try a DIY experiment, just as you said, availabilty could be questionable. And it'd be a hassle. ;x Though I will have a lot of time on my hands, but not a lot of money. XD (christmas is coming, so yeah)

Just for curiousitys sake, any idea on how much this amp would be worth?
 
Fenris_Ulf said:
Plus, putting two in series will double the resistance, which will halve the current going through them.
Click to expand...
That’s not correct.
It’s true that putting two is series will double the resistance (actually the impedance), but the current through a series circuit is the same through both speakers. It is not halved.

If he did it his original way, he would be connecting the two speakers in parallel into one of the two channels. In that case the current would increase.

Everything else you mentioned was fine. :p
 
warbird said:
That’s not correct.
It’s true that putting two is series will double the resistance (actually the impedance), but the current through a series circuit is the same through both speakers. It is not halved.

If he did it his original way, he would be connecting the two speakers in parallel into one of the two channels. In that case the current would increase.

Everything else you mentioned was fine. :p
Click to expand...

I meant that the overall current would be halved by doubling the resistance.

V=IR

if V is constant (the volume/gain setting on the amp), then if you double R, I must be half. The current is the same for both speakers (assuming they are identical speakers), but the overall current outputted by the amp is reduced in half. Also, each speaker would only see half the voltage, meaning that each would be running at 1/4 the power of a single speaker. It's still not a good idea.
 
Nuzzles said:
Thanks. I won't double up on speakers. I promise. ^_^

I was thinking about getting my current speakers repaired....They're in REALLY bad condition, The speakers themselves are literally falling apart... o_O I heard the term "refoaming" so I guess that's what I'd be doing? However, new speakers still would be nice...

The 'bigger' speakers seem fine at the moment, but the mid and tweeters are a bit fucked up. I'm guessing I could just replace them in the same cabinet?

If worse comes to worst, I could probably try a DIY experiment, just as you said, availabilty could be questionable. And it'd be a hassle. ;x Though I will have a lot of time on my hands, but not a lot of money. XD (christmas is coming, so yeah)

Just for curiousitys sake, any idea on how much this amp would be worth?
Click to expand...

Generally it's easier to re-foam the woofers than the mids or tweeters. Since you've got time, you might want to do some research on what's available locally in NZ and then asking questions on web boards to get an idea of what direction to go. You don't have to spend alot, but research ahead of time will probably keep you from making alot of mistakes.

I'm not sure how much that amp would be worth. It's not a bad amp, but most collectors look for something like Marantz, Harmon Kardon, or one of the more boutique brands rather than a more consumer brand. Philips was still a good name at the time, but the 8-16 ohm limitation might make some people a bit hesitant.
 
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