Sony TA-313 vs Sony TA-F4A........which one???

[mark31385]

Afternoon every one.

Just a few quick easy to answer questions for a "noobie"

I've been looking at 2 amplifiers that I like the look of for modifying and restoring, they are the Sony TA-313 and Sony TA-F4A.

I only want to buy one but want it to have the best potential for modifying as this will be a nice winter project.

Has anyone had any experience with these amps both from the late 70s?

And which one would be the better of them?

Thankyou in advance

[ilimzn]

Originally Posted by mark31385

Afternoon every one.

Just a few quick easy to answer questions for a "noobie"

I've been looking at 2 amplifiers that I like the look of for modifying and restoring, they are the Sony TA-313 and Sony TA-F4A.

I only want to buy one but want it to have the best potential for modifying as this will be a nice winter project.

Has anyone had any experience with these amps both from the late 70s?

And which one would be the better of them?

Thankyou in advance

Get the service manuals for these via HiFi Engine | Download Free User/ Service Manuals, Amplifier, Receiver, CD, Tape, Tuner, Video or a similar site, it's the basic 'tool' for evaluating your tweaking options.
Check if any of those uses an integrated output module, like the STK series, or an integrated driver, this will limit your options.
Also, some of the TA-F single digit amps used a switching power supply, which also limits what you can do with it.

[Mooly]

I'm not familiar with the TAF4 (it looks nicer than the TA313 though).

The TA 313 uses an oddball hybrid (I think) power module but has the curiosity value of a built in spring delay line/reverb.

Honestly... if your into the vintage hifi gear scene and if they are cosmetically good I would get them both.

[mark31385]

Mooly,

thankyou, you always give good advice.

The TA-313 and its power supply did look interesting and had some curious parts. The TA313 is in ok condition but would need work. Just been looking over the schematics for both of them.

The TA-F4A looks perfect condition and I prefer the look of it lol and has more power. But the IC it uses I have no info on, its a sony CX171. so not sure what upgrade potential is there.

I'm tempted to get both, but i'd only ever use one. and it will be my first venture in to vintage. But after getting my new job, they have all the toys in the workshop so i can play around with it abit

Hmmm I might just get both if the price is right, But I'm with you Mooly the TA-F4A is better. Wonder what its potential is.

[Mooly]

I haven't got the TAF4 circuit but is the CX171 used as a driver for a discrete output stage ? I'm thinking of the TAF6, as I think that used that IC too.

[Mooly]

It is the CX171 thats a driver stage,

Sony TA-F6B PSU repair

[mark31385]

Mooly, I have both schematics for them, would it help if I posted them up?

I'm not sure how far I can go, I was thinking of replacing most of the components for modern day equivalents, upgrading the volume pot, copper base toroidal transformer. And a re-solder.

[mark31385]

Yeah sorry my bad it is the drive stage lol. The F4A looks like pure solid state opposed to the 313

[mark31385]

The power amps on the F4A are 2SC1986 and the 313 is IC based

[Mooly]

By all means post them up. Put them in a zipped folder if the size is over the pdf limit.

I guess you are really down to replacing things like all the electroylitics and any presets.

Some power amps might show signs of instability if the original (probably slow by todays standards) semiconductors are replaced. It is a might... just something to be fully aware and check along the way.