ITT Schaub-Lorenz Tiny Super - sounds horrid!

[chipbutty]

True but I was having problems visualising things from that side. I think I may go back to that plan and try and reverse my brain somehow

I recorded an FM and MW daytime bandscan here. I know it's not the best way to judge audio of any device. I think it sounds better on medium wave. Quick medium wave scan starts at 5:30m.

[ms660]

Sounds ok to me for a tinny little loudspeaker.

Lawrence.

[chipbutty]

Yes it does sound a little better than it did. Apparently it shouldn't sound tinny but it does to my ears. Especially on FM. Hopefully it will continue to improve once my ears burn in .

Originally Posted by ms660

Sounds ok to me for a tinny little loudspeaker.

Lawrence.

[Nuvistor]

MW frequency response is curtailed around 4-5 KHz, on FM it can be as high as 15 KHz so MW may sound more mellow.
It sounds ok to me as well but my hearing only extends to around 8Khz.

[chipbutty]

Yes I think you make a good point. At the moment those higher frequencies on FM sound a bit harsh. Unfortunately I have bat like hearing which isn't always a good thing!

Originally Posted by Nuvistor

MW frequency response is curtailed around 4-5 KHz, on FM it can be as high as 15 KHz so MW may sound more mellow.
It sounds ok to me as well but my hearing only extends to around 8Khz.

[crackle]

I think the radio sounds more or less right.
When I tune a radio I rock the tuning back and forth to find the sweet spot on the dial, rather than just stop at a point.
I could not see if you had the telescopic antenna extended, this will improve the strength of reception and this can effect the tonal quality on FM.

Here is a link to a recording of my ITT-KB Tiny Super being tuned over the FM band.
https://www.youtube.com/watch?v=YO4MtX1WrFc

Mike

[chipbutty]

Thanks for the video Mike. Sounds similar to mine. Perhaps I'm just not a big fan of the sound signature of this radio.

You probably couldn't see the subtle movement of my finger when I find the station. I wasn't just stopping when I find a station, I continue to adjust with slight movements of the tuning wheel with my finger. Yes the telescopic was fully extended for FM.

A bit of background. I'm a fairly long time radio user and dxer. I like SW, MW and FM (eskip, tropo) dxing. I have several modern radios for shortwave and medium dxing. I do like older radios, mainly for their audio quality, looks and operation. The Tiny Super will be a nice addition. I fancy a Touring International at some point.

Originally Posted by crackle

I think the radio sounds more or less right.
When I tune a radio I rock the tuning back and forth to find the sweet spot on the dial, rather than just stop at a point.
I could not see if you had the telescopic antenna extended, this will improve the strength of reception and this can effect the tonal quality on FM.

Here is a link to a recording of my ITT-KB Tiny Super being tuned over the FM band.
https://www.youtube.com/watch?v=YO4MtX1WrFc

Mike

[simpsons]

Ahh. The answer is simple. Listening to a radio placed on the window ledge will sound quite different to when placed on a larger surface which can act as a soundboard.

Place the radio on a soft surface, such as the cushion of an arm chair and you will be surprised how much better it will sound.

Another factor is audio compression. Used far too much in my opinion, to both make the station the loudest on the dial and seemingly make the station more punchy. Use Radio 3 as a datum and hear the difference.

When you think of how little baffle area such a small radio has and the use of plastic for weight and visual appeal, the sound quality from its eliptical loudspeaker is very good.

Chris

[chipbutty]

Mike, I've listened to your recording again and yours has much more low end than mine. This is what is missing on mine and why it sounds a bit harsh. It's all mids and treble.

[chipbutty]

Good suggestions and I've tried it on various surfaces. There's a problem with the low end on mine. It's virtually non existent and all I have are mids and treble.

Originally Posted by simpsons

Ahh. The answer is simple. Listening to a radio placed on the window ledge will sound quite different to when placed on a larger surface which can act as a soundboard.

Place the radio on a soft surface, such as the cushion of an arm chair and you will be surprised how much better it will sound.

Another factor is audio compression. Used far too much in my opinion, to both make the station the loudest on the dial and seemingly make the station more punchy. Use Radio 3 as a datum and hear the difference.

When you think of how little baffle area such a small radio has and the use of plastic for weight and visual appeal, the sound quality from its eliptical loudspeaker is very good.

Chris

[chipbutty]

Hi Mike - I have the board out now. I'm a little unsure from the diagram exactly where I should be measuring from. The negative leg of C361 to positive on C360? I get 0v.

Update: C361 to C363 4.5v on partially used batteries

Originally Posted by crackle

If the audio sounds in in headphones then suspect the speaker is faulty, I have known this when the radio has been stored in damp conditions.

If the sound is poor also in the headphones then check the voltage between the 2 points shown on this diagram. You should measure exactly half the battery voltage, so if the battery measures 9.5v then the voltage at the point at the end of the blue arrow should be -4.75v.
This is a view looking at the copper track side of the printed circuit.
Attachment 210168

Mike

[crackle]

With set switched on but volume off, check the exact battery voltage and then compare the voltage at the mid point should be EXACTLY half.
This will tell if the 2 output transistors and the associated resistors are still balanced.
You could also check the capacitors arrowed in pink. or if you do not have an ESR meter just change them.

Mike

[chipbutty]

Thanks Mike. I get 9.08v on the battery, 4.5v on the midpoint. Is that ok?

Originally Posted by crackle

With set switched on but volume off, check the exact battery voltage and then compare the voltage at the mid point should be EXACTLY half.
This will tell if the 2 output transistors and the associated resistors are still balanced.
You could also check the capacitors arrowed in pink. or if you do not have an ESR meter just change them.

Mike

[crackle]

It should be 4.54v but not knowing what meter you have and allowing for inaccuracies of your meter I suppose it is near enough.

Mike

[chipbutty]

Sorry. Yes it was 4.54v. So other than replace the two caps you mention and the speaker there's probably not much more I can do? I imagine an original speaker is hard to come by without buying another radio.

Originally Posted by crackle

It should be 4.54v but not knowing what meter you have and allowing for inaccuracies of your meter I suppose it is near enough.

Mike

[Nuvistor]

Leave the radio playing on the strongest station on FM, this will put a voltage across c353 and help reform it. Without a station tuned in there will be no voltage across it.
If that doesn’t help you could change the capacitors but I don’t think there would be much if any improvement.
If the MW sounds better than FM with less treble you could always introduce some top cut to FM only. Bit of a bodge but if that’s the only way you can listen to it, just make the bodge easy to remove.
Appears your hearing is very good at the high frequencies. Wish mine was, It’s 8Khz in one ear only 4khz in the other.
Edit, I don’t think the speaker is faulty.

[trsomian]

Looking at that diagram the output coupling capacitor appears to be only 200u, so base will never be good, even with a 12R5 loudspeaker

[chipbutty]

Thanks. I have it playing now. A sweatshirt covering the speaker grill so I don't have to listen to it!

Even MW can sound very bright and harsh.

Originally Posted by Nuvistor

Leave the radio playing on the strongest station on FM, this will put a voltage across c353 and help reform it. Without a station tuned in there will be no voltage across it.
If that doesn’t help you could change the capacitors but I don’t think there would be much if any improvement.
If the MW sounds better than FM with less treble you could always introduce some top cut to FM only. Bit of a bodge but if that’s the only way you can listen to it, just make the bodge easy to remove.
Appears your hearing is very good at the high frequencies. Wish mine was, It’s 8Khz in one ear only 4khz in the other.
Edit, I don’t think the speaker is faulty.

[chipbutty]

Interesting. Reading around of how this radio sounds with descriptions such as 'rich' and 'full bodied' it doesn't correlate to my experience. But sit three people in front of a hifi system and they will come up with different adjectives to describe the sound. I guess we all have different ears and there could well be audible differences between any two of the same model. This radio has been sat in a box for nearly fifty years after all! Mine isn't a sound I would want to listen to for very long. It's quite fatiguing. There has been an improvement since day one but none for the past two days.

Originally Posted by trsomian

Looking at that diagram the output coupling capacitor appears to be only 200u, so base will never be good, even with a 12R5 loudspeaker

[ajgriff]

Let's face it this radio was called the Tiny Super for a reason. Such a small radio isn't going to have startling bass characteristics. After all it was designed with 'go anywhere' portability in mind and not stunning audio performance. It looks to me to be a very pleasing example of its type.

Alan