[ebuddy]

Okay... I've been using a Nady 850 amp to feed a single 8ohm long-throw sub. The Nady appears to be crapping out and to get me by for a while, a buddy brings over a Sony TA-N55ES stereo bridgeable amplifier. This is a consumer-grade, vintage amp, but a lot of folks are using these old amps in their rigs.

Here is a picture of the amp (two pictured, but I'm only using one)


I will number the posts for clearer direction
1234 (Terminal A across the top)
5678 (Terminal B across the bottom)

Typically, to bridge this amp I'd want to use one post from terminal A and one post from terminal B, but which ones??? Right next to posts (1) and (5) is a tiny white label that says "MONO - "
right next to posts (4) and (8) is a tiny white label that says "MONO +". In theory I'd want to connect the red (hot) to the MONO + post on A and the ground to MONO - post on B, but this seems counterintuitive and I don't want to let the ghost out of my buddy's vintage amplifier.

Where to connect?

[subego]

Not an expert, big grain of salt and all that, but I think the only way you would use A and B in bridging mode is to power two mono speakers, both sharing the one bridged amp, the same way you'd use A and B to power four separate speakers in stereo (two speakers on each channel, both sharing that channel's amp).

So you should use either A or B. I think you could use one post from A and one from B, but that would only work if you select A+B on the front.

I also get the feeling you connect hot to hot, but ummm... that's pretty freakin' scary. Presumably the switch by the input makes everything kosher, but I'm not necessarily super confident.

It is the only setup which makes sense to me though. The label is insisting that in mono mode 1 and 5 are not hot, even though we look all red and stuff.

PS: I'm listening to a DA80ES receiver right at this very moment. Sony used to make some first class gear.

[ebuddy]

Last night I ended up connecting the red lead to MONO+ on post 4 and the blue/ground lead to MONO - on post 1. I've got the back of the unit switched to 'mono' and the front switched to A + B which to your point addresses what would otherwise be counterintuitive circuitry. i.e. Posts 1 and 4 are both red, but I'm connected to them.

I talked to my buddy and he told me to go for whatever I thought would be correct, no worries. I now see why these things are still coveted... Holy mackerel this thing puts out a lot of detailed sound for vintage consumer-grade equipment! It worked and very well.

Thanks for your input subego.

[subego]

My pleasure.

[Spheric Harlot]

Originally Posted by ebuddy 

Holy mackerel this thing puts out a lot of detailed sound for vintage consumer-grade equipment! It worked and very well.

People tend to forget that "consumer-grade" has only come to mean "dirt cheap" within the past twenty-five years or so.

This stuff used to be EXPENSIVE.

[ShortcutToMoncton]

Well the TA-N55ES was made only 20 years ago - right in the middle of that full-blown "we're gonna made this stuff dirt cheap" era - and it was never that expensive, but it's definitely got a reputation as a fantastic amp for the money! Lots of people seem to rave about them online.

greg