TA-3A issue with gain

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Hello folks, it's been a few years since I've been here. Almost forgot I was a member. haha

I have an old TA-3A that I've just recaped the power supply on. The tuner sounds great and gets nice and loud. However the issue is when I try plug in anything that's line level. Like a CD player or from a cell phone mp3 player etc.

I end up having to turn the volume all the way up on both device just to get it to a regular listening volume. I have to use the loudness knob to get it to start producing any kind of volume. I've tried all the input "cd, aux1, aux2 etc. The same deal.

The preamp jumpers are installed in the back too.

Is there something I'm doing wrong here or might there be an issue with this amp?

Thanks in advance,

Mike Drz.
Ok, thanks for your help. I guess Im just not familiar with what loudness does. Does it attenuate the preamp signal? It works ok with it in 'normal' position, but when I switch to to tuner I have to turn it all the way down. Maybe the antenna I'm using has high gain.
Do you use an antenna amplifier?

With volume at 9 o’clock it should be pretty loud with any input. (roughly a 100 db at peaks, unless you have a very big room or speakers with extremely low efficiency.)

CD and Tuner is about the same for me with a simple "T" FM-antenna. With turntable I need to raise volume a bit more to get the same level.
The FM antenna is a large bay antenna mounted on the roof of my home. None are powered antennas. The AM is just a standard small loop. Both AM and FM are around the same volume level. I think it is working ok at this point.

I just have to turn remember to adjust the volume when switching between tuner and line in.
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Sounds like you might have a partly-blown input selector IC there or two (it uses a bunch of LC7816s, the main input switching being handled by U204/206). Input protection on this unit is wholly inadequate, I'd say - a whopping 47 ohms in series, no diodes to the rails, no opamp buffers. Not exactly how you want to treat one of these somewhat sensitive ICs. With some bad luck, you (or a previous owner) blew up inputs one by one during testing, depending on what you were connecting... Yeah, stupid RCA connectors that tend to make contact on the tip first (except for a few "pro" types designed not to do that).

So what I'd do would be:
* get up to 4 LC7816 to replace the blown ones
* replace all the 47R input series resistors by 330R-1k, downsizing the 1n parallel caps to 220-330-ish pF (NP0 type or film) if installed (those may have been a West Germany special)
* optionally install normally-reverse-biased protection diodes (small-signal or preferably Schottky, Vr >= 25-ish V) going to +/-18 V for all inputs - with these in, 330R resistors should do, without them I'd stay closer to 680R-1k
The origins of this amp are some what of a mystery. It used to be used in a retail store to play muzak. Before that it was just left behind by an electronics store that went out of business many years ago. It was given to me by the last owner when she left that rental space.

It looks like somebody has already been in the chasis, there are some Jamicon caps in a few places.

I don't want to spend much replacing parts on this. I think it will work ok the way it is as long as nothing further fails. It's mostly used for radio tuner and phono amp.
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.